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 */
29static const struct i2c_device_id si470x_i2c_id[] = {
30	/* Generic Entry */
31	{ "si470x", 0 },
32	/* Terminating entry */
33	{ }
34};
35MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
36
37
38/**************************************************************************
39 * Module Parameters
40 **************************************************************************/
41
42/* Radio Nr */
43static int radio_nr = -1;
44module_param(radio_nr, int, 0444);
45MODULE_PARM_DESC(radio_nr, "Radio Nr");
46
47/* RDS buffer blocks */
48static unsigned int rds_buf = 100;
49module_param(rds_buf, uint, 0444);
50MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
51
52/* RDS maximum block errors */
53static 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 */
58module_param(max_rds_errors, ushort, 0644);
59MODULE_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 */
84static 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(radio->client->adapter, msgs, 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 */
108static 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(radio->client->adapter, msgs, 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 */
138static 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(radio->client->adapter, msgs, 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 */
169static int si470x_fops_open(struct file *file)
170{
171	struct si470x_device *radio = video_drvdata(file);
172	int retval = v4l2_fh_open(file);
173
174	if (retval)
175		return retval;
176
177	if (v4l2_fh_is_singular_file(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
191done:
192	if (retval)
193		v4l2_fh_release(file);
194	return retval;
195}
196
197
198/*
199 * si470x_fops_release - file release
200 */
201static int si470x_fops_release(struct file *file)
202{
203	struct si470x_device *radio = video_drvdata(file);
204
205	if (v4l2_fh_is_singular_file(file))
206		/* stop radio */
207		si470x_stop(radio);
208
209	return v4l2_fh_release(file);
210}
211
212
213
214/**************************************************************************
215 * Video4Linux Interface
216 **************************************************************************/
217
218/*
219 * si470x_vidioc_querycap - query device capabilities
220 */
221static 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 */
238static 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(rds, &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
325end:
326	return IRQ_HANDLED;
327}
328
329
330/*
331 * si470x_i2c_probe - probe for the device
332 */
333static int si470x_i2c_probe(struct i2c_client *client)
334{
335	struct si470x_device *radio;
336	int retval = 0;
337	unsigned char version_warning = 0;
338
339	/* private data allocation and initialization */
340	radio = devm_kzalloc(&client->dev, sizeof(*radio), GFP_KERNEL);
341	if (!radio) {
342		retval = -ENOMEM;
343		goto err_initial;
344	}
345
346	radio->client = client;
347	radio->band = 1; /* Default to 76 - 108 MHz */
348	mutex_init(&radio->lock);
349	init_completion(&radio->completion);
350
351	radio->get_register = si470x_get_register;
352	radio->set_register = si470x_set_register;
353	radio->fops_open = si470x_fops_open;
354	radio->fops_release = si470x_fops_release;
355	radio->vidioc_querycap = si470x_vidioc_querycap;
356
357	retval = v4l2_device_register(&client->dev, &radio->v4l2_dev);
358	if (retval < 0) {
359		dev_err(&client->dev, "couldn't register v4l2_device\n");
360		goto err_initial;
361	}
362
363	v4l2_ctrl_handler_init(&radio->hdl, 2);
364	v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
365			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
366	v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
367			V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
368	if (radio->hdl.error) {
369		retval = radio->hdl.error;
370		dev_err(&client->dev, "couldn't register control\n");
371		goto err_all;
372	}
373
374	/* video device initialization */
375	radio->videodev = si470x_viddev_template;
376	radio->videodev.ctrl_handler = &radio->hdl;
377	radio->videodev.lock = &radio->lock;
378	radio->videodev.v4l2_dev = &radio->v4l2_dev;
379	radio->videodev.release = video_device_release_empty;
380	radio->videodev.device_caps =
381		V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | V4L2_CAP_TUNER |
382		V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
383	video_set_drvdata(&radio->videodev, radio);
384
385	radio->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
386						    GPIOD_OUT_LOW);
387	if (IS_ERR(radio->gpio_reset)) {
