/*++
 * linux/drivers/video/wmt/dev-cec.c
 * WonderMedia video post processor (VPP) driver
 *
 * Copyright c 2013  WonderMedia  Technologies, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * WonderMedia Technologies, Inc.
 * 4F, 533, Chung-Cheng Road, Hsin-Tien, Taipei 231, R.O.C
--*/

#define DEV_CEC_C

/* #define DEBUG */
#include <linux/platform_device.h>
#include <linux/major.h>
#include <linux/cdev.h>
#include <linux/netlink.h>
#include <net/sock.h>
#include "cec.h"
#include "vpp.h"

#define DRIVER_NAME "wmt-cec"

#define TXNORSP	0x8000 /* Tx no response interrupt */
#define TXLSARB	0x2000 /* Tx lose arbitration */
#define TXDONE	0x0100 /* Tx done */
#define RXFAIL	0x0002 /* Rx fail, details in Rx10 */
#define RXDONE	0x0001 /* Rx done */

#define MAX_RETRY 3
#define MAX_TIMEOUT 5000

static int tx_state;

static struct cdev *wmt_cec_cdev;
static DEFINE_SEMAPHORE(wmt_cec_sem);

struct wmt_cec_msg recv_msg;
static void wmt_cec_do_rx_notify(struct work_struct *ptr)
{
	vpp_netlink_notify(USER_PID, DEVICE_RX_DATA, (int)&recv_msg);
}
DECLARE_DELAYED_WORK(wmt_cec_rx_work, wmt_cec_do_rx_notify);


/* receive message interrupt handling */
static void wmt_cec_do_recv(void)
{
	memset(&recv_msg, 0, sizeof(recv_msg));
	/* get received data */
	recv_msg.msglen = wmt_cec_rx_data(recv_msg.msgdata);
	if (recv_msg.msglen > MAX_MSG_BYTE)
		recv_msg.msglen = MAX_MSG_BYTE;

	DBGMSG("read a received byte! msglen: %d\n", recv_msg.msglen);

	/* clear receive blockage */

	/* notify AP the received message, let AP decide what to response */
	schedule_delayed_work(&wmt_cec_rx_work, HZ / 10);
}

/* check if logic address is valid */
static int bvalidaddr(char addr)
{
	if (addr > 15)
		return 0;
	return 1;
}

/* make sure cec line is not busy */
static int tx_get_cecline(void)
{
	int timeout = 400;

	while (timeout-- > 0) {
		/* if not busy */
		if (1)
			return 0;
		msleep(1);
	}
	return -ETIMEDOUT;
}

/* transfer a time*/
DECLARE_COMPLETION(txcomp);
static int wmt_cec_do_xfer_one(char *msgdata, int msglen)
{
	int ret;
	unsigned long  jiffies;

	ret = tx_get_cecline();
	if (ret != 0)
		ret = -EAGAIN;

	wmt_cec_tx_data(msgdata, msglen);

	jiffies = msecs_to_jiffies((unsigned int)MAX_TIMEOUT);
	jiffies = wait_for_completion_timeout(&txcomp, jiffies);
	if (jiffies == 0)
		return -EAGAIN;

	if (tx_state == TXLSARB)
		return -EAGAIN;

	return tx_state;
}

/* transfer a message, including retransmission if needed*/
static int wmt_cec_do_xfer(char *msgdata, int msglen)
{
	int retry;
	int ret;
	char srcaddr, tgtaddr;

	if (msglen < 1) {
		DPRINT("[CEC] xfer: invalid message, msglen is less than 1.\n");
		return -1;
	}

	srcaddr = (msgdata[0] & 0xf0) >> 4;
	tgtaddr = (msgdata[0] & 0x0f);
	if (!bvalidaddr(srcaddr) || !bvalidaddr(tgtaddr)) {
		DPRINT("[CEC] xfer: invalid logic address in msg data.\n");
		return -1;
	}

	for (retry = 0; retry < MAX_RETRY; retry++) {
		ret = wmt_cec_do_xfer_one(msgdata, msglen);
		if (ret != -EAGAIN)
			goto out;
		DPRINT("[CEC] Retrying transmission (%d)\n", retry);
		udelay(100);
	}
	return -EAGAIN;
out:
	/* if polling message ret is no-response, set logical address register,
		and enable slave mode */
	if (srcaddr == tgtaddr && msglen == 1) {
		if (ret == TXNORSP) {
			DBGMSG("[CEC] logic addr register is 0x%x\n", tgtaddr);
			return 0;
		} else
			return -1;
	} else if (ret == TXDONE)
		return 0;
	else
		return -1;
}

