linux-imx

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright (C) 2017 Sean Young <sean@mess.org>

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/gpio/consumer.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 "gpio-ir-tx"

#define DEVICE_NAME "GPIO IR Bit Banging Transmitter"

​

struct gpio_ir {

    struct gpio_desc *gpio;

    unsigned int carrier;

    unsigned int duty_cycle;

    /* we need a spinlock to hold the cpu while transmitting */

    spinlock_t lock;

};

​

static const struct of_device_id gpio_ir_tx_of_match[] = {

    { .compatible = "gpio-ir-tx", },

    { },

};

MODULE_DEVICE_TABLE(of, gpio_ir_tx_of_match);

​

static int gpio_ir_tx_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle)

{

    struct gpio_ir *gpio_ir = dev->priv;

​

    gpio_ir->duty_cycle = duty_cycle;

​

    return 0;

}

​

static int gpio_ir_tx_set_carrier(struct rc_dev *dev, u32 carrier)

{

    struct gpio_ir *gpio_ir = dev->priv;

​

    if (!carrier)

        return -EINVAL;

​

    gpio_ir->carrier = carrier;

​

    return 0;

}

​

static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf,

              unsigned int count)

{

    struct gpio_ir *gpio_ir = dev->priv;

    unsigned long flags;

    ktime_t edge;

    /*

     * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on

     * m68k ndelay(s64) does not compile; so use s32 rather than s64.

     */

    s32 delta;