/*
 * drivers/media/rc/sunxi-gpio-ir.c
 *
 * Copyright (c) 2013-2018 Allwinnertech Co., Ltd.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <media/rc-core.h>
#include <linux/platform_data/media/sunxi-gpio-ir.h>
#include <linux/pwm.h>
#include <linux/sunxi-gpio.h>
#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/uaccess.h>
#include <linux/completion.h>

#define GPIO_IR_DRIVER_NAME	"sunxi-gpio-rc"
#define GPIO_IR_DEVICE_NAME	"sunxi_gpio_ir"

#define GPIO_IR_TIMEOUT	MS_TO_NS(12)
#define GPIO_IR_CARRIER_FREQ 38000 /*38K*/
#define GPIO_IR_DUTY_CYCLE 33      /*33.33%*/
#define GPIO_IR_PERIOD (int)(1000000000UL/GPIO_IR_CARRIER_FREQ)

#define TX_BUFF_LEN 512

struct gpio_rc_dev {
	struct rc_dev *rcdev;
	struct pwm_device *pwm;
	int gpio_rx_nr;
	int gpio_tx_nr;
	bool active_low;
	bool pwm_used;
	int	pwm_port;
	int tx_carrier_freq;
	int tx_duty_cycle;
	spinlock_t tx_lock;
	spinlock_t carr_lock;
	struct mutex pwm_lock;
	struct timer_list flush_timer;
	struct hrtimer tx_hrtimer;
	struct completion tx_completion;
	unsigned int tx_raw_buf[512];
	int raw_count;
	int tx_index;
};

static void ir_send_carrier(struct gpio_rc_dev *gpio_dev, int time_us)
{
	int i;
	unsigned long flags;
	unsigned long period_ns, on_ns, off_ns;
	unsigned long carrier_freq, carrier_num;
	unsigned long duty_cycle;

	carrier_freq = gpio_dev->tx_carrier_freq;
	duty_cycle = gpio_dev->tx_duty_cycle;

	period_ns = 1000000000UL / carrier_freq;

	on_ns = period_ns * duty_cycle / 100;
	off_ns = period_ns * (100 - duty_cycle) / 100;

	carrier_num = US_TO_NS(time_us) / period_ns;

	spin_lock_irqsave(&gpio_dev->carr_lock, flags);

	for (i = 0; i < carrier_num; i++) {
		gpio_set_value(gpio_dev->gpio_tx_nr, 1);
		ndelay(on_ns);
		gpio_set_value(gpio_dev->gpio_tx_nr, 0);
		ndelay(off_ns);
	}
	gpio_set_value(gpio_dev->gpio_tx_nr, 0);

	spin_unlock_irqrestore(&gpio_dev->carr_lock, flags);
}

#ifdef CONFIG_OF
/*
 * Translate OpenFirmware node properties into platform_data
 */
static int gpio_ir_get_devtree_pdata(struct device *dev,
				  struct gpio_ir_platform_data *pdata)
{
	struct device_node *np = dev->of_node;
	struct gpio_config config;
	u32 rx_protos_type[24];
	int num_type;
	int gpio;
	int pwm;
	int ret, i;

	/* probe() takes care of map_name == NULL or allowed_protos == 0 */
	pdata->map_name = of_get_property(np, "linux,rc-map-name", NULL);
	dev_dbg(dev, "rc-map-name: (%s)\n", pdata->map_name);

	num_type = of_property_count_u32_elems(np, "linux,ir-rx-protos");
	if (num_type > sizeof(rx_protos_type))
		num_type = sizeof(rx_protos_type);

	ret = of_property_read_u32_array(np, "linux,ir-rx-protos",
						 rx_protos_type,
						 num_type);
	if (ret) {
		dev_err(dev,
			"failed to read linux,ir-protos-type: %d\n", ret);
		pdata->allowed_protos = 0;
		return ret;
	}

	for (i = 0; i < num_type; i++)
		pdata->allowed_protos |= 1 << rx_protos_type[i];
	dev_dbg(dev, "allowed_protos: (0x%x)\n", (u32)pdata->allowed_protos);

