target/linux/brcm2708/patches-3.18/0015-lirc-added-support-for-RaspberryPi-GPIO.patch

   1 From 96fbef3b8f8ab61f7f32d52b54d7993117a5fdbc Mon Sep 17 00:00:00 2001
   2 From: Aron Szabo <aron@aron.ws>
   3 Date: Sat, 16 Jun 2012 12:15:55 +0200
   4 Subject: [PATCH 015/114] lirc: added support for RaspberryPi GPIO
   5
   6 lirc_rpi: Use read_current_timer to determine transmitter delay. Thanks to jjmz and others
   7 See: https://github.com/raspberrypi/linux/issues/525
   8
   9 lirc: Remove restriction on gpio pins that can be used with lirc
  10
  11 Compute Module, for example could use different pins
  12
  13 lirc_rpi: Add parameter to specify input pin pull
  14
  15 Depending on the connected IR circuitry it might be desirable to change the
  16 gpios internal pull from it pull-down default behaviour. Add a module
  17 parameter to allow the user to set it explicitly.
  18
  19 Signed-off-by: Julian Scheel <julian@jusst.de>
  20
  21 lirc-rpi: Use the higher-level irq control functions
  22
  23 This module used to access the irq_chip methods of the
  24 gpio controller directly, rather than going through the
  25 standard enable_irq/irq_set_irq_type functions. This
  26 caused problems on pinctrl-bcm2835 which only implements
  27 the irq_enable/disable methods and not irq_unmask/mask.
  28
  29 lirc-rpi: Correct the interrupt usage
  30
  31 1) Correct the use of enable_irq (i.e. don't call it so often)
  32 2) Correct the shutdown sequence.
  33 3) Avoid a bcm2708_gpio driver quirk by setting the irq flags earlier
  34 ---
  35  drivers/staging/media/lirc/Kconfig    |   6 +
  36  drivers/staging/media/lirc/Makefile   |   1 +
  37  drivers/staging/media/lirc/lirc_rpi.c | 659 ++++++++++++++++++++++++++++++++++
  38  3 files changed, 666 insertions(+)
  39  create mode 100644 drivers/staging/media/lirc/lirc_rpi.c
  40
  41 --- a/drivers/staging/media/lirc/Kconfig
  42 +++ b/drivers/staging/media/lirc/Kconfig
  43 @@ -38,6 +38,12 @@ config LIRC_PARALLEL
  44         help
  45           Driver for Homebrew Parallel Port Receivers
  46
  47 +config LIRC_RPI
  48 +       tristate "Homebrew GPIO Port Receiver/Transmitter for the RaspberryPi"
  49 +       depends on LIRC
  50 +       help
  51 +         Driver for Homebrew GPIO Port Receiver/Transmitter for the RaspberryPi
  52 +
  53  config LIRC_SASEM
  54         tristate "Sasem USB IR Remote"
  55         depends on LIRC && USB
  56 --- a/drivers/staging/media/lirc/Makefile
  57 +++ b/drivers/staging/media/lirc/Makefile
  58 @@ -7,6 +7,7 @@ obj-$(CONFIG_LIRC_BT829)        += lirc_bt829.o
  59  obj-$(CONFIG_LIRC_IGORPLUGUSB) += lirc_igorplugusb.o
  60  obj-$(CONFIG_LIRC_IMON)                += lirc_imon.o
  61  obj-$(CONFIG_LIRC_PARALLEL)    += lirc_parallel.o
  62 +obj-$(CONFIG_LIRC_RPI)         += lirc_rpi.o
  63  obj-$(CONFIG_LIRC_SASEM)       += lirc_sasem.o
  64  obj-$(CONFIG_LIRC_SERIAL)      += lirc_serial.o
  65  obj-$(CONFIG_LIRC_SIR)         += lirc_sir.o
  66 --- /dev/null
  67 +++ b/drivers/staging/media/lirc/lirc_rpi.c
  68 @@ -0,0 +1,659 @@
  69 +/*
  70 + * lirc_rpi.c
  71 + *
  72 + * lirc_rpi - Device driver that records pulse- and pause-lengths
  73 + *           (space-lengths) (just like the lirc_serial driver does)
  74 + *           between GPIO interrupt events on the Raspberry Pi.
