1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * drivers/media/radio/si470x/radio-si470x-i2c.c |
4 | * |
5 | * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers |
6 | * |
7 | * Copyright (c) 2009 Samsung Electronics Co.Ltd |
8 | * Author: Joonyoung Shim <jy0922.shim@samsung.com> |
9 | */ |
10 | |
11 | |
12 | /* driver definitions */ |
13 | #define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>"; |
14 | #define DRIVER_CARD "Silicon Labs Si470x FM Radio" |
15 | #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers" |
16 | #define DRIVER_VERSION "1.0.2" |
17 | |
18 | /* kernel includes */ |
19 | #include <linux/i2c.h> |
20 | #include <linux/slab.h> |
21 | #include <linux/delay.h> |
22 | #include <linux/gpio/consumer.h> |
23 | #include <linux/interrupt.h> |
24 | |
25 | #include "radio-si470x.h" |
26 | |
27 | |
28 | /* I2C Device ID List */ |
29 | static const struct i2c_device_id si470x_i2c_id[] = { |
30 | /* Generic Entry */ |
31 | { "si470x" , 0 }, |
32 | /* Terminating entry */ |
33 | { } |
34 | }; |
35 | MODULE_DEVICE_TABLE(i2c, si470x_i2c_id); |
36 | |
37 | |
38 | /************************************************************************** |
39 | * Module Parameters |
40 | **************************************************************************/ |
41 | |
42 | /* Radio Nr */ |
43 | static int radio_nr = -1; |
44 | module_param(radio_nr, int, 0444); |
45 | MODULE_PARM_DESC(radio_nr, "Radio Nr" ); |
46 | |
47 | /* RDS buffer blocks */ |
48 | static unsigned int rds_buf = 100; |
49 | module_param(rds_buf, uint, 0444); |
50 | MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*" ); |
51 | |
52 | /* RDS maximum block errors */ |
53 | static unsigned short max_rds_errors = 1; |
54 | /* 0 means 0 errors requiring correction */ |
55 | /* 1 means 1-2 errors requiring correction (used by original USBRadio.exe) */ |
56 | /* 2 means 3-5 errors requiring correction */ |
57 | /* 3 means 6+ errors or errors in checkword, correction not possible */ |
58 | module_param(max_rds_errors, ushort, 0644); |
59 | MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*" ); |
60 | |
61 | |
62 | |
63 | /************************************************************************** |
64 | * I2C Definitions |
65 | **************************************************************************/ |
66 | |
67 | /* Write starts with the upper byte of register 0x02 */ |
68 | #define WRITE_REG_NUM 8 |
69 | #define WRITE_INDEX(i) (i + 0x02) |
70 | |
71 | /* Read starts with the upper byte of register 0x0a */ |
72 | #define READ_REG_NUM RADIO_REGISTER_NUM |
73 | #define READ_INDEX(i) ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM) |
74 | |
75 | |
76 | |
77 | /************************************************************************** |
78 | * General Driver Functions - REGISTERs |
79 | **************************************************************************/ |
80 | |
81 | /* |
82 | * si470x_get_register - read register |
83 | */ |
84 | static int si470x_get_register(struct si470x_device *radio, int regnr) |
85 | { |
86 | __be16 buf[READ_REG_NUM]; |
87 | struct i2c_msg msgs[1] = { |
88 | { |
89 | .addr = radio->client->addr, |
90 | .flags = I2C_M_RD, |
91 | .len = sizeof(u16) * READ_REG_NUM, |
92 | .buf = (void *)buf |
93 | }, |
94 | }; |
95 | |
96 | if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1) |
97 | return -EIO; |
98 | |
99 | radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]); |
100 | |
101 | return 0; |
102 | } |
103 | |
104 | |
105 | /* |
106 | * si470x_set_register - write register |
107 | */ |
