/*
 * Driver for pwm demo on Firefly board.
 *
 * Copyright (C) 2016, Zhongshan T-chip Intelligent Technology Co.,ltd.
 * Copyright 2006  Tek.Leung
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/pwm.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include <dt-bindings/pwm/pwm.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/init.h>

#define SYS_DEV_CONFIG 1

static int gval = 0;
struct firefly_pwm_data {
	int pwm_id;
	struct pwm_device *pwm;
	unsigned int period;
	unsigned int pwm_period_ns;
	unsigned int duty_ns;
	bool enabled;
};
struct firefly_pwm_data g_firefly_pdata;

#ifdef SYS_DEV_CONFIG
static ssize_t firefly_pwm_store(struct device *dev,
				 struct device_attribute *attr, const char *buf,
				 size_t count)
{
	unsigned long state;
	int c, ret;
	ret = kstrtoul(buf, 10, &state);
	if (state > g_firefly_pdata.pwm_period_ns)
		state = g_firefly_pdata.pwm_period_ns;
	else if (state < 0)
		state = 0;
	c = state;
	if (ret)
		return ret;

	g_firefly_pdata.enabled = true;
	pwm_config(g_firefly_pdata.pwm, c, g_firefly_pdata.pwm_period_ns);
	pwm_enable(g_firefly_pdata.pwm);
	gval = c;

	return count;
}
static ssize_t firefly_pwm_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%u\n", gval);
}

static struct kobject *pwm_kobj;
static DEVICE_ATTR(firefly_pwm, (S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP),
		   firefly_pwm_show, firefly_pwm_store);
#endif

static int firefly_pwm_status_update(struct firefly_pwm_data *pdata)
{
	if (pdata->enabled)
		return 0;

	pwm_enable(pdata->pwm);
	pwm_config(pdata->pwm, pdata->duty_ns, g_firefly_pdata.pwm_period_ns);
	pdata->enabled = true;
	gval = pdata->duty_ns;
	return 0;
}
ssize_t firefly_pwm_parse_dt(struct firefly_pwm_data *firefly_pdata,
			     struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	const __be32 *duty_ns;
	int len;

	duty_ns = of_get_property(np, "duty_ns", &len);
	if (duty_ns)
		firefly_pdata->duty_ns = be32_to_cpu(*duty_ns);

	return 0;
}

static int firefly_pwm_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct firefly_pwm_data *firefly_pdata = pdev->dev.platform_data;
	int ret;
	struct pwm_args pargs;

	printk("firefly pwm probe start \n");
	if (!np) {
		dev_err(&pdev->dev, "Device Tree node missing\n");
		return -EINVAL;
	}

	firefly_pdata =
		devm_kzalloc(&pdev->dev, sizeof(*firefly_pdata), GFP_KERNEL);
	if (!firefly_pdata)
		return -ENOMEM;

	firefly_pdata->enabled = false;
	firefly_pdata->pwm = devm_pwm_get(&(pdev->dev), NULL);
	if (IS_ERR(firefly_pdata->pwm)) {
		dev_err(&pdev->dev, "unable to request legacy PWM\n");
		ret = PTR_ERR(firefly_pdata->pwm);
		goto err;
	}

	if (np)
		ret = firefly_pwm_parse_dt(firefly_pdata, pdev);

	pwm_get_args(firefly_pdata->pwm, &pargs);

	firefly_pdata->pwm_period_ns = pargs.period;
	printk("firefly pwm firefly_pdata->pwm_period_ns : %d \n",
	       firefly_pdata->pwm_period_ns);
	if (firefly_pdata->pwm_period_ns > 0)
		pwm_set_period(firefly_pdata->pwm,
			       firefly_pdata->pwm_period_ns);

	firefly_pdata->period = pwm_get_period(firefly_pdata->pwm);
	printk("firefly pwm firefly_pdata->period : %d \n",
	       firefly_pdata->period);

	g_firefly_pdata = *firefly_pdata;
	firefly_pwm_status_update(firefly_pdata);
	printk("%s: Firefly PWM Demo !\n", __func__);

#ifdef SYS_DEV_CONFIG
	pwm_kobj = kobject_create_and_add("pwm", NULL);
	if (pwm_kobj == NULL) {
		printk("create kobject fail \n");
		ret = -ENOMEM;
		goto err;
	}

	ret = sysfs_create_file(pwm_kobj, &dev_attr_firefly_pwm.attr);
	if (ret) {
		printk("pwm firefly_sysfs_init: sysfs_create_group failed\n");
		goto err;
	}
#endif
	return 0;
err:
#ifdef SYS_DEV_CONFIG
	kobject_del(pwm_kobj);
#endif
	devm_kfree(&pdev->dev, firefly_pdata);
	return ret;
}

static int firefly_pwm_remove(struct platform_device *pdev)
{
	struct firefly_pwm_data *firefly_pdata = pdev->dev.platform_data;
#ifdef SYS_DEV_CONFIG
	kobject_del(pwm_kobj);
#endif
	devm_kfree(&pdev->dev, firefly_pdata);
	return 0;
}

static const struct of_device_id firefly_pwm_dt_ids[] = {
	{ .compatible = "firefly,rk3588-pwm" },
	{}
};
MODULE_DEVICE_TABLE(of, firefly_pwm_dt_ids);

static struct platform_driver firefly_pwm_driver = {
	.driver = {
		.name = "firefly-pwm",
		.of_match_table = firefly_pwm_dt_ids,
	},
	.probe = firefly_pwm_probe,
	.remove = firefly_pwm_remove,
};
module_platform_driver(firefly_pwm_driver);
MODULE_AUTHOR("maocl <service@t-firefly.com>");
MODULE_DESCRIPTION("Firefly PWM driver");
MODULE_ALIAS("platform:firefly-pwm");
MODULE_LICENSE("GPL");