1 From a46ef8c727cf42ab2434d5f19eea7b9a88649d22 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 016/203] lirc: added support for RaspberryPi GPIO
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
9 lirc: Remove restriction on gpio pins that can be used with lirc
11 Compute Module, for example could use different pins
13 lirc_rpi: Add parameter to specify input pin pull
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.
19 Signed-off-by: Julian Scheel <julian@jusst.de>
21 lirc-rpi: Use the higher-level irq control functions
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.
29 lirc-rpi: Correct the interrupt usage
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
35 lirc-rpi: use getnstimeofday instead of read_current_timer
37 read_current_timer isn't guaranteed to return values in
38 microseconds, and indeed it doesn't on a Pi2.
42 lirc-rpi: Add device tree support, and a suitable overlay
44 The overlay supports DT parameters that match the old module
45 parameters, except that gpio_in_pull should be set using the
46 strings "up", "down" or "off".
48 lirc-rpi: Also support pinctrl-bcm2835 in non-DT mode
50 drivers/staging/media/lirc/Kconfig | 6 +
51 drivers/staging/media/lirc/Makefile | 1 +
52 drivers/staging/media/lirc/lirc_rpi.c | 765 ++++++++++++++++++++++++++++++++++
53 3 files changed, 772 insertions(+)
54 create mode 100644 drivers/staging/media/lirc/lirc_rpi.c
56 --- a/drivers/staging/media/lirc/Kconfig
57 +++ b/drivers/staging/media/lirc/Kconfig
58 @@ -32,6 +32,12 @@ config LIRC_PARALLEL
60 Driver for Homebrew Parallel Port Receivers
63 + tristate "Homebrew GPIO Port Receiver/Transmitter for the RaspberryPi"
66 + Driver for Homebrew GPIO Port Receiver/Transmitter for the RaspberryPi
69 tristate "Sasem USB IR Remote"
70 depends on LIRC && USB
71 --- a/drivers/staging/media/lirc/Makefile
72 +++ b/drivers/staging/media/lirc/Makefile
74 obj-$(CONFIG_LIRC_BT829) += lirc_bt829.o
75 obj-$(CONFIG_LIRC_IMON) += lirc_imon.o
76 obj-$(CONFIG_LIRC_PARALLEL) += lirc_parallel.o
77 +obj-$(CONFIG_LIRC_RPI) += lirc_rpi.o
78 obj-$(CONFIG_LIRC_SASEM) += lirc_sasem.o
79 obj-$(CONFIG_LIRC_SERIAL) += lirc_serial.o
80 obj-$(CONFIG_LIRC_SIR) += lirc_sir.o
82 +++ b/drivers/staging/media/lirc/lirc_rpi.c
87 + * lirc_rpi - Device driver that records pulse- and pause-lengths
88 + * (space-lengths) (just like the lirc_serial driver does)
89 + * between GPIO interrupt events on the Raspberry Pi.
90 + * Lots of code has been taken from the lirc_serial module,
91 + * so I would like say thanks to the authors.
93 + * Copyright (C) 2012 Aron Robert Szabo <aron@reon.hu>,
94 + * Michael Bishop <cleverca22@gmail.com>
95 + * This program is free software; you can redistribute it and/or modify
96 + * it under the terms of the GNU General Public License as published by
97 + * the Free Software Foundation; either version 2 of the License, or
98 + * (at your option) any later version.
100 + * This program is distributed in the hope that it will be useful,
101 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
102 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
103 + * GNU General Public License for more details.
