saa5246a.c

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/*
 * 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/mm.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/smp_lock.h>
#include <linux/mutex.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 SAA5246A, SAA5281 Teletext decoder driver");
MODULE_LICENSE("GPL");

#define MAJOR_VERSION 1		/* driver major version number */
#define MINOR_VERSION 8		/* driver minor version number */

/* Number of DAUs = number of pages that can be searched at the same time. */
#define NUM_DAUS 4

#define NUM_ROWS_PER_PAGE 40

/* first column is 0 (not 1) */
#define POS_TIME_START 32
#define POS_TIME_END 39

#define POS_HEADER_START 7
#define POS_HEADER_END 31

/* Returns 'true' if the part of the videotext page described with req contains
   (at least parts of) the time field */
#define REQ_CONTAINS_TIME(p_req) \
	((p_req)->start <= POS_TIME_END && \
	 (p_req)->end   >= POS_TIME_START)

/* Returns 'true' if the part of the videotext page described with req contains
   (at least parts of) the page header */
#define REQ_CONTAINS_HEADER(p_req) \
	((p_req)->start <= POS_HEADER_END && \
	 (p_req)->end   >= POS_HEADER_START)

/*****************************************************************************/
/* Mode register numbers of the SAA5246A				     */
/*****************************************************************************/
#define SAA5246A_REGISTER_R0    0
#define SAA5246A_REGISTER_R1    1
#define SAA5246A_REGISTER_R2    2
#define SAA5246A_REGISTER_R3    3
#define SAA5246A_REGISTER_R4    4
#define SAA5246A_REGISTER_R5    5
#define SAA5246A_REGISTER_R6    6
#define SAA5246A_REGISTER_R7    7
#define SAA5246A_REGISTER_R8    8
#define SAA5246A_REGISTER_R9    9
#define SAA5246A_REGISTER_R10  10
#define SAA5246A_REGISTER_R11  11
#define SAA5246A_REGISTER_R11B 11

/* SAA5246A mode registers often autoincrement to the next register.
   Therefore we use variable argument lists. The following macro indicates
   the end of a command list. */
#define COMMAND_END (-1)

/*****************************************************************************/
/* Contents of the mode registers of the SAA5246A			     */
/*****************************************************************************/
/* Register R0 (Advanced Control) */
#define R0_SELECT_R11					   0x00
#define R0_SELECT_R11B					   0x01

#define R0_PLL_TIME_CONSTANT_LONG			   0x00
#define R0_PLL_TIME_CONSTANT_SHORT			   0x02

#define R0_ENABLE_nODD_EVEN_OUTPUT			   0x00
#define R0_DISABLE_nODD_EVEN_OUTPUT			   0x04

#define R0_ENABLE_HDR_POLL				   0x00
#define R0_DISABLE_HDR_POLL				   0x10

#define R0_DO_NOT_FORCE_nODD_EVEN_LOW_IF_PICTURE_DISPLAYED 0x00
#define R0_FORCE_nODD_EVEN_LOW_IF_PICTURE_DISPLAYED	   0x20

#define R0_NO_FREE_RUN_PLL				   0x00
#define R0_FREE_RUN_PLL					   0x40

#define R0_NO_AUTOMATIC_FASTEXT_PROMPT			   0x00
#define R0_AUTOMATIC_FASTEXT_PROMPT			   0x80

/* Register R1 (Mode) */
#define R1_INTERLACED_312_AND_HALF_312_AND_HALF_LINES	   0x00
#define R1_NON_INTERLACED_312_313_LINES			   0x01
#define R1_NON_INTERLACED_312_312_LINES			   0x02
#define R1_FFB_LEADING_EDGE_IN_FIRST_BROAD_PULSE	   0x03
#define R1_FFB_LEADING_EDGE_IN_SECOND_BROAD_PULSE	   0x07

#define R1_DEW						   0x00
#define R1_FULL_FIELD					   0x08

#define R1_EXTENDED_PACKET_DISABLE			   0x00
#define R1_EXTENDED_PACKET_ENABLE			   0x10