108 | static int si470x_set_register(struct si470x_device *radio, int regnr) |
109 | { |
110 | int i; |
111 | __be16 buf[WRITE_REG_NUM]; |
112 | struct i2c_msg msgs[1] = { |
113 | { |
114 | .addr = radio->client->addr, |
115 | .len = sizeof(u16) * WRITE_REG_NUM, |
116 | .buf = (void *)buf |
117 | }, |
118 | }; |
119 | |
120 | for (i = 0; i < WRITE_REG_NUM; i++) |
121 | buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]); |
122 | |
123 | if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1) |
124 | return -EIO; |
125 | |
126 | return 0; |
127 | } |
128 | |
129 | |
130 | |
131 | /************************************************************************** |
132 | * General Driver Functions - ENTIRE REGISTERS |
133 | **************************************************************************/ |
134 | |
135 | /* |
136 | * si470x_get_all_registers - read entire registers |
137 | */ |
138 | static int si470x_get_all_registers(struct si470x_device *radio) |
139 | { |
140 | int i; |
141 | __be16 buf[READ_REG_NUM]; |
142 | struct i2c_msg msgs[1] = { |
143 | { |
144 | .addr = radio->client->addr, |
145 | .flags = I2C_M_RD, |
146 | .len = sizeof(u16) * READ_REG_NUM, |
147 | .buf = (void *)buf |
148 | }, |
149 | }; |
150 | |
151 | if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1) |
152 | return -EIO; |
153 | |
154 | for (i = 0; i < READ_REG_NUM; i++) |
155 | radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]); |
156 | |
157 | return 0; |
158 | } |
159 | |
160 | |
161 | |
162 | /************************************************************************** |
163 | * File Operations Interface |
164 | **************************************************************************/ |
165 | |
166 | /* |
167 | * si470x_fops_open - file open |
168 | */ |
169 | static int si470x_fops_open(struct file *file) |
170 | { |
171 | struct si470x_device *radio = video_drvdata(file); |
172 | int retval = v4l2_fh_open(filp: file); |
173 | |
174 | if (retval) |
175 | return retval; |
176 | |
177 | if (v4l2_fh_is_singular_file(filp: file)) { |
178 | /* start radio */ |
179 | retval = si470x_start(radio); |
180 | if (retval < 0) |
181 | goto done; |
182 | |
183 | /* enable RDS / STC interrupt */ |
184 | radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN; |
185 | radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN; |
186 | radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2; |
187 | radio->registers[SYSCONFIG1] |= 0x1 << 2; |
188 | retval = si470x_set_register(radio, SYSCONFIG1); |
189 | } |
190 | |
191 | done: |
192 | if (retval) |
193 | v4l2_fh_release(filp: file); |
194 | return retval; |
195 | } |
196 | |
197 | |
198 | /* |
199 | * si470x_fops_release - file release |
200 | */ |
201 | static int si470x_fops_release(struct file *file) |
202 | { |
203 | struct si470x_device *radio = video_drvdata(file); |
204 | |
205 | if (v4l2_fh_is_singular_file(filp: file)) |
206 | /* stop radio */ |
207 | si470x_stop(radio); |
208 | |
209 | return v4l2_fh_release(filp: file); |
210 | } |
211 | |
212 | |
213 | |
214 | /************************************************************************** |
215 | * Video4Linux Interface |
216 | **************************************************************************/ |
217 | |
218 | /* |
219 | * si470x_vidioc_querycap - query device capabilities |
220 | */ |
221 | static int si470x_vidioc_querycap(struct file *file, void *priv, |
222 | struct v4l2_capability *capability) |
223 | { |
224 | strscpy(capability->driver, DRIVER_NAME, sizeof(capability->driver)); |