105 + * You should have received a copy of the GNU General Public License
106 + * along with this program; if not, write to the Free Software
107 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
110 +#include <linux/module.h>
111 +#include <linux/errno.h>
112 +#include <linux/interrupt.h>
113 +#include <linux/sched.h>
114 +#include <linux/kernel.h>
115 +#include <linux/time.h>
116 +#include <linux/timex.h>
117 +#include <linux/timekeeping.h>
118 +#include <linux/string.h>
119 +#include <linux/delay.h>
120 +#include <linux/platform_device.h>
121 +#include <linux/irq.h>
122 +#include <linux/spinlock.h>
123 +#include <media/lirc.h>
124 +#include <media/lirc_dev.h>
125 +#include <mach/gpio.h>
126 +#include <linux/gpio.h>
127 +#include <linux/of_platform.h>
129 +#include <linux/platform_data/bcm2708.h>
131 +#define LIRC_DRIVER_NAME "lirc_rpi"
132 +#define RBUF_LEN 256
133 +#define LIRC_TRANSMITTER_LATENCY 50
135 +#ifndef MAX_UDELAY_MS
136 +#define MAX_UDELAY_US 5000
138 +#define MAX_UDELAY_US (MAX_UDELAY_MS*1000)
141 +#define dprintk(fmt, args...) \
144 + printk(KERN_DEBUG LIRC_DRIVER_NAME ": " \
148 +/* module parameters */
150 +/* set the default GPIO input pin */
151 +static int gpio_in_pin = 18;
152 +/* set the default pull behaviour for input pin */
153 +static int gpio_in_pull = BCM2708_PULL_DOWN;
154 +/* set the default GPIO output pin */
155 +static int gpio_out_pin = 17;
156 +/* enable debugging messages */
158 +/* -1 = auto, 0 = active high, 1 = active low */
159 +static int sense = -1;
160 +/* use softcarrier by default */
161 +static bool softcarrier = 1;
162 +/* 0 = do not invert output, 1 = invert output */
163 +static bool invert = 0;
165 +struct gpio_chip *gpiochip;
168 +/* forward declarations */
169 +static long send_pulse(unsigned long length);
170 +static void send_space(long length);
171 +static void lirc_rpi_exit(void);
173 +static struct platform_device *lirc_rpi_dev;
174 +static struct timeval lasttv = { 0, 0 };
175 +static struct lirc_buffer rbuf;
176 +static spinlock_t lock;
178 +/* initialized/set in init_timing_params() */
179 +static unsigned int freq = 38000;
180 +static unsigned int duty_cycle = 50;
181 +static unsigned long period;
182 +static unsigned long pulse_width;
183 +static unsigned long space_width;
185 +static void safe_udelay(unsigned long usecs)
187 + while (usecs > MAX_UDELAY_US) {
188 + udelay(MAX_UDELAY_US);
189 + usecs -= MAX_UDELAY_US;
194 +static unsigned long read_current_us(void)
196 + struct timespec now;
197 + getnstimeofday(&now);
198 + return (now.tv_sec * 1000000) + (now.tv_nsec/1000);
201 +static int init_timing_params(unsigned int new_duty_cycle,
202 + unsigned int new_freq)
204 + if (1000 * 1000000L / new_freq * new_duty_cycle / 100 <=
205 + LIRC_TRANSMITTER_LATENCY)
207 + if (1000 * 1000000L / new_freq * (100 - new_duty_cycle) / 100 <=
208 + LIRC_TRANSMITTER_LATENCY)
210 + duty_cycle = new_duty_cycle;
212 + period = 1000 * 1000000L / freq;
213 + pulse_width = period * duty_cycle / 100;
214 + space_width = period - pulse_width;
215 + dprintk("in init_timing_params, freq=%d pulse=%ld, "
216 + "space=%ld\n", freq, pulse_width, space_width);
220 +static long send_pulse_softcarrier(unsigned long length)
223 + unsigned long actual, target;
224 + unsigned long actual_us, initial_us, target_us;
228 + actual = 0; target = 0; flag = 0;
229 + actual_us = read_current_us();
231 + while (actual < length) {
233 + gpiochip->set(gpiochip, gpio_out_pin, invert);
234 + target += space_width;