#define R1_DAUS_ALL_ON					   0x00
#define R1_DAUS_ALL_OFF					   0x20

#define R1_7_BITS_PLUS_PARITY				   0x00
#define R1_8_BITS_NO_PARITY				   0x40

#define R1_VCS_TO_SCS					   0x00
#define R1_NO_VCS_TO_SCS				   0x80

/* Register R2 (Page request address) */
#define R2_IN_R3_SELECT_PAGE_HUNDREDS			   0x00
#define R2_IN_R3_SELECT_PAGE_TENS			   0x01
#define R2_IN_R3_SELECT_PAGE_UNITS			   0x02
#define R2_IN_R3_SELECT_HOURS_TENS			   0x03
#define R2_IN_R3_SELECT_HOURS_UNITS			   0x04
#define R2_IN_R3_SELECT_MINUTES_TENS			   0x05
#define R2_IN_R3_SELECT_MINUTES_UNITS			   0x06

#define R2_DAU_0					   0x00
#define R2_DAU_1					   0x10
#define R2_DAU_2					   0x20
#define R2_DAU_3					   0x30

#define R2_BANK_0					   0x00
#define R2_BANK 1					   0x40

#define R2_HAMMING_CHECK_ON				   0x80
#define R2_HAMMING_CHECK_OFF				   0x00

/* Register R3 (Page request data) */
#define R3_PAGE_HUNDREDS_0				   0x00
#define R3_PAGE_HUNDREDS_1				   0x01
#define R3_PAGE_HUNDREDS_2				   0x02
#define R3_PAGE_HUNDREDS_3				   0x03
#define R3_PAGE_HUNDREDS_4				   0x04
#define R3_PAGE_HUNDREDS_5				   0x05
#define R3_PAGE_HUNDREDS_6				   0x06
#define R3_PAGE_HUNDREDS_7				   0x07

#define R3_HOLD_PAGE					   0x00
#define R3_UPDATE_PAGE					   0x08

#define R3_PAGE_HUNDREDS_DO_NOT_CARE			   0x00
#define R3_PAGE_HUNDREDS_DO_CARE			   0x10

#define R3_PAGE_TENS_DO_NOT_CARE			   0x00
#define R3_PAGE_TENS_DO_CARE				   0x10

#define R3_PAGE_UNITS_DO_NOT_CARE			   0x00
#define R3_PAGE_UNITS_DO_CARE				   0x10

#define R3_HOURS_TENS_DO_NOT_CARE			   0x00
#define R3_HOURS_TENS_DO_CARE				   0x10

#define R3_HOURS_UNITS_DO_NOT_CARE			   0x00
#define R3_HOURS_UNITS_DO_CARE				   0x10

#define R3_MINUTES_TENS_DO_NOT_CARE			   0x00
#define R3_MINUTES_TENS_DO_CARE				   0x10

#define R3_MINUTES_UNITS_DO_NOT_CARE			   0x00
#define R3_MINUTES_UNITS_DO_CARE			   0x10

/* Register R4 (Display chapter) */
#define R4_DISPLAY_PAGE_0				   0x00
#define R4_DISPLAY_PAGE_1				   0x01
#define R4_DISPLAY_PAGE_2				   0x02
#define R4_DISPLAY_PAGE_3				   0x03
#define R4_DISPLAY_PAGE_4				   0x04
#define R4_DISPLAY_PAGE_5				   0x05
#define R4_DISPLAY_PAGE_6				   0x06
#define R4_DISPLAY_PAGE_7				   0x07

/* Register R5 (Normal display control) */
#define R5_PICTURE_INSIDE_BOXING_OFF			   0x00
#define R5_PICTURE_INSIDE_BOXING_ON			   0x01

#define R5_PICTURE_OUTSIDE_BOXING_OFF			   0x00
#define R5_PICTURE_OUTSIDE_BOXING_ON			   0x02

#define R5_TEXT_INSIDE_BOXING_OFF			   0x00
#define R5_TEXT_INSIDE_BOXING_ON			   0x04

#define R5_TEXT_OUTSIDE_BOXING_OFF			   0x00
#define R5_TEXT_OUTSIDE_BOXING_ON			   0x08