  75 + *           Lots of code has been taken from the lirc_serial module,
  76 + *           so I would like say thanks to the authors.
  77 + *
  78 + * Copyright (C) 2012 Aron Robert Szabo <aron@reon.hu>,
  79 + *                   Michael Bishop <cleverca22@gmail.com>
  80 + *  This program is free software; you can redistribute it and/or modify
  81 + *  it under the terms of the GNU General Public License as published by
  82 + *  the Free Software Foundation; either version 2 of the License, or
  83 + *  (at your option) any later version.
  84 + *
  85 + *  This program is distributed in the hope that it will be useful,
  86 + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  87 + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  88 + *  GNU General Public License for more details.
  89 + *
  90 + *  You should have received a copy of the GNU General Public License
  91 + *  along with this program; if not, write to the Free Software
  92 + *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  93 + */
  94 +
  95 +#include <linux/module.h>
  96 +#include <linux/errno.h>
  97 +#include <linux/interrupt.h>
  98 +#include <linux/sched.h>
  99 +#include <linux/kernel.h>
 100 +#include <linux/time.h>
 101 +#include <linux/timex.h>
 102 +#include <linux/string.h>
 103 +#include <linux/delay.h>
 104 +#include <linux/platform_device.h>
 105 +#include <linux/irq.h>
 106 +#include <linux/spinlock.h>
 107 +#include <media/lirc.h>
 108 +#include <media/lirc_dev.h>
 109 +#include <mach/gpio.h>
 110 +#include <linux/gpio.h>
 111 +
 112 +#include <linux/platform_data/bcm2708.h>
 113 +
 114 +#define LIRC_DRIVER_NAME "lirc_rpi"
 115 +#define RBUF_LEN 256
 116 +#define LIRC_TRANSMITTER_LATENCY 50
 117 +
 118 +#ifndef MAX_UDELAY_MS
 119 +#define MAX_UDELAY_US 5000
 120 +#else
 121 +#define MAX_UDELAY_US (MAX_UDELAY_MS*1000)
 122 +#endif
 123 +
 124 +#define dprintk(fmt, args...)                                  \
 125 +       do {                                                    \
 126 +               if (debug)                                      \
 127 +                       printk(KERN_DEBUG LIRC_DRIVER_NAME ": " \
 128 +                              fmt, ## args);                   \
 129 +       } while (0)
 130 +
 131 +/* module parameters */
 132 +
 133 +/* set the default GPIO input pin */
 134 +static int gpio_in_pin = 18;
 135 +/* set the default pull behaviour for input pin */
 136 +static int gpio_in_pull = BCM2708_PULL_DOWN;
 137 +/* set the default GPIO output pin */
 138 +static int gpio_out_pin = 17;
 139 +/* enable debugging messages */
 140 +static bool debug;
 141 +/* -1 = auto, 0 = active high, 1 = active low */
 142 +static int sense = -1;
 143 +/* use softcarrier by default */
 144 +static bool softcarrier = 1;
 145 +/* 0 = do not invert output, 1 = invert output */
 146 +static bool invert = 0;
 147 +
 148 +struct gpio_chip *gpiochip;
 149 +static int irq_num;
 150 +
 151 +/* forward declarations */
 152 +static long send_pulse(unsigned long length);
 153 +static void send_space(long length);
 154 +static void lirc_rpi_exit(void);
 155 +
 156 +static struct platform_device *lirc_rpi_dev;
 157 +static struct timeval lasttv = { 0, 0 };
 158 +static struct lirc_buffer rbuf;
 159 +static spinlock_t lock;
 160 +
 161 +/* initialized/set in init_timing_params() */
 162 +static unsigned int freq = 38000;
 163 +static unsigned int duty_cycle = 50;
 164 +static unsigned long period;
 165 +static unsigned long pulse_width;
