drivers/media/video/saa7164/saa7164-cards.c

/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010 Steven Toth <stoth@kernellabs.com>
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/delay.h>

#include "saa7164.h"

/* The Bridge API needs to understand register widths (in bytes) for the
 * attached I2C devices, so we can simplify the virtual i2c mechansms
 * and keep the -i2c.c implementation clean.
 */
#define REGLEN_8bit	1
#define REGLEN_16bit	2

struct saa7164_board saa7164_boards[] = {
	[SAA7164_BOARD_UNKNOWN] = {
		/* Bridge will not load any firmware, without knowing
		 * the rev this would be fatal. */
		.name		= "Unknown",
	},
	[SAA7164_BOARD_UNKNOWN_REV2] = {
		/* Bridge will load the v2 f/w and dump descriptors */
		/* Required during new board bringup */
		.name		= "Generic Rev2",
		.chiprev	= SAA7164_CHIP_REV2,
	},
	[SAA7164_BOARD_UNKNOWN_REV3] = {
		/* Bridge will load the v2 f/w and dump descriptors */
		/* Required during new board bringup */
		.name		= "Generic Rev3",
		.chiprev	= SAA7164_CHIP_REV3,
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2200] = {
		.name		= "Hauppauge WinTV-HVR2200",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV3,
		.unit		= {{
			.id		= 0x1d,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1b,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1e,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x10 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1f,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x12 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2200_2] = {
		.name		= "Hauppauge WinTV-HVR2200",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV2,
		.unit		= {{
			.id		= 0x06,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x05,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x10 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1e,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1f,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x12 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2200_3] = {
		.name		= "Hauppauge WinTV-HVR2200",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV2,
		.unit		= {{
			.id		= 0x1d,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x05,
			.type		= SAA7164_UNIT_ANALOG_DEMODULATOR,
			.name		= "TDA8290-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x84 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1b,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1c,
			.type		= SAA7164_UNIT_ANALOG_DEMODULATOR,
			.name		= "TDA8290-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x84 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1e,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x10 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1f,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "TDA10048-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x12 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2250] = {
		.name		= "Hauppauge WinTV-HVR2250",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV3,
		.unit		= {{
			.id		= 0x22,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x07,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x08,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x1e,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x20,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x23,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2250_2] = {
		.name		= "Hauppauge WinTV-HVR2250",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV3,
		.unit		= {{
			.id		= 0x28,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x07,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x08,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x24,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x26,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x29,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
	[SAA7164_BOARD_HAUPPAUGE_HVR2250_3] = {
		.name		= "Hauppauge WinTV-HVR2250",
		.porta		= SAA7164_MPEG_DVB,
		.portb		= SAA7164_MPEG_DVB,
		.portc		= SAA7164_MPEG_ENCODER,
		.portd		= SAA7164_MPEG_ENCODER,
		.chiprev	= SAA7164_CHIP_REV3,
		.unit		= {{
			.id		= 0x26,
			.type		= SAA7164_UNIT_EEPROM,
			.name		= "4K EEPROM",
			.i2c_bus_nr	= SAA7164_I2C_BUS_0,
			.i2c_bus_addr	= 0xa0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x04,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-1",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x07,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x08,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-1 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_1,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x22,
			.type		= SAA7164_UNIT_TUNER,
			.name		= "TDA18271-2",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0xc0 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x24,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (TOP)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x32 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		}, {
			.id		= 0x27,
			.type		= SAA7164_UNIT_DIGITAL_DEMODULATOR,
			.name		= "CX24228/S5H1411-2 (QAM)",
			.i2c_bus_nr	= SAA7164_I2C_BUS_2,
			.i2c_bus_addr	= 0x34 >> 1,
			.i2c_reg_len	= REGLEN_8bit,
		} },
	},
};
const unsigned int saa7164_bcount = ARRAY_SIZE(saa7164_boards);