225 | strscpy(capability->card, DRIVER_CARD, sizeof(capability->card)); |
226 | return 0; |
227 | } |
228 | |
229 | |
230 | |
231 | /************************************************************************** |
232 | * I2C Interface |
233 | **************************************************************************/ |
234 | |
235 | /* |
236 | * si470x_i2c_interrupt - interrupt handler |
237 | */ |
238 | static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id) |
239 | { |
240 | struct si470x_device *radio = dev_id; |
241 | unsigned char regnr; |
242 | unsigned char blocknum; |
243 | unsigned short bler; /* rds block errors */ |
244 | unsigned short rds; |
245 | unsigned char tmpbuf[3]; |
246 | int retval = 0; |
247 | |
248 | /* check Seek/Tune Complete */ |
249 | retval = si470x_get_register(radio, STATUSRSSI); |
250 | if (retval < 0) |
251 | goto end; |
252 | |
253 | if (radio->registers[STATUSRSSI] & STATUSRSSI_STC) |
254 | complete(&radio->completion); |
255 | |
256 | /* safety checks */ |
257 | if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0) |
258 | goto end; |
259 | |
260 | /* Update RDS registers */ |
261 | for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) { |
262 | retval = si470x_get_register(radio, STATUSRSSI + regnr); |
263 | if (retval < 0) |
264 | goto end; |
265 | } |
266 | |
267 | /* get rds blocks */ |
268 | if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) |
269 | /* No RDS group ready, better luck next time */ |
270 | goto end; |
271 | |
272 | for (blocknum = 0; blocknum < 4; blocknum++) { |
273 | switch (blocknum) { |
274 | default: |
275 | bler = (radio->registers[STATUSRSSI] & |
276 | STATUSRSSI_BLERA) >> 9; |
277 | rds = radio->registers[RDSA]; |
278 | break; |
279 | case 1: |
280 | bler = (radio->registers[READCHAN] & |
281 | READCHAN_BLERB) >> 14; |
282 | rds = radio->registers[RDSB]; |
283 | break; |
284 | case 2: |
285 | bler = (radio->registers[READCHAN] & |
286 | READCHAN_BLERC) >> 12; |
287 | rds = radio->registers[RDSC]; |
288 | break; |
289 | case 3: |
290 | bler = (radio->registers[READCHAN] & |
291 | READCHAN_BLERD) >> 10; |
292 | rds = radio->registers[RDSD]; |
293 | break; |
294 | } |
295 | |
296 | /* Fill the V4L2 RDS buffer */ |
297 | put_unaligned_le16(val: rds, p: &tmpbuf); |
298 | tmpbuf[2] = blocknum; /* offset name */ |
299 | tmpbuf[2] |= blocknum << 3; /* received offset */ |
300 | if (bler > max_rds_errors) |
301 | tmpbuf[2] |= 0x80; /* uncorrectable errors */ |
302 | else if (bler > 0) |
303 | tmpbuf[2] |= 0x40; /* corrected error(s) */ |
304 | |
305 | /* copy RDS block to internal buffer */ |
306 | memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3); |
307 | radio->wr_index += 3; |
308 | |
309 | /* wrap write pointer */ |
310 | if (radio->wr_index >= radio->buf_size) |
311 | radio->wr_index = 0; |
312 | |
313 | /* check for overflow */ |
314 | if (radio->wr_index == radio->rd_index) { |
315 | /* increment and wrap read pointer */ |
316 | radio->rd_index += 3; |
317 | if (radio->rd_index >= radio->buf_size) |
318 | radio->rd_index = 0; |
319 | } |
320 | } |
321 | |
322 | if (radio->wr_index != radio->rd_index) |
323 | wake_up_interruptible(&radio->read_queue); |
324 | |
325 | end: |
326 | return IRQ_HANDLED; |
327 | } |
328 | |
329 | |
330 | /* |
331 | * si470x_i2c_probe - probe for the device |
332 | */ |
333 | static int si470x_i2c_probe(struct i2c_client *client) |
334 | { |
335 | struct si470x_device *radio; |
336 | int retval = 0; |
337 | |
338 | /* private data allocation and initialization */ |
339 | radio = devm_kzalloc(dev: &client->dev, size: sizeof(*radio), GFP_KERNEL); |