 166 +static unsigned long space_width;
 167 +
 168 +static void safe_udelay(unsigned long usecs)
 169 +{
 170 +       while (usecs > MAX_UDELAY_US) {
 171 +               udelay(MAX_UDELAY_US);
 172 +               usecs -= MAX_UDELAY_US;
 173 +       }
 174 +       udelay(usecs);
 175 +}
 176 +
 177 +static int init_timing_params(unsigned int new_duty_cycle,
 178 +       unsigned int new_freq)
 179 +{
 180 +       if (1000 * 1000000L / new_freq * new_duty_cycle / 100 <=
 181 +           LIRC_TRANSMITTER_LATENCY)
 182 +               return -EINVAL;
 183 +       if (1000 * 1000000L / new_freq * (100 - new_duty_cycle) / 100 <=
 184 +           LIRC_TRANSMITTER_LATENCY)
 185 +               return -EINVAL;
 186 +       duty_cycle = new_duty_cycle;
 187 +       freq = new_freq;
 188 +       period = 1000 * 1000000L / freq;
 189 +       pulse_width = period * duty_cycle / 100;
 190 +       space_width = period - pulse_width;
 191 +       dprintk("in init_timing_params, freq=%d pulse=%ld, "
 192 +               "space=%ld\n", freq, pulse_width, space_width);
 193 +       return 0;
 194 +}
 195 +
 196 +static long send_pulse_softcarrier(unsigned long length)
 197 +{
 198 +       int flag;
 199 +       unsigned long actual, target;
 200 +       unsigned long actual_us, initial_us, target_us;
 201 +
 202 +       length *= 1000;
 203 +
 204 +       actual = 0; target = 0; flag = 0;
 205 +       read_current_timer(&actual_us);
 206 +
 207 +       while (actual < length) {
 208 +               if (flag) {
 209 +                       gpiochip->set(gpiochip, gpio_out_pin, invert);
 210 +                       target += space_width;
 211 +               } else {
 212 +                       gpiochip->set(gpiochip, gpio_out_pin, !invert);
 213 +                       target += pulse_width;
 214 +               }
 215 +               initial_us = actual_us;
 216 +               target_us = actual_us + (target - actual) / 1000;
 217 +               /*
 218 +                * Note - we've checked in ioctl that the pulse/space
 219 +                * widths are big enough so that d is > 0
 220 +                */
 221 +               if  ((int)(target_us - actual_us) > 0)
 222 +                       udelay(target_us - actual_us);
 223 +               read_current_timer(&actual_us);
 224 +               actual += (actual_us - initial_us) * 1000;
 225 +               flag = !flag;
 226 +       }
 227 +       return (actual-length) / 1000;
 228 +}
 229 +
 230 +static long send_pulse(unsigned long length)
 231 +{
 232 +       if (length <= 0)
 233 +               return 0;
 234 +
 235 +       if (softcarrier) {
 236 +               return send_pulse_softcarrier(length);
 237 +       } else {
 238 +               gpiochip->set(gpiochip, gpio_out_pin, !invert);
 239 +               safe_udelay(length);
 240 +               return 0;
 241 +       }
 242 +}
 243 +
 244 +static void send_space(long length)
 245 +{
 246 +       gpiochip->set(gpiochip, gpio_out_pin, invert);
 247 +       if (length <= 0)
 248 +               return;
 249 +       safe_udelay(length);
 250 +}
 251 +
 252 +static void rbwrite(int l)
 253 +{
 254 +       if (lirc_buffer_full(&rbuf)) {
 255 +               /* no new signals will be accepted */
 256 +               dprintk("Buffer overrun\n");
 257 +               return;
 258 +       }
 259 +       lirc_buffer_write(&rbuf, (void *)&l);
 260 +}
 261 +
 262 +static void frbwrite(int l)
 263 +{