236 + gpiochip->set(gpiochip, gpio_out_pin, !invert);
237 + target += pulse_width;
239 + initial_us = actual_us;
240 + target_us = actual_us + (target - actual) / 1000;
242 + * Note - we've checked in ioctl that the pulse/space
243 + * widths are big enough so that d is > 0
245 + if ((int)(target_us - actual_us) > 0)
246 + udelay(target_us - actual_us);
247 + actual_us = read_current_us();
248 + actual += (actual_us - initial_us) * 1000;
251 + return (actual-length) / 1000;
254 +static long send_pulse(unsigned long length)
260 + return send_pulse_softcarrier(length);
262 + gpiochip->set(gpiochip, gpio_out_pin, !invert);
263 + safe_udelay(length);
268 +static void send_space(long length)
270 + gpiochip->set(gpiochip, gpio_out_pin, invert);
273 + safe_udelay(length);
276 +static void rbwrite(int l)
278 + if (lirc_buffer_full(&rbuf)) {
279 + /* no new signals will be accepted */
280 + dprintk("Buffer overrun\n");
283 + lirc_buffer_write(&rbuf, (void *)&l);
286 +static void frbwrite(int l)
288 + /* simple noise filter */
289 + static int pulse, space;
290 + static unsigned int ptr;
292 + if (ptr > 0 && (l & PULSE_BIT)) {
293 + pulse += l & PULSE_MASK;
296 + rbwrite(pulse | PULSE_BIT);
302 + if (!(l & PULSE_BIT)) {
312 + if (space > PULSE_MASK)
313 + space = PULSE_MASK;
315 + if (space > PULSE_MASK)
316 + space = PULSE_MASK;
321 + rbwrite(pulse | PULSE_BIT);
329 +static irqreturn_t irq_handler(int i, void *blah, struct pt_regs *regs)
336 + /* use the GPIO signal level */
337 + signal = gpiochip->get(gpiochip, gpio_in_pin);
340 + /* get current time */
341 + do_gettimeofday(&tv);
343 + /* calc time since last interrupt in microseconds */
344 + deltv = tv.tv_sec-lasttv.tv_sec;
345 + if (tv.tv_sec < lasttv.tv_sec ||
346 + (tv.tv_sec == lasttv.tv_sec &&
347 + tv.tv_usec < lasttv.tv_usec)) {
348 + printk(KERN_WARNING LIRC_DRIVER_NAME
349 + ": AIEEEE: your clock just jumped backwards\n");
350 + printk(KERN_WARNING LIRC_DRIVER_NAME
351 + ": %d %d %lx %lx %lx %lx\n", signal, sense,
352 + tv.tv_sec, lasttv.tv_sec,
353 + tv.tv_usec, lasttv.tv_usec);
355 + } else if (deltv > 15) {
356 + data = PULSE_MASK; /* really long time */
357 + if (!(signal^sense)) {
359 + printk(KERN_WARNING LIRC_DRIVER_NAME
360 + ": AIEEEE: %d %d %lx %lx %lx %lx\n",
361 + signal, sense, tv.tv_sec, lasttv.tv_sec,
362 + tv.tv_usec, lasttv.tv_usec);
364 + * detecting pulse while this
367 + sense = sense ? 0 : 1;
370 + data = (int) (deltv*1000000 +
371 + (tv.tv_usec - lasttv.tv_usec));
373 + frbwrite(signal^sense ? data : (data|PULSE_BIT));
375 + wake_up_interruptible(&rbuf.wait_poll);
378 + return IRQ_HANDLED;
381 +static int is_right_chip(struct gpio_chip *chip, void *data)
383 + dprintk("is_right_chip %s %d\n", chip->label, strcmp(data, chip->label));
385 + if (strcmp(data, chip->label) == 0)
390 +static inline int read_bool_property(const struct device_node *np,
391 + const char *propname,
395 + int err = of_property_read_u32(np, propname, &value);
397 + *out_value = (value != 0);
401 +static void read_pin_settings(struct device_node *node)
407 + of_property_read_u32_index(
415 + err = of_property_read_u32_index(
421 + if (function == 1) /* Output */
422 + gpio_out_pin = pin;
423 + else if (function == 0) /* Input */
429 +static int init_port(void)
431 + int i, nlow, nhigh, ret;
432 + struct device_node *node;
434 + node = lirc_rpi_dev->dev.of_node;
436 + gpiochip = gpiochip_find("bcm2708_gpio", is_right_chip);
439 + * Because of the lack of a setpull function, only support
440 + * pinctrl-bcm2835 if using device tree.
