1 /* 2 * drivers/media/radio/si470x/radio-si470x-i2c.c 3 * 4 * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers 5 * 6 * Copyright (c) 2009 Samsung Electronics Co.Ltd 7 * Author: Joonyoung Shim <jy0922.shim@samsung.com> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 24 25 /* driver definitions */ 26 #define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>"; 27 #define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver" 28 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers" 29 #define DRIVER_VERSION "1.0.2" 30 31 /* kernel includes */ 32 #include <linux/i2c.h> 33 #include <linux/slab.h> 34 #include <linux/delay.h> 35 #include <linux/interrupt.h> 36 37 #include "radio-si470x.h" 38 39 40 /* I2C Device ID List */ 41 static const struct i2c_device_id si470x_i2c_id[] = { 42 /* Generic Entry */ 43 { "si470x", 0 }, 44 /* Terminating entry */ 45 { } 46 }; 47 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id); 48 49 50 51 /************************************************************************** 52 * Module Parameters 53 **************************************************************************/ 54 55 /* Radio Nr */ 56 static int radio_nr = -1; 57 module_param(radio_nr, int, 0444); 58 MODULE_PARM_DESC(radio_nr, "Radio Nr"); 59 60 /* RDS buffer blocks */ 61 static unsigned int rds_buf = 100; 62 module_param(rds_buf, uint, 0444); 63 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*"); 64 65 /* RDS maximum block errors */ 66 static unsigned short max_rds_errors = 1; 67 /* 0 means 0 errors requiring correction */ 68 /* 1 means 1-2 errors requiring correction (used by original USBRadio.exe) */ 69 /* 2 means 3-5 errors requiring correction */ 70 /* 3 means 6+ errors or errors in checkword, correction not possible */ 71 module_param(max_rds_errors, ushort, 0644); 72 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*"); 73 74 75 76 /************************************************************************** 77 * I2C Definitions 78 **************************************************************************/ 79 80 /* Write starts with the upper byte of register 0x02 */ 81 #define WRITE_REG_NUM 8 82 #define WRITE_INDEX(i) (i + 0x02) 83 84 /* Read starts with the upper byte of register 0x0a */ 85 #define READ_REG_NUM RADIO_REGISTER_NUM 86 #define READ_INDEX(i) ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM) 87 88 89 90 /************************************************************************** 91 * General Driver Functions - REGISTERs 92 **************************************************************************/ 93 94 /* 95 * si470x_get_register - read register 96 */ 97 int si470x_get_register(struct si470x_device *radio, int regnr) 98 { 99 u16 buf[READ_REG_NUM]; 100 struct i2c_msg msgs[1] = { 101 { 102 .addr = radio->client->addr, 103 .flags = I2C_M_RD, 104 .len = sizeof(u16) * READ_REG_NUM, 105 .buf = (void *)buf 106 }, 107 }; 108 109 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1) 110 return -EIO; 111 112 radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]); 113 114 return 0; 115 } 116 117 118 /* 119 * si470x_set_register - write register 120 */ 121 int si470x_set_register(struct si470x_device *radio, int regnr) 122 { 123 int i; 124 u16 buf[WRITE_REG_NUM]; 125 struct i2c_msg msgs[1] = { 126 { 127 .addr = radio->client->addr, 128 .len = sizeof(u16) * WRITE_REG_NUM, 129 .buf = (void *)buf 130 }, 131 }; 132 133 for (i = 0; i < WRITE_REG_NUM; i++) 134 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]); 135 136 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1) 137 return -EIO; 138 139 return 0; 140 } 141 142 143 144 /************************************************************************** 145 * General Driver Functions - ENTIRE REGISTERS 146 **************************************************************************/ 147 148 /* 149 * si470x_get_all_registers - read entire registers 150 */ 151 static int si470x_get_all_registers(struct si470x_device *radio) 152 { 153 int i; 154 u16 buf[READ_REG_NUM]; 155 struct i2c_msg msgs[1] = { 156 { 157 .addr = radio->client->addr, 158 .flags = I2C_M_RD, 159 .len = sizeof(u16) * READ_REG_NUM, 160 .buf = (void *)buf 161 }, 162 }; 163 164 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1) 165 return -EIO; 166 167 for (i = 0; i < READ_REG_NUM; i++) 168 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]); 169 170 return 0; 171 } 172 173 174 175 /************************************************************************** 176 * File Operations Interface 177 **************************************************************************/ 178 179 /* 