 264 +       /* simple noise filter */
 265 +       static int pulse, space;
 266 +       static unsigned int ptr;
 267 +
 268 +       if (ptr > 0 && (l & PULSE_BIT)) {
 269 +               pulse += l & PULSE_MASK;
 270 +               if (pulse > 250) {
 271 +                       rbwrite(space);
 272 +                       rbwrite(pulse | PULSE_BIT);
 273 +                       ptr = 0;
 274 +                       pulse = 0;
 275 +               }
 276 +               return;
 277 +       }
 278 +       if (!(l & PULSE_BIT)) {
 279 +               if (ptr == 0) {
 280 +                       if (l > 20000) {
 281 +                               space = l;
 282 +                               ptr++;
 283 +                               return;
 284 +                       }
 285 +               } else {
 286 +                       if (l > 20000) {
 287 +                               space += pulse;
 288 +                               if (space > PULSE_MASK)
 289 +                                       space = PULSE_MASK;
 290 +                               space += l;
 291 +                               if (space > PULSE_MASK)
 292 +                                       space = PULSE_MASK;
 293 +                               pulse = 0;
 294 +                               return;
 295 +                       }
 296 +                       rbwrite(space);
 297 +                       rbwrite(pulse | PULSE_BIT);
 298 +                       ptr = 0;
 299 +                       pulse = 0;
 300 +               }
 301 +       }
 302 +       rbwrite(l);
 303 +}
 304 +
 305 +static irqreturn_t irq_handler(int i, void *blah, struct pt_regs *regs)
 306 +{
 307 +       struct timeval tv;
 308 +       long deltv;
 309 +       int data;
 310 +       int signal;
 311 +
 312 +       /* use the GPIO signal level */
 313 +       signal = gpiochip->get(gpiochip, gpio_in_pin);
 314 +
 315 +       if (sense != -1) {
 316 +               /* get current time */
 317 +               do_gettimeofday(&tv);
 318 +
 319 +               /* calc time since last interrupt in microseconds */
 320 +               deltv = tv.tv_sec-lasttv.tv_sec;
 321 +               if (tv.tv_sec < lasttv.tv_sec ||
 322 +                   (tv.tv_sec == lasttv.tv_sec &&
 323 +                    tv.tv_usec < lasttv.tv_usec)) {
 324 +                       printk(KERN_WARNING LIRC_DRIVER_NAME
 325 +                              ": AIEEEE: your clock just jumped backwards\n");
 326 +                       printk(KERN_WARNING LIRC_DRIVER_NAME
 327 +                              ": %d %d %lx %lx %lx %lx\n", signal, sense,
 328 +                              tv.tv_sec, lasttv.tv_sec,
 329 +                              tv.tv_usec, lasttv.tv_usec);
 330 +                       data = PULSE_MASK;
 331 +               } else if (deltv > 15) {
 332 +                       data = PULSE_MASK; /* really long time */
 333 +                       if (!(signal^sense)) {
 334 +                               /* sanity check */
 335 +                               printk(KERN_WARNING LIRC_DRIVER_NAME
 336 +                                      ": AIEEEE: %d %d %lx %lx %lx %lx\n",
 337 +                                      signal, sense, tv.tv_sec, lasttv.tv_sec,
 338 +                                      tv.tv_usec, lasttv.tv_usec);
 339 +                               /*
 340 +                                * detecting pulse while this
 341 +                                * MUST be a space!
