saa5249.c

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/*
 * Modified in order to keep it compatible both with new and old videotext IOCTLs by
 * Michael Geng <[e-mail]>
 *
 *	Cleaned up to use existing videodev interface and allow the idea
 *	of multiple teletext decoders on the video4linux iface. Changed i2c
 *	to cover addressing clashes on device busses. It's also rebuilt so
 *	you can add arbitary multiple teletext devices to Linux video4linux
 *	now (well 32 anyway).
 *
 *	Alan Cox <[e-mail]>
 *
 *	The original driver was heavily modified to match the i2c interface
 *	It was truncated to use the WinTV boards, too.
 *
 *	Copyright (c) 1998 Richard Guenther <[e-mail]>
 *
 *	Derived From
 *
 * vtx.c:
 * This is a loadable character-device-driver for videotext-interfaces
 * (aka teletext). Please check the Makefile/README for a list of supported
 * interfaces.
 *
 * Copyright (c) 1994-97 Martin Buck  <[e-mail]>
 *
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/videotext.h>
#include <linux/videodev.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-i2c-drv-legacy.h>
#include "compat.h"

MODULE_AUTHOR("Michael Geng <[e-mail]>");
MODULE_DESCRIPTION("Philips SAA5249 Teletext decoder driver");
MODULE_LICENSE("GPL");

#define VTX_VER_MAJ 1
#define VTX_VER_MIN 8


#define NUM_DAUS 4
#define NUM_BUFS 8

static const int disp_modes[8][3] =
{
	{ 0x46, 0x03, 0x03 },	/* DISPOFF */
	{ 0x46, 0xcc, 0xcc },	/* DISPNORM */
	{ 0x44, 0x0f, 0x0f },	/* DISPTRANS */
	{ 0x46, 0xcc, 0x46 },	/* DISPINS */
	{ 0x44, 0x03, 0x03 },	/* DISPOFF, interlaced */
	{ 0x44, 0xcc, 0xcc },	/* DISPNORM, interlaced */
	{ 0x44, 0x0f, 0x0f },	/* DISPTRANS, interlaced */
	{ 0x44, 0xcc, 0x46 }	/* DISPINS, interlaced */
};



#define PAGE_WAIT    msecs_to_jiffies(300)	/* Time between requesting page and */
						/* checking status bits */
#define PGBUF_EXPIRE msecs_to_jiffies(15000)	/* Time to wait before retransmitting */
						/* page regardless of infobits */
typedef struct {
	u8 pgbuf[VTX_VIRTUALSIZE];		/* Page-buffer */
	u8 laststat[10];			/* Last value of infobits for DAU */
	u8 sregs[7];				/* Page-request registers */
	unsigned long expire;			/* Time when page will be expired */
	unsigned clrfound : 1;			/* VTXIOCCLRFOUND has been called */
	unsigned stopped : 1;			/* VTXIOCSTOPDAU has been called */
} vdau_t;

struct saa5249_device
{
	vdau_t vdau[NUM_DAUS];			/* Data for virtual DAUs (the 5249 only has one */
						/* real DAU, so we have to simulate some more) */
	int vtx_use_count;
	int is_searching[NUM_DAUS];
	int disp_mode;
	int virtual_mode;
	struct i2c_client *client;
	unsigned long in_use;
	struct mutex lock;
};


#define CCTWR 34		/* I睠 write/read-address of vtx-chip */
#define CCTRD 35
#define NOACK_REPEAT 10		/* Retry access this many times on failure */
#define CLEAR_DELAY   msecs_to_jiffies(50)	/* Time required to clear a page */
#define READY_TIMEOUT msecs_to_jiffies(30)	/* Time to wait for ready signal of I2C-bus interface */
#define INIT_DELAY 500		/* Time in usec to wait at initialization of CEA interface */
#define START_DELAY 10		/* Time in usec to wait before starting write-cycle (CEA) */