180 * si470x_fops_open - file open 181 */ 182 int si470x_fops_open(struct file *file) 183 { 184 struct si470x_device *radio = video_drvdata(file); 185 int retval = v4l2_fh_open(file); 186 187 if (retval) 188 return retval; 189 190 if (v4l2_fh_is_singular_file(file)) { 191 /* start radio */ 192 retval = si470x_start(radio); 193 if (retval < 0) 194 goto done; 195 196 /* enable RDS / STC interrupt */ 197 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN; 198 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN; 199 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2; 200 radio->registers[SYSCONFIG1] |= 0x1 << 2; 201 retval = si470x_set_register(radio, SYSCONFIG1); 202 } 203 204 done: 205 if (retval) 206 v4l2_fh_release(file); 207 return retval; 208 } 209 210 211 /* 212 * si470x_fops_release - file release 213 */ 214 int si470x_fops_release(struct file *file) 215 { 216 struct si470x_device *radio = video_drvdata(file); 217 218 if (v4l2_fh_is_singular_file(file)) 219 /* stop radio */ 220 si470x_stop(radio); 221 222 return v4l2_fh_release(file); 223 } 224 225 226 227 /************************************************************************** 228 * Video4Linux Interface 229 **************************************************************************/ 230 231 /* 232 * si470x_vidioc_querycap - query device capabilities 233 */ 234 int si470x_vidioc_querycap(struct file *file, void *priv, 235 struct v4l2_capability *capability) 236 { 237 strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver)); 238 strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card)); 239 capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | 240 V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE; 241 capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS; 242 243 return 0; 244 } 245 246 247 248 /************************************************************************** 249 * I2C Interface 250 **************************************************************************/ 251 252 /* 253 * si470x_i2c_interrupt - interrupt handler 254 */ 255 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id) 256 { 257 struct si470x_device *radio = dev_id; 258 unsigned char regnr; 259 unsigned char blocknum; 260 unsigned short bler; /* rds block errors */ 261 unsigned short rds; 262 unsigned char tmpbuf[3]; 263 int retval = 0; 264 265 /* check Seek/Tune Complete */ 266 retval = si470x_get_register(radio, STATUSRSSI); 267 if (retval < 0) 268 goto end; 269 270 if (radio->registers[STATUSRSSI] & STATUSRSSI_STC) 271 complete(&radio->completion); 272 273 /* safety checks */ 274 if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0) 275 goto end; 276 277 /* Update RDS registers */ 278 for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) { 279 retval = si470x_get_register(radio, STATUSRSSI + regnr); 280 if (retval < 0) 281 goto end; 282 } 283 284 /* get rds blocks */ 285 if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) 286 /* No RDS group ready, better luck next time */ 287 goto end; 288 289 for (blocknum = 0; blocknum < 4; blocknum++) { 290 switch (blocknum) { 291 default: 292 bler = (radio->registers[STATUSRSSI] & 293 STATUSRSSI_BLERA) >> 9; 294 rds = radio->registers[RDSA]; 295 break; 296 case 1: 297 bler = (radio->registers[READCHAN] & 298 READCHAN_BLERB) >> 14; 299 rds = radio->registers[RDSB]; 300 break; 301 case 2: 302 bler = (radio->registers[READCHAN] & 303 READCHAN_BLERC) >> 12; 304 rds = radio->registers[RDSC]; 305 break; 306 case 3: 307 bler = (radio->registers[READCHAN] & 308 READCHAN_BLERD) >> 10; 309 rds = radio->registers[RDSD]; 310 break; 311 } 312 313 /* Fill the V4L2 RDS buffer */ 314 put_unaligned_le16(rds, &tmpbuf); 315 tmpbuf[2] = blocknum; /* offset name */ 316 tmpbuf[2] |= blocknum << 3; /* received offset */ 317 if (bler > max_rds_errors) 318 tmpbuf[2] |= 0x80; /* uncorrectable errors */ 319 else if (bler > 0) 320 tmpbuf[2] |= 0x40; /* corrected error(s) */ 321 322 /* copy RDS block to internal buffer */ 323 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3); 324 radio->wr_index += 3; 325 326 /* wrap write pointer */ 327 if (radio->wr_index >= radio->buf_size) 328 radio->wr_index = 0; 329 330 /* check for overflow */ 331 if (radio->wr_index == radio->rd_index) { 332 /* increment and wrap read pointer */ 333 radio->rd_index += 3; 334 if (radio->rd_index >= radio->buf_size) 335 radio->rd_index = 0; 336 } 337 } 338 339 if (radio->wr_index != radio->rd_index) 340 wake_up_interruptible(&radio->read_queue); 341 342 end: 343 return IRQ_HANDLED; 344 } 345 346 347 /* 348 * si470x_i2c_probe - probe for the device 349 */ 350 static