#define R5_CONTRAST_REDUCTION_INSIDE_BOXING_OFF		   0x00
#define R5_CONTRAST_REDUCTION_INSIDE_BOXING_ON		   0x10

#define R5_CONTRAST_REDUCTION_OUTSIDE_BOXING_OFF	   0x00
#define R5_CONTRAST_REDUCTION_OUTSIDE_BOXING_ON		   0x20

#define R5_BACKGROUND_COLOR_INSIDE_BOXING_OFF		   0x00
#define R5_BACKGROUND_COLOR_INSIDE_BOXING_ON		   0x40

#define R5_BACKGROUND_COLOR_OUTSIDE_BOXING_OFF		   0x00
#define R5_BACKGROUND_COLOR_OUTSIDE_BOXING_ON		   0x80

/* Register R6 (Newsflash display) */
#define R6_NEWSFLASH_PICTURE_INSIDE_BOXING_OFF		   0x00
#define R6_NEWSFLASH_PICTURE_INSIDE_BOXING_ON		   0x01

#define R6_NEWSFLASH_PICTURE_OUTSIDE_BOXING_OFF		   0x00
#define R6_NEWSFLASH_PICTURE_OUTSIDE_BOXING_ON		   0x02

#define R6_NEWSFLASH_TEXT_INSIDE_BOXING_OFF		   0x00
#define R6_NEWSFLASH_TEXT_INSIDE_BOXING_ON		   0x04

#define R6_NEWSFLASH_TEXT_OUTSIDE_BOXING_OFF		   0x00
#define R6_NEWSFLASH_TEXT_OUTSIDE_BOXING_ON		   0x08

#define R6_NEWSFLASH_CONTRAST_REDUCTION_INSIDE_BOXING_OFF  0x00
#define R6_NEWSFLASH_CONTRAST_REDUCTION_INSIDE_BOXING_ON   0x10

#define R6_NEWSFLASH_CONTRAST_REDUCTION_OUTSIDE_BOXING_OFF 0x00
#define R6_NEWSFLASH_CONTRAST_REDUCTION_OUTSIDE_BOXING_ON  0x20

#define R6_NEWSFLASH_BACKGROUND_COLOR_INSIDE_BOXING_OFF    0x00
#define R6_NEWSFLASH_BACKGROUND_COLOR_INSIDE_BOXING_ON	   0x40

#define R6_NEWSFLASH_BACKGROUND_COLOR_OUTSIDE_BOXING_OFF   0x00
#define R6_NEWSFLASH_BACKGROUND_COLOR_OUTSIDE_BOXING_ON    0x80

/* Register R7 (Display mode) */
#define R7_BOX_OFF_ROW_0				   0x00
#define R7_BOX_ON_ROW_0					   0x01

#define R7_BOX_OFF_ROW_1_TO_23				   0x00
#define R7_BOX_ON_ROW_1_TO_23				   0x02

#define R7_BOX_OFF_ROW_24				   0x00
#define R7_BOX_ON_ROW_24				   0x04

#define R7_SINGLE_HEIGHT				   0x00
#define R7_DOUBLE_HEIGHT				   0x08

#define R7_TOP_HALF					   0x00
#define R7_BOTTOM_HALF					   0x10

#define R7_REVEAL_OFF					   0x00
#define R7_REVEAL_ON					   0x20

#define R7_CURSER_OFF					   0x00
#define R7_CURSER_ON					   0x40

#define R7_STATUS_BOTTOM				   0x00
#define R7_STATUS_TOP					   0x80

/* Register R8 (Active chapter) */
#define R8_ACTIVE_CHAPTER_0				   0x00
#define R8_ACTIVE_CHAPTER_1				   0x01
#define R8_ACTIVE_CHAPTER_2				   0x02
#define R8_ACTIVE_CHAPTER_3				   0x03
#define R8_ACTIVE_CHAPTER_4				   0x04
#define R8_ACTIVE_CHAPTER_5				   0x05
#define R8_ACTIVE_CHAPTER_6				   0x06
#define R8_ACTIVE_CHAPTER_7				   0x07

#define R8_CLEAR_MEMORY					   0x08
#define R8_DO_NOT_CLEAR_MEMORY				   0x00

/* Register R9 (Curser row) */
#define R9_CURSER_ROW_0					   0x00
#define R9_CURSER_ROW_1					   0x01
#define R9_CURSER_ROW_2					   0x02
#define R9_CURSER_ROW_25				   0x19