 342 +                                */
 343 +                               sense = sense ? 0 : 1;
 344 +                       }
 345 +               } else {
 346 +                       data = (int) (deltv*1000000 +
 347 +                                     (tv.tv_usec - lasttv.tv_usec));
 348 +               }
 349 +               frbwrite(signal^sense ? data : (data|PULSE_BIT));
 350 +               lasttv = tv;
 351 +               wake_up_interruptible(&rbuf.wait_poll);
 352 +       }
 353 +
 354 +       return IRQ_HANDLED;
 355 +}
 356 +
 357 +static int is_right_chip(struct gpio_chip *chip, void *data)
 358 +{
 359 +       dprintk("is_right_chip %s %d\n", chip->label, strcmp(data, chip->label));
 360 +
 361 +       if (strcmp(data, chip->label) == 0)
 362 +               return 1;
 363 +       return 0;
 364 +}
 365 +
 366 +static int init_port(void)
 367 +{
 368 +       int i, nlow, nhigh, ret;
 369 +
 370 +       gpiochip = gpiochip_find("bcm2708_gpio", is_right_chip);
 371 +
 372 +       if (!gpiochip)
 373 +               return -ENODEV;
 374 +
 375 +       if (gpio_request(gpio_out_pin, LIRC_DRIVER_NAME " ir/out")) {
 376 +               printk(KERN_ALERT LIRC_DRIVER_NAME
 377 +                      ": cant claim gpio pin %d\n", gpio_out_pin);
 378 +               ret = -ENODEV;
 379 +               goto exit_init_port;
 380 +       }
 381 +
 382 +       if (gpio_request(gpio_in_pin, LIRC_DRIVER_NAME " ir/in")) {
 383 +               printk(KERN_ALERT LIRC_DRIVER_NAME
 384 +                      ": cant claim gpio pin %d\n", gpio_in_pin);
 385 +               ret = -ENODEV;
 386 +               goto exit_gpio_free_out_pin;
 387 +       }
 388 +
 389 +       bcm2708_gpio_setpull(gpiochip, gpio_in_pin, gpio_in_pull);
 390 +       gpiochip->direction_input(gpiochip, gpio_in_pin);
 391 +       gpiochip->direction_output(gpiochip, gpio_out_pin, 1);
 392 +       gpiochip->set(gpiochip, gpio_out_pin, invert);
 393 +
 394 +       irq_num = gpiochip->to_irq(gpiochip, gpio_in_pin);
 395 +       dprintk("to_irq %d\n", irq_num);
 396 +
 397 +       /* if pin is high, then this must be an active low receiver. */
 398 +       if (sense == -1) {
 399 +               /* wait 1/2 sec for the power supply */
 400 +               msleep(500);
 401 +
 402 +               /*
 403 +                * probe 9 times every 0.04s, collect "votes" for
 404 +                * active high/low
 405 +                */
 406 +               nlow = 0;
 407 +               nhigh = 0;
 408 +               for (i = 0; i < 9; i++) {
 409 +                       if (gpiochip->get(gpiochip, gpio_in_pin))
 410 +                               nlow++;
 411 +                       else
 412 +                               nhigh++;
 413 +                       msleep(40);
 414 +               }
 415 +               sense = (nlow >= nhigh ? 1 : 0);
 416 +               printk(KERN_INFO LIRC_DRIVER_NAME
 417 +                      ": auto-detected active %s receiver on GPIO pin %d\n",
 418 +                      sense ? "low" : "high", gpio_in_pin);
 419 +       } else {
 420 +               printk(KERN_INFO LIRC_DRIVER_NAME
 421 +                      ": manually using active %s receiver on GPIO pin %d\n",
 422 +                      sense ? "low" : "high", gpio_in_pin);
 423 +       }
 424 +
 425 +       return 0;
 426 +
 427 +       exit_gpio_free_out_pin:
 428 +       gpio_free(gpio_out_pin);