int si470x_i2c_probe(struct i2c_client *client, 351 const struct i2c_device_id *id) 352 { 353 struct si470x_device *radio; 354 int retval = 0; 355 unsigned char version_warning = 0; 356 357 /* private data allocation and initialization */ 358 radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL); 359 if (!radio) { 360 retval = -ENOMEM; 361 goto err_initial; 362 } 363 364 radio->client = client; 365 radio->band = 1; /* Default to 76 - 108 MHz */ 366 mutex_init(&radio->lock); 367 init_completion(&radio->completion); 368 369 /* video device initialization */ 370 radio->videodev = si470x_viddev_template; 371 video_set_drvdata(&radio->videodev, radio); 372 373 /* power up : need 110ms */ 374 radio->registers[POWERCFG] = POWERCFG_ENABLE; 375 if (si470x_set_register(radio, POWERCFG) < 0) { 376 retval = -EIO; 377 goto err_radio; 378 } 379 msleep(110); 380 381 /* get device and chip versions */ 382 if (si470x_get_all_registers(radio) < 0) { 383 retval = -EIO; 384 goto err_radio; 385 } 386 dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n", 387 radio->registers[DEVICEID], radio->registers[CHIPID]); 388 if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) { 389 dev_warn(&client->dev, 390 "This driver is known to work with " 391 "firmware version %hu,\n", RADIO_FW_VERSION); 392 dev_warn(&client->dev, 393 "but the device has firmware version %hu.\n", 394 radio->registers[CHIPID] & CHIPID_FIRMWARE); 395 version_warning = 1; 396 } 397 398 /* give out version warning */ 399 if (version_warning == 1) { 400 dev_warn(&client->dev, 401 "If you have some trouble using this driver,\n"); 402 dev_warn(&client->dev, 403 "please report to V4L ML at " 404 "linux-media@vger.kernel.org\n"); 405 } 406 407 /* set initial frequency */ 408 si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */ 409 410 /* rds buffer allocation */ 411 radio->buf_size = rds_buf * 3; 412 radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL); 413 if (!radio->buffer) { 414 retval = -EIO; 415 goto err_radio; 416 } 417 418 /* rds buffer configuration */ 419 radio->wr_index = 0; 420 radio->rd_index = 0; 421 init_waitqueue_head(&radio->read_queue); 422 423 retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt, 424 IRQF_TRIGGER_FALLING, DRIVER_NAME, radio); 425 if (retval) { 426 dev_err(&client->dev, "Failed to register interrupt\n"); 427 goto err_rds; 428 } 429 430 /* register video device */ 431 retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, 432 radio_nr); 433 if (retval) { 434 dev_warn(&client->dev, "Could not register video device\n"); 435 goto err_all; 436 } 437 i2c_set_clientdata(client, radio); 438 439 return 0; 440 err_all: 441 free_irq(client->irq, radio); 442 err_rds: 443 kfree(radio->buffer); 444 err_radio: 445 kfree(radio); 446 err_initial: 447 return retval; 448 } 449 450 451 /* 452 * si470x_i2c_remove - remove the device 453 */ 454 static int si470x_i2c_remove(struct i2c_client *client) 455 { 456 struct si470x_device *radio = i2c_get_clientdata(client); 457 458 free_irq(client->irq, radio); 459 video_unregister_device(&radio->videodev); 460 kfree(radio); 461 462 return 0; 463 } 464 465 466 #ifdef CONFIG_PM_SLEEP 467 /* 468 * si470x_i2c_suspend - suspend the device 469 */ 470 static int si470x_i2c_suspend(struct device *dev) 471 { 472 struct i2c_client *client = to_i2c_client(dev); 473 struct si470x_device *radio = i2c_get_clientdata(client); 474 475 /* power down */ 476 radio->registers[POWERCFG] |= POWERCFG_DISABLE; 477 if (si470x_set_register(radio, POWERCFG) < 0) 478 return -EIO; 479 480 return 0; 481 } 482 483 484 /* 485 * si470x_i2c_resume - resume the device 486 */ 487 static int si470x_i2c_resume(struct device *dev) 488 { 489 struct i2c_client *client = to_i2c_client(dev); 490 struct si470x_device *radio = i2c_get_clientdata(client); 491 492 /* power up : need 110ms */ 493 radio->registers[POWERCFG] |= POWERCFG_ENABLE; 494 if (si470x_set_register(radio, POWERCFG) < 0) 495 return -EIO; 496 msleep(110); 497 498 return 0; 499 } 500 501 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume); 502 #endif 503 504 505 /* 506 * si470x_i2c_driver - i2c driver interface 507 */ 508 static struct i2c_driver si470x_i2c_driver = { 509 .driver = { 510 .name = "si470x", 511 .owner = THIS_MODULE, 512 #ifdef CONFIG_PM_SLEEP 513 .pm = &si470x_i2c_pm, 514 #endif 515 }, 516 .probe = si470x_i2c_probe, 517 .remove = si470x_i2c_remove, 518 .id_table = si470x_i2c_id, 519 }; 520 521 module_i2c_driver(si470x_i2c_driver); 522 523 MODULE_LICENSE("GPL"); 524 MODULE_AUTHOR(DRIVER_AUTHOR); 525 MODULE_DESCRIPTION(DRIVER_DESC); 526 MODULE_VERSION(DRIVER_VERSION); 527