#define VTX_DEV_MINOR 0

static struct video_device saa_template;	/* Declared near bottom */

/*
 *	Wait the given number of jiffies (10ms). This calls the scheduler, so the actual
 *	delay may be longer.
 */

static void jdelay(unsigned long delay)
{
	sigset_t oldblocked = current->blocked;

	spin_lock_irq(&current->sighand->siglock);
	sigfillset(&current->blocked);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	msleep_interruptible(jiffies_to_msecs(delay));

	spin_lock_irq(&current->sighand->siglock);
	current->blocked = oldblocked;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
}


/*
 *	I2C interfaces
 */

static int i2c_sendbuf(struct saa5249_device *t, int reg, int count, u8 *data)
{
	char buf[64];

	buf[0] = reg;
	memcpy(buf+1, data, count);

	if (i2c_master_send(t->client, buf, count + 1) == count + 1)
		return 0;
	return -1;
}

static int i2c_senddata(struct saa5249_device *t, ...)
{
	unsigned char buf[64];
	int v;
	int ct = 0;
	va_list argp;
	va_start(argp,t);

	while ((v = va_arg(argp, int)) != -1)
		buf[ct++] = v;

	va_end(argp);
	return i2c_sendbuf(t, buf[0], ct-1, buf+1);
}

/* Get count number of bytes from I虏C-device at address adr, store them in buf. Start & stop
 * handshaking is done by this routine, ack will be sent after the last byte to inhibit further
 * sending of data. If uaccess is 'true', data is written to user-space with put_user.
 * Returns -1 if I虏C-device didn't send acknowledge, 0 otherwise
 */

static int i2c_getdata(struct saa5249_device *t, int count, u8 *buf)
{
	if(i2c_master_recv(t->client, buf, count)!=count)
		return -1;
	return 0;
}


/*
 *	Standard character-device-driver functions
 */

static int do_saa5249_ioctl(struct inode *inode, struct file *file,
			    unsigned int cmd, void *arg)
{
	static int virtual_mode = false;
	struct saa5249_device *t = video_drvdata(file);

	switch (cmd) {
	case VTXIOCGETINFO:
	{
		vtx_info_t *info = arg;
		info->version_major = VTX_VER_MAJ;
		info->version_minor = VTX_VER_MIN;
		info->numpages = NUM_DAUS;
		/*info->cct_type = CCT_TYPE;*/
		return 0;
	}

	case VTXIOCCLRPAGE:
	{
		vtx_pagereq_t *req = arg;

		if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
			return -EINVAL;
		memset(t->vdau[req->pgbuf].pgbuf, ' ', sizeof(t->vdau[0].pgbuf));
		t->vdau[req->pgbuf].clrfound = true;
		return 0;
	}

	case VTXIOCCLRFOUND:
	{
		vtx_pagereq_t *req = arg;

		if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
			return -EINVAL;
		t->vdau[req->pgbuf].clrfound = true;
		return 0;
	}

	case VTXIOCPAGEREQ:
	{
		vtx_pagereq_t *req = arg;
		if (!(req->pagemask & PGMASK_PAGE))
			req->page = 0;
		if (!(req->pagemask & PGMASK_HOUR))
			req->hour = 0;
		if (!(req->pagemask & PGMASK_MINUTE))
			req->minute = 0;
		if (req->page < 0 || req->page > 0x8ff) /* 7FF ?? */
			return -EINVAL;
		req->page &= 0x7ff;
		if (req->hour < 0 || req->hour > 0x3f || req->minute < 0 || req->minute > 0x7f ||
			req->pagemask < 0 || req->pagemask >= PGMASK_MAX || req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
			return -EINVAL;
		t->vdau[req->pgbuf].sregs[0] = (req->pagemask & PG_HUND ? 0x10 : 0) | (req->page / 0x100);
		t->vdau[req->pgbuf].sregs[1] = (req->pagemask & PG_TEN ? 0x10 : 0) | ((req->page / 0x10) & 0xf);
		t->vdau[req->pgbuf].sregs[2] = (req->pagemask & PG_UNIT ? 0x10 : 0) | (req->page & 0xf);
		t->vdau[req->pgbuf].sregs[3] = (req->pagemask & HR_TEN ? 0x10 : 0) | (req->hour / 0x10);
		t->vdau[req->pgbuf].sregs[4] = (req->pagemask & HR_UNIT ? 0x10 : 0) | (req->hour & 0xf);
		t->vdau[req->pgbuf].sregs[5] = (req->pagemask & MIN_TEN ? 0x10 : 0) | (req->minute / 0x10);
		t->vdau[req->pgbuf].sregs[6] = (req->pagemask & MIN_UNIT ? 0x10 : 0) | (req->minute & 0xf);
		t->vdau[req->pgbuf].stopped = false;
		t->vdau[req->pgbuf].clrfound = true;
		t->is_searching[req->pgbuf] = true;
		return 0;
	}

