1 | // SPDX-License-Identifier: GPL-2.0 |
---|---|
2 | |
3 | #include <linux/anon_inodes.h> |
4 | #include <linux/atomic.h> |
5 | #include <linux/bitmap.h> |
6 | #include <linux/build_bug.h> |
7 | #include <linux/cdev.h> |
8 | #include <linux/cleanup.h> |
9 | #include <linux/compat.h> |
10 | #include <linux/compiler.h> |
11 | #include <linux/device.h> |
12 | #include <linux/err.h> |
13 | #include <linux/file.h> |
14 | #include <linux/gpio.h> |
15 | #include <linux/gpio/driver.h> |
16 | #include <linux/hte.h> |
17 | #include <linux/interrupt.h> |
18 | #include <linux/irqreturn.h> |
19 | #include <linux/kfifo.h> |
20 | #include <linux/module.h> |
21 | #include <linux/mutex.h> |
22 | #include <linux/overflow.h> |
23 | #include <linux/pinctrl/consumer.h> |
24 | #include <linux/poll.h> |
25 | #include <linux/seq_file.h> |
26 | #include <linux/spinlock.h> |
27 | #include <linux/string.h> |
28 | #include <linux/timekeeping.h> |
29 | #include <linux/uaccess.h> |
30 | #include <linux/workqueue.h> |
31 | |
32 | #include <uapi/linux/gpio.h> |
33 | |
34 | #include "gpiolib.h" |
35 | #include "gpiolib-cdev.h" |
36 | |
37 | /* |
38 | * Array sizes must ensure 64-bit alignment and not create holes in the |
39 | * struct packing. |
40 | */ |
41 | static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); |
42 | static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); |
43 | |
44 | /* |
45 | * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility |
46 | */ |
47 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); |
48 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); |
49 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); |
50 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); |
51 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); |
52 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); |
53 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); |
54 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); |
55 | |
56 | /* Character device interface to GPIO. |
57 | * |
58 | * The GPIO character device, /dev/gpiochipN, provides userspace an |
59 | * interface to gpiolib GPIOs via ioctl()s. |
60 | */ |
61 | |
62 | /* |
63 | * GPIO line handle management |
64 | */ |
65 | |
66 | #ifdef CONFIG_GPIO_CDEV_V1 |
67 | /** |
68 | * struct linehandle_state - contains the state of a userspace handle |
69 | * @gdev: the GPIO device the handle pertains to |
70 | * @label: consumer label used to tag descriptors |
71 | * @descs: the GPIO descriptors held by this handle |
72 | * @num_descs: the number of descriptors held in the descs array |
73 | */ |
74 | struct linehandle_state { |
75 | struct gpio_device *gdev; |
76 | const char *label; |
77 | struct gpio_desc *descs[GPIOHANDLES_MAX]; |
78 | u32 num_descs; |
79 | }; |
80 | |
81 | #define GPIOHANDLE_REQUEST_VALID_FLAGS \ |
82 | (GPIOHANDLE_REQUEST_INPUT | \ |
83 | GPIOHANDLE_REQUEST_OUTPUT | \ |
84 | GPIOHANDLE_REQUEST_ACTIVE_LOW | \ |
85 | GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ |
86 | GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ |
87 | GPIOHANDLE_REQUEST_BIAS_DISABLE | \ |
88 | GPIOHANDLE_REQUEST_OPEN_DRAIN | \ |
89 | GPIOHANDLE_REQUEST_OPEN_SOURCE) |
90 | |
91 | #define GPIOHANDLE_REQUEST_DIRECTION_FLAGS \ |
92 | (GPIOHANDLE_REQUEST_INPUT | \ |
93 | GPIOHANDLE_REQUEST_OUTPUT) |
94 | |
95 | static int linehandle_validate_flags(u32 flags) |
96 | { |
97 | /* Return an error if an unknown flag is set */ |
98 | if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) |
99 | return -EINVAL; |
100 | |
101 | /* |
102 | * Do not allow both INPUT & OUTPUT flags to be set as they are |
103 | * contradictory. |
104 | */ |
105 | if ((flags & GPIOHANDLE_REQUEST_INPUT) && |
106 | (flags & GPIOHANDLE_REQUEST_OUTPUT)) |
107 | return -EINVAL; |
108 | |
109 | /* |
110 | * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If |
111 | * the hardware actually supports enabling both at the same time the |
112 | * electrical result would be disastrous. |
113 | */ |
114 | if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && |
115 | (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) |
116 | return -EINVAL; |
117 | |
118 | /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ |
119 | if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && |
120 | ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || |
121 | (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) |
122 | return -EINVAL; |
123 | |
124 | /* Bias flags only allowed for input or output mode. */ |
125 | if (!((flags & GPIOHANDLE_REQUEST_INPUT) || |
126 | (flags & GPIOHANDLE_REQUEST_OUTPUT)) && |
127 | ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || |
128 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || |
129 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) |
130 | return -EINVAL; |
131 | |
132 | /* Only one bias flag can be set. */ |
133 | if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && |
134 | (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | |
135 | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || |
136 | ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && |
137 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) |
138 | return -EINVAL; |
139 | |
140 | return 0; |
141 | } |
142 | |
143 | static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp) |
144 | { |
145 | unsigned long flags = READ_ONCE(*flagsp); |
146 | |
147 | assign_bit(FLAG_ACTIVE_LOW, &flags, |
148 | lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); |
149 | assign_bit(FLAG_OPEN_DRAIN, &flags, |
150 | lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); |
151 | assign_bit(FLAG_OPEN_SOURCE, &flags, |
152 | lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); |
153 | assign_bit(FLAG_PULL_UP, &flags, |
154 | lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); |
155 | assign_bit(FLAG_PULL_DOWN, &flags, |
156 | lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); |
157 | assign_bit(FLAG_BIAS_DISABLE, &flags, |
158 | lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); |
159 | |
160 | WRITE_ONCE(*flagsp, flags); |
161 | } |
162 | |
163 | static long linehandle_set_config(struct linehandle_state *lh, |
164 | void __user *ip) |
165 | { |
166 | struct gpiohandle_config gcnf; |
167 | struct gpio_desc *desc; |
168 | int i, ret; |
169 | u32 lflags; |
170 | |
171 | if (copy_from_user(to: &gcnf, from: ip, n: sizeof(gcnf))) |
172 | return -EFAULT; |
173 | |
174 | lflags = gcnf.flags; |
175 | ret = linehandle_validate_flags(flags: lflags); |
176 | if (ret) |
177 | return ret; |
178 | |
179 | /* Lines must be reconfigured explicitly as input or output. */ |
180 | if (!(lflags & GPIOHANDLE_REQUEST_DIRECTION_FLAGS)) |
181 | return -EINVAL; |
182 | |
183 | for (i = 0; i < lh->num_descs; i++) { |
184 | desc = lh->descs[i]; |
185 | linehandle_flags_to_desc_flags(lflags, flagsp: &desc->flags); |
186 | |
187 | if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { |
188 | int val = !!gcnf.default_values[i]; |
189 | |
190 | ret = gpiod_direction_output_nonotify(desc, value: val); |
191 | if (ret) |
192 | return ret; |
193 | } else { |
194 | ret = gpiod_direction_input_nonotify(desc); |
195 | if (ret) |
196 | return ret; |
197 | } |
198 | |
199 | gpiod_line_state_notify(desc, action: GPIO_V2_LINE_CHANGED_CONFIG); |
200 | } |
201 | return 0; |
202 | } |
203 | |
204 | static long linehandle_ioctl(struct file *file, unsigned int cmd, |
205 | unsigned long arg) |
206 | { |
207 | struct linehandle_state *lh = file->private_data; |
208 | void __user *ip = (void __user *)arg; |
209 | struct gpiohandle_data ghd; |
210 | DECLARE_BITMAP(vals, GPIOHANDLES_MAX); |
211 | unsigned int i; |
212 | int ret; |
213 | |
214 | guard(srcu)(l: &lh->gdev->srcu); |
215 | |
216 | if (!rcu_access_pointer(lh->gdev->chip)) |
217 | return -ENODEV; |
218 | |
219 | switch (cmd) { |
220 | case GPIOHANDLE_GET_LINE_VALUES_IOCTL: |
221 | /* NOTE: It's okay to read values of output lines */ |
222 | ret = gpiod_get_array_value_complex(raw: false, can_sleep: true, |
223 | array_size: lh->num_descs, desc_array: lh->descs, |
224 | NULL, value_bitmap: vals); |
225 | if (ret) |
226 | return ret; |
227 | |
228 | memset(&ghd, 0, sizeof(ghd)); |
229 | for (i = 0; i < lh->num_descs; i++) |
230 | ghd.values[i] = test_bit(i, vals); |
231 | |
232 | if (copy_to_user(to: ip, from: &ghd, n: sizeof(ghd))) |
233 | return -EFAULT; |
234 | |
235 | return 0; |
236 | case GPIOHANDLE_SET_LINE_VALUES_IOCTL: |
237 | /* |
238 | * All line descriptors were created at once with the same |
239 | * flags so just check if the first one is really output. |
240 | */ |
241 | if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) |
242 | return -EPERM; |
243 | |
244 | if (copy_from_user(to: &ghd, from: ip, n: sizeof(ghd))) |
245 | return -EFAULT; |
246 | |
247 | /* Clamp all values to [0,1] */ |
248 | for (i = 0; i < lh->num_descs; i++) |
249 | __assign_bit(i, vals, ghd.values[i]); |
250 | |
251 | /* Reuse the array setting function */ |
252 | return gpiod_set_array_value_complex(raw: false, |
253 | can_sleep: true, |
254 | array_size: lh->num_descs, |
255 | desc_array: lh->descs, |
256 | NULL, |
257 | value_bitmap: vals); |
258 | case GPIOHANDLE_SET_CONFIG_IOCTL: |
259 | return linehandle_set_config(lh, ip); |
260 | default: |
261 | return -EINVAL; |
262 | } |
263 | } |
264 | |
265 | #ifdef CONFIG_COMPAT |
266 | static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, |
267 | unsigned long arg) |
268 | { |
269 | return linehandle_ioctl(file, cmd, arg: (unsigned long)compat_ptr(uptr: arg)); |
270 | } |
271 | #endif |
272 | |
273 | static void linehandle_free(struct linehandle_state *lh) |
274 | { |
275 | int i; |
276 | |
277 | for (i = 0; i < lh->num_descs; i++) |
278 | if (lh->descs[i]) |
279 | gpiod_free(desc: lh->descs[i]); |
280 | kfree(objp: lh->label); |
281 | gpio_device_put(gdev: lh->gdev); |
282 | kfree(objp: lh); |
283 | } |
284 | |
285 | static int linehandle_release(struct inode *inode, struct file *file) |
286 | { |
287 | linehandle_free(lh: file->private_data); |
288 | return 0; |
289 | } |
290 | |
291 | static const struct file_operations linehandle_fileops = { |
292 | .release = linehandle_release, |
293 | .owner = THIS_MODULE, |
294 | .llseek = noop_llseek, |
295 | .unlocked_ioctl = linehandle_ioctl, |
296 | #ifdef CONFIG_COMPAT |
297 | .compat_ioctl = linehandle_ioctl_compat, |
298 | #endif |
299 | }; |
300 | |
301 | static int linehandle_create(struct gpio_device *gdev, void __user *ip) |
302 | { |
303 | struct gpiohandle_request handlereq; |
304 | struct linehandle_state *lh; |
305 | struct file *file; |
306 | int fd, i, ret; |
307 | u32 lflags; |
308 | |
309 | if (copy_from_user(to: &handlereq, from: ip, n: sizeof(handlereq))) |
310 | return -EFAULT; |
311 | if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) |
312 | return -EINVAL; |
313 | |
314 | lflags = handlereq.flags; |
315 | |
316 | ret = linehandle_validate_flags(flags: lflags); |
317 | if (ret) |
318 | return ret; |
319 | |
320 | lh = kzalloc(sizeof(*lh), GFP_KERNEL); |
321 | if (!lh) |
322 | return -ENOMEM; |
323 | lh->gdev = gpio_device_get(gdev); |
324 | |
325 | if (handlereq.consumer_label[0] != '\0') { |
326 | /* label is only initialized if consumer_label is set */ |
327 | lh->label = kstrndup(s: handlereq.consumer_label, |
328 | len: sizeof(handlereq.consumer_label) - 1, |
329 | GFP_KERNEL); |
330 | if (!lh->label) { |
331 | ret = -ENOMEM; |
332 | goto out_free_lh; |
333 | } |
334 | } |
335 | |
336 | lh->num_descs = handlereq.lines; |
337 | |
338 | /* Request each GPIO */ |
339 | for (i = 0; i < handlereq.lines; i++) { |
340 | u32 offset = handlereq.lineoffsets[i]; |
341 | struct gpio_desc *desc = gpio_device_get_desc(gdev, hwnum: offset); |
342 | |
343 | if (IS_ERR(ptr: desc)) { |
344 | ret = PTR_ERR(ptr: desc); |
345 | goto out_free_lh; |
346 | } |
347 | |
348 | ret = gpiod_request_user(desc, label: lh->label); |
349 | if (ret) |
350 | goto out_free_lh; |
351 | lh->descs[i] = desc; |
352 | linehandle_flags_to_desc_flags(lflags: handlereq.flags, flagsp: &desc->flags); |
353 | |
354 | ret = gpiod_set_transitory(desc, transitory: false); |
355 | if (ret < 0) |
356 | goto out_free_lh; |
357 | |
358 | /* |
359 | * Lines have to be requested explicitly for input |
360 | * or output, else the line will be treated "as is". |
361 | */ |
362 | if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { |
