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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * drivers/media/radio/si470x/radio-si470x-i2c.c4 *5 * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers6 *7 * Copyright (c) 2009 Samsung Electronics Co.Ltd8 * 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" },32 /* Terminating entry */33 { }34};35MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);36 37 38/**************************************************************************39 * Module Parameters40 **************************************************************************/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 Definitions65 **************************************************************************/66 67/* Write starts with the upper byte of register 0x02 */68#define WRITE_REG_NUM 869#define WRITE_INDEX(i) (i + 0x02)70 71/* Read starts with the upper byte of register 0x0a */72#define READ_REG_NUM RADIO_REGISTER_NUM73#define READ_INDEX(i) ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)74 75 76 77/**************************************************************************78 * General Driver Functions - REGISTERs79 **************************************************************************/80 81/*82 * si470x_get_register - read register83 */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 *)buf93 },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 register107 */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 *)buf117 },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 REGISTERS133 **************************************************************************/134 135/*136 * si470x_get_all_registers - read entire registers137 */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 *)buf148 },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 Interface164 **************************************************************************/165 166/*167 * si470x_fops_open - file open168 */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 release200 */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 Interface216 **************************************************************************/217 218/*219 * si470x_vidioc_querycap - query device capabilities220 */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 Interface233 **************************************************************************/234 235/*236 * si470x_i2c_interrupt - interrupt handler237 */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 device332 */333static 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(&client->dev, 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(&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(&client->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(&radio->hdl, &si470x_ctrl_ops,364 V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);365 v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,366 V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 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(&radio->videodev, radio);383 384 radio->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",385 GPIOD_OUT_LOW);386 if (IS_ERR(radio->gpio_reset)) {387 retval = PTR_ERR(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(radio->gpio_reset, 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(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, 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(&client->dev, 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(&client->dev, client->irq, NULL,435 si470x_i2c_interrupt,436 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,437 DRIVER_NAME, 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(&radio->videodev, VFL_TYPE_RADIO,445 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, radio);451 452 return 0;453err_all:454 v4l2_ctrl_handler_free(&radio->hdl);455 v4l2_device_unregister(&radio->v4l2_dev);456err_initial:457 return retval;458}459 460 461/*462 * si470x_i2c_remove - remove the device463 */464static void si470x_i2c_remove(struct i2c_client *client)465{466 struct si470x_device *radio = i2c_get_clientdata(client);467 468 video_unregister_device(&radio->videodev);469 470 if (radio->gpio_reset)471 gpiod_set_value(radio->gpio_reset, 0);472 473 v4l2_ctrl_handler_free(&radio->hdl);474 v4l2_device_unregister(&radio->v4l2_dev);475}476 477 478#ifdef CONFIG_PM_SLEEP479/*480 * si470x_i2c_suspend - suspend the device481 */482static 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 device498 */499static 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(110);509 510 return 0;511}512 513static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);514#endif515 516#if IS_ENABLED(CONFIG_OF)517static const struct of_device_id si470x_of_match[] = {518 { .compatible = "silabs,si470x" },519 { },520};521MODULE_DEVICE_TABLE(of, si470x_of_match);522#endif523 524/*525 * si470x_i2c_driver - i2c driver interface526 */527static 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_SLEEP532 .pm = &si470x_i2c_pm,533#endif534 },535 .probe = si470x_i2c_probe,536 .remove = si470x_i2c_remove,537 .id_table = si470x_i2c_id,538};539 540module_i2c_driver(si470x_i2c_driver);541 542MODULE_LICENSE("GPL");543MODULE_AUTHOR(DRIVER_AUTHOR);544MODULE_DESCRIPTION(DRIVER_DESC);545MODULE_VERSION(DRIVER_VERSION);546