388		retval = PTR_ERR(radio->gpio_reset);
389		dev_err(&client->dev, "Failed to request gpio: %d\n", retval);
390		goto err_all;
391	}
392
393	if (radio->gpio_reset)
394		gpiod_set_value(radio->gpio_reset, 1);
395
396	/* power up : need 110ms */
397	radio->registers[POWERCFG] = POWERCFG_ENABLE;
398	if (si470x_set_register(radio, POWERCFG) < 0) {
399		retval = -EIO;
400		goto err_all;
401	}
402	msleep(110);
403
404	/* get device and chip versions */
405	if (si470x_get_all_registers(radio) < 0) {
406		retval = -EIO;
407		goto err_all;
408	}
409	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
410			radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
411	if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
412		dev_warn(&client->dev,
413			"This driver is known to work with firmware version %hu,\n",
414			RADIO_FW_VERSION);
415		dev_warn(&client->dev,
416			"but the device has firmware version %hu.\n",
417			radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
418		version_warning = 1;
419	}
420
421	/* give out version warning */
422	if (version_warning == 1) {
423		dev_warn(&client->dev,
424			"If you have some trouble using this driver,\n");
425		dev_warn(&client->dev,
426			"please report to V4L ML at linux-media@vger.kernel.org\n");
427	}
428
429	/* set initial frequency */
430	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
431
432	/* rds buffer allocation */
433	radio->buf_size = rds_buf * 3;
434	radio->buffer = devm_kmalloc(&client->dev, radio->buf_size, GFP_KERNEL);
435	if (!radio->buffer) {
436		retval = -EIO;
437		goto err_all;
438	}
439
440	/* rds buffer configuration */
441	radio->wr_index = 0;
442	radio->rd_index = 0;
443	init_waitqueue_head(&radio->read_queue);
444
445	retval = devm_request_threaded_irq(&client->dev, client->irq, NULL,
446					   si470x_i2c_interrupt,
447					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
448					   DRIVER_NAME, radio);
449	if (retval) {
450		dev_err(&client->dev, "Failed to register interrupt\n");
451		goto err_all;
452	}
453
454	/* register video device */
455	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
456			radio_nr);
457	if (retval) {
458		dev_warn(&client->dev, "Could not register video device\n");
459		goto err_all;
460	}
461	i2c_set_clientdata(client, radio);
462
463	return 0;
464err_all:
465	v4l2_ctrl_handler_free(&radio->hdl);
466	v4l2_device_unregister(&radio->v4l2_dev);
467err_initial:
468	return retval;
469}
470
471
472/*
473 * si470x_i2c_remove - remove the device
474 */
475static int si470x_i2c_remove(struct i2c_client *client)
476{
477	struct si470x_device *radio = i2c_get_clientdata(client);
478
479	video_unregister_device(&radio->videodev);
480
481	if (radio->gpio_reset)
482		gpiod_set_value(radio->gpio_reset, 0);
483
484	v4l2_ctrl_handler_free(&radio->hdl);
485	v4l2_device_unregister(&radio->v4l2_dev);
486	return 0;
487}
488
489
490#ifdef CONFIG_PM_SLEEP
491/*
492 * si470x_i2c_suspend - suspend the device
493 */
494static int si470x_i2c_suspend(struct device *dev)
495{
496	struct i2c_client *client = to_i2c_client(dev);
497	struct si470x_device *radio = i2c_get_clientdata(client);
498
499	/* power down */
500	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
501	if (si470x_set_register(radio, POWERCFG) < 0)
502		return -EIO;
503
504	return 0;
505}
506
507
508/*
509 * si470x_i2c_resume - resume the device
510 */
511static int si470x_i2c_resume(struct device *dev)
512{
513	struct i2c_client *client = to_i2c_client(dev);
514	struct si470x_device *radio = i2c_get_clientdata(client);
515
516	/* power up : need 110ms */
517	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
518	if (si470x_set_register(radio, POWERCFG) < 0)
519		return -EIO;
520	msleep(110);
521
522	return 0;
523}
524
525static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
526#endif
527
528#if IS_ENABLED(CONFIG_OF)
529static const struct of_device_id si470x_of_match[] = {
530	{ .compatible = "silabs,si470x" },
531	{ },
532};
533MODULE_DEVICE_TABLE(of, si470x_of_match);
534#endif
535
536/*
537 * si470x_i2c_driver - i2c driver interface
538 */
539static struct i2c_driver si470x_i2c_driver = {
540	.driver = {
541		.name		= "si470x",
542		.of_match_table = of_match_ptr(si470x_of_match),
543#ifdef CONFIG_PM_SLEEP
544		.pm		= &si470x_i2c_pm,
545#endif
546	},
547	.probe_new		= si470x_i2c_probe,
548	.remove			= si470x_i2c_remove,
549	.id_table		= si470x_i2c_id,
550};
551
552module_i2c_driver(si470x_i2c_driver);
553
554MODULE_LICENSE("GPL");
555MODULE_AUTHOR(DRIVER_AUTHOR);
556MODULE_DESCRIPTION(DRIVER_DESC);
557MODULE_VERSION(DRIVER_VERSION);
558