1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Internal GPIO functions. |
4 | * |
5 | * Copyright (C) 2013, Intel Corporation |
6 | * Author: Mika Westerberg <mika.westerberg@linux.intel.com> |
7 | */ |
8 | |
9 | #ifndef GPIOLIB_H |
10 | #define GPIOLIB_H |
11 | |
12 | #include <linux/cdev.h> |
13 | #include <linux/device.h> |
14 | #include <linux/err.h> |
15 | #include <linux/gpio/consumer.h> /* for enum gpiod_flags */ |
16 | #include <linux/gpio/driver.h> |
17 | #include <linux/module.h> |
18 | #include <linux/notifier.h> |
19 | #include <linux/spinlock.h> |
20 | #include <linux/srcu.h> |
21 | #include <linux/workqueue.h> |
22 | |
23 | #define GPIOCHIP_NAME "gpiochip" |
24 | |
25 | /** |
26 | * struct gpio_device - internal state container for GPIO devices |
27 | * @dev: the GPIO device struct |
28 | * @chrdev: character device for the GPIO device |
29 | * @id: numerical ID number for the GPIO chip |
30 | * @mockdev: class device used by the deprecated sysfs interface (may be |
31 | * NULL) |
32 | * @owner: helps prevent removal of modules exporting active GPIOs |
33 | * @chip: pointer to the corresponding gpiochip, holding static |
34 | * data for this device |
35 | * @descs: array of ngpio descriptors. |
36 | * @valid_mask: If not %NULL, holds bitmask of GPIOs which are valid to be |
37 | * used from the chip. |
38 | * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users |
39 | * @ngpio: the number of GPIO lines on this GPIO device, equal to the size |
40 | * of the @descs array. |
41 | * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep |
42 | * implying that they cannot be used from atomic context |
43 | * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned |
44 | * at device creation time. |
45 | * @label: a descriptive name for the GPIO device, such as the part number |
46 | * or name of the IP component in a System on Chip. |
47 | * @data: per-instance data assigned by the driver |
48 | * @list: links gpio_device:s together for traversal |
49 | * @line_state_notifier: used to notify subscribers about lines being |
50 | * requested, released or reconfigured |
51 | * @line_state_lock: RW-spinlock protecting the line state notifier |
52 | * @line_state_wq: used to emit line state events from a separate thread in |
53 | * process context |
54 | * @device_notifier: used to notify character device wait queues about the GPIO |
55 | * device being unregistered |
56 | * @srcu: protects the pointer to the underlying GPIO chip |
57 | * @pin_ranges: range of pins served by the GPIO driver |
58 | * |
59 | * This state container holds most of the runtime variable data |
60 | * for a GPIO device and can hold references and live on after the |
61 | * GPIO chip has been removed, if it is still being used from |
62 | * userspace. |
63 | */ |
64 | struct gpio_device { |
65 | struct device dev; |
66 | struct cdev chrdev; |
67 | int id; |
68 | struct device *mockdev; |
69 | struct module *owner; |
70 | struct gpio_chip __rcu *chip; |
71 | struct gpio_desc *descs; |
72 | unsigned long *valid_mask; |
73 | struct srcu_struct desc_srcu; |
74 | unsigned int base; |
75 | u16 ngpio; |
76 | bool can_sleep; |
77 | const char *label; |
78 | void *data; |
79 | struct list_head list; |
80 | struct raw_notifier_head line_state_notifier; |
81 | rwlock_t line_state_lock; |
82 | struct workqueue_struct *line_state_wq; |
83 | struct blocking_notifier_head device_notifier; |
84 | struct srcu_struct srcu; |
85 | |
86 | #ifdef CONFIG_PINCTRL |
87 | /* |
88 | * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally |
89 | * describe the actual pin range which they serve in an SoC. This |
90 | * information would be used by pinctrl subsystem to configure |
91 | * corresponding pins for gpio usage. |
92 | */ |
93 | struct list_head pin_ranges; |
94 | #endif |
95 | }; |
96 | |
97 | static inline struct gpio_device *to_gpio_device(struct device *dev) |
98 | { |
99 | return container_of(dev, struct gpio_device, dev); |
100 | } |
101 | |
102 | /* GPIO suffixes used for ACPI and device tree lookup */ |
103 | extern const char *const gpio_suffixes[]; |