 429 +
 430 +       exit_init_port:
 431 +       return ret;
 432 +}
 433 +
 434 +// called when the character device is opened
 435 +static int set_use_inc(void *data)
 436 +{
 437 +       int result;
 438 +
 439 +       /* initialize timestamp */
 440 +       do_gettimeofday(&lasttv);
 441 +
 442 +       result = request_irq(irq_num,
 443 +                            (irq_handler_t) irq_handler,
 444 +                            IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING,
 445 +                            LIRC_DRIVER_NAME, (void*) 0);
 446 +
 447 +       switch (result) {
 448 +       case -EBUSY:
 449 +               printk(KERN_ERR LIRC_DRIVER_NAME
 450 +                      ": IRQ %d is busy\n",
 451 +                      irq_num);
 452 +               return -EBUSY;
 453 +       case -EINVAL:
 454 +               printk(KERN_ERR LIRC_DRIVER_NAME
 455 +                      ": Bad irq number or handler\n");
 456 +               return -EINVAL;
 457 +       default:
 458 +               dprintk("Interrupt %d obtained\n",
 459 +                       irq_num);
 460 +               break;
 461 +       };
 462 +
 463 +       /* initialize pulse/space widths */
 464 +       init_timing_params(duty_cycle, freq);
 465 +
 466 +       return 0;
 467 +}
 468 +
 469 +static void set_use_dec(void *data)
 470 +{
 471 +       /* GPIO Pin Falling/Rising Edge Detect Disable */
 472 +       irq_set_irq_type(irq_num, 0);
 473 +       disable_irq(irq_num);
 474 +
 475 +       free_irq(irq_num, (void *) 0);
 476 +
 477 +       dprintk(KERN_INFO LIRC_DRIVER_NAME
 478 +               ": freed IRQ %d\n", irq_num);
 479 +}
 480 +
 481 +static ssize_t lirc_write(struct file *file, const char *buf,
 482 +       size_t n, loff_t *ppos)
 483 +{
 484 +       int i, count;
 485 +       unsigned long flags;
 486 +       long delta = 0;
 487 +       int *wbuf;
 488 +
 489 +       count = n / sizeof(int);
 490 +       if (n % sizeof(int) || count % 2 == 0)
 491 +               return -EINVAL;
 492 +       wbuf = memdup_user(buf, n);
 493 +       if (IS_ERR(wbuf))
 494 +               return PTR_ERR(wbuf);
 495 +       spin_lock_irqsave(&lock, flags);
 496 +
 497 +       for (i = 0; i < count; i++) {
 498 +               if (i%2)
 499 +                       send_space(wbuf[i] - delta);
 500 +               else
 501 +                       delta = send_pulse(wbuf[i]);
 502 +       }
 503 +       gpiochip->set(gpiochip, gpio_out_pin, invert);
 504 +
 505 +       spin_unlock_irqrestore(&lock, flags);
 506 +       kfree(wbuf);
 507 +       return n;
 508 +}
 509 +
 510 +static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 511 +{
 512 +       int result;
 513 +       __u32 value;
 514 +
 515 +       switch (cmd) {
 516 +       case LIRC_GET_SEND_MODE:
 517 +               return -ENOIOCTLCMD;
 518 +               break;
 519 +
 520 +       case LIRC_SET_SEND_MODE:
 521 +               result = get_user(value, (__u32 *) arg);
 522 +               if (result)
 523 +                       return result;
 524 +               /* only LIRC_MODE_PULSE supported */
 525 +               if (value != LIRC_MODE_PULSE)
 526 +                       return -ENOSYS;
 527 +               break;
 528 +
 529 +       case LIRC_GET_LENGTH:
 530 +               return -ENOSYS;
 531 +               break;
 532 +
 533 +       case LIRC_SET_SEND_DUTY_CYCLE:
 534 +               dprintk("SET_SEND_DUTY_CYCLE\n");
 535 +               result = get_user(value, (__u32 *) arg);
 536 +               if (result)
 537 +                       return result;
 538 +               if (value <= 0 || value > 100)
 539 +                       return -EINVAL;
 540 +               return init_timing_params(value, freq);
 541 +               break;
 542 +
 543 +       case LIRC_SET_SEND_CARRIER:
 544 +               dprintk("SET_SEND_CARRIER\n");
 545 +               result = get_user(value, (__u32 *) arg);
 546 +               if (result)
 547 +                       return result;
 548 +               if (value > 500000 || value < 20000)
 549 +                       return -EINVAL;
 550 +               return init_timing_params(duty_cycle, value);
 551 +               break;
 552 +
 553 +       default:
 554 +               return lirc_dev_fop_ioctl(filep, cmd, arg);
 555 +       }
 556 +       return 0;
 557 +}
 558 +
 559 +static const struct file_operations lirc_fops = {
 560 +       .owner          = THIS_MODULE,
 561 +       .write          = lirc_write,
 562 +       .unlocked_ioctl = lirc_ioctl,
 563 +       .read           = lirc_dev_fop_read,
 564 +       .poll           = lirc_dev_fop_poll,
 565 +       .open           = lirc_dev_fop_open,
 566 +       .release        = lirc_dev_fop_close,
 567 +       .llseek         = no_llseek,
 568 +};
 569 +
 570 +static struct lirc_driver driver = {
 571 +       .name           = LIRC_DRIVER_NAME,
 572 +       .minor          = -1,
 573 +       .code_length    = 1,
 574 +       .sample_rate    = 0,
 575 +       .data           = NULL,
 576 +       .add_to_buf     = NULL,
 577 +       .rbuf           = &rbuf,
 578 +       .set_use_inc    = set_use_inc,
 579 +       .set_use_dec    = set_use_dec,
 580 +       .fops           = &lirc_fops,
 581 +       .dev            = NULL,
 582 +       .owner          = THIS_MODULE,
 583 +};
 584 +
 585 +static struct platform_driver lirc_rpi_driver = {
 586 +       .driver = {
 587 +               .name   = LIRC_DRIVER_NAME,
 588 +               .owner  = THIS_MODULE,
 589 +       },
 590 +};
 591 +
 592 +static int __init lirc_rpi_init(void)
 593 +{
 594 +       int result;
 595 +
 596 +       /* Init read buffer. */
 597 +       result = lirc_buffer_init(&rbuf, sizeof(int), RBUF_LEN);
 598 +       if (result < 0)
 599 +               return -ENOMEM;
 600 +
 601 +       result = platform_driver_register(&lirc_rpi_driver);
 602 +       if (result) {
 603 +               printk(KERN_ERR LIRC_DRIVER_NAME
 604 +                      ": lirc register returned %d\n", result);
 605 +               goto exit_buffer_free;
 606 +       }
 607 +
 608 +       lirc_rpi_dev = platform_device_alloc(LIRC_DRIVER_NAME, 0);
 609 +       if (!lirc_rpi_dev) {
 610 +               result = -ENOMEM;
 611 +               goto exit_driver_unregister;
 612 +       }
 613 +
 614 +       result = platform_device_add(lirc_rpi_dev);
 615 +       if (result)
 616 +               goto exit_device_put;
 617 +
 618 +       return 0;
 619 +
 620 +       exit_device_put:
 621 +       platform_device_put(lirc_rpi_dev);
 622 +
 623 +       exit_driver_unregister:
 624 +       platform_driver_unregister(&lirc_rpi_driver);
 625 +
 626 +       exit_buffer_free:
 627 +       lirc_buffer_free(&rbuf);
 628 +
 629 +       return result;
 630 +}
 631 +
 632 +static void lirc_rpi_exit(void)