340 | if (!radio) { |
341 | retval = -ENOMEM; |
342 | goto err_initial; |
343 | } |
344 | |
345 | radio->client = client; |
346 | radio->band = 1; /* Default to 76 - 108 MHz */ |
347 | mutex_init(&radio->lock); |
348 | init_completion(x: &radio->completion); |
349 | |
350 | radio->get_register = si470x_get_register; |
351 | radio->set_register = si470x_set_register; |
352 | radio->fops_open = si470x_fops_open; |
353 | radio->fops_release = si470x_fops_release; |
354 | radio->vidioc_querycap = si470x_vidioc_querycap; |
355 | |
356 | retval = v4l2_device_register(dev: &client->dev, v4l2_dev: &radio->v4l2_dev); |
357 | if (retval < 0) { |
358 | dev_err(&client->dev, "couldn't register v4l2_device\n" ); |
359 | goto err_initial; |
360 | } |
361 | |
362 | v4l2_ctrl_handler_init(&radio->hdl, 2); |
363 | v4l2_ctrl_new_std(hdl: &radio->hdl, ops: &si470x_ctrl_ops, |
364 | V4L2_CID_AUDIO_MUTE, min: 0, max: 1, step: 1, def: 1); |
365 | v4l2_ctrl_new_std(hdl: &radio->hdl, ops: &si470x_ctrl_ops, |
366 | V4L2_CID_AUDIO_VOLUME, min: 0, max: 15, step: 1, def: 15); |
367 | if (radio->hdl.error) { |
368 | retval = radio->hdl.error; |
369 | dev_err(&client->dev, "couldn't register control\n" ); |
370 | goto err_all; |
371 | } |
372 | |
373 | /* video device initialization */ |
374 | radio->videodev = si470x_viddev_template; |
375 | radio->videodev.ctrl_handler = &radio->hdl; |
376 | radio->videodev.lock = &radio->lock; |
377 | radio->videodev.v4l2_dev = &radio->v4l2_dev; |
378 | radio->videodev.release = video_device_release_empty; |
379 | radio->videodev.device_caps = |
380 | V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | V4L2_CAP_TUNER | |
381 | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE; |
382 | video_set_drvdata(vdev: &radio->videodev, data: radio); |
383 | |
384 | radio->gpio_reset = devm_gpiod_get_optional(dev: &client->dev, con_id: "reset" , |
385 | flags: GPIOD_OUT_LOW); |
386 | if (IS_ERR(ptr: radio->gpio_reset)) { |
387 | retval = PTR_ERR(ptr: radio->gpio_reset); |
388 | dev_err(&client->dev, "Failed to request gpio: %d\n" , retval); |
389 | goto err_all; |
390 | } |
391 | |
392 | if (radio->gpio_reset) |
393 | gpiod_set_value(desc: radio->gpio_reset, value: 1); |
394 | |
395 | /* power up : need 110ms */ |
396 | radio->registers[POWERCFG] = POWERCFG_ENABLE; |
397 | if (si470x_set_register(radio, POWERCFG) < 0) { |
398 | retval = -EIO; |
399 | goto err_all; |
400 | } |
401 | msleep(msecs: 110); |
402 | |
403 | /* get device and chip versions */ |
404 | if (si470x_get_all_registers(radio) < 0) { |
405 | retval = -EIO; |
406 | goto err_all; |
407 | } |
408 | dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n" , |
409 | radio->registers[DEVICEID], radio->registers[SI_CHIPID]); |
410 | if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) { |
411 | dev_warn(&client->dev, |
412 | "This driver is known to work with firmware version %u, but the device has firmware version %u.\n" |
413 | "If you have some trouble using this driver, please report to V4L ML at linux-media@vger.kernel.org\n" , |
414 | RADIO_FW_VERSION, |
415 | radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE); |
416 | } |
417 | |
418 | /* set initial frequency */ |
419 | si470x_set_freq(radio, freq: 87.5 * FREQ_MUL); /* available in all regions */ |
420 | |
421 | /* rds buffer allocation */ |
422 | radio->buf_size = rds_buf * 3; |
423 | radio->buffer = devm_kmalloc(dev: &client->dev, size: radio->buf_size, GFP_KERNEL); |
424 | if (!radio->buffer) { |
425 | retval = -EIO; |
426 | goto err_all; |