363 | int val = !!handlereq.default_values[i]; |
364 | |
365 | ret = gpiod_direction_output_nonotify(desc, value: val); |
366 | if (ret) |
367 | goto out_free_lh; |
368 | } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { |
369 | ret = gpiod_direction_input_nonotify(desc); |
370 | if (ret) |
371 | goto out_free_lh; |
372 | } |
373 | |
374 | gpiod_line_state_notify(desc, action: GPIO_V2_LINE_CHANGED_REQUESTED); |
375 | |
376 | dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
377 | offset); |
378 | } |
379 | |
380 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
381 | if (fd < 0) { |
382 | ret = fd; |
383 | goto out_free_lh; |
384 | } |
385 | |
386 | file = anon_inode_getfile(name: "gpio-linehandle", |
387 | fops: &linehandle_fileops, |
388 | priv: lh, |
389 | O_RDONLY | O_CLOEXEC); |
390 | if (IS_ERR(ptr: file)) { |
391 | ret = PTR_ERR(ptr: file); |
392 | goto out_put_unused_fd; |
393 | } |
394 | |
395 | handlereq.fd = fd; |
396 | if (copy_to_user(to: ip, from: &handlereq, n: sizeof(handlereq))) { |
397 | /* |
398 | * fput() will trigger the release() callback, so do not go onto |
399 | * the regular error cleanup path here. |
400 | */ |
401 | fput(file); |
402 | put_unused_fd(fd); |
403 | return -EFAULT; |
404 | } |
405 | |
406 | fd_install(fd, file); |
407 | |
408 | dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", |
409 | lh->num_descs); |
410 | |
411 | return 0; |
412 | |
413 | out_put_unused_fd: |
414 | put_unused_fd(fd); |
415 | out_free_lh: |
416 | linehandle_free(lh); |
417 | return ret; |
418 | } |
419 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
420 | |
421 | /** |
422 | * struct line - contains the state of a requested line |
423 | * @desc: the GPIO descriptor for this line. |
424 | * @req: the corresponding line request |
425 | * @irq: the interrupt triggered in response to events on this GPIO |
426 | * @edflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or |
427 | * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied |
428 | * @timestamp_ns: cache for the timestamp storing it between hardirq and |
429 | * IRQ thread, used to bring the timestamp close to the actual event |
430 | * @req_seqno: the seqno for the current edge event in the sequence of |
431 | * events for the corresponding line request. This is drawn from the @req. |
432 | * @line_seqno: the seqno for the current edge event in the sequence of |
433 | * events for this line. |
434 | * @work: the worker that implements software debouncing |
435 | * @sw_debounced: flag indicating if the software debouncer is active |
436 | * @level: the current debounced physical level of the line |
437 | * @hdesc: the Hardware Timestamp Engine (HTE) descriptor |
438 | * @raw_level: the line level at the time of event |
439 | * @total_discard_seq: the running counter of the discarded events |
440 | * @last_seqno: the last sequence number before debounce period expires |
441 | */ |
442 | struct line { |
443 | struct gpio_desc *desc; |
444 | /* |
445 | * -- edge detector specific fields -- |
446 | */ |
447 | struct linereq *req; |
448 | unsigned int irq; |
449 | /* |
450 | * The flags for the active edge detector configuration. |
451 | * |
452 | * edflags is set by linereq_create(), linereq_free(), and |
453 | * linereq_set_config(), which are themselves mutually |
454 | * exclusive, and is accessed by edge_irq_thread(), |
455 | * process_hw_ts_thread() and debounce_work_func(), |
456 | * which can all live with a slightly stale value. |
457 | */ |
458 | u64 edflags; |
459 | /* |
460 | * timestamp_ns and req_seqno are accessed only by |
461 | * edge_irq_handler() and edge_irq_thread(), which are themselves |
462 | * mutually exclusive, so no additional protection is necessary. |
463 | */ |
464 | u64 timestamp_ns; |
465 | u32 req_seqno; |
466 | /* |
467 | * line_seqno is accessed by either edge_irq_thread() or |
468 | * debounce_work_func(), which are themselves mutually exclusive, |
469 | * so no additional protection is necessary. |
470 | */ |
471 | u32 line_seqno; |
472 | /* |
473 | * -- debouncer specific fields -- |
474 | */ |
475 | struct delayed_work work; |
476 | /* |
477 | * sw_debounce is accessed by linereq_set_config(), which is the |
478 | * only setter, and linereq_get_values(), which can live with a |
479 | * slightly stale value. |
480 | */ |
481 | unsigned int sw_debounced; |
482 | /* |
483 | * level is accessed by debounce_work_func(), which is the only |
484 | * setter, and linereq_get_values() which can live with a slightly |
485 | * stale value. |
486 | */ |
487 | unsigned int level; |
488 | #ifdef CONFIG_HTE |
489 | struct hte_ts_desc hdesc; |
490 | /* |
491 | * HTE provider sets line level at the time of event. The valid |
492 | * value is 0 or 1 and negative value for an error. |
493 | */ |
494 | int raw_level; |
495 | /* |
496 | * when sw_debounce is set on HTE enabled line, this is running |
497 | * counter of the discarded events. |
498 | */ |
499 | u32 total_discard_seq; |
500 | /* |
501 | * when sw_debounce is set on HTE enabled line, this variable records |
502 | * last sequence number before debounce period expires. |
503 | */ |
504 | u32 last_seqno; |
505 | #endif /* CONFIG_HTE */ |
506 | }; |
507 | |
508 | /** |
509 | * struct linereq - contains the state of a userspace line request |
510 | * @gdev: the GPIO device the line request pertains to |
511 | * @label: consumer label used to tag GPIO descriptors |
512 | * @num_lines: the number of lines in the lines array |
513 | * @wait: wait queue that handles blocking reads of events |
514 | * @device_unregistered_nb: notifier block for receiving gdev unregister events |
515 | * @event_buffer_size: the number of elements allocated in @events |
516 | * @events: KFIFO for the GPIO events |
517 | * @seqno: the sequence number for edge events generated on all lines in |
518 | * this line request. Note that this is not used when @num_lines is 1, as |
519 | * the line_seqno is then the same and is cheaper to calculate. |
520 | * @config_mutex: mutex for serializing ioctl() calls to ensure consistency |
521 | * of configuration, particularly multi-step accesses to desc flags. |
522 | * @lines: the lines held by this line request, with @num_lines elements. |
523 | */ |
524 | struct linereq { |
525 | struct gpio_device *gdev; |
526 | const char *label; |
527 | u32 num_lines; |
528 | wait_queue_head_t wait; |
529 | struct notifier_block device_unregistered_nb; |
530 | u32 event_buffer_size; |
531 | DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); |
532 | atomic_t seqno; |
533 | struct mutex config_mutex; |
534 | struct line lines[] __counted_by(num_lines); |
535 | }; |
536 | |
537 | #define GPIO_V2_LINE_BIAS_FLAGS \ |
538 | (GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ |
539 | GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ |
540 | GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
541 | |
542 | #define GPIO_V2_LINE_DIRECTION_FLAGS \ |
543 | (GPIO_V2_LINE_FLAG_INPUT | \ |
544 | GPIO_V2_LINE_FLAG_OUTPUT) |
545 | |
546 | #define GPIO_V2_LINE_DRIVE_FLAGS \ |
547 | (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ |
548 | GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
549 | |
550 | #define GPIO_V2_LINE_EDGE_FLAGS \ |
551 | (GPIO_V2_LINE_FLAG_EDGE_RISING | \ |
552 | GPIO_V2_LINE_FLAG_EDGE_FALLING) |
553 | |
554 | #define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS |
555 | |
556 | #define GPIO_V2_LINE_VALID_FLAGS \ |
557 | (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ |
558 | GPIO_V2_LINE_DIRECTION_FLAGS | \ |
559 | GPIO_V2_LINE_DRIVE_FLAGS | \ |
560 | GPIO_V2_LINE_EDGE_FLAGS | \ |
561 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ |
562 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ |
563 | GPIO_V2_LINE_BIAS_FLAGS) |
564 | |
565 | /* subset of flags relevant for edge detector configuration */ |
566 | #define GPIO_V2_LINE_EDGE_DETECTOR_FLAGS \ |
567 | (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ |
568 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ |
569 | GPIO_V2_LINE_EDGE_FLAGS) |
570 | |
571 | static int linereq_unregistered_notify(struct notifier_block *nb, |
572 | unsigned long action, void *data) |
573 | { |
574 | struct linereq *lr = container_of(nb, struct linereq, |
575 | device_unregistered_nb); |
576 | |
577 | wake_up_poll(&lr->wait, EPOLLIN | EPOLLERR); |
578 | |
579 | return NOTIFY_OK; |
580 | } |
581 | |
582 | static void linereq_put_event(struct linereq *lr, |
583 | struct gpio_v2_line_event *le) |
584 | { |
585 | bool overflow = false; |
586 | |
587 | scoped_guard(spinlock, &lr->wait.lock) { |
588 | if (kfifo_is_full(&lr->events)) { |
589 | overflow = true; |
590 | kfifo_skip(&lr->events); |
591 | } |
592 | kfifo_in(&lr->events, le, 1); |
593 | } |
594 | if (!overflow) |
595 | wake_up_poll(&lr->wait, EPOLLIN); |
596 | else |
597 | pr_debug_ratelimited("event FIFO is full - event dropped\n"); |
598 | } |
599 | |
600 | static u64 line_event_timestamp(struct line *line) |
601 | { |
602 | if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) |
603 | return ktime_get_real_ns(); |
604 | else if (IS_ENABLED(CONFIG_HTE) && |
605 | test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) |
606 | return line->timestamp_ns; |
607 | |
608 | return ktime_get_ns(); |
609 | } |
610 | |
611 | static u32 line_event_id(int level) |
612 | { |
613 | return level ? GPIO_V2_LINE_EVENT_RISING_EDGE : |
614 | GPIO_V2_LINE_EVENT_FALLING_EDGE; |
615 | } |
616 | |
617 | static inline char *make_irq_label(const char *orig) |
618 | { |
619 | char *new; |
620 | |
621 | if (!orig) |
622 | return NULL; |
623 | |
624 | new = kstrdup_and_replace(src: orig, old: '/', new: ':', GFP_KERNEL); |
625 | if (!new) |
626 | return ERR_PTR(error: -ENOMEM); |
627 | |
628 | return new; |
629 | } |
630 | |
631 | static inline void free_irq_label(const char *label) |
632 | { |
633 | kfree(objp: label); |
634 | } |
635 | |
636 | #ifdef CONFIG_HTE |
637 | |
638 | static enum hte_return process_hw_ts_thread(void *p) |
639 | { |
640 | struct line *line; |
641 | struct linereq *lr; |
642 | struct gpio_v2_line_event le; |
643 | u64 edflags; |
644 | int level; |
645 | |
646 | if (!p) |
647 | return HTE_CB_HANDLED; |
648 | |
649 | line = p; |
650 | lr = line->req; |
651 | |
652 | memset(&le, 0, sizeof(le)); |
653 | |
654 | le.timestamp_ns = line->timestamp_ns; |
655 | edflags = READ_ONCE(line->edflags); |
656 | |
657 | switch (edflags & GPIO_V2_LINE_EDGE_FLAGS) { |
658 | case GPIO_V2_LINE_FLAG_EDGE_BOTH: |
659 | level = (line->raw_level >= 0) ? |
660 | line->raw_level : |
661 | gpiod_get_raw_value_cansleep(desc: line->desc); |
662 | |
663 | if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
664 | level = !level; |
665 | |
666 | le.id = line_event_id(level); |
667 | break; |
668 | case GPIO_V2_LINE_FLAG_EDGE_RISING: |
669 | le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
670 | break; |
671 | case GPIO_V2_LINE_FLAG_EDGE_FALLING: |
672 | le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
673 | break; |
674 | default: |
675 | return HTE_CB_HANDLED; |
676 | } |
677 | le.line_seqno = line->line_seqno; |
678 | le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; |
679 | le.offset = gpio_chip_hwgpio(desc: line->desc); |
680 | |
681 | linereq_put_event(lr, le: &le); |
682 | |
683 | return HTE_CB_HANDLED; |
684 | } |
685 | |
686 | static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p) |
687 | { |
688 | struct line *line; |
689 | struct linereq *lr; |
690 | int diff_seqno = 0; |
691 | |
692 | if (!ts || !p) |
693 | return HTE_CB_HANDLED; |
694 | |
695 | line = p; |
696 | line->timestamp_ns = ts->tsc; |
697 | line->raw_level = ts->raw_level; |
698 | lr = line->req; |
699 | |
700 | if (READ_ONCE(line->sw_debounced)) { |
701 | line->total_discard_seq++; |
702 | line->last_seqno = ts->seq; |
703 | mod_delayed_work(wq: system_wq, dwork: &line->work, |
704 | delay: usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); |
705 | } else { |
706 | if (unlikely(ts->seq < line->line_seqno)) |
707 | return HTE_CB_HANDLED; |
708 | |
709 | diff_seqno = ts->seq - line->line_seqno; |
710 | line->line_seqno = ts->seq; |
711 | if (lr->num_lines != 1) |
712 | line->req_seqno = atomic_add_return(i: diff_seqno, |
713 | v: &lr->seqno); |
714 | |
715 | return HTE_RUN_SECOND_CB; |
716 | } |
717 | |
718 | return HTE_CB_HANDLED; |
719 | } |
720 | |