/* irq handling function */
irqreturn_t wmt_cec_do_irq(int irq, void *dev_id)
{
	int sts;

	sts = wmt_cec_get_int();
	wmt_cec_clr_int(sts);
	if (sts & BIT0) { /* tx done */
		DBGMSG("[CEC] write ok int\n");
		complete(&txcomp);
		tx_state = TXDONE;
	}
	if (sts & BIT1) { /* rx done */
		DBGMSG("[CEC] read ok int\n");
		wmt_cec_do_recv();
	}
	if (sts & BIT2) { /* rx error */
		DBGMSG("[CEC] read error int\n");
	}
	if (sts & BIT3) { /* tx arb fail */
		DBGMSG("[CEC] wr arb fail int\n");
		complete(&txcomp);
		tx_state = TXLSARB;
	}
	if (sts & BIT4) { /* tx no ack */
/*		DBGMSG("[CEC] write no ack int(addr not match)\n"); */
		complete(&txcomp);
		tx_state = TXNORSP;
	}
	return IRQ_HANDLED;
}

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

	DBGMSG("[CEC] wmt_cec_open\n");

	down(&wmt_cec_sem);
	wmt_cec_rx_enable(1);
	up(&wmt_cec_sem);
	return ret;
} /* End of videodecoder_open() */

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

	DBGMSG("[CEC] wmt_cec_release\n");

	down(&wmt_cec_sem);
	wmt_cec_rx_enable(0);
	up(&wmt_cec_sem);
	return ret;
} /* End of videodecoder_release() */

static long wmt_cec_ioctl(
	struct file *filp,
	unsigned int cmd,
	unsigned long arg
)
{
	int ret = -EINVAL;

	DBGMSG("[CEC] wmt_cec_ioctl 0x%x,0x%x\n", cmd, arg);

	/* check type and number, if fail return ENOTTY */
	if (_IOC_TYPE(cmd) != WMT_CEC_IOC_MAGIC)
		return -ENOTTY;
	if (_IOC_NR(cmd) > WMT_CEC_IOC_MAXNR)
		return -ENOTTY;

	/* check argument area */
	if (_IOC_DIR(cmd) & _IOC_READ)
		ret = !access_ok(VERIFY_WRITE,
			(void __user *) arg, _IOC_SIZE(cmd));
	else if (_IOC_DIR(cmd) & _IOC_WRITE)
		ret = !access_ok(VERIFY_READ,
			(void __user *) arg, _IOC_SIZE(cmd));
	else
		ret = 0;

	if (ret)
		return -EFAULT;

	down(&wmt_cec_sem);
	switch (cmd) {
	case CECIO_TX_DATA:
		{
		struct wmt_cec_msg msg;

		ret = copy_from_user((void *) &msg, (const void *)arg,
					sizeof(struct wmt_cec_msg));
		wmt_cec_do_xfer(msg.msgdata, msg.msglen);
		}
		break;
	case CECIO_TX_LOGADDR:
		wmt_cec_set_logical_addr((arg & 0xFF00) >> 8, arg & 0xFF, 1);
		break;
	case CECIO_RX_PHYADDR:
		{
		wmt_phy_addr_t parm;

		parm.phy_addr = edid_get_hdmi_phy_addr();
		ret = copy_to_user((void *)arg, (void *)&parm,
					sizeof(wmt_phy_addr_t));
		}
		break;
	default:
		DBGMSG("[CEC] *W* wmt_cec_ioctl cmd 0x%x\n", cmd);
		break;
	}
	up(&wmt_cec_sem);
	return ret;
} /* End of videodecoder_ioctl() */

static int wmt_cec_mmap(
	struct file *filp,
	struct vm_area_struct *vma
)
{
	int ret = -EINVAL;
	down(&wmt_cec_sem);
	up(&wmt_cec_sem);
	return ret;
}

static ssize_t wmt_cec_read(
	struct file *filp,
	char __user *buf,
	size_t count,
	loff_t *f_pos
)
{
	ssize_t ret = 0;
	down(&wmt_cec_sem);
	up(&wmt_cec_sem);
	return ret;
} /* videodecoder_read */

static ssize_t wmt_cec_write(
	struct file *filp,
	const char __user *buf,
	size_t count,
	loff_t *f_pos
)
{
	ssize_t ret = 0;
	down(&wmt_cec_sem);
	up(&wmt_cec_sem);
	return ret;
} /* End of videodecoder_write() */

const struct file_operations wmt_cec_fops = {
	.owner          = THIS_MODULE,
	.open           = wmt_cec_open,
	.release        = wmt_cec_release,
	.read           = wmt_cec_read,
	.write          = wmt_cec_write,
	.unlocked_ioctl = wmt_cec_ioctl,
	.mmap           = wmt_cec_mmap,
};

static int __init wmt_cec_probe
(
	struct platform_device *dev /*!<; // a pointer to struct device */
)
{
	dev_t dev_no;
	int ret;