442 + if (!gpiochip && node)
443 + gpiochip = gpiochip_find("pinctrl-bcm2835", is_right_chip);
446 + pr_err(LIRC_DRIVER_NAME ": gpio chip not found!\n");
451 + struct device_node *pins_node;
453 + pins_node = of_parse_phandle(node, "pinctrl-0", 0);
455 + printk(KERN_ERR LIRC_DRIVER_NAME
456 + ": pinctrl settings not found!\n");
458 + goto exit_init_port;
461 + read_pin_settings(pins_node);
463 + of_property_read_u32(node, "rpi,sense", &sense);
465 + read_bool_property(node, "rpi,softcarrier", &softcarrier);
467 + read_bool_property(node, "rpi,invert", &invert);
469 + read_bool_property(node, "rpi,debug", &debug);
474 + if (gpio_in_pin >= BCM2708_NR_GPIOS ||
475 + gpio_out_pin >= BCM2708_NR_GPIOS) {
477 + printk(KERN_ERR LIRC_DRIVER_NAME
478 + ": invalid GPIO pin(s) specified!\n");
479 + goto exit_init_port;
482 + if (gpio_request(gpio_out_pin, LIRC_DRIVER_NAME " ir/out")) {
483 + printk(KERN_ALERT LIRC_DRIVER_NAME
484 + ": cant claim gpio pin %d\n", gpio_out_pin);
486 + goto exit_init_port;
489 + if (gpio_request(gpio_in_pin, LIRC_DRIVER_NAME " ir/in")) {
490 + printk(KERN_ALERT LIRC_DRIVER_NAME
491 + ": cant claim gpio pin %d\n", gpio_in_pin);
493 + goto exit_gpio_free_out_pin;
496 + bcm2708_gpio_setpull(gpiochip, gpio_in_pin, gpio_in_pull);
497 + gpiochip->direction_input(gpiochip, gpio_in_pin);
498 + gpiochip->direction_output(gpiochip, gpio_out_pin, 1);
501 + gpiochip->set(gpiochip, gpio_out_pin, invert);
503 + irq_num = gpiochip->to_irq(gpiochip, gpio_in_pin);
504 + dprintk("to_irq %d\n", irq_num);
506 + /* if pin is high, then this must be an active low receiver. */
508 + /* wait 1/2 sec for the power supply */
512 + * probe 9 times every 0.04s, collect "votes" for
517 + for (i = 0; i < 9; i++) {
518 + if (gpiochip->get(gpiochip, gpio_in_pin))
524 + sense = (nlow >= nhigh ? 1 : 0);
525 + printk(KERN_INFO LIRC_DRIVER_NAME
526 + ": auto-detected active %s receiver on GPIO pin %d\n",
527 + sense ? "low" : "high", gpio_in_pin);
529 + printk(KERN_INFO LIRC_DRIVER_NAME
530 + ": manually using active %s receiver on GPIO pin %d\n",
531 + sense ? "low" : "high", gpio_in_pin);
536 + exit_gpio_free_out_pin:
537 + gpio_free(gpio_out_pin);
543 +// called when the character device is opened
544 +static int set_use_inc(void *data)
548 + /* initialize timestamp */
549 + do_gettimeofday(&lasttv);
551 + result = request_irq(irq_num,
552 + (irq_handler_t) irq_handler,
553 + IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING,
554 + LIRC_DRIVER_NAME, (void*) 0);
558 + printk(KERN_ERR LIRC_DRIVER_NAME
559 + ": IRQ %d is busy\n",
563 + printk(KERN_ERR LIRC_DRIVER_NAME
564 + ": Bad irq number or handler\n");
567 + dprintk("Interrupt %d obtained\n",
572 + /* initialize pulse/space widths */
573 + init_timing_params(duty_cycle, freq);