721 | static int hte_edge_setup(struct line *line, u64 eflags) |
722 | { |
723 | int ret; |
724 | unsigned long flags = 0; |
725 | struct hte_ts_desc *hdesc = &line->hdesc; |
726 | |
727 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
728 | flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
729 | HTE_FALLING_EDGE_TS : |
730 | HTE_RISING_EDGE_TS; |
731 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
732 | flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
733 | HTE_RISING_EDGE_TS : |
734 | HTE_FALLING_EDGE_TS; |
735 | |
736 | line->total_discard_seq = 0; |
737 | |
738 | hte_init_line_attr(desc: hdesc, line_id: desc_to_gpio(desc: line->desc), edge_flags: flags, NULL, |
739 | data: line->desc); |
740 | |
741 | ret = hte_ts_get(NULL, desc: hdesc, index: 0); |
742 | if (ret) |
743 | return ret; |
744 | |
745 | return hte_request_ts_ns(desc: hdesc, cb: process_hw_ts, tcb: process_hw_ts_thread, |
746 | data: line); |
747 | } |
748 | |
749 | #else |
750 | |
751 | static int hte_edge_setup(struct line *line, u64 eflags) |
752 | { |
753 | return 0; |
754 | } |
755 | #endif /* CONFIG_HTE */ |
756 | |
757 | static irqreturn_t edge_irq_thread(int irq, void *p) |
758 | { |
759 | struct line *line = p; |
760 | struct linereq *lr = line->req; |
761 | struct gpio_v2_line_event le; |
762 | |
763 | /* Do not leak kernel stack to userspace */ |
764 | memset(&le, 0, sizeof(le)); |
765 | |
766 | if (line->timestamp_ns) { |
767 | le.timestamp_ns = line->timestamp_ns; |
768 | } else { |
769 | /* |
770 | * We may be running from a nested threaded interrupt in |
771 | * which case we didn't get the timestamp from |
772 | * edge_irq_handler(). |
773 | */ |
774 | le.timestamp_ns = line_event_timestamp(line); |
775 | if (lr->num_lines != 1) |
776 | line->req_seqno = atomic_inc_return(v: &lr->seqno); |
777 | } |
778 | line->timestamp_ns = 0; |
779 | |
780 | switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) { |
781 | case GPIO_V2_LINE_FLAG_EDGE_BOTH: |
782 | le.id = line_event_id(level: gpiod_get_value_cansleep(desc: line->desc)); |
783 | break; |
784 | case GPIO_V2_LINE_FLAG_EDGE_RISING: |
785 | le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
786 | break; |
787 | case GPIO_V2_LINE_FLAG_EDGE_FALLING: |
788 | le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
789 | break; |
790 | default: |
791 | return IRQ_NONE; |
792 | } |
793 | line->line_seqno++; |
794 | le.line_seqno = line->line_seqno; |
795 | le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; |
796 | le.offset = gpio_chip_hwgpio(desc: line->desc); |
797 | |
798 | linereq_put_event(lr, le: &le); |
799 | |
800 | return IRQ_HANDLED; |
801 | } |
802 | |
803 | static irqreturn_t edge_irq_handler(int irq, void *p) |
804 | { |
805 | struct line *line = p; |
806 | struct linereq *lr = line->req; |
807 | |
808 | /* |
809 | * Just store the timestamp in hardirq context so we get it as |
810 | * close in time as possible to the actual event. |
811 | */ |
812 | line->timestamp_ns = line_event_timestamp(line); |
813 | |
814 | if (lr->num_lines != 1) |
815 | line->req_seqno = atomic_inc_return(v: &lr->seqno); |
816 | |
817 | return IRQ_WAKE_THREAD; |
818 | } |
819 | |
820 | /* |
821 | * returns the current debounced logical value. |
822 | */ |
823 | static bool debounced_value(struct line *line) |
824 | { |
825 | bool value; |
826 | |
827 | /* |
828 | * minor race - debouncer may be stopped here, so edge_detector_stop() |
829 | * must leave the value unchanged so the following will read the level |
830 | * from when the debouncer was last running. |
831 | */ |
832 | value = READ_ONCE(line->level); |
833 | |
834 | if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
835 | value = !value; |
836 | |
837 | return value; |
838 | } |
839 | |
840 | static irqreturn_t debounce_irq_handler(int irq, void *p) |
841 | { |
842 | struct line *line = p; |
843 | |
844 | mod_delayed_work(wq: system_wq, dwork: &line->work, |
845 | delay: usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); |
846 | |
847 | return IRQ_HANDLED; |
848 | } |
849 | |
850 | static void debounce_work_func(struct work_struct *work) |
851 | { |
852 | struct gpio_v2_line_event le; |
853 | struct line *line = container_of(work, struct line, work.work); |
854 | struct linereq *lr; |
855 | u64 eflags, edflags = READ_ONCE(line->edflags); |
856 | int level = -1; |
857 | #ifdef CONFIG_HTE |
858 | int diff_seqno; |
859 | |
860 | if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) |
861 | level = line->raw_level; |
862 | #endif |
863 | if (level < 0) |
864 | level = gpiod_get_raw_value_cansleep(desc: line->desc); |
865 | if (level < 0) { |
866 | pr_debug_ratelimited("debouncer failed to read line value\n"); |
867 | return; |
868 | } |
869 | |
870 | if (READ_ONCE(line->level) == level) |
871 | return; |
872 | |
873 | WRITE_ONCE(line->level, level); |
874 | |
875 | /* -- edge detection -- */ |
876 | eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; |
877 | if (!eflags) |
878 | return; |
879 | |
880 | /* switch from physical level to logical - if they differ */ |
881 | if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
882 | level = !level; |
883 | |
884 | /* ignore edges that are not being monitored */ |
885 | if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || |
886 | ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) |
887 | return; |
888 | |
889 | /* Do not leak kernel stack to userspace */ |
890 | memset(&le, 0, sizeof(le)); |
891 | |
892 | lr = line->req; |
893 | le.timestamp_ns = line_event_timestamp(line); |
894 | le.offset = gpio_chip_hwgpio(desc: line->desc); |
895 | #ifdef CONFIG_HTE |
896 | if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) { |
897 | /* discard events except the last one */ |
898 | line->total_discard_seq -= 1; |
899 | diff_seqno = line->last_seqno - line->total_discard_seq - |
900 | line->line_seqno; |
901 | line->line_seqno = line->last_seqno - line->total_discard_seq; |
902 | le.line_seqno = line->line_seqno; |
903 | le.seqno = (lr->num_lines == 1) ? |
904 | le.line_seqno : atomic_add_return(i: diff_seqno, v: &lr->seqno); |
905 | } else |
906 | #endif /* CONFIG_HTE */ |
907 | { |
908 | line->line_seqno++; |
909 | le.line_seqno = line->line_seqno; |
910 | le.seqno = (lr->num_lines == 1) ? |
911 | le.line_seqno : atomic_inc_return(v: &lr->seqno); |
912 | } |
913 | |
914 | le.id = line_event_id(level); |
915 | |
916 | linereq_put_event(lr, le: &le); |
917 | } |
918 | |
919 | static int debounce_setup(struct line *line, unsigned int debounce_period_us) |
920 | { |
921 | unsigned long irqflags; |
922 | int ret, level, irq; |
923 | char *label; |
924 | |
925 | /* |
926 | * Try hardware. Skip gpiod_set_config() to avoid emitting two |
927 | * CHANGED_CONFIG line state events. |
928 | */ |
929 | ret = gpio_do_set_config(desc: line->desc, |
930 | config: pinconf_to_config_packed(param: PIN_CONFIG_INPUT_DEBOUNCE, |
931 | argument: debounce_period_us)); |
932 | if (ret != -ENOTSUPP) |
933 | return ret; |
934 | |
935 | if (debounce_period_us) { |
936 | /* setup software debounce */ |
937 | level = gpiod_get_raw_value_cansleep(desc: line->desc); |
938 | if (level < 0) |
939 | return level; |
940 | |
941 | if (!(IS_ENABLED(CONFIG_HTE) && |
942 | test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) { |
943 | irq = gpiod_to_irq(desc: line->desc); |
944 | if (irq < 0) |
945 | return -ENXIO; |
946 | |
947 | label = make_irq_label(orig: line->req->label); |
948 | if (IS_ERR(ptr: label)) |
949 | return -ENOMEM; |
950 | |
951 | irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; |
952 | ret = request_irq(irq, handler: debounce_irq_handler, flags: irqflags, |
953 | name: label, dev: line); |
954 | if (ret) { |
955 | free_irq_label(label); |
956 | return ret; |
957 | } |
958 | line->irq = irq; |
959 | } else { |
960 | ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH); |
961 | if (ret) |
962 | return ret; |
963 | } |
964 | |
965 | WRITE_ONCE(line->level, level); |
966 | WRITE_ONCE(line->sw_debounced, 1); |
967 | } |
968 | return 0; |
969 | } |
970 | |
971 | static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, |
972 | unsigned int line_idx) |
973 | { |
974 | unsigned int i; |
975 | u64 mask = BIT_ULL(line_idx); |
976 | |
977 | for (i = 0; i < lc->num_attrs; i++) { |
978 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
979 | (lc->attrs[i].mask & mask)) |
980 | return true; |
981 | } |
982 | return false; |
983 | } |
984 | |
985 | static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, |
986 | unsigned int line_idx) |
987 | { |
988 | unsigned int i; |
989 | u64 mask = BIT_ULL(line_idx); |
990 | |
991 | for (i = 0; i < lc->num_attrs; i++) { |
992 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
993 | (lc->attrs[i].mask & mask)) |
994 | return lc->attrs[i].attr.debounce_period_us; |
995 | } |
996 | return 0; |
997 | } |
998 | |
999 | static void edge_detector_stop(struct line *line) |
1000 | { |
1001 | if (line->irq) { |
1002 | free_irq_label(label: free_irq(line->irq, line)); |
1003 | line->irq = 0; |
1004 | } |
1005 | |
1006 | #ifdef CONFIG_HTE |
1007 | if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) |
1008 | hte_ts_put(desc: &line->hdesc); |
1009 | #endif |
1010 | |
1011 | cancel_delayed_work_sync(dwork: &line->work); |
1012 | WRITE_ONCE(line->sw_debounced, 0); |
1013 | WRITE_ONCE(line->edflags, 0); |
1014 | if (line->desc) |
1015 | WRITE_ONCE(line->desc->debounce_period_us, 0); |
1016 | /* do not change line->level - see comment in debounced_value() */ |
1017 | } |
1018 | |
1019 | static int edge_detector_fifo_init(struct linereq *req) |
1020 | { |
1021 | if (kfifo_initialized(&req->events)) |
1022 | return 0; |
1023 | |
1024 | return kfifo_alloc(&req->events, req->event_buffer_size, GFP_KERNEL); |
1025 | } |
1026 | |
1027 | static int edge_detector_setup(struct line *line, |
1028 | struct gpio_v2_line_config *lc, |
1029 | unsigned int line_idx, u64 edflags) |
1030 | { |
1031 | u32 debounce_period_us; |
1032 | unsigned long irqflags = 0; |
1033 | u64 eflags; |
1034 | int irq, ret; |
1035 | char *label; |
1036 | |
1037 | eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; |
1038 | if (eflags) { |
1039 | ret = edge_detector_fifo_init(req: line->req); |
1040 | if (ret) |
1041 | return ret; |
1042 | } |
1043 | if (gpio_v2_line_config_debounced(lc, line_idx)) { |
1044 | debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); |
1045 | ret = debounce_setup(line, debounce_period_us); |
1046 | if (ret) |
1047 | return ret; |
1048 | WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
1049 | } |
1050 | |
1051 | /* detection disabled or sw debouncer will provide edge detection */ |
1052 | if (!eflags || READ_ONCE(line->sw_debounced)) |
1053 | return 0; |
1054 | |
1055 | if (IS_ENABLED(CONFIG_HTE) && |
1056 | (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) |
1057 | return hte_edge_setup(line, eflags: edflags); |
1058 | |
1059 | irq = gpiod_to_irq(desc: line->desc); |
1060 | if (irq < 0) |
1061 | return -ENXIO; |
1062 | |
1063 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
1064 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
1065 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; |
1066 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
1067 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
1068 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; |
1069 | irqflags |= IRQF_ONESHOT; |
1070 | |
1071 | label = make_irq_label(orig: line->req->label); |
1072 | if (IS_ERR(ptr: label)) |
1073 | return PTR_ERR(ptr: label); |
1074 | |
1075 | /* Request a thread to read the events */ |
1076 | ret = request_threaded_irq(irq, handler: edge_irq_handler, thread_fn: edge_irq_thread, |
1077 | flags: irqflags, name: label, dev: line); |
1078 | if (ret) { |
1079 | free_irq_label(label); |
1080 | return ret; |
1081 | } |
1082 | |
1083 | line->irq = irq; |
1084 | return 0; |
1085 | } |
1086 | |
1087 | static int edge_detector_update(struct line *line, |
1088 | struct gpio_v2_line_config *lc, |
1089 | unsigned int line_idx, u64 edflags) |
1090 | { |
1091 | u64 active_edflags = READ_ONCE(line->edflags); |
1092 | unsigned int debounce_period_us = |
1093 | gpio_v2_line_config_debounce_period(lc, line_idx); |
1094 | |
1095 | if ((active_edflags == edflags) && |
1096 | (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us)) |
1097 | return 0; |
1098 | |