	DBGMSG("[CEC] Enter wmt_cec_probe\n");

	wmt_cec_init_hw();
	wmt_cec_set_logical_addr(4, 0xf, 1); /* default set boardcast address */
	wmt_cec_rx_enable(0);
	/* wmt_cec_enable_loopback(1); */

	dev_no = MKDEV(CEC_MAJOR, 0);
	ret = register_chrdev_region(dev_no, 1, "wmtcec");
	if (ret < 0) {
		DPRINT("can't get %s dev major %d\n", DRIVER_NAME, CEC_MAJOR);
		return ret;
	}

	/* register char device */
	wmt_cec_cdev = cdev_alloc();
	if (!wmt_cec_cdev) {
		DPRINT("alloc dev error.\n");
		return -ENOMEM;
	}

	cdev_init(wmt_cec_cdev, &wmt_cec_fops);
	ret = cdev_add(wmt_cec_cdev, dev_no, 1);
	if (ret) {
		DPRINT("reg char dev error(%d).\n", ret);
		cdev_del(wmt_cec_cdev);
		return ret;
	}

	if (vpp_request_irq(IRQ_VPP_IRQ20, wmt_cec_do_irq,
		SA_INTERRUPT, "cec", (void *) 0))
		DPRINT("*E* request CEC ISR fail\n");
	cec_regs->int_enable = 0x1f;
	DBGMSG("[CEC] Exit wmt_cec_probe(0x%x)\n", dev_no);
	return 0;
} /* End of wmt_cec_probe */

static int wmt_cec_remove
(
	struct platform_device *dev /*!<; // a pointer point to struct device */
)
{
	return 0;
} /* End of wmt_cec_remove */

#ifdef CONFIG_PM
static int wmt_cec_suspend
(
	struct platform_device *pDev,	/*!<; // a pointer to struct device */
	pm_message_t state		/*!<; // suspend state */
)
{
	DPRINT("Enter wmt_cec_suspend\n");
	wmt_cec_do_suspend();
	return 0;
} /* End of wmt_cec_suspend */

static int wmt_cec_resume
(
	struct platform_device *pDev	/*!<; // a pointer to struct device */
)
{
	DPRINT("Enter wmt_cec_resume\n");
	wmt_cec_do_resume();
	return 0;
} /* End of wmt_cec_resume */
#else
#define wmt_cec_suspend NULL
#define wmt_cec_resume NULL
#endif

/***************************************************************************
	device driver struct define
****************************************************************************/
static struct platform_driver wmt_cec_driver = {
	.driver.name    = "wmtcec", /* equal to platform device name. */
	.driver.bus     = &platform_bus_type,
	.probe          = wmt_cec_probe,
	.remove         = wmt_cec_remove,
	.suspend        = wmt_cec_suspend,
	.resume         = wmt_cec_resume,
};

/***************************************************************************
	platform device struct define
****************************************************************************/
static u64 wmt_cec_dma_mask = 0xffffffffUL;
static struct platform_device wmt_cec_device = {
	.name   = "wmtcec",
	.dev    = {
		.dma_mask = &wmt_cec_dma_mask,
		.coherent_dma_mask = ~0,
	},
#if 0
	.id     = 0,
	.dev    = {
		.release = wmt_cec_platform_release,
	},
	.num_resources  = 0,    /* ARRAY_SIZE(wmt_cec_resources), */
	.resource       = NULL, /* wmt_cec_resources, */
#endif
};

static int __init wmt_cec_init(void)
{
	int ret;
	char buf[100];
	int varlen = 100;
	unsigned int cec_enable = 0;

	if (wmt_getsyspara("wmt.display.cec", buf, &varlen) == 0)
		vpp_parse_param(buf, &cec_enable, 1, 0);

	if (cec_enable == 0)
		return 0;

	DBGMSG(KERN_ALERT "Enter wmt_cec_init\n");

	ret = platform_driver_register(&wmt_cec_driver);
	if (!ret) {
		ret = platform_device_register(&wmt_cec_device);
		if (ret)
			platform_driver_unregister(&wmt_cec_driver);
	}
	return ret;
}

static void __exit wmt_cec_exit(void)
{
	dev_t dev_no;

	DBGMSG(KERN_ALERT "Enter wmt_cec_exit\n");

	platform_driver_unregister(&wmt_cec_driver);
	platform_device_unregister(&wmt_cec_device);
	dev_no = MKDEV(CEC_MAJOR, 0);
	unregister_chrdev_region(dev_no, 1);
	return;
}

module_init(wmt_cec_init);
module_exit(wmt_cec_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("WMT CEC driver");
MODULE_AUTHOR("WMT TECH");
MODULE_VERSION("1.0.0");