/* linux/drivers/media/video/samsung/tvout/s5p_cec_ctrl.c
 *
 * Copyright (c) 2009 Samsung Electronics
 *		http://www.samsung.com/
 *
 * cec interface file for Samsung TVOut driver
 *
 * 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/slab.h>
#include <linux/uaccess.h>
#include <linux/poll.h>
#include <linux/miscdevice.h>
#include <linux/clk.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <plat/tvout.h>

#include "cec.h"

#define CEC_IOC_MAGIC        'c'
#define CEC_IOC_SETLADDR     _IOW(CEC_IOC_MAGIC, 0, unsigned int)

#define VERSION   "1.0" /* Driver version number */
#define CEC_MINOR 243	/* Major 10, Minor 242, /dev/cec */


#define CEC_STATUS_TX_RUNNING       (1<<0)
#define CEC_STATUS_TX_TRANSFERRING  (1<<1)
#define CEC_STATUS_TX_DONE          (1<<2)
#define CEC_STATUS_TX_ERROR         (1<<3)
#define CEC_STATUS_TX_BYTES         (0xFF<<8)
#define CEC_STATUS_RX_RUNNING       (1<<16)
#define CEC_STATUS_RX_RECEIVING     (1<<17)
#define CEC_STATUS_RX_DONE          (1<<18)
#define CEC_STATUS_RX_ERROR         (1<<19)
#define CEC_STATUS_RX_BCAST         (1<<20)
#define CEC_STATUS_RX_BYTES         (0xFF<<24)


/* CEC Rx buffer size */
#define CEC_RX_BUFF_SIZE            16
/* CEC Tx buffer size */
#define CEC_TX_BUFF_SIZE            16

#define TV_CLK_GET_WITH_ERR_CHECK(clk, pdev, clk_name)			\
		do {							\
			clk = clk_get(&pdev->dev, clk_name);		\
			if (IS_ERR(clk)) {				\
				printk(KERN_ERR				\
				"failed to find clock %s\n", clk_name);	\
				return -ENOENT;				\
			}						\
		} while (0);

static atomic_t hdmi_on = ATOMIC_INIT(0);
static DEFINE_MUTEX(cec_lock);
struct clk *hdmi_cec_clk;

static int s5p_cec_open(struct inode *inode, struct file *file)
{
	int ret = 0;

	mutex_lock(&cec_lock);
	clk_enable(hdmi_cec_clk);

	if (atomic_read(&hdmi_on)) {
		tvout_dbg("do not allow multiple open for tvout cec\n");
		ret = -EBUSY;
		goto err_multi_open;
	} else
		atomic_inc(&hdmi_on);

	s5p_cec_reset();

	s5p_cec_set_divider();

	s5p_cec_threshold();

	s5p_cec_unmask_tx_interrupts();

	s5p_cec_set_rx_state(STATE_RX);
	s5p_cec_unmask_rx_interrupts();
	s5p_cec_enable_rx();

err_multi_open:
	mutex_unlock(&cec_lock);

	return ret;
}

static int s5p_cec_release(struct inode *inode, struct file *file)
{
	atomic_dec(&hdmi_on);

	s5p_cec_mask_tx_interrupts();
	s5p_cec_mask_rx_interrupts();

	clk_disable(hdmi_cec_clk);
	clk_put(hdmi_cec_clk);

	return 0;
}

static ssize_t s5p_cec_read(struct file *file, char __user *buffer,
			size_t count, loff_t *ppos)
{
	ssize_t retval;
	unsigned long spin_flags;

	if (wait_event_interruptible(cec_rx_struct.waitq,
			atomic_read(&cec_rx_struct.state) == STATE_DONE)) {
		return -ERESTARTSYS;
	}
	spin_lock_irqsave(&cec_rx_struct.lock, spin_flags);

	if (cec_rx_struct.size > count) {
		spin_unlock_irqrestore(&cec_rx_struct.lock, spin_flags);