	case VTXIOCGETSTAT:
	{
		vtx_pagereq_t *req = arg;
		u8 infobits[10];
		vtx_pageinfo_t info;
		int a;

		if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
			return -EINVAL;
		if (!t->vdau[req->pgbuf].stopped) {
			if (i2c_senddata(t, 2, 0, -1) ||
				i2c_sendbuf(t, 3, sizeof(t->vdau[0].sregs), t->vdau[req->pgbuf].sregs) ||
				i2c_senddata(t, 8, 0, 25, 0, ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', -1) ||
				i2c_senddata(t, 2, 0, t->vdau[req->pgbuf].sregs[0] | 8, -1) ||
				i2c_senddata(t, 8, 0, 25, 0, -1))
				return -EIO;
			jdelay(PAGE_WAIT);
			if (i2c_getdata(t, 10, infobits))
				return -EIO;

			if (!(infobits[8] & 0x10) && !(infobits[7] & 0xf0) &&	/* check FOUND-bit */
				(memcmp(infobits, t->vdau[req->pgbuf].laststat, sizeof(infobits)) ||
				time_after_eq(jiffies, t->vdau[req->pgbuf].expire)))
			{		/* check if new page arrived */
				if (i2c_senddata(t, 8, 0, 0, 0, -1) ||
					i2c_getdata(t, VTX_PAGESIZE, t->vdau[req->pgbuf].pgbuf))
					return -EIO;
				t->vdau[req->pgbuf].expire = jiffies + PGBUF_EXPIRE;
				memset(t->vdau[req->pgbuf].pgbuf + VTX_PAGESIZE, ' ', VTX_VIRTUALSIZE - VTX_PAGESIZE);
				if (t->virtual_mode) {
					/* Packet X/24 */
					if (i2c_senddata(t, 8, 0, 0x20, 0, -1) ||
						i2c_getdata(t, 40, t->vdau[req->pgbuf].pgbuf + VTX_PAGESIZE + 20 * 40))
						return -EIO;
					/* Packet X/27/0 */
					if (i2c_senddata(t, 8, 0, 0x21, 0, -1) ||
						i2c_getdata(t, 40, t->vdau[req->pgbuf].pgbuf + VTX_PAGESIZE + 16 * 40))
						return -EIO;
					/* Packet 8/30/0...8/30/15
					 * FIXME: AFAIK, the 5249 does hamming-decoding for some bytes in packet 8/30,
					 *        so we should undo this here.
					 */
					if (i2c_senddata(t, 8, 0, 0x22, 0, -1) ||
						i2c_getdata(t, 40, t->vdau[req->pgbuf].pgbuf + VTX_PAGESIZE + 23 * 40))
						return -EIO;
				}
				t->vdau[req->pgbuf].clrfound = false;
				memcpy(t->vdau[req->pgbuf].laststat, infobits, sizeof(infobits));
			} else {
				memcpy(infobits, t->vdau[req->pgbuf].laststat, sizeof(infobits));
			}
		} else {
			memcpy(infobits, t->vdau[req->pgbuf].laststat, sizeof(infobits));
		}

		info.pagenum = ((infobits[8] << 8) & 0x700) | ((infobits[1] << 4) & 0xf0) | (infobits[0] & 0x0f);
		if (info.pagenum < 0x100)
			info.pagenum += 0x800;
		info.hour = ((infobits[5] << 4) & 0x30) | (infobits[4] & 0x0f);
		info.minute = ((infobits[3] << 4) & 0x70) | (infobits[2] & 0x0f);
		info.charset = ((infobits[7] >> 1) & 7);
		info.delete = !!(infobits[3] & 8);