578 +static void set_use_dec(void *data)
580 + /* GPIO Pin Falling/Rising Edge Detect Disable */
581 + irq_set_irq_type(irq_num, 0);
582 + disable_irq(irq_num);
584 + free_irq(irq_num, (void *) 0);
586 + dprintk(KERN_INFO LIRC_DRIVER_NAME
587 + ": freed IRQ %d\n", irq_num);
590 +static ssize_t lirc_write(struct file *file, const char *buf,
591 + size_t n, loff_t *ppos)
594 + unsigned long flags;
598 + count = n / sizeof(int);
599 + if (n % sizeof(int) || count % 2 == 0)
601 + wbuf = memdup_user(buf, n);
603 + return PTR_ERR(wbuf);
604 + spin_lock_irqsave(&lock, flags);
606 + for (i = 0; i < count; i++) {
608 + send_space(wbuf[i] - delta);
610 + delta = send_pulse(wbuf[i]);
612 + gpiochip->set(gpiochip, gpio_out_pin, invert);
614 + spin_unlock_irqrestore(&lock, flags);
619 +static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
625 + case LIRC_GET_SEND_MODE:
626 + return -ENOIOCTLCMD;
629 + case LIRC_SET_SEND_MODE:
630 + result = get_user(value, (__u32 *) arg);
633 + /* only LIRC_MODE_PULSE supported */
634 + if (value != LIRC_MODE_PULSE)
638 + case LIRC_GET_LENGTH:
642 + case LIRC_SET_SEND_DUTY_CYCLE:
643 + dprintk("SET_SEND_DUTY_CYCLE\n");
644 + result = get_user(value, (__u32 *) arg);
647 + if (value <= 0 || value > 100)
649 + return init_timing_params(value, freq);
652 + case LIRC_SET_SEND_CARRIER:
653 + dprintk("SET_SEND_CARRIER\n");
654 + result = get_user(value, (__u32 *) arg);
657 + if (value > 500000 || value < 20000)
659 + return init_timing_params(duty_cycle, value);
663 + return lirc_dev_fop_ioctl(filep, cmd, arg);
668 +static const struct file_operations lirc_fops = {
669 + .owner = THIS_MODULE,
670 + .write = lirc_write,
671 + .unlocked_ioctl = lirc_ioctl,
672 + .read = lirc_dev_fop_read,
673 + .poll = lirc_dev_fop_poll,
674 + .open = lirc_dev_fop_open,
675 + .release = lirc_dev_fop_close,
676 + .llseek = no_llseek,
679 +static struct lirc_driver driver = {
680 + .name = LIRC_DRIVER_NAME,
685 + .add_to_buf = NULL,
687 + .set_use_inc = set_use_inc,
688 + .set_use_dec = set_use_dec,
689 + .fops = &lirc_fops,
691 + .owner = THIS_MODULE,
694 +static const struct of_device_id lirc_rpi_of_match[] = {
695 + { .compatible = "rpi,lirc-rpi", },
698 +MODULE_DEVICE_TABLE(of, lirc_rpi_of_match);
700 +static struct platform_driver lirc_rpi_driver = {
702 + .name = LIRC_DRIVER_NAME,
703 + .owner = THIS_MODULE,
704 + .of_match_table = of_match_ptr(lirc_rpi_of_match),
708 +static int __init lirc_rpi_init(void)
710 + struct device_node *node;
713 + /* Init read buffer. */
714 + result = lirc_buffer_init(&rbuf, sizeof(int), RBUF_LEN);
718 + result = platform_driver_register(&lirc_rpi_driver);
720 + printk(KERN_ERR LIRC_DRIVER_NAME
721 + ": lirc register returned %d\n", result);
722 + goto exit_buffer_free;