		return -1;
	}

	if (copy_to_user(buffer, cec_rx_struct.buffer, cec_rx_struct.size)) {
		spin_unlock_irqrestore(&cec_rx_struct.lock, spin_flags);
		printk(KERN_ERR " copy_to_user() failed!\n");

		return -EFAULT;
	}

	retval = cec_rx_struct.size;

	s5p_cec_set_rx_state(STATE_RX);
	spin_unlock_irqrestore(&cec_rx_struct.lock, spin_flags);

	return retval;
}

static ssize_t s5p_cec_write(struct file *file, const char __user *buffer,
			size_t count, loff_t *ppos)
{
	char *data;

	/* check data size */

	if (count > CEC_TX_BUFF_SIZE || count == 0)
		return -1;

	data = kmalloc(count, GFP_KERNEL);

	if (!data) {
		printk(KERN_ERR " kmalloc() failed!\n");

		return -1;
	}

	if (copy_from_user(data, buffer, count)) {
		printk(KERN_ERR " copy_from_user() failed!\n");
		kfree(data);

		return -EFAULT;
	}

	s5p_cec_copy_packet(data, count);

	kfree(data);

	/* wait for interrupt */
	if (wait_event_interruptible(cec_tx_struct.waitq,
		atomic_read(&cec_tx_struct.state)
		!= STATE_TX)) {

		return -ERESTARTSYS;
	}

	if (atomic_read(&cec_tx_struct.state) == STATE_ERROR)
		return -1;

	return count;
}

#if 0
static int s5p_cec_ioctl(struct inode *inode, struct file *file, u32 cmd,
			unsigned long arg)
#else
static long s5p_cec_ioctl(struct file *file, unsigned int cmd,
						unsigned long arg)
#endif
{
	u32 laddr;

	switch (cmd) {
	case CEC_IOC_SETLADDR:
		if (get_user(laddr, (u32 __user *) arg))
			return -EFAULT;

		tvout_dbg("logical address = 0x%02x\n", laddr);

		s5p_cec_set_addr(laddr);
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static u32 s5p_cec_poll(struct file *file, poll_table *wait)
{
	poll_wait(file, &cec_rx_struct.waitq, wait);

	if (atomic_read(&cec_rx_struct.state) == STATE_DONE)
		return POLLIN | POLLRDNORM;

	return 0;
}

static const struct file_operations cec_fops = {
	.owner   = THIS_MODULE,
	.open    = s5p_cec_open,
	.release = s5p_cec_release,
	.read    = s5p_cec_read,
	.write   = s5p_cec_write,
#if 1
	.unlocked_ioctl = s5p_cec_ioctl,
#else
	.ioctl   = s5p_cec_ioctl,
#endif
	.poll    = s5p_cec_poll,
};

static struct miscdevice cec_misc_device = {
	.minor = CEC_MINOR,
	.name  = "CEC",
	.fops  = &cec_fops,
};

static irqreturn_t s5p_cec_irq_handler(int irq, void *dev_id)
{

	u32 status = 0;

	status = s5p_cec_get_status();

	if (status & CEC_STATUS_TX_DONE) {
		if (status & CEC_STATUS_TX_ERROR) {
			tvout_dbg(" CEC_STATUS_TX_ERROR!\n");
			s5p_cec_set_tx_state(STATE_ERROR);
		} else {
			tvout_dbg(" CEC_STATUS_TX_DONE!\n");
			s5p_cec_set_tx_state(STATE_DONE);
		}

		s5p_clr_pending_tx();

		wake_up_interruptible(&cec_tx_struct.waitq);
	}

	if (status & CEC_STATUS_RX_DONE) {
		if (status & CEC_STATUS_RX_ERROR) {
			tvout_dbg(" CEC_STATUS_RX_ERROR!\n");
			s5p_cec_rx_reset();

		} else {
			u32 size;

			tvout_dbg(" CEC_STATUS_RX_DONE!\n");