1099 | /* sw debounced and still will be...*/ |
1100 | if (debounce_period_us && READ_ONCE(line->sw_debounced)) { |
1101 | WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
1102 | /* |
1103 | * ensure event fifo is initialised if edge detection |
1104 | * is now enabled. |
1105 | */ |
1106 | if (edflags & GPIO_V2_LINE_EDGE_FLAGS) |
1107 | return edge_detector_fifo_init(req: line->req); |
1108 | |
1109 | return 0; |
1110 | } |
1111 | |
1112 | /* reconfiguring edge detection or sw debounce being disabled */ |
1113 | if ((line->irq && !READ_ONCE(line->sw_debounced)) || |
1114 | (active_edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) || |
1115 | (!debounce_period_us && READ_ONCE(line->sw_debounced))) |
1116 | edge_detector_stop(line); |
1117 | |
1118 | return edge_detector_setup(line, lc, line_idx, edflags); |
1119 | } |
1120 | |
1121 | static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, |
1122 | unsigned int line_idx) |
1123 | { |
1124 | unsigned int i; |
1125 | u64 mask = BIT_ULL(line_idx); |
1126 | |
1127 | for (i = 0; i < lc->num_attrs; i++) { |
1128 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && |
1129 | (lc->attrs[i].mask & mask)) |
1130 | return lc->attrs[i].attr.flags; |
1131 | } |
1132 | return lc->flags; |
1133 | } |
1134 | |
1135 | static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, |
1136 | unsigned int line_idx) |
1137 | { |
1138 | unsigned int i; |
1139 | u64 mask = BIT_ULL(line_idx); |
1140 | |
1141 | for (i = 0; i < lc->num_attrs; i++) { |
1142 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && |
1143 | (lc->attrs[i].mask & mask)) |
1144 | return !!(lc->attrs[i].attr.values & mask); |
1145 | } |
1146 | return 0; |
1147 | } |
1148 | |
1149 | static int gpio_v2_line_flags_validate(u64 flags) |
1150 | { |
1151 | /* Return an error if an unknown flag is set */ |
1152 | if (flags & ~GPIO_V2_LINE_VALID_FLAGS) |
1153 | return -EINVAL; |
1154 | |
1155 | if (!IS_ENABLED(CONFIG_HTE) && |
1156 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) |
1157 | return -EOPNOTSUPP; |
1158 | |
1159 | /* |
1160 | * Do not allow both INPUT and OUTPUT flags to be set as they are |
1161 | * contradictory. |
1162 | */ |
1163 | if ((flags & GPIO_V2_LINE_FLAG_INPUT) && |
1164 | (flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
1165 | return -EINVAL; |
1166 | |
1167 | /* Only allow one event clock source */ |
1168 | if (IS_ENABLED(CONFIG_HTE) && |
1169 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME) && |
1170 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) |
1171 | return -EINVAL; |
1172 | |
1173 | /* Edge detection requires explicit input. */ |
1174 | if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && |
1175 | !(flags & GPIO_V2_LINE_FLAG_INPUT)) |
1176 | return -EINVAL; |
1177 | |
1178 | /* |
1179 | * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single |
1180 | * request. If the hardware actually supports enabling both at the |
1181 | * same time the electrical result would be disastrous. |
1182 | */ |
1183 | if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && |
1184 | (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) |
1185 | return -EINVAL; |
1186 | |
1187 | /* Drive requires explicit output direction. */ |
1188 | if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && |
1189 | !(flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
1190 | return -EINVAL; |
1191 | |
1192 | /* Bias requires explicit direction. */ |
1193 | if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && |
1194 | !(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) |
1195 | return -EINVAL; |
1196 | |
1197 | /* Only one bias flag can be set. */ |
1198 | if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && |
1199 | (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | |
1200 | GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || |
1201 | ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && |
1202 | (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) |
1203 | return -EINVAL; |
1204 | |
1205 | return 0; |
1206 | } |
1207 | |
1208 | static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, |
1209 | unsigned int num_lines) |
1210 | { |
1211 | unsigned int i; |
1212 | u64 flags; |
1213 | int ret; |
1214 | |
1215 | if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) |
1216 | return -EINVAL; |
1217 | |
1218 | if (!mem_is_zero(s: lc->padding, n: sizeof(lc->padding))) |
1219 | return -EINVAL; |
1220 | |
1221 | for (i = 0; i < num_lines; i++) { |
1222 | flags = gpio_v2_line_config_flags(lc, line_idx: i); |
1223 | ret = gpio_v2_line_flags_validate(flags); |
1224 | if (ret) |
1225 | return ret; |
1226 | |
1227 | /* debounce requires explicit input */ |
1228 | if (gpio_v2_line_config_debounced(lc, line_idx: i) && |
1229 | !(flags & GPIO_V2_LINE_FLAG_INPUT)) |
1230 | return -EINVAL; |
1231 | } |
1232 | return 0; |
1233 | } |
1234 | |
1235 | static void gpio_v2_line_config_flags_to_desc_flags(u64 lflags, |
1236 | unsigned long *flagsp) |
1237 | { |
1238 | unsigned long flags = READ_ONCE(*flagsp); |
1239 | |
1240 | assign_bit(FLAG_ACTIVE_LOW, &flags, |
1241 | lflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); |
1242 | |
1243 | if (lflags & GPIO_V2_LINE_FLAG_OUTPUT) |
1244 | set_bit(FLAG_IS_OUT, addr: &flags); |
1245 | else if (lflags & GPIO_V2_LINE_FLAG_INPUT) |
1246 | clear_bit(FLAG_IS_OUT, addr: &flags); |
1247 | |
1248 | assign_bit(FLAG_EDGE_RISING, &flags, |
1249 | lflags & GPIO_V2_LINE_FLAG_EDGE_RISING); |
1250 | assign_bit(FLAG_EDGE_FALLING, &flags, |
1251 | lflags & GPIO_V2_LINE_FLAG_EDGE_FALLING); |
1252 | |
1253 | assign_bit(FLAG_OPEN_DRAIN, &flags, |
1254 | lflags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); |
1255 | assign_bit(FLAG_OPEN_SOURCE, &flags, |
1256 | lflags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); |
1257 | |
1258 | assign_bit(FLAG_PULL_UP, &flags, |
1259 | lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); |
1260 | assign_bit(FLAG_PULL_DOWN, &flags, |
1261 | lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); |
1262 | assign_bit(FLAG_BIAS_DISABLE, &flags, |
1263 | lflags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); |
1264 | |
1265 | assign_bit(FLAG_EVENT_CLOCK_REALTIME, &flags, |
1266 | lflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME); |
1267 | assign_bit(FLAG_EVENT_CLOCK_HTE, &flags, |
1268 | lflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); |
1269 | |
1270 | WRITE_ONCE(*flagsp, flags); |
1271 | } |
1272 | |
1273 | static long linereq_get_values(struct linereq *lr, void __user *ip) |
1274 | { |
1275 | struct gpio_v2_line_values lv; |
1276 | DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
1277 | struct gpio_desc **descs; |
1278 | unsigned int i, didx, num_get; |
1279 | bool val; |
1280 | int ret; |
1281 | |
1282 | /* NOTE: It's ok to read values of output lines. */ |
1283 | if (copy_from_user(to: &lv, from: ip, n: sizeof(lv))) |
1284 | return -EFAULT; |
1285 | |
1286 | /* |
1287 | * gpiod_get_array_value_complex() requires compacted desc and val |
1288 | * arrays, rather than the sparse ones in lv. |
1289 | * Calculation of num_get and construction of the desc array is |
1290 | * optimized to avoid allocation for the desc array for the common |
1291 | * num_get == 1 case. |
1292 | */ |
1293 | /* scan requested lines to calculate the subset to get */ |
1294 | for (num_get = 0, i = 0; i < lr->num_lines; i++) { |
1295 | if (lv.mask & BIT_ULL(i)) { |
1296 | num_get++; |
1297 | /* capture desc for the num_get == 1 case */ |
1298 | descs = &lr->lines[i].desc; |
1299 | } |
1300 | } |
1301 | |
1302 | if (num_get == 0) |
1303 | return -EINVAL; |
1304 | |
1305 | if (num_get != 1) { |
1306 | /* build compacted desc array */ |
1307 | descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); |
1308 | if (!descs) |
1309 | return -ENOMEM; |
1310 | for (didx = 0, i = 0; i < lr->num_lines; i++) { |
1311 | if (lv.mask & BIT_ULL(i)) { |
1312 | descs[didx] = lr->lines[i].desc; |
1313 | didx++; |
1314 | } |
1315 | } |
1316 | } |
1317 | ret = gpiod_get_array_value_complex(raw: false, can_sleep: true, array_size: num_get, |
1318 | desc_array: descs, NULL, value_bitmap: vals); |
1319 | |
1320 | if (num_get != 1) |
1321 | kfree(objp: descs); |
1322 | if (ret) |
1323 | return ret; |
1324 | |
1325 | lv.bits = 0; |
1326 | for (didx = 0, i = 0; i < lr->num_lines; i++) { |
1327 | /* unpack compacted vals for the response */ |
1328 | if (lv.mask & BIT_ULL(i)) { |
1329 | if (lr->lines[i].sw_debounced) |
1330 | val = debounced_value(line: &lr->lines[i]); |
1331 | else |
1332 | val = test_bit(didx, vals); |
1333 | if (val) |
1334 | lv.bits |= BIT_ULL(i); |
1335 | didx++; |
1336 | } |
1337 | } |
1338 | |
1339 | if (copy_to_user(to: ip, from: &lv, n: sizeof(lv))) |
1340 | return -EFAULT; |
1341 | |
1342 | return 0; |
1343 | } |
1344 | |
1345 | static long linereq_set_values(struct linereq *lr, void __user *ip) |
1346 | { |
1347 | DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
1348 | struct gpio_v2_line_values lv; |
1349 | struct gpio_desc **descs; |
1350 | unsigned int i, didx, num_set; |
1351 | int ret; |
1352 | |
1353 | if (copy_from_user(to: &lv, from: ip, n: sizeof(lv))) |
1354 | return -EFAULT; |
1355 | |
1356 | guard(mutex)(T: &lr->config_mutex); |
1357 | |
1358 | /* |
1359 | * gpiod_set_array_value_complex() requires compacted desc and val |
1360 | * arrays, rather than the sparse ones in lv. |
1361 | * Calculation of num_set and construction of the descs and vals arrays |
1362 | * is optimized to minimize scanning the lv->mask, and to avoid |
1363 | * allocation for the desc array for the common num_set == 1 case. |
1364 | */ |
1365 | bitmap_zero(dst: vals, GPIO_V2_LINES_MAX); |
1366 | /* scan requested lines to determine the subset to be set */ |
1367 | for (num_set = 0, i = 0; i < lr->num_lines; i++) { |
1368 | if (lv.mask & BIT_ULL(i)) { |
1369 | /* add to compacted values */ |
1370 | if (lv.bits & BIT_ULL(i)) |
1371 | __set_bit(num_set, vals); |
1372 | num_set++; |
1373 | /* capture desc for the num_set == 1 case */ |
1374 | descs = &lr->lines[i].desc; |
1375 | } |
1376 | } |
1377 | if (num_set == 0) |
1378 | return -EINVAL; |
1379 | |
1380 | if (num_set != 1) { |
1381 | /* build compacted desc array */ |
1382 | descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); |
1383 | if (!descs) |
1384 | return -ENOMEM; |
1385 | for (didx = 0, i = 0; i < lr->num_lines; i++) { |
1386 | if (lv.mask & BIT_ULL(i)) { |
1387 | descs[didx] = lr->lines[i].desc; |
1388 | didx++; |
1389 | } |
1390 | } |
1391 | } |
1392 | ret = gpiod_set_array_value_complex(raw: false, can_sleep: true, array_size: num_set, |
1393 | desc_array: descs, NULL, value_bitmap: vals); |
1394 | |
1395 | if (num_set != 1) |
1396 | kfree(objp: descs); |
1397 | return ret; |
1398 | } |
1399 | |
1400 | static long linereq_set_config(struct linereq *lr, void __user *ip) |
1401 | { |
1402 | struct gpio_v2_line_config lc; |
1403 | struct gpio_desc *desc; |
1404 | struct line *line; |
1405 | unsigned int i; |
1406 | u64 flags, edflags; |
1407 | int ret; |
1408 | |
1409 | if (copy_from_user(to: &lc, from: ip, n: sizeof(lc))) |
1410 | return -EFAULT; |
1411 | |
1412 | ret = gpio_v2_line_config_validate(lc: &lc, num_lines: lr->num_lines); |
1413 | if (ret) |
1414 | return ret; |
1415 | |
1416 | guard(mutex)(T: &lr->config_mutex); |
1417 | |
1418 | for (i = 0; i < lr->num_lines; i++) { |
1419 | line = &lr->lines[i]; |
1420 | desc = lr->lines[i].desc; |
1421 | flags = gpio_v2_line_config_flags(lc: &lc, line_idx: i); |
1422 | /* |
1423 | * Lines not explicitly reconfigured as input or output |
1424 | * are left unchanged. |
1425 | */ |
1426 | if (!(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) |
1427 | continue; |
1428 | gpio_v2_line_config_flags_to_desc_flags(lflags: flags, flagsp: &desc->flags); |
1429 | edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; |
1430 | if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
1431 | int val = gpio_v2_line_config_output_value(lc: &lc, line_idx: i); |
1432 | |
1433 | edge_detector_stop(line); |
1434 | ret = gpiod_direction_output_nonotify(desc, value: val); |
1435 | if (ret) |
1436 | return ret; |
1437 | } else { |
1438 | ret = gpiod_direction_input_nonotify(desc); |
1439 | if (ret) |
1440 | return ret; |
1441 | |
1442 | ret = edge_detector_update(line, lc: &lc, line_idx: i, edflags); |
1443 | if (ret) |
