139 lines
3.1 KiB
C
139 lines
3.1 KiB
C
/*
|
|
* Copyright (C) 2017 Sean Young <sean@mess.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2, 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/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <media/rc-core.h>
|
|
|
|
#define DRIVER_NAME "pwm-ir-tx"
|
|
#define DEVICE_NAME "PWM IR Transmitter"
|
|
|
|
struct pwm_ir {
|
|
struct pwm_device *pwm;
|
|
unsigned int carrier;
|
|
unsigned int duty_cycle;
|
|
};
|
|
|
|
static const struct of_device_id pwm_ir_of_match[] = {
|
|
{ .compatible = "pwm-ir-tx", },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pwm_ir_of_match);
|
|
|
|
static int pwm_ir_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
|
|
{
|
|
struct pwm_ir *pwm_ir = dev->priv;
|
|
|
|
pwm_ir->duty_cycle = duty_cycle;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pwm_ir_set_carrier(struct rc_dev *dev, u32 carrier)
|
|
{
|
|
struct pwm_ir *pwm_ir = dev->priv;
|
|
|
|
if (!carrier)
|
|
return -EINVAL;
|
|
|
|
pwm_ir->carrier = carrier;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
|
|
unsigned int count)
|
|
{
|
|
struct pwm_ir *pwm_ir = dev->priv;
|
|
struct pwm_device *pwm = pwm_ir->pwm;
|
|
int i, duty, period;
|
|
ktime_t edge;
|
|
long delta;
|
|
|
|
period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier);
|
|
duty = DIV_ROUND_CLOSEST(pwm_ir->duty_cycle * period, 100);
|
|
|
|
pwm_config(pwm, duty, period);
|
|
|
|
edge = ktime_get();
|
|
|
|
for (i = 0; i < count; i++) {
|
|
if (i % 2) // space
|
|
pwm_disable(pwm);
|
|
else
|
|
pwm_enable(pwm);
|
|
|
|
edge = ktime_add_us(edge, txbuf[i]);
|
|
delta = ktime_us_delta(edge, ktime_get());
|
|
if (delta > 0)
|
|
usleep_range(delta, delta + 10);
|
|
}
|
|
|
|
pwm_disable(pwm);
|
|
|
|
return count;
|
|
}
|
|
|
|
static int pwm_ir_probe(struct platform_device *pdev)
|
|
{
|
|
struct pwm_ir *pwm_ir;
|
|
struct rc_dev *rcdev;
|
|
int rc;
|
|
|
|
pwm_ir = devm_kmalloc(&pdev->dev, sizeof(*pwm_ir), GFP_KERNEL);
|
|
if (!pwm_ir)
|
|
return -ENOMEM;
|
|
|
|
pwm_ir->pwm = devm_pwm_get(&pdev->dev, NULL);
|
|
if (IS_ERR(pwm_ir->pwm))
|
|
return PTR_ERR(pwm_ir->pwm);
|
|
|
|
pwm_ir->carrier = 38000;
|
|
pwm_ir->duty_cycle = 50;
|
|
|
|
rcdev = devm_rc_allocate_device(&pdev->dev, RC_DRIVER_IR_RAW_TX);
|
|
if (!rcdev)
|
|
return -ENOMEM;
|
|
|
|
rcdev->priv = pwm_ir;
|
|
rcdev->driver_name = DRIVER_NAME;
|
|
rcdev->device_name = DEVICE_NAME;
|
|
rcdev->tx_ir = pwm_ir_tx;
|
|
rcdev->s_tx_duty_cycle = pwm_ir_set_duty_cycle;
|
|
rcdev->s_tx_carrier = pwm_ir_set_carrier;
|
|
|
|
rc = devm_rc_register_device(&pdev->dev, rcdev);
|
|
if (rc < 0)
|
|
dev_err(&pdev->dev, "failed to register rc device\n");
|
|
|
|
return rc;
|
|
}
|
|
|
|
static struct platform_driver pwm_ir_driver = {
|
|
.probe = pwm_ir_probe,
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.of_match_table = of_match_ptr(pwm_ir_of_match),
|
|
},
|
|
};
|
|
module_platform_driver(pwm_ir_driver);
|
|
|
|
MODULE_DESCRIPTION("PWM IR Transmitter");
|
|
MODULE_AUTHOR("Sean Young <sean@mess.org>");
|
|
MODULE_LICENSE("GPL");
|