 633 +{
 634 +       if (!lirc_rpi_dev->dev.of_node)
 635 +               platform_device_unregister(lirc_rpi_dev);
 636 +       platform_driver_unregister(&lirc_rpi_driver);
 637 +       lirc_buffer_free(&rbuf);
 638 +}
 639 +
 640 +static int __init lirc_rpi_init_module(void)
 641 +{
 642 +       int result;
 643 +
 644 +       result = lirc_rpi_init();
 645 +       if (result)
 646 +               return result;
 647 +
 648 +       if (gpio_in_pin >= BCM2708_NR_GPIOS || gpio_out_pin >= BCM2708_NR_GPIOS) {
 649 +               result = -EINVAL;
 650 +               printk(KERN_ERR LIRC_DRIVER_NAME
 651 +                      ": invalid GPIO pin(s) specified!\n");
 652 +               goto exit_rpi;
 653 +       }
 654 +
 655 +       result = init_port();
 656 +       if (result < 0)
 657 +               goto exit_rpi;
 658 +
 659 +       driver.features = LIRC_CAN_SET_SEND_DUTY_CYCLE |
 660 +                         LIRC_CAN_SET_SEND_CARRIER |
 661 +                         LIRC_CAN_SEND_PULSE |
 662 +                         LIRC_CAN_REC_MODE2;
 663 +
 664 +       driver.dev = &lirc_rpi_dev->dev;
 665 +       driver.minor = lirc_register_driver(&driver);
 666 +
 667 +       if (driver.minor < 0) {
 668 +               printk(KERN_ERR LIRC_DRIVER_NAME
 669 +                      ": device registration failed with %d\n", result);
 670 +               result = -EIO;
 671 +               goto exit_rpi;
 672 +       }
 673 +
 674 +       printk(KERN_INFO LIRC_DRIVER_NAME ": driver registered!\n");
 675 +
 676 +       return 0;
 677 +
 678 +       exit_rpi:
 679 +       lirc_rpi_exit();
 680 +
 681 +       return result;
 682 +}
 683 +
 684 +static void __exit lirc_rpi_exit_module(void)
 685 +{
 686 +       lirc_unregister_driver(driver.minor);
 687 +
 688 +       gpio_free(gpio_out_pin);
 689 +       gpio_free(gpio_in_pin);
 690 +
 691 +       lirc_rpi_exit();
 692 +
 693 +       printk(KERN_INFO LIRC_DRIVER_NAME ": cleaned up module\n");
 694 +}
 695 +
 696 +module_init(lirc_rpi_init_module);
 697 +module_exit(lirc_rpi_exit_module);
 698 +
 699 +MODULE_DESCRIPTION("Infra-red receiver and blaster driver for Raspberry Pi GPIO.");
 700 +MODULE_AUTHOR("Aron Robert Szabo <aron@reon.hu>");
 701 +MODULE_AUTHOR("Michael Bishop <cleverca22@gmail.com>");
 702 +MODULE_LICENSE("GPL");
 703 +
 704 +module_param(gpio_out_pin, int, S_IRUGO);
 705 +MODULE_PARM_DESC(gpio_out_pin, "GPIO output/transmitter pin number of the BCM"
 706 +                " processor. (default 17");
 707 +
 708 +module_param(gpio_in_pin, int, S_IRUGO);
 709 +MODULE_PARM_DESC(gpio_in_pin, "GPIO input pin number of the BCM processor."
 710 +                " (default 18");
 711 +
 712 +module_param(gpio_in_pull, int, S_IRUGO);
 713 +MODULE_PARM_DESC(gpio_in_pull, "GPIO input pin pull configuration."
 714 +                " (0 = off, 1 = up, 2 = down, default down)");
 715 +
 716 +module_param(sense, int, S_IRUGO);
 717 +MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit"
 718 +                " (0 = active high, 1 = active low )");
 719 +
 720 +module_param(softcarrier, bool, S_IRUGO);
 721 +MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
 722 +
 723 +module_param(invert, bool, S_IRUGO);
 724 +MODULE_PARM_DESC(invert, "Invert output (0 = off, 1 = on, default off");
 725 +
 726 +module_param(debug, bool, S_IRUGO | S_IWUSR);
 727 +MODULE_PARM_DESC(debug, "Enable debugging messages");