725 + node = of_find_compatible_node(NULL, NULL,
726 + lirc_rpi_of_match[0].compatible);
730 + lirc_rpi_dev = of_find_device_by_node(node);
731 + WARN_ON(lirc_rpi_dev->dev.of_node != node);
735 + lirc_rpi_dev = platform_device_alloc(LIRC_DRIVER_NAME, 0);
736 + if (!lirc_rpi_dev) {
738 + goto exit_driver_unregister;
741 + result = platform_device_add(lirc_rpi_dev);
743 + goto exit_device_put;
749 + platform_device_put(lirc_rpi_dev);
751 + exit_driver_unregister:
752 + platform_driver_unregister(&lirc_rpi_driver);
755 + lirc_buffer_free(&rbuf);
760 +static void lirc_rpi_exit(void)
762 + if (!lirc_rpi_dev->dev.of_node)
763 + platform_device_unregister(lirc_rpi_dev);
764 + platform_driver_unregister(&lirc_rpi_driver);
765 + lirc_buffer_free(&rbuf);
768 +static int __init lirc_rpi_init_module(void)
772 + result = lirc_rpi_init();
776 + result = init_port();
780 + driver.features = LIRC_CAN_SET_SEND_DUTY_CYCLE |
781 + LIRC_CAN_SET_SEND_CARRIER |
782 + LIRC_CAN_SEND_PULSE |
783 + LIRC_CAN_REC_MODE2;
785 + driver.dev = &lirc_rpi_dev->dev;
786 + driver.minor = lirc_register_driver(&driver);
788 + if (driver.minor < 0) {
789 + printk(KERN_ERR LIRC_DRIVER_NAME
790 + ": device registration failed with %d\n", result);
795 + printk(KERN_INFO LIRC_DRIVER_NAME ": driver registered!\n");
805 +static void __exit lirc_rpi_exit_module(void)
807 + lirc_unregister_driver(driver.minor);
809 + gpio_free(gpio_out_pin);
810 + gpio_free(gpio_in_pin);
814 + printk(KERN_INFO LIRC_DRIVER_NAME ": cleaned up module\n");
817 +module_init(lirc_rpi_init_module);
818 +module_exit(lirc_rpi_exit_module);
820 +MODULE_DESCRIPTION("Infra-red receiver and blaster driver for Raspberry Pi GPIO.");
821 +MODULE_AUTHOR("Aron Robert Szabo <aron@reon.hu>");
822 +MODULE_AUTHOR("Michael Bishop <cleverca22@gmail.com>");
823 +MODULE_LICENSE("GPL");
825 +module_param(gpio_out_pin, int, S_IRUGO);
826 +MODULE_PARM_DESC(gpio_out_pin, "GPIO output/transmitter pin number of the BCM"
827 + " processor. (default 17");
829 +module_param(gpio_in_pin, int, S_IRUGO);
830 +MODULE_PARM_DESC(gpio_in_pin, "GPIO input pin number of the BCM processor."
833 +module_param(gpio_in_pull, int, S_IRUGO);
834 +MODULE_PARM_DESC(gpio_in_pull, "GPIO input pin pull configuration."
835 + " (0 = off, 1 = up, 2 = down, default down)");
837 +module_param(sense, int, S_IRUGO);
838 +MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit"
839 + " (0 = active high, 1 = active low )");
841 +module_param(softcarrier, bool, S_IRUGO);
842 +MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
844 +module_param(invert, bool, S_IRUGO);
845 +MODULE_PARM_DESC(invert, "Invert output (0 = off, 1 = on, default off");
847 +module_param(debug, bool, S_IRUGO | S_IWUSR);
848 +MODULE_PARM_DESC(debug, "Enable debugging messages");