104 | |
105 | #define for_each_gpio_property_name(propname, con_id) \ |
106 | for (const char * const *__suffixes = gpio_suffixes; \ |
107 | *__suffixes && ({ \ |
108 | const char *__gs = *__suffixes; \ |
109 | \ |
110 | if (con_id) \ |
111 | snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \ |
112 | else \ |
113 | snprintf(propname, sizeof(propname), "%s", __gs); \ |
114 | 1; \ |
115 | }); \ |
116 | __suffixes++) |
117 | |
118 | /** |
119 | * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes |
120 | * |
121 | * @desc: Array of pointers to the GPIO descriptors |
122 | * @size: Number of elements in desc |
123 | * @gdev: Parent GPIO device |
124 | * @get_mask: Get mask used in fastpath |
125 | * @set_mask: Set mask used in fastpath |
126 | * @invert_mask: Invert mask used in fastpath |
127 | * |
128 | * This structure is attached to struct gpiod_descs obtained from |
129 | * gpiod_get_array() and can be passed back to get/set array functions in order |
130 | * to activate fast processing path if applicable. |
131 | */ |
132 | struct gpio_array { |
133 | struct gpio_desc **desc; |
134 | unsigned int size; |
135 | struct gpio_device *gdev; |
136 | unsigned long *get_mask; |
137 | unsigned long *set_mask; |
138 | unsigned long invert_mask[]; |
139 | }; |
140 | |
141 | #define for_each_gpio_desc(gc, desc) \ |
142 | for (unsigned int __i = 0; \ |
143 | __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ |
144 | __i++) \ |
145 | |
146 | #define for_each_gpio_desc_with_flag(gc, desc, flag) \ |
147 | for_each_gpio_desc(gc, desc) \ |
148 | if (!test_bit(flag, &desc->flags)) {} else |
149 | |
150 | int gpiod_get_array_value_complex(bool raw, bool can_sleep, |
151 | unsigned int array_size, |
152 | struct gpio_desc **desc_array, |
153 | struct gpio_array *array_info, |
154 | unsigned long *value_bitmap); |
155 | int gpiod_set_array_value_complex(bool raw, bool can_sleep, |
156 | unsigned int array_size, |
157 | struct gpio_desc **desc_array, |
158 | struct gpio_array *array_info, |
159 | unsigned long *value_bitmap); |
160 | |
161 | int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); |
162 | |
163 | void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); |
164 | int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value); |
165 | int gpiod_direction_input_nonotify(struct gpio_desc *desc); |
166 | |
167 | struct gpio_desc_label { |
168 | struct rcu_head rh; |
169 | char str[]; |
170 | }; |
171 | |
172 | /** |
173 | * struct gpio_desc - Opaque descriptor for a GPIO |
174 | * |
175 | * @gdev: Pointer to the parent GPIO device |
176 | * @flags: Binary descriptor flags |
177 | * @label: Name of the consumer |
178 | * @name: Line name |
179 | * @hog: Pointer to the device node that hogs this line (if any) |
180 | * @debounce_period_us: Debounce period in microseconds |
181 | * |
182 | * These are obtained using gpiod_get() and are preferable to the old |
183 | * integer-based handles. |
184 | * |
185 | * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be |
186 | * valid until the GPIO is released. |
187 | */ |
188 | struct gpio_desc { |
189 | struct gpio_device *gdev; |
190 | unsigned long flags; |
191 | /* flag symbols are bit numbers */ |
192 | #define FLAG_REQUESTED 0 |
193 | #define FLAG_IS_OUT 1 |
194 | #define FLAG_EXPORT 2 /* protected by sysfs_lock */ |
195 | #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ |
196 | #define FLAG_ACTIVE_LOW 6 /* value has active low */ |
197 | #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ |
198 | #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ |
199 | #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ |
200 | #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ |
201 | #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ |
202 | #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ |
203 | #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ |
204 | #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ |
205 | #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ |
206 | #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ |
207 | #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ |
208 | #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ |
209 | #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ |
210 | |
211 | /* Connection label */ |
212 | struct gpio_desc_label __rcu *label; |
213 | /* Name of the GPIO */ |
214 | const char *name; |
215 | #ifdef CONFIG_OF_DYNAMIC |
216 | struct device_node *hog; |
217 | #endif |
218 | #ifdef CONFIG_GPIO_CDEV |
219 | /* debounce period in microseconds */ |
220 | unsigned int debounce_period_us; |
221 | #endif |
222 | }; |
223 | |
224 | #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) |
225 | |
226 | struct gpio_chip_guard { |
227 | struct gpio_device *gdev; |
228 | struct gpio_chip *gc; |
229 | int idx; |
230 | }; |
231 | |
232 | DEFINE_CLASS(gpio_chip_guard, |
233 | struct gpio_chip_guard, |
234 | srcu_read_unlock(&_T.gdev->srcu, _T.idx), |
235 | ({ |
236 | struct gpio_chip_guard _guard; |
237 | |
238 | _guard.gdev = desc->gdev; |
239 | _guard.idx = srcu_read_lock(&_guard.gdev->srcu); |
240 | _guard.gc = srcu_dereference(_guard.gdev->chip, |
241 | &_guard.gdev->srcu); |
242 | |
243 | _guard; |
244 | }), |
245 | struct gpio_desc *desc) |
246 | |
247 | int gpiod_request(struct gpio_desc *desc, const char *label); |
248 | void gpiod_free(struct gpio_desc *desc); |
249 | |
250 | static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) |
251 | { |
252 | int ret; |
253 | |
254 | ret = gpiod_request(desc, label); |
255 | if (ret == -EPROBE_DEFER) |
256 | ret = -ENODEV; |
257 | |
258 | return ret; |
259 | } |
260 | |
261 | struct gpio_desc *gpiod_find_and_request(struct device *consumer, |
262 | struct fwnode_handle *fwnode, |
263 | const char *con_id, |
264 | unsigned int idx, |
265 | enum gpiod_flags flags, |
266 | const char *label, |
267 | bool platform_lookup_allowed); |
268 | |
269 | int gpio_do_set_config(struct gpio_desc *desc, unsigned long config); |
270 | int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, |
271 | unsigned long lflags, enum gpiod_flags dflags); |
272 | int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); |
273 | int gpiod_hog(struct gpio_desc *desc, const char *name, |
274 | unsigned long lflags, enum gpiod_flags dflags); |
275 | int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); |
276 | struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); |
277 | const char *gpiod_get_label(struct gpio_desc *desc); |
278 | |
279 | /* |
280 | * Return the GPIO number of the passed descriptor relative to its chip |
281 | */ |
282 | static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) |
283 | { |
284 | return desc - &desc->gdev->descs[0]; |
285 | } |
286 | |
287 | /* With descriptor prefix */ |
288 | |
289 | #define gpiod_err(desc, fmt, ...) \ |
290 | do { \ |
291 | scoped_guard(srcu, &desc->gdev->desc_srcu) { \ |
292 | pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ |
293 | gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ |
294 | } \ |
295 | } while (0) |
296 | |
297 | #define gpiod_warn(desc, fmt, ...) \ |
298 | do { \ |
299 | scoped_guard(srcu, &desc->gdev->desc_srcu) { \ |
300 | pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ |
301 | gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ |
302 | } \ |
303 | } while (0) |
304 | |
305 | #define gpiod_dbg(desc, fmt, ...) \ |
306 | do { \ |
307 | scoped_guard(srcu, &desc->gdev->desc_srcu) { \ |
308 | pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ |
309 | gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ |
310 | } \ |
311 | } while (0) |
312 | |
313 | /* With chip prefix */ |
314 | |
315 | #define chip_err(gc, fmt, ...) \ |
316 | dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) |
317 | #define chip_warn(gc, fmt, ...) \ |
318 | dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) |
319 | #define chip_info(gc, fmt, ...) \ |
320 | dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) |
321 | #define chip_dbg(gc, fmt, ...) \ |
322 | dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) |
323 | |
324 | #endif /* GPIOLIB_H */ |
325 | |