saa5246a.c

linux-2.6.15.6

/*
 * Driver for the SAA5246A or SAA5281 Teletext (=Videotext) decoder chips from
 * Philips.
 *
 * Only capturing of Teletext pages is tested. The videotext chips also have a
 * TV output but my hardware doesn't use it. For this reason this driver does
 * not support changing any TV display settings.
 *
 * Copyright (C) 2004 Michael Geng <[e-mail]>
 *
 * Derived from
 *
 * saa5249 driver
 * Copyright (C) 1998 Richard Guenther
 * <[e-mail]>
 *
 * with changes by
 * Alan Cox <[e-mail]>
 *
 * and
 *
 * vtx.c
 * 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/sched.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/videotext.h>
#include <linux/videodev.h>
#include "saa5246a.h"

MODULE_AUTHOR("Michael Geng <[e-mail]>");
MODULE_DESCRIPTION("Philips SAA5246A, SAA5281 Teletext decoder driver");
MODULE_LICENSE("GPL");

struct saa5246a_device
{
	u8     pgbuf[NUM_DAUS][VTX_VIRTUALSIZE];
	int    is_searching[NUM_DAUS];
	struct i2c_client *client;
	struct semaphore lock;
};

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

/* Addresses to scan */
static unsigned short normal_i2c[]	 = { I2C_ADDRESS, I2C_CLIENT_END };
I2C_CLIENT_INSMOD;

static struct i2c_client client_template;

static int saa5246a_attach(struct i2c_adapter *adap, int addr, int kind)
{
	int pgbuf;
	int err;
	struct i2c_client *client;
	struct video_device *vd;
	struct saa5246a_device *t;

	printk(KERN_INFO "saa5246a: teletext chip found.\n");
	client=kmalloc(sizeof(*client), GFP_KERNEL);
	if(client==NULL)
		return -ENOMEM;
	client_template.adapter = adap;
	client_template.addr = addr;
	memcpy(client, &client_template, sizeof(*client));
	t = kmalloc(sizeof(*t), GFP_KERNEL);
	if(t==NULL)
	{
		kfree(client);
		return -ENOMEM;
	}
	memset(t, 0, sizeof(*t));
	strlcpy(client->name, IF_NAME, I2C_NAME_SIZE);
	init_MUTEX(&t->lock);

	/*
	 *	Now create a video4linux device
	 */

	vd = video_device_alloc();
	if(vd==NULL)
	{
		kfree(t);
		kfree(client);
		return -ENOMEM;
	}
	i2c_set_clientdata(client, vd);
	memcpy(vd, &saa_template, sizeof(*vd));

	for (pgbuf = 0; pgbuf < NUM_DAUS; pgbuf++)
	{
		memset(t->pgbuf[pgbuf], ' ', sizeof(t->pgbuf[0]));
		t->is_searching[pgbuf] = FALSE;
	}
	vd->priv=t;


	/*
	 *	Register it
	 */

	if((err=video_register_device(vd, VFL_TYPE_VTX,-1))<0)
	{
		kfree(t);
		kfree(client);
		video_device_release(vd);
		return err;
	}
	t->client = client;
	i2c_attach_client(client);
	return 0;
}

/*
 *	We do most of the hard work when we become a device on the i2c.
 */
static int saa5246a_probe(struct i2c_adapter *adap)
{
	if (adap->class & I2C_CLASS_TV_ANALOG)
		return i2c_probe(adap, &addr_data, saa5246a_attach);
	return 0;
}

static int saa5246a_detach(struct i2c_client *client)
{
	struct video_device *vd = i2c_get_clientdata(client);
	i2c_detach_client(client);
	video_unregister_device(vd);
	kfree(vd->priv);
	kfree(client);
	return 0;
}

static int saa5246a_command(struct i2c_client *device, unsigned int cmd,
	void *arg)
{
	return -EINVAL;
}