1444 | return ret; |
1445 | } |
1446 | |
1447 | WRITE_ONCE(line->edflags, edflags); |
1448 | |
1449 | gpiod_line_state_notify(desc, action: GPIO_V2_LINE_CHANGED_CONFIG); |
1450 | } |
1451 | return 0; |
1452 | } |
1453 | |
1454 | static long linereq_ioctl(struct file *file, unsigned int cmd, |
1455 | unsigned long arg) |
1456 | { |
1457 | struct linereq *lr = file->private_data; |
1458 | void __user *ip = (void __user *)arg; |
1459 | |
1460 | guard(srcu)(l: &lr->gdev->srcu); |
1461 | |
1462 | if (!rcu_access_pointer(lr->gdev->chip)) |
1463 | return -ENODEV; |
1464 | |
1465 | switch (cmd) { |
1466 | case GPIO_V2_LINE_GET_VALUES_IOCTL: |
1467 | return linereq_get_values(lr, ip); |
1468 | case GPIO_V2_LINE_SET_VALUES_IOCTL: |
1469 | return linereq_set_values(lr, ip); |
1470 | case GPIO_V2_LINE_SET_CONFIG_IOCTL: |
1471 | return linereq_set_config(lr, ip); |
1472 | default: |
1473 | return -EINVAL; |
1474 | } |
1475 | } |
1476 | |
1477 | #ifdef CONFIG_COMPAT |
1478 | static long linereq_ioctl_compat(struct file *file, unsigned int cmd, |
1479 | unsigned long arg) |
1480 | { |
1481 | return linereq_ioctl(file, cmd, arg: (unsigned long)compat_ptr(uptr: arg)); |
1482 | } |
1483 | #endif |
1484 | |
1485 | static __poll_t linereq_poll(struct file *file, |
1486 | struct poll_table_struct *wait) |
1487 | { |
1488 | struct linereq *lr = file->private_data; |
1489 | __poll_t events = 0; |
1490 | |
1491 | guard(srcu)(l: &lr->gdev->srcu); |
1492 | |
1493 | if (!rcu_access_pointer(lr->gdev->chip)) |
1494 | return EPOLLHUP | EPOLLERR; |
1495 | |
1496 | poll_wait(filp: file, wait_address: &lr->wait, p: wait); |
1497 | |
1498 | if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, |
1499 | &lr->wait.lock)) |
1500 | events = EPOLLIN | EPOLLRDNORM; |
1501 | |
1502 | return events; |
1503 | } |
1504 | |
1505 | static ssize_t linereq_read(struct file *file, char __user *buf, |
1506 | size_t count, loff_t *f_ps) |
1507 | { |
1508 | struct linereq *lr = file->private_data; |
1509 | struct gpio_v2_line_event le; |
1510 | ssize_t bytes_read = 0; |
1511 | int ret; |
1512 | |
1513 | guard(srcu)(l: &lr->gdev->srcu); |
1514 | |
1515 | if (!rcu_access_pointer(lr->gdev->chip)) |
1516 | return -ENODEV; |
1517 | |
1518 | if (count < sizeof(le)) |
1519 | return -EINVAL; |
1520 | |
1521 | do { |
1522 | scoped_guard(spinlock, &lr->wait.lock) { |
1523 | if (kfifo_is_empty(&lr->events)) { |
1524 | if (bytes_read) |
1525 | return bytes_read; |
1526 | |
1527 | if (file->f_flags & O_NONBLOCK) |
1528 | return -EAGAIN; |
1529 | |
1530 | ret = wait_event_interruptible_locked(lr->wait, |
1531 | !kfifo_is_empty(&lr->events)); |
1532 | if (ret) |
1533 | return ret; |
1534 | } |
1535 | |
1536 | if (kfifo_out(&lr->events, &le, 1) != 1) { |
1537 | /* |
1538 | * This should never happen - we hold the |
1539 | * lock from the moment we learned the fifo |
1540 | * is no longer empty until now. |
1541 | */ |
1542 | WARN(1, "failed to read from non-empty kfifo"); |
1543 | return -EIO; |
1544 | } |
1545 | } |
1546 | |
1547 | if (copy_to_user(to: buf + bytes_read, from: &le, n: sizeof(le))) |
1548 | return -EFAULT; |
1549 | bytes_read += sizeof(le); |
1550 | } while (count >= bytes_read + sizeof(le)); |
1551 | |
1552 | return bytes_read; |
1553 | } |
1554 | |
1555 | static void linereq_free(struct linereq *lr) |
1556 | { |
1557 | unsigned int i; |
1558 | |
1559 | if (lr->device_unregistered_nb.notifier_call) |
1560 | blocking_notifier_chain_unregister(nh: &lr->gdev->device_notifier, |
1561 | nb: &lr->device_unregistered_nb); |
1562 | |
1563 | for (i = 0; i < lr->num_lines; i++) { |
1564 | if (lr->lines[i].desc) { |
1565 | edge_detector_stop(line: &lr->lines[i]); |
1566 | gpiod_free(desc: lr->lines[i].desc); |
1567 | } |
1568 | } |
1569 | kfifo_free(&lr->events); |
1570 | kfree(objp: lr->label); |
1571 | gpio_device_put(gdev: lr->gdev); |
1572 | kvfree(addr: lr); |
1573 | } |
1574 | |
1575 | static int linereq_release(struct inode *inode, struct file *file) |
1576 | { |
1577 | struct linereq *lr = file->private_data; |
1578 | |
1579 | linereq_free(lr); |
1580 | return 0; |
1581 | } |
1582 | |
1583 | #ifdef CONFIG_PROC_FS |
1584 | static void linereq_show_fdinfo(struct seq_file *out, struct file *file) |
1585 | { |
1586 | struct linereq *lr = file->private_data; |
1587 | struct device *dev = &lr->gdev->dev; |
1588 | u16 i; |
1589 | |
1590 | seq_printf(m: out, fmt: "gpio-chip:\t%s\n", dev_name(dev)); |
1591 | |
1592 | for (i = 0; i < lr->num_lines; i++) |
1593 | seq_printf(m: out, fmt: "gpio-line:\t%d\n", |
1594 | gpio_chip_hwgpio(desc: lr->lines[i].desc)); |
1595 | } |
1596 | #endif |
1597 | |
1598 | static const struct file_operations line_fileops = { |
1599 | .release = linereq_release, |
1600 | .read = linereq_read, |
1601 | .poll = linereq_poll, |
1602 | .owner = THIS_MODULE, |
1603 | .llseek = noop_llseek, |
1604 | .unlocked_ioctl = linereq_ioctl, |
1605 | #ifdef CONFIG_COMPAT |
1606 | .compat_ioctl = linereq_ioctl_compat, |
1607 | #endif |
1608 | #ifdef CONFIG_PROC_FS |
1609 | .show_fdinfo = linereq_show_fdinfo, |
1610 | #endif |
1611 | }; |
1612 | |
1613 | static int linereq_create(struct gpio_device *gdev, void __user *ip) |
1614 | { |
1615 | struct gpio_v2_line_request ulr; |
1616 | struct gpio_v2_line_config *lc; |
1617 | struct linereq *lr; |
1618 | struct file *file; |
1619 | u64 flags, edflags; |
1620 | unsigned int i; |
1621 | int fd, ret; |
1622 | |
1623 | if (copy_from_user(to: &ulr, from: ip, n: sizeof(ulr))) |
1624 | return -EFAULT; |
1625 | |
1626 | if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) |
1627 | return -EINVAL; |
1628 | |
1629 | if (!mem_is_zero(s: ulr.padding, n: sizeof(ulr.padding))) |
1630 | return -EINVAL; |
1631 | |
1632 | lc = &ulr.config; |
1633 | ret = gpio_v2_line_config_validate(lc, num_lines: ulr.num_lines); |
1634 | if (ret) |
1635 | return ret; |
1636 | |
1637 | lr = kvzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); |
1638 | if (!lr) |
1639 | return -ENOMEM; |
1640 | lr->num_lines = ulr.num_lines; |
1641 | |
1642 | lr->gdev = gpio_device_get(gdev); |
1643 | |
1644 | for (i = 0; i < ulr.num_lines; i++) { |
1645 | lr->lines[i].req = lr; |
1646 | WRITE_ONCE(lr->lines[i].sw_debounced, 0); |
1647 | INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); |
1648 | } |
1649 | |
1650 | if (ulr.consumer[0] != '\0') { |
1651 | /* label is only initialized if consumer is set */ |
1652 | lr->label = kstrndup(s: ulr.consumer, len: sizeof(ulr.consumer) - 1, |
1653 | GFP_KERNEL); |
1654 | if (!lr->label) { |
1655 | ret = -ENOMEM; |
1656 | goto out_free_linereq; |
1657 | } |
1658 | } |
1659 | |
1660 | mutex_init(&lr->config_mutex); |
1661 | init_waitqueue_head(&lr->wait); |
1662 | INIT_KFIFO(lr->events); |
1663 | lr->event_buffer_size = ulr.event_buffer_size; |
1664 | if (lr->event_buffer_size == 0) |
1665 | lr->event_buffer_size = ulr.num_lines * 16; |
1666 | else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) |
1667 | lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; |
1668 | |
1669 | atomic_set(v: &lr->seqno, i: 0); |
1670 | |
1671 | /* Request each GPIO */ |
1672 | for (i = 0; i < ulr.num_lines; i++) { |
1673 | u32 offset = ulr.offsets[i]; |
1674 | struct gpio_desc *desc = gpio_device_get_desc(gdev, hwnum: offset); |
1675 | |
1676 | if (IS_ERR(ptr: desc)) { |
1677 | ret = PTR_ERR(ptr: desc); |
1678 | goto out_free_linereq; |
1679 | } |
1680 | |
1681 | ret = gpiod_request_user(desc, label: lr->label); |
1682 | if (ret) |
1683 | goto out_free_linereq; |
1684 | |
1685 | lr->lines[i].desc = desc; |
1686 | flags = gpio_v2_line_config_flags(lc, line_idx: i); |
1687 | gpio_v2_line_config_flags_to_desc_flags(lflags: flags, flagsp: &desc->flags); |
1688 | |
1689 | ret = gpiod_set_transitory(desc, transitory: false); |
1690 | if (ret < 0) |
1691 | goto out_free_linereq; |
1692 | |
1693 | edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; |
1694 | /* |
1695 | * Lines have to be requested explicitly for input |
1696 | * or output, else the line will be treated "as is". |
1697 | */ |
1698 | if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
1699 | int val = gpio_v2_line_config_output_value(lc, line_idx: i); |
1700 | |
1701 | ret = gpiod_direction_output_nonotify(desc, value: val); |
1702 | if (ret) |
1703 | goto out_free_linereq; |
1704 | } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
1705 | ret = gpiod_direction_input_nonotify(desc); |
1706 | if (ret) |
1707 | goto out_free_linereq; |
1708 | |
1709 | ret = edge_detector_setup(line: &lr->lines[i], lc, line_idx: i, |
1710 | edflags); |
1711 | if (ret) |
1712 | goto out_free_linereq; |
1713 | } |
1714 | |
1715 | lr->lines[i].edflags = edflags; |
1716 | |
1717 | gpiod_line_state_notify(desc, action: GPIO_V2_LINE_CHANGED_REQUESTED); |
1718 | |
1719 | dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
1720 | offset); |
1721 | } |
1722 | |
1723 | lr->device_unregistered_nb.notifier_call = linereq_unregistered_notify; |
1724 | ret = blocking_notifier_chain_register(nh: &gdev->device_notifier, |
1725 | nb: &lr->device_unregistered_nb); |
1726 | if (ret) |
1727 | goto out_free_linereq; |
1728 | |
1729 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
1730 | if (fd < 0) { |
1731 | ret = fd; |
1732 | goto out_free_linereq; |
1733 | } |
1734 | |
1735 | file = anon_inode_getfile(name: "gpio-line", fops: &line_fileops, priv: lr, |
1736 | O_RDONLY | O_CLOEXEC); |
1737 | if (IS_ERR(ptr: file)) { |
1738 | ret = PTR_ERR(ptr: file); |
1739 | goto out_put_unused_fd; |
1740 | } |
1741 | |
1742 | ulr.fd = fd; |
1743 | if (copy_to_user(to: ip, from: &ulr, n: sizeof(ulr))) { |
1744 | /* |
1745 | * fput() will trigger the release() callback, so do not go onto |
1746 | * the regular error cleanup path here. |
1747 | */ |
1748 | fput(file); |
1749 | put_unused_fd(fd); |
1750 | return -EFAULT; |
1751 | } |
1752 | |
1753 | fd_install(fd, file); |
1754 | |
1755 | dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", |
1756 | lr->num_lines); |
1757 | |
1758 | return 0; |
1759 | |
1760 | out_put_unused_fd: |
1761 | put_unused_fd(fd); |
1762 | out_free_linereq: |
1763 | linereq_free(lr); |
1764 | return ret; |
1765 | } |
1766 | |
1767 | #ifdef CONFIG_GPIO_CDEV_V1 |
1768 | |
1769 | /* |
1770 | * GPIO line event management |
1771 | */ |
1772 | |
1773 | /** |
1774 | * struct lineevent_state - contains the state of a userspace event |
1775 | * @gdev: the GPIO device the event pertains to |
1776 | * @label: consumer label used to tag descriptors |
1777 | * @desc: the GPIO descriptor held by this event |
1778 | * @eflags: the event flags this line was requested with |
1779 | * @irq: the interrupt that trigger in response to events on this GPIO |
1780 | * @wait: wait queue that handles blocking reads of events |
1781 | * @device_unregistered_nb: notifier block for receiving gdev unregister events |
1782 | * @events: KFIFO for the GPIO events |
1783 | * @timestamp: cache for the timestamp storing it between hardirq |
1784 | * and IRQ thread, used to bring the timestamp close to the actual |
1785 | * event |
1786 | */ |
1787 | struct lineevent_state { |
1788 | struct gpio_device *gdev; |
1789 | const char *label; |
1790 | struct gpio_desc *desc; |
1791 | u32 eflags; |
1792 | int irq; |
1793 | wait_queue_head_t wait; |
1794 | struct notifier_block device_unregistered_nb; |
1795 | DECLARE_KFIFO(events, struct gpioevent_data, 16); |
1796 | u64 timestamp; |
1797 | }; |
1798 | |
1799 | #define GPIOEVENT_REQUEST_VALID_FLAGS \ |
1800 | (GPIOEVENT_REQUEST_RISING_EDGE | \ |
1801 | GPIOEVENT_REQUEST_FALLING_EDGE) |
1802 | |
1803 | static __poll_t lineevent_poll(struct file *file, |
1804 | struct poll_table_struct *wait) |
1805 | { |
1806 | struct lineevent_state *le = file->private_data; |
1807 | __poll_t events = 0; |
1808 | |
1809 | guard(srcu)(l: &le->gdev->srcu); |
1810 | |
1811 | if (!rcu_access_pointer(le->gdev->chip)) |
1812 | return EPOLLHUP | EPOLLERR; |
1813 | |
1814 | poll_wait(filp: file, wait_address: &le->wait, p: wait); |
1815 | |
1816 | if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) |
1817 | events = EPOLLIN | EPOLLRDNORM; |
1818 | |
1819 | return events; |
1820 | } |
1821 | |
1822 | static int lineevent_unregistered_notify(struct notifier_block *nb, |
1823 | unsigned long action, void *data) |
1824 | { |
1825 | struct lineevent_state *le = container_of(nb, struct lineevent_state, |
1826 | device_unregistered_nb); |
1827 | |