	pdata->tx_capable = of_property_read_bool(np, "linux,tx-enable");
	pdata->pwm_tx_used = of_property_read_bool(np, "linux,tx-pwm-mode");
	if (pdata->pwm_tx_used) {
		ret = of_property_read_u32(np, "linux,pwm-port", &pwm);
		if (ret) {
			dev_err(dev,
				"failed to read linux,pwm-port: %d\n", ret);
			return ret;
		}
		pdata->pwm_port = pwm;
		dev_dbg(dev, "ir mode: pwm uesd, pwm port: (%d)\n", pwm);
	} else {
		gpio = of_get_named_gpio_flags(dev->of_node,
				"tran-gpio", 0,
				(enum of_gpio_flags *)&config);
		if (gpio < 0) {
			if (gpio != -EPROBE_DEFER)
				dev_err(dev,
				  "Failed to get gpio flags (%d)\n", gpio);
			return gpio;
		}
		pdata->gpio_tx_nr = gpio;
		dev_dbg(dev, "gpio tx num: (%d)\n", gpio);
	}

	gpio = of_get_named_gpio_flags(dev->of_node,
		"recv-gpio", 0,
		(enum of_gpio_flags *)&config);
	if (gpio < 0) {
		if (gpio != -EPROBE_DEFER)
			dev_err(dev, "Failed to get gpio flags (%d)\n", gpio);
		return gpio;
	}
	pdata->gpio_rx_nr = gpio;
	dev_dbg(dev, "gpio rx num: (%d)\n", gpio);

	return 0;
}

static const struct of_device_id gpio_ir_recv_of_match[] = {
	{ .compatible = "sunxi-gpio-ir", },
	{ },
};
MODULE_DEVICE_TABLE(of, gpio_ir_recv_of_match);

#else /* !CONFIG_OF */

#define gpio_ir_get_devtree_pdata(dev, pdata)	(-ENOSYS)

#endif

static enum hrtimer_restart tx_hrtimer_hander(struct hrtimer *timer)
{
	struct gpio_rc_dev *gpio_dev;
	DEFINE_IR_RAW_EVENT(ev);
	unsigned long period_ns, on_ns, off_ns;
	unsigned long carrier_freq;
	unsigned long duty_cycle;
	int j = 0;

	gpio_dev = container_of(timer, struct gpio_rc_dev, tx_hrtimer);
	if (!gpio_dev)
		return HRTIMER_RESTART;

	carrier_freq = gpio_dev->tx_carrier_freq;
	duty_cycle = gpio_dev->tx_duty_cycle;

	period_ns = 1000000000UL / carrier_freq;
	on_ns = period_ns * duty_cycle / 100;
	off_ns = period_ns * (100 - duty_cycle) / 100;

	if (gpio_dev->tx_index >= gpio_dev->raw_count) {
		complete(&gpio_dev->tx_completion);
		return HRTIMER_NORESTART;
	}

	j = gpio_dev->tx_index;
	ev.duration = *(gpio_dev->tx_raw_buf + j) & 0x00FFFFFF;
	/*the high byte is pulse/space flag*/
	ev.pulse = *(gpio_dev->tx_raw_buf + j) & 0xFF000000 ? true : false;
	if (ev.pulse) {
		/*carrier pluse*/
		pwm_config(gpio_dev->pwm, off_ns, period_ns);
	} else {
		pwm_config(gpio_dev->pwm, period_ns, period_ns);
	}

	/*restart next timer*/
	hrtimer_forward_now(&gpio_dev->tx_hrtimer,
		ktime_set(0, ev.duration * 1000));
	gpio_dev->tx_index++;

	return HRTIMER_RESTART;
}

static void tx_timer_start(struct rc_dev *rcdev)
{
	struct gpio_rc_dev *gpio_dev = rcdev->priv;

	hrtimer_init(&gpio_dev->tx_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	gpio_dev->tx_hrtimer.function = tx_hrtimer_hander;
	gpio_dev->tx_index = 0;
	hrtimer_start(&gpio_dev->tx_hrtimer,
		ktime_set(0, 1000*1000),
		HRTIMER_MODE_REL);
}