/* ------------------------------------------------------------------ */
/* PCI subsystem IDs                                                  */

struct saa7164_subid saa7164_subids[] = {
	{
		.subvendor = 0x0070,
		.subdevice = 0x8880,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2250,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8810,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2250,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8980,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2200,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8900,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2200_2,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8901,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2200_3,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x88A1,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2250_3,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8891,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2250_2,
	}, {
		.subvendor = 0x0070,
		.subdevice = 0x8851,
		.card      = SAA7164_BOARD_HAUPPAUGE_HVR2250_2,
	},
};
const unsigned int saa7164_idcount = ARRAY_SIZE(saa7164_subids);

void saa7164_card_list(struct saa7164_dev *dev)
{
	int i;

	if (0 == dev->pci->subsystem_vendor &&
	    0 == dev->pci->subsystem_device) {
		printk(KERN_ERR
			"%s: Board has no valid PCIe Subsystem ID and can't\n"
			"%s: be autodetected. Pass card=<n> insmod option to\n"
			"%s: workaround that. Send complaints to the vendor\n"
			"%s: of the TV card. Best regards,\n"
			"%s:         -- tux\n",
			dev->name, dev->name, dev->name, dev->name, dev->name);
	} else {
		printk(KERN_ERR
			"%s: Your board isn't known (yet) to the driver.\n"
			"%s: Try to pick one of the existing card configs via\n"
			"%s: card=<n> insmod option.  Updating to the latest\n"
			"%s: version might help as well.\n",
			dev->name, dev->name, dev->name, dev->name);
	}

	printk(KERN_ERR "%s: Here are valid choices for the card=<n> insmod "
		"option:\n", dev->name);

	for (i = 0; i < saa7164_bcount; i++)
		printk(KERN_ERR "%s:    card=%d -> %s\n",
		       dev->name, i, saa7164_boards[i].name);
}

/* TODO: clean this define up into the -cards.c structs */
#define PCIEBRIDGE_UNITID 2

void saa7164_gpio_setup(struct saa7164_dev *dev)
{


	switch (dev->board) {
	case SAA7164_BOARD_HAUPPAUGE_HVR2200:
	case SAA7164_BOARD_HAUPPAUGE_HVR2200_2:
	case SAA7164_BOARD_HAUPPAUGE_HVR2200_3:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250_2:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250_3:
		/*
		GPIO 2: s5h1411 / tda10048-1 demod reset
		GPIO 3: s5h1411 / tda10048-2 demod reset
		GPIO 7: IRBlaster Zilog reset
		 */

		/* Reset parts by going in and out of reset */
		saa7164_api_clear_gpiobit(dev, PCIEBRIDGE_UNITID, 2);
		saa7164_api_clear_gpiobit(dev, PCIEBRIDGE_UNITID, 3);

		msleep(10);

		saa7164_api_set_gpiobit(dev, PCIEBRIDGE_UNITID, 2);
		saa7164_api_set_gpiobit(dev, PCIEBRIDGE_UNITID, 3);
		break;
	}

}

static void hauppauge_eeprom(struct saa7164_dev *dev, u8 *eeprom_data)
{
	struct tveeprom tv;

	/* TODO: Assumption: eeprom on bus 0 */
	tveeprom_hauppauge_analog(&dev->i2c_bus[0].i2c_client, &tv,
		eeprom_data);

	/* Make sure we support the board model */
	switch (tv.model) {
	case 88001:
		/* Development board - Limit circulation */
		/* WinTV-HVR2250 (PCIe, Retail, full-height bracket)
		 * ATSC/QAM (TDA18271/S5H1411) and basic analog, no IR, FM */
	case 88021:
		/* WinTV-HVR2250 (PCIe, Retail, full-height bracket)
		 * ATSC/QAM (TDA18271/S5H1411) and basic analog, MCE CIR, FM */
		break;
	case 88041:
		/* WinTV-HVR2250 (PCIe, Retail, full-height bracket)
		 * ATSC/QAM (TDA18271/S5H1411) and basic analog, no IR, FM */
		break;
	case 88061:
		/* WinTV-HVR2250 (PCIe, Retail, full-height bracket)
		 * ATSC/QAM (TDA18271/S5H1411) and basic analog, FM */
		break;
	case 89519:
	case 89609:
		/* WinTV-HVR2200 (PCIe, Retail, full-height)
		 * DVB-T (TDA18271/TDA10048) and basic analog, no IR */
		break;
	case 89619:
		/* WinTV-HVR2200 (PCIe, Retail, half-height)
		 * DVB-T (TDA18271/TDA10048) and basic analog, no IR */
		break;
	default:
		printk(KERN_ERR "%s: Warning: Unknown Hauppauge model #%d\n",
			dev->name, tv.model);
		break;
	}