1828 | wake_up_poll(&le->wait, EPOLLIN | EPOLLERR); |
1829 | |
1830 | return NOTIFY_OK; |
1831 | } |
1832 | |
1833 | struct compat_gpioeevent_data { |
1834 | compat_u64 timestamp; |
1835 | u32 id; |
1836 | }; |
1837 | |
1838 | static ssize_t lineevent_read(struct file *file, char __user *buf, |
1839 | size_t count, loff_t *f_ps) |
1840 | { |
1841 | struct lineevent_state *le = file->private_data; |
1842 | struct gpioevent_data ge; |
1843 | ssize_t bytes_read = 0; |
1844 | ssize_t ge_size; |
1845 | int ret; |
1846 | |
1847 | guard(srcu)(l: &le->gdev->srcu); |
1848 | |
1849 | if (!rcu_access_pointer(le->gdev->chip)) |
1850 | return -ENODEV; |
1851 | |
1852 | /* |
1853 | * When compatible system call is being used the struct gpioevent_data, |
1854 | * in case of at least ia32, has different size due to the alignment |
1855 | * differences. Because we have first member 64 bits followed by one of |
1856 | * 32 bits there is no gap between them. The only difference is the |
1857 | * padding at the end of the data structure. Hence, we calculate the |
1858 | * actual sizeof() and pass this as an argument to copy_to_user() to |
1859 | * drop unneeded bytes from the output. |
1860 | */ |
1861 | if (compat_need_64bit_alignment_fixup()) |
1862 | ge_size = sizeof(struct compat_gpioeevent_data); |
1863 | else |
1864 | ge_size = sizeof(struct gpioevent_data); |
1865 | if (count < ge_size) |
1866 | return -EINVAL; |
1867 | |
1868 | do { |
1869 | scoped_guard(spinlock, &le->wait.lock) { |
1870 | if (kfifo_is_empty(&le->events)) { |
1871 | if (bytes_read) |
1872 | return bytes_read; |
1873 | |
1874 | if (file->f_flags & O_NONBLOCK) |
1875 | return -EAGAIN; |
1876 | |
1877 | ret = wait_event_interruptible_locked(le->wait, |
1878 | !kfifo_is_empty(&le->events)); |
1879 | if (ret) |
1880 | return ret; |
1881 | } |
1882 | |
1883 | if (kfifo_out(&le->events, &ge, 1) != 1) { |
1884 | /* |
1885 | * This should never happen - we hold the |
1886 | * lock from the moment we learned the fifo |
1887 | * is no longer empty until now. |
1888 | */ |
1889 | WARN(1, "failed to read from non-empty kfifo"); |
1890 | return -EIO; |
1891 | } |
1892 | } |
1893 | |
1894 | if (copy_to_user(to: buf + bytes_read, from: &ge, n: ge_size)) |
1895 | return -EFAULT; |
1896 | bytes_read += ge_size; |
1897 | } while (count >= bytes_read + ge_size); |
1898 | |
1899 | return bytes_read; |
1900 | } |
1901 | |
1902 | static void lineevent_free(struct lineevent_state *le) |
1903 | { |
1904 | if (le->device_unregistered_nb.notifier_call) |
1905 | blocking_notifier_chain_unregister(nh: &le->gdev->device_notifier, |
1906 | nb: &le->device_unregistered_nb); |
1907 | if (le->irq) |
1908 | free_irq_label(label: free_irq(le->irq, le)); |
1909 | if (le->desc) |
1910 | gpiod_free(desc: le->desc); |
1911 | kfree(objp: le->label); |
1912 | gpio_device_put(gdev: le->gdev); |
1913 | kfree(objp: le); |
1914 | } |
1915 | |
1916 | static int lineevent_release(struct inode *inode, struct file *file) |
1917 | { |
1918 | lineevent_free(le: file->private_data); |
1919 | return 0; |
1920 | } |
1921 | |
1922 | static long lineevent_ioctl(struct file *file, unsigned int cmd, |
1923 | unsigned long arg) |
1924 | { |
1925 | struct lineevent_state *le = file->private_data; |
1926 | void __user *ip = (void __user *)arg; |
1927 | struct gpiohandle_data ghd; |
1928 | |
1929 | guard(srcu)(l: &le->gdev->srcu); |
1930 | |
1931 | if (!rcu_access_pointer(le->gdev->chip)) |
1932 | return -ENODEV; |
1933 | |
1934 | /* |
1935 | * We can get the value for an event line but not set it, |
1936 | * because it is input by definition. |
1937 | */ |
1938 | if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { |
1939 | int val; |
1940 | |
1941 | memset(&ghd, 0, sizeof(ghd)); |
1942 | |
1943 | val = gpiod_get_value_cansleep(desc: le->desc); |
1944 | if (val < 0) |
1945 | return val; |
1946 | ghd.values[0] = val; |
1947 | |
1948 | if (copy_to_user(to: ip, from: &ghd, n: sizeof(ghd))) |
1949 | return -EFAULT; |
1950 | |
1951 | return 0; |
1952 | } |
1953 | return -EINVAL; |
1954 | } |
1955 | |
1956 | #ifdef CONFIG_COMPAT |
1957 | static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, |
1958 | unsigned long arg) |
1959 | { |
1960 | return lineevent_ioctl(file, cmd, arg: (unsigned long)compat_ptr(uptr: arg)); |
1961 | } |
1962 | #endif |
1963 | |
1964 | static const struct file_operations lineevent_fileops = { |
1965 | .release = lineevent_release, |
1966 | .read = lineevent_read, |
1967 | .poll = lineevent_poll, |
1968 | .owner = THIS_MODULE, |
1969 | .llseek = noop_llseek, |
1970 | .unlocked_ioctl = lineevent_ioctl, |
1971 | #ifdef CONFIG_COMPAT |
1972 | .compat_ioctl = lineevent_ioctl_compat, |
1973 | #endif |
1974 | }; |
1975 | |
1976 | static irqreturn_t lineevent_irq_thread(int irq, void *p) |
1977 | { |
1978 | struct lineevent_state *le = p; |
1979 | struct gpioevent_data ge; |
1980 | int ret; |
1981 | |
1982 | /* Do not leak kernel stack to userspace */ |
1983 | memset(&ge, 0, sizeof(ge)); |
1984 | |
1985 | /* |
1986 | * We may be running from a nested threaded interrupt in which case |
1987 | * we didn't get the timestamp from lineevent_irq_handler(). |
1988 | */ |
1989 | if (!le->timestamp) |
1990 | ge.timestamp = ktime_get_ns(); |
1991 | else |
1992 | ge.timestamp = le->timestamp; |
1993 | |
1994 | if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE |
1995 | && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { |
1996 | int level = gpiod_get_value_cansleep(desc: le->desc); |
1997 | |
1998 | if (level) |
1999 | /* Emit low-to-high event */ |
2000 | ge.id = GPIOEVENT_EVENT_RISING_EDGE; |
2001 | else |
2002 | /* Emit high-to-low event */ |
2003 | ge.id = GPIOEVENT_EVENT_FALLING_EDGE; |
2004 | } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { |
2005 | /* Emit low-to-high event */ |
2006 | ge.id = GPIOEVENT_EVENT_RISING_EDGE; |
2007 | } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { |
2008 | /* Emit high-to-low event */ |
2009 | ge.id = GPIOEVENT_EVENT_FALLING_EDGE; |
2010 | } else { |
2011 | return IRQ_NONE; |
2012 | } |
2013 | |
2014 | ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, |
2015 | 1, &le->wait.lock); |
2016 | if (ret) |
2017 | wake_up_poll(&le->wait, EPOLLIN); |
2018 | else |
2019 | pr_debug_ratelimited("event FIFO is full - event dropped\n"); |
2020 | |
2021 | return IRQ_HANDLED; |
2022 | } |
2023 | |
2024 | static irqreturn_t lineevent_irq_handler(int irq, void *p) |
2025 | { |
2026 | struct lineevent_state *le = p; |
2027 | |
2028 | /* |
2029 | * Just store the timestamp in hardirq context so we get it as |
2030 | * close in time as possible to the actual event. |
2031 | */ |
2032 | le->timestamp = ktime_get_ns(); |
2033 | |
2034 | return IRQ_WAKE_THREAD; |
2035 | } |
2036 | |
2037 | static int lineevent_create(struct gpio_device *gdev, void __user *ip) |
2038 | { |
2039 | struct gpioevent_request eventreq; |
2040 | struct lineevent_state *le; |
2041 | struct gpio_desc *desc; |
2042 | struct file *file; |
2043 | u32 offset; |
2044 | u32 lflags; |
2045 | u32 eflags; |
2046 | int fd; |
2047 | int ret; |
2048 | int irq, irqflags = 0; |
2049 | char *label; |
2050 | |
2051 | if (copy_from_user(to: &eventreq, from: ip, n: sizeof(eventreq))) |
2052 | return -EFAULT; |
2053 | |
2054 | offset = eventreq.lineoffset; |
2055 | lflags = eventreq.handleflags; |
2056 | eflags = eventreq.eventflags; |
2057 | |
2058 | desc = gpio_device_get_desc(gdev, hwnum: offset); |
2059 | if (IS_ERR(ptr: desc)) |
2060 | return PTR_ERR(ptr: desc); |
2061 | |
2062 | /* Return an error if a unknown flag is set */ |
2063 | if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || |
2064 | (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) |
2065 | return -EINVAL; |
2066 | |
2067 | /* This is just wrong: we don't look for events on output lines */ |
2068 | if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || |
2069 | (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || |
2070 | (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) |
2071 | return -EINVAL; |
2072 | |
2073 | /* Only one bias flag can be set. */ |
2074 | if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && |
2075 | (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | |
2076 | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || |
2077 | ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && |
2078 | (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) |
2079 | return -EINVAL; |
2080 | |
2081 | le = kzalloc(sizeof(*le), GFP_KERNEL); |
2082 | if (!le) |
2083 | return -ENOMEM; |
2084 | le->gdev = gpio_device_get(gdev); |
2085 | |
2086 | if (eventreq.consumer_label[0] != '\0') { |
2087 | /* label is only initialized if consumer_label is set */ |
2088 | le->label = kstrndup(s: eventreq.consumer_label, |
2089 | len: sizeof(eventreq.consumer_label) - 1, |
2090 | GFP_KERNEL); |
2091 | if (!le->label) { |
2092 | ret = -ENOMEM; |
2093 | goto out_free_le; |
2094 | } |
2095 | } |
2096 | |
2097 | ret = gpiod_request_user(desc, label: le->label); |
2098 | if (ret) |
2099 | goto out_free_le; |
2100 | le->desc = desc; |
2101 | le->eflags = eflags; |
2102 | |
2103 | linehandle_flags_to_desc_flags(lflags, flagsp: &desc->flags); |
2104 | |
2105 | ret = gpiod_direction_input(desc); |
2106 | if (ret) |
2107 | goto out_free_le; |
2108 | |
2109 | gpiod_line_state_notify(desc, action: GPIO_V2_LINE_CHANGED_REQUESTED); |
2110 | |
2111 | irq = gpiod_to_irq(desc); |
2112 | if (irq <= 0) { |
2113 | ret = -ENODEV; |
2114 | goto out_free_le; |
2115 | } |
2116 | |
2117 | if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) |
2118 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
2119 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; |
2120 | if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) |
2121 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
2122 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; |
2123 | irqflags |= IRQF_ONESHOT; |
2124 | |
2125 | INIT_KFIFO(le->events); |
2126 | init_waitqueue_head(&le->wait); |
2127 | |
2128 | le->device_unregistered_nb.notifier_call = lineevent_unregistered_notify; |
2129 | ret = blocking_notifier_chain_register(nh: &gdev->device_notifier, |
2130 | nb: &le->device_unregistered_nb); |
2131 | if (ret) |
2132 | goto out_free_le; |
2133 | |
2134 | label = make_irq_label(orig: le->label); |
2135 | if (IS_ERR(ptr: label)) { |
2136 | ret = PTR_ERR(ptr: label); |
2137 | goto out_free_le; |
2138 | } |
2139 | |
2140 | /* Request a thread to read the events */ |
2141 | ret = request_threaded_irq(irq, |
2142 | handler: lineevent_irq_handler, |
2143 | thread_fn: lineevent_irq_thread, |
2144 | flags: irqflags, |
2145 | name: label, |
2146 | dev: le); |
2147 | if (ret) { |
2148 | free_irq_label(label); |
2149 | goto out_free_le; |
2150 | } |
2151 | |
2152 | le->irq = irq; |
2153 | |
2154 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
2155 | if (fd < 0) { |
2156 | ret = fd; |
2157 | goto out_free_le; |
2158 | } |
2159 | |
2160 | file = anon_inode_getfile(name: "gpio-event", |
2161 | fops: &lineevent_fileops, |
2162 | priv: le, |
2163 | O_RDONLY | O_CLOEXEC); |
2164 | if (IS_ERR(ptr: file)) { |
2165 | ret = PTR_ERR(ptr: file); |
2166 | goto out_put_unused_fd; |
2167 | } |
2168 | |
2169 | eventreq.fd = fd; |
2170 | if (copy_to_user(to: ip, from: &eventreq, n: sizeof(eventreq))) { |
2171 | /* |
2172 | * fput() will trigger the release() callback, so do not go onto |
2173 | * the regular error cleanup path here. |
2174 | */ |
2175 | fput(file); |
2176 | put_unused_fd(fd); |
2177 | return -EFAULT; |
2178 | } |
2179 | |
2180 | fd_install(fd, file); |
2181 | |
2182 | return 0; |
2183 | |
2184 | out_put_unused_fd: |
2185 | put_unused_fd(fd); |
2186 | out_free_le: |
2187 | lineevent_free(le); |
2188 | return ret; |
2189 | } |
2190 | |
2191 | static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, |
2192 | struct gpioline_info *info_v1) |
2193 | { |
2194 | u64 flagsv2 = info_v2->flags; |
2195 | |
2196 | memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); |
2197 | memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); |
2198 | info_v1->line_offset = info_v2->offset; |
2199 | info_v1->flags = 0; |
2200 | |
2201 | if (flagsv2 & GPIO_V2_LINE_FLAG_USED) |
2202 | info_v1->flags |= GPIOLINE_FLAG_KERNEL; |
2203 | |
2204 | if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) |
2205 | info_v1->flags |= GPIOLINE_FLAG_IS_OUT; |
