diff options
Diffstat (limited to 'drivers/media/rc/ir-rx51.c')
-rw-r--r-- | drivers/media/rc/ir-rx51.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-rx51.c b/drivers/media/rc/ir-rx51.c new file mode 100644 index 000000000..8a93f7468 --- /dev/null +++ b/drivers/media/rc/ir-rx51.c @@ -0,0 +1,305 @@ +/* + * Copyright (C) 2008 Nokia Corporation + * + * Based on lirc_serial.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/wait.h> +#include <linux/pwm.h> +#include <linux/of.h> +#include <linux/hrtimer.h> + +#include <media/rc-core.h> + +#define WBUF_LEN 256 + +struct ir_rx51 { + struct rc_dev *rcdev; + struct pwm_device *pwm; + struct hrtimer timer; + struct device *dev; + wait_queue_head_t wqueue; + + unsigned int freq; /* carrier frequency */ + unsigned int duty_cycle; /* carrier duty cycle */ + int wbuf[WBUF_LEN]; + int wbuf_index; + unsigned long device_is_open; +}; + +static inline void ir_rx51_on(struct ir_rx51 *ir_rx51) +{ + pwm_enable(ir_rx51->pwm); +} + +static inline void ir_rx51_off(struct ir_rx51 *ir_rx51) +{ + pwm_disable(ir_rx51->pwm); +} + +static int init_timing_params(struct ir_rx51 *ir_rx51) +{ + struct pwm_device *pwm = ir_rx51->pwm; + int duty, period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, ir_rx51->freq); + + duty = DIV_ROUND_CLOSEST(ir_rx51->duty_cycle * period, 100); + + pwm_config(pwm, duty, period); + + return 0; +} + +static enum hrtimer_restart ir_rx51_timer_cb(struct hrtimer *timer) +{ + struct ir_rx51 *ir_rx51 = container_of(timer, struct ir_rx51, timer); + ktime_t now; + + if (ir_rx51->wbuf_index < 0) { + dev_err_ratelimited(ir_rx51->dev, + "BUG wbuf_index has value of %i\n", + ir_rx51->wbuf_index); + goto end; + } + + /* + * If we happen to hit an odd latency spike, loop through the + * pulses until we catch up. + */ + do { + u64 ns; + + if (ir_rx51->wbuf_index >= WBUF_LEN) + goto end; + if (ir_rx51->wbuf[ir_rx51->wbuf_index] == -1) + goto end; + + if (ir_rx51->wbuf_index % 2) + ir_rx51_off(ir_rx51); + else + ir_rx51_on(ir_rx51); + + ns = US_TO_NS(ir_rx51->wbuf[ir_rx51->wbuf_index]); + hrtimer_add_expires_ns(timer, ns); + + ir_rx51->wbuf_index++; + + now = timer->base->get_time(); + + } while (hrtimer_get_expires_tv64(timer) < now); + + return HRTIMER_RESTART; +end: + /* Stop TX here */ + ir_rx51_off(ir_rx51); + ir_rx51->wbuf_index = -1; + + wake_up_interruptible(&ir_rx51->wqueue); + + return HRTIMER_NORESTART; +} + +static int ir_rx51_tx(struct rc_dev *dev, unsigned int *buffer, + unsigned int count) +{ + struct ir_rx51 *ir_rx51 = dev->priv; + + if (count > WBUF_LEN) + return -EINVAL; + + memcpy(ir_rx51->wbuf, buffer, count * sizeof(unsigned int)); + + /* Wait any pending transfers to finish */ + wait_event_interruptible(ir_rx51->wqueue, ir_rx51->wbuf_index < 0); + + init_timing_params(ir_rx51); + if (count < WBUF_LEN) + ir_rx51->wbuf[count] = -1; /* Insert termination mark */ + + /* + * REVISIT: Adjust latency requirements so the device doesn't go in too + * deep sleep states with pm_qos_add_request(). + */ + + ir_rx51_on(ir_rx51); + ir_rx51->wbuf_index = 1; + hrtimer_start(&ir_rx51->timer, + ns_to_ktime(US_TO_NS(ir_rx51->wbuf[0])), + HRTIMER_MODE_REL); + /* + * Don't return back to the userspace until the transfer has + * finished + */ + wait_event_interruptible(ir_rx51->wqueue, ir_rx51->wbuf_index < 0); + + /* REVISIT: Remove pm_qos constraint, we can sleep again */ + + return count; +} + +static int ir_rx51_open(struct rc_dev *dev) +{ + struct ir_rx51 *ir_rx51 = dev->priv; + + if (test_and_set_bit(1, &ir_rx51->device_is_open)) + return -EBUSY; + + ir_rx51->pwm = pwm_get(ir_rx51->dev, NULL); + if (IS_ERR(ir_rx51->pwm)) { + int res = PTR_ERR(ir_rx51->pwm); + + dev_err(ir_rx51->dev, "pwm_get failed: %d\n", res); + return res; + } + + return 0; +} + +static void ir_rx51_release(struct rc_dev *dev) +{ + struct ir_rx51 *ir_rx51 = dev->priv; + + hrtimer_cancel(&ir_rx51->timer); + ir_rx51_off(ir_rx51); + pwm_put(ir_rx51->pwm); + + clear_bit(1, &ir_rx51->device_is_open); +} + +static struct ir_rx51 ir_rx51 = { + .duty_cycle = 50, + .wbuf_index = -1, +}; + +static int ir_rx51_set_duty_cycle(struct rc_dev *dev, u32 duty) +{ + struct ir_rx51 *ir_rx51 = dev->priv; + + ir_rx51->duty_cycle = duty; + + return 0; +} + +static int ir_rx51_set_tx_carrier(struct rc_dev *dev, u32 carrier) +{ + struct ir_rx51 *ir_rx51 = dev->priv; + + if (carrier > 500000 || carrier < 20000) + return -EINVAL; + + ir_rx51->freq = carrier; + + return 0; +} + +#ifdef CONFIG_PM + +static int ir_rx51_suspend(struct platform_device *dev, pm_message_t state) +{ + /* + * In case the device is still open, do not suspend. Normally + * this should not be a problem as lircd only keeps the device + * open only for short periods of time. We also don't want to + * get involved with race conditions that might happen if we + * were in a middle of a transmit. Thus, we defer any suspend + * actions until transmit has completed. + */ + if (test_and_set_bit(1, &ir_rx51.device_is_open)) + return -EAGAIN; + + clear_bit(1, &ir_rx51.device_is_open); + + return 0; +} + +static int ir_rx51_resume(struct platform_device *dev) +{ + return 0; +} + +#else + +#define ir_rx51_suspend NULL +#define ir_rx51_resume NULL + +#endif /* CONFIG_PM */ + +static int ir_rx51_probe(struct platform_device *dev) +{ + struct pwm_device *pwm; + struct rc_dev *rcdev; + + pwm = pwm_get(&dev->dev, NULL); + if (IS_ERR(pwm)) { + int err = PTR_ERR(pwm); + + if (err != -EPROBE_DEFER) + dev_err(&dev->dev, "pwm_get failed: %d\n", err); + return err; + } + + /* Use default, in case userspace does not set the carrier */ + ir_rx51.freq = DIV_ROUND_CLOSEST(pwm_get_period(pwm), NSEC_PER_SEC); + pwm_put(pwm); + + hrtimer_init(&ir_rx51.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + ir_rx51.timer.function = ir_rx51_timer_cb; + + ir_rx51.dev = &dev->dev; + + rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW_TX); + if (!rcdev) + return -ENOMEM; + + rcdev->priv = &ir_rx51; + rcdev->open = ir_rx51_open; + rcdev->close = ir_rx51_release; + rcdev->tx_ir = ir_rx51_tx; + rcdev->s_tx_duty_cycle = ir_rx51_set_duty_cycle; + rcdev->s_tx_carrier = ir_rx51_set_tx_carrier; + rcdev->driver_name = KBUILD_MODNAME; + + ir_rx51.rcdev = rcdev; + + return devm_rc_register_device(&dev->dev, ir_rx51.rcdev); +} + +static int ir_rx51_remove(struct platform_device *dev) +{ + return 0; +} + +static const struct of_device_id ir_rx51_match[] = { + { + .compatible = "nokia,n900-ir", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, ir_rx51_match); + +static struct platform_driver ir_rx51_platform_driver = { + .probe = ir_rx51_probe, + .remove = ir_rx51_remove, + .suspend = ir_rx51_suspend, + .resume = ir_rx51_resume, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = of_match_ptr(ir_rx51_match), + }, +}; +module_platform_driver(ir_rx51_platform_driver); + +MODULE_DESCRIPTION("IR TX driver for Nokia RX51"); +MODULE_AUTHOR("Nokia Corporation"); +MODULE_LICENSE("GPL"); |