/* outside interface: transmit */
static int gpio_transmit_ir(struct rc_dev *rcdev, unsigned int *txbuf,
				unsigned int count)
{
	struct gpio_rc_dev *gpio_dev = rcdev->priv;

	int i = 0;
	unsigned long flags;
	DEFINE_IR_RAW_EVENT(ev);

	dev_dbg(&rcdev->dev, "IR tX: transmit %d raw data\n", count);
	/*gpio tx mode*/
	if (!gpio_dev->pwm_used) {
		spin_lock_irqsave(&gpio_dev->tx_lock, flags);

		for (i = 0; i < count; i++) {
			ev.duration = *(txbuf + i) & 0x00FFFFFF;
			/*the high byte is pulse/space flag*/
			ev.pulse = *(txbuf + i) & 0xFF000000 ? true : false;
			if (ev.pulse)
				/*carrier pluse*/
				ir_send_carrier(gpio_dev, ev.duration);
			else
				udelay(ev.duration);/*ir space*/
		}
		spin_unlock_irqrestore(&gpio_dev->tx_lock, flags);
	} else {
		mutex_lock(&gpio_dev->pwm_lock);
		memcpy(gpio_dev->tx_raw_buf,
			txbuf,
			count * sizeof(unsigned int));
		gpio_dev->raw_count = count;
		/*pwm enable*/
		pwm_config(gpio_dev->pwm, GPIO_IR_PERIOD, GPIO_IR_PERIOD);
		pwm_enable(gpio_dev->pwm);
		tx_timer_start(rcdev);

		/*wait for transmit completed*/
		wait_for_completion(&gpio_dev->tx_completion);
		dev_dbg(&rcdev->dev, "IR tX: pwm transmit one frame\n");

		hrtimer_cancel(&gpio_dev->tx_hrtimer);
		pwm_disable(gpio_dev->pwm);
		mutex_unlock(&gpio_dev->pwm_lock);
	}

	return count;
}

/* set the tx carrier freq, guess it's in Hz... */
static int gpio_set_tx_carrier(struct rc_dev *rcdev, u32 carrier)
{
	unsigned long flags;
	struct gpio_rc_dev *gpio_dev = rcdev->priv;

	dev_dbg(&rcdev->dev, "GPIO IR: carrier freq: %d\n", carrier);

	spin_lock_irqsave(&gpio_dev->tx_lock, flags);
	gpio_dev->tx_carrier_freq = carrier;
	spin_unlock_irqrestore(&gpio_dev->tx_lock, flags);

	return 0;
}

/* set the tx duty cycle by controlling the pulse width */
static int gpio_set_tx_duty_cycle(struct rc_dev *rcdev, u32 duty_cycle)
{
	unsigned long flags;
	struct gpio_rc_dev *gpio_dev = rcdev->priv;

	dev_dbg(&rcdev->dev, "GPIO IR: duty cycle: %d\n", duty_cycle);

	spin_lock_irqsave(&gpio_dev->tx_lock, flags);
	gpio_dev->tx_duty_cycle = duty_cycle;
	spin_unlock_irqrestore(&gpio_dev->tx_lock, flags);

	return 0;
}

static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
{
	struct gpio_rc_dev *gpio_dev = dev_id;
	int gval;
	int rc = 0;
	enum raw_event_type type = IR_SPACE;

	gval = gpio_get_value(gpio_dev->gpio_rx_nr);

	if (gval < 0)
		goto err_get_value;

	if (gpio_dev->active_low)
		gval = !gval;

	if (gval == 1)
		type = IR_PULSE;

	rc = ir_raw_event_store_edge(gpio_dev->rcdev, type);
	if (rc < 0)
		goto err_get_value;

	mod_timer(&gpio_dev->flush_timer,
		  jiffies + nsecs_to_jiffies(gpio_dev->rcdev->timeout));

	ir_raw_event_handle(gpio_dev->rcdev);

err_get_value:
	return IRQ_HANDLED;
}

static void flush_timer(unsigned long arg)
{
	struct gpio_rc_dev *gpio_dev = (struct gpio_rc_dev *)arg;
	DEFINE_IR_RAW_EVENT(ev);