/*
 *	I2C interfaces
 */

static struct i2c_driver i2c_driver_videotext =
{
	.owner 		= THIS_MODULE,
	.name 		= IF_NAME,		/* name */
	.id 		= I2C_DRIVERID_SAA5249, /* in i2c.h */
	.flags 		= I2C_DF_NOTIFY,
	.attach_adapter = saa5246a_probe,
	.detach_client  = saa5246a_detach,
	.command 	= saa5246a_command
};

static struct i2c_client client_template = {
	.driver		= &i2c_driver_videotext,
	.name		= "(unset)",
};

static int i2c_sendbuf(struct saa5246a_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 saa5246a_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;
	return i2c_sendbuf(t, buf[0], ct-1, buf+1);
}

/* Get count number of bytes from I睠-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睠-device didn't send
 * acknowledge, 0 otherwise
 */
static int i2c_getdata(struct saa5246a_device *t, int count, u8 *buf)
{
	if(i2c_master_recv(t->client, buf, count)!=count)
		return -1;
	return 0;
}

/* When a page is found then the not FOUND bit in one of the status registers
 * of the SAA5264A chip is cleared. Unfortunately this bit is not set
 * automatically when a new page is requested. Instead this function must be
 * called after a page has been requested.
 *
 * Return value: 0 if successful
 */
static int saa5246a_clear_found_bit(struct saa5246a_device *t,
	unsigned char dau_no)
{
	unsigned char row_25_column_8;

	if (i2c_senddata(t, SAA5246A_REGISTER_R8,

		dau_no |
		R8_DO_NOT_CLEAR_MEMORY,

		R9_CURSER_ROW_25,

		R10_CURSER_COLUMN_8,

		COMMAND_END) ||
		i2c_getdata(t, 1, &row_25_column_8))
	{
		return -EIO;
	}
	row_25_column_8 |= ROW25_COLUMN8_PAGE_NOT_FOUND;
	if (i2c_senddata(t, SAA5246A_REGISTER_R8,

		dau_no |
		R8_DO_NOT_CLEAR_MEMORY,

		R9_CURSER_ROW_25,

		R10_CURSER_COLUMN_8,

		row_25_column_8,

		COMMAND_END))
	{
		return -EIO;
	}

	return 0;
}

/* Requests one videotext page as described in req. The fields of req are
 * checked and an error is returned if something is invalid.
 *
 * Return value: 0 if successful
 */
static int saa5246a_request_page(struct saa5246a_device *t,
    vtx_pagereq_t *req)
{
	if (req->pagemask < 0 || req->pagemask >= PGMASK_MAX)
		return -EINVAL;
	if (req->pagemask & PGMASK_PAGE)
		if (req->page < 0 || req->page > PAGE_MAX)
			return -EINVAL;
	if (req->pagemask & PGMASK_HOUR)
		if (req->hour < 0 || req->hour > HOUR_MAX)
			return -EINVAL;
	if (req->pagemask & PGMASK_MINUTE)
		if (req->minute < 0 || req->minute > MINUTE_MAX)
			return -EINVAL;
	if (req->pgbuf < 0 || req->pgbuf >= NUM_DAUS)
		return -EINVAL;

	if (i2c_senddata(t, SAA5246A_REGISTER_R2,

		R2_IN_R3_SELECT_PAGE_HUNDREDS |
		req->pgbuf << 4 |
		R2_BANK_0 |
		R2_HAMMING_CHECK_OFF,

		HUNDREDS_OF_PAGE(req->page) |
		R3_HOLD_PAGE |
		(req->pagemask & PG_HUND ?
			R3_PAGE_HUNDREDS_DO_CARE :
			R3_PAGE_HUNDREDS_DO_NOT_CARE),

		TENS_OF_PAGE(req->page) |
		(req->pagemask & PG_TEN ?
			R3_PAGE_TENS_DO_CARE :
			R3_PAGE_TENS_DO_NOT_CARE),

		UNITS_OF_PAGE(req->page) |
		(req->pagemask & PG_UNIT ?
			R3_PAGE_UNITS_DO_CARE :
			R3_PAGE_UNITS_DO_NOT_CARE),