427 | } |
428 | |
429 | /* rds buffer configuration */ |
430 | radio->wr_index = 0; |
431 | radio->rd_index = 0; |
432 | init_waitqueue_head(&radio->read_queue); |
433 | |
434 | retval = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, NULL, |
435 | thread_fn: si470x_i2c_interrupt, |
436 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
437 | DRIVER_NAME, dev_id: radio); |
438 | if (retval) { |
439 | dev_err(&client->dev, "Failed to register interrupt\n" ); |
440 | goto err_all; |
441 | } |
442 | |
443 | /* register video device */ |
444 | retval = video_register_device(vdev: &radio->videodev, type: VFL_TYPE_RADIO, |
445 | nr: radio_nr); |
446 | if (retval) { |
447 | dev_warn(&client->dev, "Could not register video device\n" ); |
448 | goto err_all; |
449 | } |
450 | i2c_set_clientdata(client, data: radio); |
451 | |
452 | return 0; |
453 | err_all: |
454 | v4l2_ctrl_handler_free(hdl: &radio->hdl); |
455 | v4l2_device_unregister(v4l2_dev: &radio->v4l2_dev); |
456 | err_initial: |
457 | return retval; |
458 | } |
459 | |
460 | |
461 | /* |
462 | * si470x_i2c_remove - remove the device |
463 | */ |
464 | static void si470x_i2c_remove(struct i2c_client *client) |
465 | { |
466 | struct si470x_device *radio = i2c_get_clientdata(client); |
467 | |
468 | video_unregister_device(vdev: &radio->videodev); |
469 | |
470 | if (radio->gpio_reset) |
471 | gpiod_set_value(desc: radio->gpio_reset, value: 0); |
472 | |
473 | v4l2_ctrl_handler_free(hdl: &radio->hdl); |
474 | v4l2_device_unregister(v4l2_dev: &radio->v4l2_dev); |
475 | } |
476 | |
477 | |
478 | #ifdef CONFIG_PM_SLEEP |
479 | /* |
480 | * si470x_i2c_suspend - suspend the device |
481 | */ |
482 | static int si470x_i2c_suspend(struct device *dev) |
483 | { |
484 | struct i2c_client *client = to_i2c_client(dev); |
485 | struct si470x_device *radio = i2c_get_clientdata(client); |
486 | |
487 | /* power down */ |
488 | radio->registers[POWERCFG] |= POWERCFG_DISABLE; |
489 | if (si470x_set_register(radio, POWERCFG) < 0) |
490 | return -EIO; |
491 | |
492 | return 0; |
493 | } |
494 | |
495 | |
496 | /* |
497 | * si470x_i2c_resume - resume the device |
498 | */ |
499 | static int si470x_i2c_resume(struct device *dev) |
500 | { |
501 | struct i2c_client *client = to_i2c_client(dev); |
502 | struct si470x_device *radio = i2c_get_clientdata(client); |
503 | |
504 | /* power up : need 110ms */ |
505 | radio->registers[POWERCFG] |= POWERCFG_ENABLE; |
506 | if (si470x_set_register(radio, POWERCFG) < 0) |
507 | return -EIO; |
508 | msleep(msecs: 110); |
509 | |
510 | return 0; |
511 | } |
512 | |
513 | static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume); |
514 | #endif |
515 | |
516 | #if IS_ENABLED(CONFIG_OF) |
517 | static const struct of_device_id si470x_of_match[] = { |
518 | { .compatible = "silabs,si470x" }, |
519 | { }, |
520 | }; |
521 | MODULE_DEVICE_TABLE(of, si470x_of_match); |
522 | #endif |
523 | |
524 | /* |
525 | * si470x_i2c_driver - i2c driver interface |
526 | */ |
527 | static struct i2c_driver si470x_i2c_driver = { |
528 | .driver = { |
529 | .name = "si470x" , |
530 | .of_match_table = of_match_ptr(si470x_of_match), |
531 | #ifdef CONFIG_PM_SLEEP |
532 | .pm = &si470x_i2c_pm, |
533 | #endif |
534 | }, |
535 | .probe = si470x_i2c_probe, |
536 | .remove = si470x_i2c_remove, |
537 | .id_table = si470x_i2c_id, |
538 | }; |
539 | |
540 | module_i2c_driver(si470x_i2c_driver); |
541 | |
542 | MODULE_LICENSE("GPL" ); |
543 | MODULE_AUTHOR(DRIVER_AUTHOR); |
544 | MODULE_DESCRIPTION(DRIVER_DESC); |
545 | MODULE_VERSION(DRIVER_VERSION); |
546 | |