	ev.timeout = true;
	ev.duration = gpio_dev->rcdev->timeout;
	ir_raw_event_store(gpio_dev->rcdev, &ev);
	ir_raw_event_handle(gpio_dev->rcdev);
}

static int gpio_ir_recv_probe(struct platform_device *pdev)
{
	struct gpio_rc_dev *gpio_dev;
	struct rc_dev *rcdev;
	struct gpio_ir_platform_data *pdata =
					pdev->dev.platform_data;
	int rc;

	if (pdev->dev.of_node) {
		struct gpio_ir_platform_data *dtpdata =
			devm_kzalloc(&pdev->dev, sizeof(*dtpdata), GFP_KERNEL);
		if (!dtpdata)
			return -ENOMEM;

		rc = gpio_ir_get_devtree_pdata(&pdev->dev, dtpdata);
		if (rc)
			return rc;
		pdata = dtpdata;
	}

	if (!pdata)
		return -EINVAL;

	if (pdata->gpio_rx_nr < 0)
		return -EINVAL;

	gpio_dev = kzalloc(sizeof(struct gpio_rc_dev), GFP_KERNEL);
	if (!gpio_dev)
		return -ENOMEM;

	rcdev = rc_allocate_device();
	if (!rcdev) {
		rc = -ENOMEM;
		goto err_allocate_device;
	}

	rcdev->priv = gpio_dev;
	rcdev->driver_type = RC_DRIVER_IR_RAW;
	rcdev->input_name = GPIO_IR_DEVICE_NAME;
	rcdev->input_phys = GPIO_IR_DEVICE_NAME "/input0";
	rcdev->input_id.bustype = BUS_HOST;
	rcdev->input_id.vendor = 0x0001;
	rcdev->input_id.product = 0x0001;
	rcdev->input_id.version = 0x0100;
	rcdev->dev.parent = &pdev->dev;
	rcdev->driver_name = GPIO_IR_DRIVER_NAME;
	rcdev->min_timeout = 0;
	rcdev->timeout = GPIO_IR_TIMEOUT;
	rcdev->max_timeout = 10 * GPIO_IR_TIMEOUT;
	if (pdata->allowed_protos)
		rcdev->allowed_protocols = pdata->allowed_protos;
	else
		rcdev->allowed_protocols = RC_BIT_ALL;
	rcdev->map_name = pdata->map_name ?: RC_MAP_EMPTY;

	/* set up transmitter related values if needed */
	if (pdata->tx_capable) {
		rcdev->tx_ir = gpio_transmit_ir;
		rcdev->s_tx_carrier = gpio_set_tx_carrier;
		rcdev->s_tx_duty_cycle = gpio_set_tx_duty_cycle;
	}

	setup_timer(&gpio_dev->flush_timer, flush_timer,
		    (unsigned long)gpio_dev);

	rc = gpio_request(pdata->gpio_rx_nr, "gpio-ir-recv");
	if (rc < 0)
		goto err_gpio_request;

	rc	= gpio_direction_input(pdata->gpio_rx_nr);
	if (rc < 0)
		goto err_gpio_direction_input;

	/*the pulse always reversed*/
	pdata->active_low = gpio_get_value(pdata->gpio_rx_nr);

	if (!pdata->pwm_tx_used) {
		rc = gpio_request(pdata->gpio_tx_nr, "gpio-ir-trans");
		if (rc < 0)
			goto err_gpio_direction_input;

		rc  = gpio_direction_output(pdata->gpio_tx_nr, 0);
		if (rc < 0)
			goto err_gpio_direction_output;

		gpio_dev->gpio_tx_nr = pdata->gpio_tx_nr;
	} else {
		gpio_dev->pwm_used = pdata->pwm_tx_used;
		gpio_dev->pwm_port = pdata->pwm_port;
	}

	gpio_dev->rcdev = rcdev;
	gpio_dev->gpio_rx_nr = pdata->gpio_rx_nr;
	gpio_dev->active_low = pdata->active_low;
	gpio_dev->tx_carrier_freq = GPIO_IR_CARRIER_FREQ;
	gpio_dev->tx_duty_cycle = GPIO_IR_DUTY_CYCLE;