2206 | |
2207 | if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
2208 | info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; |
2209 | |
2210 | if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) |
2211 | info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; |
2212 | if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
2213 | info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; |
2214 | |
2215 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) |
2216 | info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; |
2217 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) |
2218 | info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; |
2219 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
2220 | info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; |
2221 | } |
2222 | |
2223 | static void gpio_v2_line_info_changed_to_v1( |
2224 | struct gpio_v2_line_info_changed *lic_v2, |
2225 | struct gpioline_info_changed *lic_v1) |
2226 | { |
2227 | memset(lic_v1, 0, sizeof(*lic_v1)); |
2228 | gpio_v2_line_info_to_v1(info_v2: &lic_v2->info, info_v1: &lic_v1->info); |
2229 | lic_v1->timestamp = lic_v2->timestamp_ns; |
2230 | lic_v1->event_type = lic_v2->event_type; |
2231 | } |
2232 | |
2233 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
2234 | |
2235 | static void gpio_desc_to_lineinfo(struct gpio_desc *desc, |
2236 | struct gpio_v2_line_info *info, bool atomic) |
2237 | { |
2238 | u32 debounce_period_us; |
2239 | unsigned long dflags; |
2240 | const char *label; |
2241 | |
2242 | CLASS(gpio_chip_guard, guard)(desc); |
2243 | if (!guard.gc) |
2244 | return; |
2245 | |
2246 | memset(info, 0, sizeof(*info)); |
2247 | info->offset = gpio_chip_hwgpio(desc); |
2248 | |
2249 | if (desc->name) |
2250 | strscpy(info->name, desc->name, sizeof(info->name)); |
2251 | |
2252 | dflags = READ_ONCE(desc->flags); |
2253 | |
2254 | scoped_guard(srcu, &desc->gdev->desc_srcu) { |
2255 | label = gpiod_get_label(desc); |
2256 | if (label && test_bit(FLAG_REQUESTED, &dflags)) |
2257 | strscpy(info->consumer, label, |
2258 | sizeof(info->consumer)); |
2259 | } |
2260 | |
2261 | /* |
2262 | * Userspace only need know that the kernel is using this GPIO so it |
2263 | * can't use it. |
2264 | * The calculation of the used flag is slightly racy, as it may read |
2265 | * desc, gc and pinctrl state without a lock covering all three at |
2266 | * once. Worst case if the line is in transition and the calculation |
2267 | * is inconsistent then it looks to the user like they performed the |
2268 | * read on the other side of the transition - but that can always |
2269 | * happen. |
2270 | * The definitive test that a line is available to userspace is to |
2271 | * request it. |
2272 | */ |
2273 | if (test_bit(FLAG_REQUESTED, &dflags) || |
2274 | test_bit(FLAG_IS_HOGGED, &dflags) || |
2275 | test_bit(FLAG_EXPORT, &dflags) || |
2276 | test_bit(FLAG_SYSFS, &dflags) || |
2277 | !gpiochip_line_is_valid(gc: guard.gc, offset: info->offset)) { |
2278 | info->flags |= GPIO_V2_LINE_FLAG_USED; |
2279 | } else if (!atomic) { |
2280 | if (!pinctrl_gpio_can_use_line(gc: guard.gc, offset: info->offset)) |
2281 | info->flags |= GPIO_V2_LINE_FLAG_USED; |
2282 | } |
2283 | |
2284 | if (test_bit(FLAG_IS_OUT, &dflags)) |
2285 | info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; |
2286 | else |
2287 | info->flags |= GPIO_V2_LINE_FLAG_INPUT; |
2288 | |
2289 | if (test_bit(FLAG_ACTIVE_LOW, &dflags)) |
2290 | info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; |
2291 | |
2292 | if (test_bit(FLAG_OPEN_DRAIN, &dflags)) |
2293 | info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; |
2294 | if (test_bit(FLAG_OPEN_SOURCE, &dflags)) |
2295 | info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; |
2296 | |
2297 | if (test_bit(FLAG_BIAS_DISABLE, &dflags)) |
2298 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; |
2299 | if (test_bit(FLAG_PULL_DOWN, &dflags)) |
2300 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; |
2301 | if (test_bit(FLAG_PULL_UP, &dflags)) |
2302 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; |
2303 | |
2304 | if (test_bit(FLAG_EDGE_RISING, &dflags)) |
2305 | info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; |
2306 | if (test_bit(FLAG_EDGE_FALLING, &dflags)) |
2307 | info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; |
2308 | |
2309 | if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &dflags)) |
2310 | info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME; |
2311 | else if (test_bit(FLAG_EVENT_CLOCK_HTE, &dflags)) |
2312 | info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE; |
2313 | |
2314 | debounce_period_us = READ_ONCE(desc->debounce_period_us); |
2315 | if (debounce_period_us) { |
2316 | info->attrs[info->num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; |
2317 | info->attrs[info->num_attrs].debounce_period_us = |
2318 | debounce_period_us; |
2319 | info->num_attrs++; |
2320 | } |
2321 | } |
2322 | |
2323 | struct gpio_chardev_data { |
2324 | struct gpio_device *gdev; |
2325 | wait_queue_head_t wait; |
2326 | DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); |
2327 | struct notifier_block lineinfo_changed_nb; |
2328 | struct notifier_block device_unregistered_nb; |
2329 | unsigned long *watched_lines; |
2330 | #ifdef CONFIG_GPIO_CDEV_V1 |
2331 | atomic_t watch_abi_version; |
2332 | #endif |
2333 | struct file *fp; |
2334 | }; |
2335 | |
2336 | static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) |
2337 | { |
2338 | struct gpio_device *gdev = cdev->gdev; |
2339 | struct gpiochip_info chipinfo; |
2340 | |
2341 | memset(&chipinfo, 0, sizeof(chipinfo)); |
2342 | |
2343 | strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); |
2344 | strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); |
2345 | chipinfo.lines = gdev->ngpio; |
2346 | if (copy_to_user(to: ip, from: &chipinfo, n: sizeof(chipinfo))) |
2347 | return -EFAULT; |
2348 | return 0; |
2349 | } |
2350 | |
2351 | #ifdef CONFIG_GPIO_CDEV_V1 |
2352 | /* |
2353 | * returns 0 if the versions match, else the previously selected ABI version |
2354 | */ |
2355 | static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, |
2356 | unsigned int version) |
2357 | { |
2358 | int abiv = atomic_cmpxchg(v: &cdata->watch_abi_version, old: 0, new: version); |
2359 | |
2360 | if (abiv == version) |
2361 | return 0; |
2362 | |
2363 | return abiv; |
2364 | } |
2365 | |
2366 | static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, |
2367 | bool watch) |
2368 | { |
2369 | struct gpio_desc *desc; |
2370 | struct gpioline_info lineinfo; |
2371 | struct gpio_v2_line_info lineinfo_v2; |
2372 | |
2373 | if (copy_from_user(to: &lineinfo, from: ip, n: sizeof(lineinfo))) |
2374 | return -EFAULT; |
2375 | |
2376 | /* this doubles as a range check on line_offset */ |
2377 | desc = gpio_device_get_desc(gdev: cdev->gdev, hwnum: lineinfo.line_offset); |
2378 | if (IS_ERR(ptr: desc)) |
2379 | return PTR_ERR(ptr: desc); |
2380 | |
2381 | if (watch) { |
2382 | if (lineinfo_ensure_abi_version(cdata: cdev, version: 1)) |
2383 | return -EPERM; |
2384 | |
2385 | if (test_and_set_bit(nr: lineinfo.line_offset, addr: cdev->watched_lines)) |
2386 | return -EBUSY; |
2387 | } |
2388 | |
2389 | gpio_desc_to_lineinfo(desc, info: &lineinfo_v2, atomic: false); |
2390 | gpio_v2_line_info_to_v1(info_v2: &lineinfo_v2, info_v1: &lineinfo); |
2391 | |
2392 | if (copy_to_user(to: ip, from: &lineinfo, n: sizeof(lineinfo))) { |
2393 | if (watch) |
2394 | clear_bit(nr: lineinfo.line_offset, addr: cdev->watched_lines); |
2395 | return -EFAULT; |
2396 | } |
2397 | |
2398 | return 0; |
2399 | } |
2400 | #endif |
2401 | |
2402 | static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, |
2403 | bool watch) |
2404 | { |
2405 | struct gpio_desc *desc; |
2406 | struct gpio_v2_line_info lineinfo; |
2407 | |
2408 | if (copy_from_user(to: &lineinfo, from: ip, n: sizeof(lineinfo))) |
2409 | return -EFAULT; |
2410 | |
2411 | if (!mem_is_zero(s: lineinfo.padding, n: sizeof(lineinfo.padding))) |
2412 | return -EINVAL; |
2413 | |
2414 | desc = gpio_device_get_desc(gdev: cdev->gdev, hwnum: lineinfo.offset); |
2415 | if (IS_ERR(ptr: desc)) |
2416 | return PTR_ERR(ptr: desc); |
2417 | |
2418 | if (watch) { |
2419 | #ifdef CONFIG_GPIO_CDEV_V1 |
2420 | if (lineinfo_ensure_abi_version(cdata: cdev, version: 2)) |
2421 | return -EPERM; |
2422 | #endif |
2423 | if (test_and_set_bit(nr: lineinfo.offset, addr: cdev->watched_lines)) |
2424 | return -EBUSY; |
2425 | } |
2426 | gpio_desc_to_lineinfo(desc, info: &lineinfo, atomic: false); |
2427 | |
2428 | if (copy_to_user(to: ip, from: &lineinfo, n: sizeof(lineinfo))) { |
2429 | if (watch) |
2430 | clear_bit(nr: lineinfo.offset, addr: cdev->watched_lines); |
2431 | return -EFAULT; |
2432 | } |
2433 | |
2434 | return 0; |
2435 | } |
2436 | |
2437 | static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) |
2438 | { |
2439 | __u32 offset; |
2440 | |
2441 | if (copy_from_user(to: &offset, from: ip, n: sizeof(offset))) |
2442 | return -EFAULT; |
2443 | |
2444 | if (offset >= cdev->gdev->ngpio) |
2445 | return -EINVAL; |
2446 | |
2447 | if (!test_and_clear_bit(nr: offset, addr: cdev->watched_lines)) |
2448 | return -EBUSY; |
2449 | |
2450 | return 0; |
2451 | } |
2452 | |
2453 | /* |
2454 | * gpio_ioctl() - ioctl handler for the GPIO chardev |
2455 | */ |
2456 | static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
2457 | { |
2458 | struct gpio_chardev_data *cdev = file->private_data; |
2459 | struct gpio_device *gdev = cdev->gdev; |
2460 | void __user *ip = (void __user *)arg; |
2461 | |
2462 | guard(srcu)(l: &gdev->srcu); |
2463 | |
2464 | /* We fail any subsequent ioctl():s when the chip is gone */ |
2465 | if (!rcu_access_pointer(gdev->chip)) |
2466 | return -ENODEV; |
2467 | |
2468 | /* Fill in the struct and pass to userspace */ |
2469 | switch (cmd) { |
2470 | case GPIO_GET_CHIPINFO_IOCTL: |
2471 | return chipinfo_get(cdev, ip); |
2472 | #ifdef CONFIG_GPIO_CDEV_V1 |
2473 | case GPIO_GET_LINEHANDLE_IOCTL: |
2474 | return linehandle_create(gdev, ip); |
2475 | case GPIO_GET_LINEEVENT_IOCTL: |
2476 | return lineevent_create(gdev, ip); |
2477 | case GPIO_GET_LINEINFO_IOCTL: |
2478 | return lineinfo_get_v1(cdev, ip, watch: false); |
2479 | case GPIO_GET_LINEINFO_WATCH_IOCTL: |
2480 | return lineinfo_get_v1(cdev, ip, watch: true); |
2481 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
2482 | case GPIO_V2_GET_LINEINFO_IOCTL: |
2483 | return lineinfo_get(cdev, ip, watch: false); |
2484 | case GPIO_V2_GET_LINEINFO_WATCH_IOCTL: |
2485 | return lineinfo_get(cdev, ip, watch: true); |
2486 | case GPIO_V2_GET_LINE_IOCTL: |
2487 | return linereq_create(gdev, ip); |
2488 | case GPIO_GET_LINEINFO_UNWATCH_IOCTL: |
2489 | return lineinfo_unwatch(cdev, ip); |
2490 | default: |
2491 | return -EINVAL; |
2492 | } |
2493 | } |
2494 | |
2495 | #ifdef CONFIG_COMPAT |
2496 | static long gpio_ioctl_compat(struct file *file, unsigned int cmd, |
2497 | unsigned long arg) |
2498 | { |
2499 | return gpio_ioctl(file, cmd, arg: (unsigned long)compat_ptr(uptr: arg)); |
2500 | } |
2501 | #endif |
2502 | |
2503 | struct lineinfo_changed_ctx { |
2504 | struct work_struct work; |
2505 | struct gpio_v2_line_info_changed chg; |
2506 | struct gpio_device *gdev; |
2507 | struct gpio_chardev_data *cdev; |
2508 | }; |
2509 | |
2510 | static void lineinfo_changed_func(struct work_struct *work) |
2511 | { |
2512 | struct lineinfo_changed_ctx *ctx = |
2513 | container_of(work, struct lineinfo_changed_ctx, work); |
2514 | struct gpio_chip *gc; |
2515 | int ret; |
2516 | |
2517 | if (!(ctx->chg.info.flags & GPIO_V2_LINE_FLAG_USED)) { |
2518 | /* |
2519 | * If nobody set the USED flag earlier, let's see with pinctrl |
2520 | * now. We're doing this late because it's a sleeping function. |
2521 | * Pin functions are in general much more static and while it's |
2522 | * not 100% bullet-proof, it's good enough for most cases. |
2523 | */ |
2524 | scoped_guard(srcu, &ctx->gdev->srcu) { |
2525 | gc = srcu_dereference(ctx->gdev->chip, &ctx->gdev->srcu); |
2526 | if (gc && |
2527 | !pinctrl_gpio_can_use_line(gc, offset: ctx->chg.info.offset)) |
2528 | ctx->chg.info.flags |= GPIO_V2_LINE_FLAG_USED; |
2529 | } |
2530 | } |
2531 | |
2532 | ret = kfifo_in_spinlocked(&ctx->cdev->events, &ctx->chg, 1, |
2533 | &ctx->cdev->wait.lock); |
2534 | if (ret) |