		TENS_OF_HOUR(req->hour) |
		(req->pagemask & HR_TEN ?
			R3_HOURS_TENS_DO_CARE :
			R3_HOURS_TENS_DO_NOT_CARE),

		UNITS_OF_HOUR(req->hour) |
		(req->pagemask & HR_UNIT ?
			R3_HOURS_UNITS_DO_CARE :
			R3_HOURS_UNITS_DO_NOT_CARE),

		TENS_OF_MINUTE(req->minute) |
		(req->pagemask & MIN_TEN ?
			R3_MINUTES_TENS_DO_CARE :
			R3_MINUTES_TENS_DO_NOT_CARE),

		UNITS_OF_MINUTE(req->minute) |
		(req->pagemask & MIN_UNIT ?
			R3_MINUTES_UNITS_DO_CARE :
			R3_MINUTES_UNITS_DO_NOT_CARE),

		COMMAND_END) || i2c_senddata(t, SAA5246A_REGISTER_R2,

		R2_IN_R3_SELECT_PAGE_HUNDREDS |
		req->pgbuf << 4 |
		R2_BANK_0 |
		R2_HAMMING_CHECK_OFF,

		HUNDREDS_OF_PAGE(req->page) |
		R3_UPDATE_PAGE |
		(req->pagemask & PG_HUND ?
			R3_PAGE_HUNDREDS_DO_CARE :
			R3_PAGE_HUNDREDS_DO_NOT_CARE),

		COMMAND_END))
	{
		return -EIO;
	}

	t->is_searching[req->pgbuf] = TRUE;
	return 0;
}

/* This routine decodes the page number from the infobits contained in line 25.
 *
 * Parameters:
 * infobits: must be bits 0 to 9 of column 25
 *
 * Return value: page number coded in hexadecimal, i. e. page 123 is coded 0x123
 */
static inline int saa5246a_extract_pagenum_from_infobits(
    unsigned char infobits[10])
{
	int page_hundreds, page_tens, page_units;

	page_units    = infobits[0] & ROW25_COLUMN0_PAGE_UNITS;
	page_tens     = infobits[1] & ROW25_COLUMN1_PAGE_TENS;
	page_hundreds = infobits[8] & ROW25_COLUMN8_PAGE_HUNDREDS;

	/* page 0x.. means page 8.. */
	if (page_hundreds == 0)
		page_hundreds = 8;

	return((page_hundreds << 8) | (page_tens << 4) | page_units);
}

/* Decodes the hour from the infobits contained in line 25.
 *
 * Parameters:
 * infobits: must be bits 0 to 9 of column 25
 *
 * Return: hour coded in hexadecimal, i. e. 12h is coded 0x12
 */
static inline int saa5246a_extract_hour_from_infobits(
    unsigned char infobits[10])
{
	int hour_tens, hour_units;

	hour_units = infobits[4] & ROW25_COLUMN4_HOUR_UNITS;
	hour_tens  = infobits[5] & ROW25_COLUMN5_HOUR_TENS;

	return((hour_tens << 4) | hour_units);
}

/* Decodes the minutes from the infobits contained in line 25.
 *
 * Parameters:
 * infobits: must be bits 0 to 9 of column 25
 *
 * Return: minutes coded in hexadecimal, i. e. 10min is coded 0x10
 */
static inline int saa5246a_extract_minutes_from_infobits(
    unsigned char infobits[10])
{
	int minutes_tens, minutes_units;

	minutes_units = infobits[2] & ROW25_COLUMN2_MINUTES_UNITS;
	minutes_tens  = infobits[3] & ROW25_COLUMN3_MINUTES_TENS;

	return((minutes_tens << 4) | minutes_units);
}

/* Reads the status bits contained in the first 10 columns of the first line
 * and extracts the information into info.
 *
 * Return value: 0 if successful
 */
static inline int saa5246a_get_status(struct saa5246a_device *t,
    vtx_pageinfo_t *info, unsigned char dau_no)
{
	unsigned char infobits[10];
	int column;

	if (dau_no >= NUM_DAUS)
		return -EINVAL;