/* Register R10 (Curser column) */
#define R10_CURSER_COLUMN_0				   0x00
#define R10_CURSER_COLUMN_6				   0x06
#define R10_CURSER_COLUMN_8				   0x08

/*****************************************************************************/
/* Row 25 control data in column 0 to 9					     */
/*****************************************************************************/
#define ROW25_COLUMN0_PAGE_UNITS			   0x0F

#define ROW25_COLUMN1_PAGE_TENS				   0x0F

#define ROW25_COLUMN2_MINUTES_UNITS			   0x0F

#define ROW25_COLUMN3_MINUTES_TENS			   0x07
#define ROW25_COLUMN3_DELETE_PAGE			   0x08

#define ROW25_COLUMN4_HOUR_UNITS			   0x0F

#define ROW25_COLUMN5_HOUR_TENS				   0x03
#define ROW25_COLUMN5_INSERT_HEADLINE			   0x04
#define ROW25_COLUMN5_INSERT_SUBTITLE			   0x08

#define ROW25_COLUMN6_SUPPRESS_HEADER			   0x01
#define ROW25_COLUMN6_UPDATE_PAGE			   0x02
#define ROW25_COLUMN6_INTERRUPTED_SEQUENCE		   0x04
#define ROW25_COLUMN6_SUPPRESS_DISPLAY			   0x08

#define ROW25_COLUMN7_SERIAL_MODE			   0x01
#define ROW25_COLUMN7_CHARACTER_SET			   0x0E

#define ROW25_COLUMN8_PAGE_HUNDREDS			   0x07
#define ROW25_COLUMN8_PAGE_NOT_FOUND			   0x10

#define ROW25_COLUMN9_PAGE_BEING_LOOKED_FOR		   0x20

#define ROW25_COLUMN0_TO_7_HAMMING_ERROR		   0x10

/*****************************************************************************/
/* Helper macros for extracting page, hour and minute digits		     */
/*****************************************************************************/
/* BYTE_POS  0 is at row 0, column 0,
   BYTE_POS  1 is at row 0, column 1,
   BYTE_POS 40 is at row 1, column 0, (with NUM_ROWS_PER_PAGE = 40)
   BYTE_POS 41 is at row 1, column 1, (with NUM_ROWS_PER_PAGE = 40),
   ... */
#define ROW(BYTE_POS)    (BYTE_POS / NUM_ROWS_PER_PAGE)
#define COLUMN(BYTE_POS) (BYTE_POS % NUM_ROWS_PER_PAGE)

/*****************************************************************************/
/* Helper macros for extracting page, hour and minute digits		     */
/*****************************************************************************/
/* Macros for extracting hundreds, tens and units of a page number which
   must be in the range 0 ... 0x799.
   Note that page is coded in hexadecimal, i.e. 0x123 means page 123.
   page 0x.. means page 8.. */
#define HUNDREDS_OF_PAGE(page) (((page) / 0x100) & 0x7)
#define TENS_OF_PAGE(page)     (((page) / 0x10)  & 0xF)
#define UNITS_OF_PAGE(page)     ((page) & 0xF)

/* Macros for extracting tens and units of a hour information which
   must be in the range 0 ... 0x24.
   Note that hour is coded in hexadecimal, i.e. 0x12 means 12 hours */
#define TENS_OF_HOUR(hour)  ((hour) / 0x10)
#define UNITS_OF_HOUR(hour) ((hour) & 0xF)

/* Macros for extracting tens and units of a minute information which
   must be in the range 0 ... 0x59.
   Note that minute is coded in hexadecimal, i.e. 0x12 means 12 minutes */
#define TENS_OF_MINUTE(minute)  ((minute) / 0x10)
#define UNITS_OF_MINUTE(minute) ((minute) & 0xF)

#define HOUR_MAX   0x23
#define MINUTE_MAX 0x59
#define PAGE_MAX   0x8FF


struct saa5246a_device
{
	u8     pgbuf[NUM_DAUS][VTX_VIRTUALSIZE];
	int    is_searching[NUM_DAUS];
	struct i2c_client *client;
	unsigned long in_use;
	struct mutex lock;
};

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

/*
 *	I2C interfaces
 */

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;

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

/* Get count number of bytes from I²C-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 I²C-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,