	/* initialize spinlocks */
	spin_lock_init(&gpio_dev->tx_lock);
	spin_lock_init(&gpio_dev->carr_lock);
	init_completion(&gpio_dev->tx_completion);
	mutex_init(&gpio_dev->pwm_lock);

	rc = rc_register_device(rcdev);
	if (rc < 0) {
		dev_err(&pdev->dev, "failed to register rc device\n");
		goto err_register_rc_device;
	}

	platform_set_drvdata(pdev, gpio_dev);

	rc = request_any_context_irq(gpio_to_irq(pdata->gpio_rx_nr),
			gpio_ir_recv_irq,
			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
			"gpio-ir-recv-irq", gpio_dev);
	if (rc < 0)
		goto err_request_irq;

	if (pdata->pwm_tx_used) {
		gpio_dev->pwm = pwm_request(gpio_dev->pwm_port, "ir tx");
		if (IS_ERR(gpio_dev->pwm)) {
			dev_err(&pdev->dev, "Unable to request PWM for ir dev!\n");
				goto err_request_pwm;
		}
	}

	dev_info(&pdev->dev, "gpio ir probe succeed\n");
	return 0;

err_request_pwm:
	free_irq(gpio_to_irq(gpio_dev->gpio_rx_nr), gpio_dev);
err_request_irq:
	rc_unregister_device(rcdev);
err_register_rc_device:
err_gpio_direction_output:
	gpio_free(pdata->gpio_tx_nr);
err_gpio_direction_input:
	gpio_free(pdata->gpio_rx_nr);
err_gpio_request:
	rc_free_device(rcdev);
err_allocate_device:
	kfree(gpio_dev);
	return rc;
}

static int gpio_ir_recv_remove(struct platform_device *pdev)
{
	struct gpio_rc_dev *gpio_dev = platform_get_drvdata(pdev);

	free_irq(gpio_to_irq(gpio_dev->gpio_rx_nr), gpio_dev);
	del_timer_sync(&gpio_dev->flush_timer);
	rc_unregister_device(gpio_dev->rcdev);
	gpio_free(gpio_dev->gpio_rx_nr);
	pwm_free(gpio_dev->pwm);
	kfree(gpio_dev);

	return 0;
}

#ifdef CONFIG_PM
static int gpio_ir_recv_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct gpio_rc_dev *gpio_dev = platform_get_drvdata(pdev);

	if (device_may_wakeup(dev))
		enable_irq_wake(gpio_to_irq(gpio_dev->gpio_rx_nr));
	else
		disable_irq(gpio_to_irq(gpio_dev->gpio_rx_nr));

	return 0;
}

static int gpio_ir_recv_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct gpio_rc_dev *gpio_dev = platform_get_drvdata(pdev);

	if (device_may_wakeup(dev))
		disable_irq_wake(gpio_to_irq(gpio_dev->gpio_rx_nr));
	else
		enable_irq(gpio_to_irq(gpio_dev->gpio_rx_nr));

	return 0;
}

static const struct dev_pm_ops gpio_ir_recv_pm_ops = {
	.suspend        = gpio_ir_recv_suspend,
	.resume         = gpio_ir_recv_resume,
};
#endif

static struct platform_driver gpio_ir_recv_driver = {
	.probe  = gpio_ir_recv_probe,
	.remove = gpio_ir_recv_remove,
	.driver = {
		.name   = GPIO_IR_DRIVER_NAME,
		.owner	= THIS_MODULE,
		.of_match_table = gpio_ir_recv_of_match,
#ifdef CONFIG_PM
		.pm	= &gpio_ir_recv_pm_ops,
#endif
	},
};
module_platform_driver(gpio_ir_recv_driver);

MODULE_DESCRIPTION("GPIO IR Receiver driver");
MODULE_AUTHOR("xudong@allwinnertech.com");
MODULE_LICENSE("GPL v2");