	printk(KERN_INFO "%s: Hauppauge eeprom: model=%d\n", dev->name,
		tv.model);
}

void saa7164_card_setup(struct saa7164_dev *dev)
{
	static u8 eeprom[256];

	if (dev->i2c_bus[0].i2c_rc == 0) {
		if (saa7164_api_read_eeprom(dev, &eeprom[0],
			sizeof(eeprom)) < 0)
			return;
	}

	switch (dev->board) {
	case SAA7164_BOARD_HAUPPAUGE_HVR2200:
	case SAA7164_BOARD_HAUPPAUGE_HVR2200_2:
	case SAA7164_BOARD_HAUPPAUGE_HVR2200_3:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250_2:
	case SAA7164_BOARD_HAUPPAUGE_HVR2250_3:
		hauppauge_eeprom(dev, &eeprom[0]);
		break;
	}
}

/* With most other drivers, the kernel expects to communicate with subdrivers
 * through i2c. This bridge does not allow that, it does not expose any direct
 * access to I2C. Instead we have to communicate through the device f/w for
 * register access to 'processing units'. Each unit has a unique
 * id, regardless of how the physical implementation occurs across
 * the three physical i2c busses. The being said if we want leverge of
 * the existing kernel drivers for tuners and demods we have to 'speak i2c',
 * to this bridge implements 3 virtual i2c buses. This is a helper function
 * for those.
 *
 * Description: Translate the kernels notion of an i2c address and bus into
 * the appropriate unitid.
 */
int saa7164_i2caddr_to_unitid(struct saa7164_i2c *bus, int addr)
{
	/* For a given bus and i2c device address, return the saa7164 unique
	 * unitid. < 0 on error */

	struct saa7164_dev *dev = bus->dev;
	struct saa7164_unit *unit;
	int i;

	for (i = 0; i < SAA7164_MAX_UNITS; i++) {
		unit = &saa7164_boards[dev->board].unit[i];

		if (unit->type == SAA7164_UNIT_UNDEFINED)
			continue;
		if ((bus->nr == unit->i2c_bus_nr) &&
			(addr == unit->i2c_bus_addr))
			return unit->id;
	}

	return -1;
}

/* The 7164 API needs to know the i2c register length in advance.
 * this is a helper function. Based on a specific chip addr and bus return the
 * reg length.
 */
int saa7164_i2caddr_to_reglen(struct saa7164_i2c *bus, int addr)
{
	/* For a given bus and i2c device address, return the
	 * saa7164 registry address width. < 0 on error
	 */

	struct saa7164_dev *dev = bus->dev;
	struct saa7164_unit *unit;
	int i;

	for (i = 0; i < SAA7164_MAX_UNITS; i++) {
		unit = &saa7164_boards[dev->board].unit[i];

		if (unit->type == SAA7164_UNIT_UNDEFINED)
			continue;

		if ((bus->nr == unit->i2c_bus_nr) &&
			(addr == unit->i2c_bus_addr))
			return unit->i2c_reg_len;
	}

	return -1;
}
/* TODO: implement a 'findeeprom' functio like the above and fix any other
 * eeprom related todo's in -api.c.
 */

/* Translate a unitid into a x readable device name, for display purposes.  */
char *saa7164_unitid_name(struct saa7164_dev *dev, u8 unitid)
{
	char *undefed = "UNDEFINED";
	char *bridge = "BRIDGE";
	struct saa7164_unit *unit;
	int i;

	if (unitid == 0)
		return bridge;

	for (i = 0; i < SAA7164_MAX_UNITS; i++) {
		unit = &saa7164_boards[dev->board].unit[i];

		if (unit->type == SAA7164_UNIT_UNDEFINED)
			continue;

		if (unitid == unit->id)
				return unit->name;
	}

	return undefed;
}