			/* copy data from internal buffer */
			size = status >> 24;

			spin_lock(&cec_rx_struct.lock);

			s5p_cec_get_rx_buf(size, cec_rx_struct.buffer);

			cec_rx_struct.size = size;

			s5p_cec_set_rx_state(STATE_DONE);

			spin_unlock(&cec_rx_struct.lock);

			s5p_cec_enable_rx();
		}

		/* clear interrupt pending bit */
		s5p_clr_pending_rx();

		wake_up_interruptible(&cec_rx_struct.waitq);
	}

	return IRQ_HANDLED;
}

static int __devinit s5p_cec_probe(struct platform_device *pdev)
{
	struct s5p_platform_cec *pdata;
	u8 *buffer;
	int ret;
	struct resource *res;

	pdata = to_tvout_plat(&pdev->dev);

	if (pdata->cfg_gpio)
		pdata->cfg_gpio(pdev);


	s5p_cec_mem_probe(pdev);

	if (misc_register(&cec_misc_device)) {
		printk(KERN_WARNING " Couldn't register device 10, %d.\n",
			CEC_MINOR);

		return -EBUSY;
	}

#if 0
	irq_num = platform_get_irq(pdev, 0);

	if (irq_num < 0) {
		printk(KERN_ERR  "failed to get %s irq resource\n", "cec");
		ret = -ENOENT;

		return ret;
	}
#endif

	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "failed to get irq resource.\n");
		ret = -ENOENT;
		return ret;
	}

	ret = request_irq(res->start, s5p_cec_irq_handler, IRQF_DISABLED,
		pdev->name, &pdev->id);

	if (ret != 0) {
		printk(KERN_ERR  "failed to install %s irq (%d)\n", "cec", ret);

		return ret;
	}

	init_waitqueue_head(&cec_rx_struct.waitq);
	spin_lock_init(&cec_rx_struct.lock);
	init_waitqueue_head(&cec_tx_struct.waitq);

	buffer = kmalloc(CEC_TX_BUFF_SIZE, GFP_KERNEL);

	if (!buffer) {
		printk(KERN_ERR " kmalloc() failed!\n");
		misc_deregister(&cec_misc_device);

		return -EIO;
	}

	cec_rx_struct.buffer = buffer;

	cec_rx_struct.size   = 0;
	TV_CLK_GET_WITH_ERR_CHECK(hdmi_cec_clk, pdev, "sclk_cec");

	dev_info(&pdev->dev, "probe successful\n");

	return 0;
}

static int __devexit s5p_cec_remove(struct platform_device *pdev)
{
	return 0;
}

#ifdef CONFIG_PM
static int s5p_cec_suspend(struct platform_device *dev, pm_message_t state)
{
	return 0;
}

static int s5p_cec_resume(struct platform_device *dev)
{
	return 0;
}
#else
#define s5p_cec_suspend NULL
#define s5p_cec_resume NULL
#endif

static struct platform_driver s5p_cec_driver = {
	.probe		= s5p_cec_probe,
	.remove		= __devexit_p(s5p_cec_remove),
	.suspend	= s5p_cec_suspend,
	.resume		= s5p_cec_resume,
	.driver		= {
		.name	= "s5p-tvout-cec",
		.owner	= THIS_MODULE,
	},
};

static char banner[] __initdata =
	"S5P CEC for Exynos4 Driver, (c) 2009 Samsung Electronics\n";

static int __init s5p_cec_init(void)
{
	int ret;

	printk(banner);

	ret = platform_driver_register(&s5p_cec_driver);

	if (ret) {
		printk(KERN_ERR "Platform Device Register Failed %d\n", ret);

		return -1;
	}

	return 0;
}

static void __exit s5p_cec_exit(void)
{
	kfree(cec_rx_struct.buffer);

	platform_driver_unregister(&s5p_cec_driver);
}

module_init(s5p_cec_init);
module_exit(s5p_cec_exit);

MODULE_AUTHOR("SangPil Moon");
MODULE_DESCRIPTION("S5P CEC driver");
MODULE_LICENSE("GPL");