2535 | wake_up_poll(&ctx->cdev->wait, EPOLLIN); |
2536 | else |
2537 | pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); |
2538 | |
2539 | gpio_device_put(gdev: ctx->gdev); |
2540 | fput(ctx->cdev->fp); |
2541 | kfree(objp: ctx); |
2542 | } |
2543 | |
2544 | static int lineinfo_changed_notify(struct notifier_block *nb, |
2545 | unsigned long action, void *data) |
2546 | { |
2547 | struct gpio_chardev_data *cdev = |
2548 | container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); |
2549 | struct lineinfo_changed_ctx *ctx; |
2550 | struct gpio_desc *desc = data; |
2551 | |
2552 | if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines)) |
2553 | return NOTIFY_DONE; |
2554 | |
2555 | /* |
2556 | * If this is called from atomic context (for instance: with a spinlock |
2557 | * taken by the atomic notifier chain), any sleeping calls must be done |
2558 | * outside of this function in process context of the dedicated |
2559 | * workqueue. |
2560 | * |
2561 | * Let's gather as much info as possible from the descriptor and |
2562 | * postpone just the call to pinctrl_gpio_can_use_line() until the work |
2563 | * is executed. |
2564 | */ |
2565 | |
2566 | ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC); |
2567 | if (!ctx) { |
2568 | pr_err("Failed to allocate memory for line info notification\n"); |
2569 | return NOTIFY_DONE; |
2570 | } |
2571 | |
2572 | ctx->chg.event_type = action; |
2573 | ctx->chg.timestamp_ns = ktime_get_ns(); |
2574 | gpio_desc_to_lineinfo(desc, info: &ctx->chg.info, atomic: true); |
2575 | /* Keep the GPIO device alive until we emit the event. */ |
2576 | ctx->gdev = gpio_device_get(gdev: desc->gdev); |
2577 | ctx->cdev = cdev; |
2578 | /* Keep the file descriptor alive too. */ |
2579 | get_file(f: ctx->cdev->fp); |
2580 | |
2581 | INIT_WORK(&ctx->work, lineinfo_changed_func); |
2582 | queue_work(wq: ctx->gdev->line_state_wq, work: &ctx->work); |
2583 | |
2584 | return NOTIFY_OK; |
2585 | } |
2586 | |
2587 | static int gpio_device_unregistered_notify(struct notifier_block *nb, |
2588 | unsigned long action, void *data) |
2589 | { |
2590 | struct gpio_chardev_data *cdev = container_of(nb, |
2591 | struct gpio_chardev_data, |
2592 | device_unregistered_nb); |
2593 | |
2594 | wake_up_poll(&cdev->wait, EPOLLIN | EPOLLERR); |
2595 | |
2596 | return NOTIFY_OK; |
2597 | } |
2598 | |
2599 | static __poll_t lineinfo_watch_poll(struct file *file, |
2600 | struct poll_table_struct *pollt) |
2601 | { |
2602 | struct gpio_chardev_data *cdev = file->private_data; |
2603 | __poll_t events = 0; |
2604 | |
2605 | guard(srcu)(l: &cdev->gdev->srcu); |
2606 | |
2607 | if (!rcu_access_pointer(cdev->gdev->chip)) |
2608 | return EPOLLHUP | EPOLLERR; |
2609 | |
2610 | poll_wait(filp: file, wait_address: &cdev->wait, p: pollt); |
2611 | |
2612 | if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, |
2613 | &cdev->wait.lock)) |
2614 | events = EPOLLIN | EPOLLRDNORM; |
2615 | |
2616 | return events; |
2617 | } |
2618 | |
2619 | static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, |
2620 | size_t count, loff_t *off) |
2621 | { |
2622 | struct gpio_chardev_data *cdev = file->private_data; |
2623 | struct gpio_v2_line_info_changed event; |
2624 | ssize_t bytes_read = 0; |
2625 | int ret; |
2626 | size_t event_size; |
2627 | |
2628 | guard(srcu)(l: &cdev->gdev->srcu); |
2629 | |
2630 | if (!rcu_access_pointer(cdev->gdev->chip)) |
2631 | return -ENODEV; |
2632 | |
2633 | #ifndef CONFIG_GPIO_CDEV_V1 |
2634 | event_size = sizeof(struct gpio_v2_line_info_changed); |
2635 | if (count < event_size) |
2636 | return -EINVAL; |
2637 | #endif |
2638 | |
2639 | do { |
2640 | scoped_guard(spinlock, &cdev->wait.lock) { |
2641 | if (kfifo_is_empty(&cdev->events)) { |
2642 | if (bytes_read) |
2643 | return bytes_read; |
2644 | |
2645 | if (file->f_flags & O_NONBLOCK) |
2646 | return -EAGAIN; |
2647 | |
2648 | ret = wait_event_interruptible_locked(cdev->wait, |
2649 | !kfifo_is_empty(&cdev->events)); |
2650 | if (ret) |
2651 | return ret; |
2652 | } |
2653 | #ifdef CONFIG_GPIO_CDEV_V1 |
2654 | /* must be after kfifo check so watch_abi_version is set */ |
2655 | if (atomic_read(v: &cdev->watch_abi_version) == 2) |
2656 | event_size = sizeof(struct gpio_v2_line_info_changed); |
2657 | else |
2658 | event_size = sizeof(struct gpioline_info_changed); |
2659 | if (count < event_size) |
2660 | return -EINVAL; |
2661 | #endif |
2662 | if (kfifo_out(&cdev->events, &event, 1) != 1) { |
2663 | /* |
2664 | * This should never happen - we hold the |
2665 | * lock from the moment we learned the fifo |
2666 | * is no longer empty until now. |
2667 | */ |
2668 | WARN(1, "failed to read from non-empty kfifo"); |
2669 | return -EIO; |
2670 | } |
2671 | } |
2672 | |
2673 | #ifdef CONFIG_GPIO_CDEV_V1 |
2674 | if (event_size == sizeof(struct gpio_v2_line_info_changed)) { |
2675 | if (copy_to_user(to: buf + bytes_read, from: &event, n: event_size)) |
2676 | return -EFAULT; |
2677 | } else { |
2678 | struct gpioline_info_changed event_v1; |
2679 | |
2680 | gpio_v2_line_info_changed_to_v1(lic_v2: &event, lic_v1: &event_v1); |
2681 | if (copy_to_user(to: buf + bytes_read, from: &event_v1, |
2682 | n: event_size)) |
2683 | return -EFAULT; |
2684 | } |
2685 | #else |
2686 | if (copy_to_user(buf + bytes_read, &event, event_size)) |
2687 | return -EFAULT; |
2688 | #endif |
2689 | bytes_read += event_size; |
2690 | } while (count >= bytes_read + sizeof(event)); |
2691 | |
2692 | return bytes_read; |
2693 | } |
2694 | |
2695 | /** |
2696 | * gpio_chrdev_open() - open the chardev for ioctl operations |
2697 | * @inode: inode for this chardev |
2698 | * @file: file struct for storing private data |
2699 | * |
2700 | * Returns: |
2701 | * 0 on success, or negative errno on failure. |
2702 | */ |
2703 | static int gpio_chrdev_open(struct inode *inode, struct file *file) |
2704 | { |
2705 | struct gpio_device *gdev = container_of(inode->i_cdev, |
2706 | struct gpio_device, chrdev); |
2707 | struct gpio_chardev_data *cdev; |
2708 | int ret = -ENOMEM; |
2709 | |
2710 | guard(srcu)(l: &gdev->srcu); |
2711 | |
2712 | /* Fail on open if the backing gpiochip is gone */ |
2713 | if (!rcu_access_pointer(gdev->chip)) |
2714 | return -ENODEV; |
2715 | |
2716 | cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); |
2717 | if (!cdev) |
2718 | return -ENODEV; |
2719 | |
2720 | cdev->watched_lines = bitmap_zalloc(nbits: gdev->ngpio, GFP_KERNEL); |
2721 | if (!cdev->watched_lines) |
2722 | goto out_free_cdev; |
2723 | |
2724 | init_waitqueue_head(&cdev->wait); |
2725 | INIT_KFIFO(cdev->events); |
2726 | cdev->gdev = gpio_device_get(gdev); |
2727 | |
2728 | cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; |
2729 | scoped_guard(write_lock_irqsave, &gdev->line_state_lock) |
2730 | ret = raw_notifier_chain_register(nh: &gdev->line_state_notifier, |
2731 | nb: &cdev->lineinfo_changed_nb); |
2732 | if (ret) |
2733 | goto out_free_bitmap; |
2734 | |
2735 | cdev->device_unregistered_nb.notifier_call = |
2736 | gpio_device_unregistered_notify; |
2737 | ret = blocking_notifier_chain_register(nh: &gdev->device_notifier, |
2738 | nb: &cdev->device_unregistered_nb); |
2739 | if (ret) |
2740 | goto out_unregister_line_notifier; |
2741 | |
2742 | file->private_data = cdev; |
2743 | cdev->fp = file; |
2744 | |
2745 | ret = nonseekable_open(inode, filp: file); |
2746 | if (ret) |
2747 | goto out_unregister_device_notifier; |
2748 | |
2749 | return ret; |
2750 | |
2751 | out_unregister_device_notifier: |
2752 | blocking_notifier_chain_unregister(nh: &gdev->device_notifier, |
2753 | nb: &cdev->device_unregistered_nb); |
2754 | out_unregister_line_notifier: |
2755 | scoped_guard(write_lock_irqsave, &gdev->line_state_lock) |
2756 | raw_notifier_chain_unregister(nh: &gdev->line_state_notifier, |
2757 | nb: &cdev->lineinfo_changed_nb); |
2758 | out_free_bitmap: |
2759 | gpio_device_put(gdev); |
2760 | bitmap_free(bitmap: cdev->watched_lines); |
2761 | out_free_cdev: |
2762 | kfree(objp: cdev); |
2763 | return ret; |
2764 | } |
2765 | |
2766 | /** |
2767 | * gpio_chrdev_release() - close chardev after ioctl operations |
2768 | * @inode: inode for this chardev |
2769 | * @file: file struct for storing private data |
2770 | * |
2771 | * Returns: |
2772 | * 0 on success, or negative errno on failure. |
2773 | */ |
2774 | static int gpio_chrdev_release(struct inode *inode, struct file *file) |
2775 | { |
2776 | struct gpio_chardev_data *cdev = file->private_data; |
2777 | struct gpio_device *gdev = cdev->gdev; |
2778 | |
2779 | blocking_notifier_chain_unregister(nh: &gdev->device_notifier, |
2780 | nb: &cdev->device_unregistered_nb); |
2781 | scoped_guard(write_lock_irqsave, &gdev->line_state_lock) |
2782 | raw_notifier_chain_unregister(nh: &gdev->line_state_notifier, |
2783 | nb: &cdev->lineinfo_changed_nb); |
2784 | bitmap_free(bitmap: cdev->watched_lines); |
2785 | gpio_device_put(gdev); |
2786 | kfree(objp: cdev); |
2787 | |
2788 | return 0; |
2789 | } |
2790 | |
2791 | static const struct file_operations gpio_fileops = { |
2792 | .release = gpio_chrdev_release, |
2793 | .open = gpio_chrdev_open, |
2794 | .poll = lineinfo_watch_poll, |
2795 | .read = lineinfo_watch_read, |
2796 | .owner = THIS_MODULE, |
2797 | .unlocked_ioctl = gpio_ioctl, |
2798 | #ifdef CONFIG_COMPAT |
2799 | .compat_ioctl = gpio_ioctl_compat, |
2800 | #endif |
2801 | }; |
2802 | |
2803 | int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) |
2804 | { |
2805 | struct gpio_chip *gc; |
2806 | int ret; |
2807 | |
2808 | cdev_init(&gdev->chrdev, &gpio_fileops); |
2809 | gdev->chrdev.owner = THIS_MODULE; |
2810 | gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); |
2811 | |
2812 | gdev->line_state_wq = alloc_ordered_workqueue("%s", WQ_HIGHPRI, |
2813 | dev_name(&gdev->dev)); |
2814 | if (!gdev->line_state_wq) |
2815 | return -ENOMEM; |
2816 | |
2817 | ret = cdev_device_add(cdev: &gdev->chrdev, dev: &gdev->dev); |
2818 | if (ret) |
2819 | return ret; |
2820 | |
2821 | guard(srcu)(l: &gdev->srcu); |
2822 | gc = srcu_dereference(gdev->chip, &gdev->srcu); |
2823 | if (!gc) |
2824 | return -ENODEV; |
2825 | |
2826 | chip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id); |
2827 | |
2828 | return 0; |
2829 | } |
2830 | |
2831 | void gpiolib_cdev_unregister(struct gpio_device *gdev) |
2832 | { |
2833 | destroy_workqueue(wq: gdev->line_state_wq); |
2834 | cdev_device_del(cdev: &gdev->chrdev, dev: &gdev->dev); |
2835 | blocking_notifier_call_chain(nh: &gdev->device_notifier, val: 0, NULL); |
2836 | } |
2837 |
Definitions
- linehandle_state
- linehandle_validate_flags
- linehandle_flags_to_desc_flags
- linehandle_set_config
- linehandle_ioctl
- linehandle_ioctl_compat
- linehandle_free
- linehandle_release
- linehandle_fileops
- linehandle_create
- line
- linereq
- linereq_unregistered_notify
- linereq_put_event
- line_event_timestamp
- line_event_id
- make_irq_label
- free_irq_label
- process_hw_ts_thread
- process_hw_ts
- hte_edge_setup
- edge_irq_thread
- edge_irq_handler
- debounced_value
- debounce_irq_handler
- debounce_work_func
- debounce_setup
- gpio_v2_line_config_debounced
- gpio_v2_line_config_debounce_period
- edge_detector_stop
- edge_detector_fifo_init
- edge_detector_setup
- edge_detector_update
- gpio_v2_line_config_flags
- gpio_v2_line_config_output_value
- gpio_v2_line_flags_validate
- gpio_v2_line_config_validate
- gpio_v2_line_config_flags_to_desc_flags
- linereq_get_values
- linereq_set_values
- linereq_set_config
- linereq_ioctl
- linereq_ioctl_compat
- linereq_poll
- linereq_read
- linereq_free
- linereq_release
- linereq_show_fdinfo
- line_fileops
- linereq_create
- lineevent_state
- lineevent_poll
- lineevent_unregistered_notify
- compat_gpioeevent_data
- lineevent_read
- lineevent_free
- lineevent_release
- lineevent_ioctl
- lineevent_ioctl_compat
- lineevent_fileops
- lineevent_irq_thread
- lineevent_irq_handler
- lineevent_create
- gpio_v2_line_info_to_v1
- gpio_v2_line_info_changed_to_v1
- gpio_desc_to_lineinfo
- gpio_chardev_data
- chipinfo_get
- lineinfo_ensure_abi_version
- lineinfo_get_v1
- lineinfo_get
- lineinfo_unwatch
- gpio_ioctl
- gpio_ioctl_compat
- lineinfo_changed_ctx
- lineinfo_changed_func
- lineinfo_changed_notify
- gpio_device_unregistered_notify
- lineinfo_watch_poll
- lineinfo_watch_read
- gpio_chrdev_open
- gpio_chrdev_release
- gpio_fileops
- gpiolib_cdev_register
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