linux/drivers/i2c/busses/i2c-cbus-gpio.c

/*
 * CBUS I2C driver for Nokia Internet Tablets.
 *
 * Copyright (C) 2004-2010 Nokia Corporation
 *
 * Based on code written by Juha Yrjölä, David Weinehall, Mikko Ylinen and
 * Felipe Balbi. Converted to I2C driver by Aaro Koskinen.
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file "COPYING" in the main directory of this
 * archive for more details.
 *
 * 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.
 */

#include <linux/io.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

/*
 * Bit counts are derived from Nokia implementation. These should be checked
 * if other CBUS implementations appear.
 */
#define CBUS_ADDR_BITS …
#define CBUS_REG_BITS …

struct cbus_host { … };

/**
 * cbus_send_bit - sends one bit over the bus
 * @host: the host we're using
 * @bit: one bit of information to send
 */
static void cbus_send_bit(struct cbus_host *host, unsigned bit)
{ … }

/**
 * cbus_send_data - sends @len amount of data over the bus
 * @host: the host we're using
 * @data: the data to send
 * @len: size of the transfer
 */
static void cbus_send_data(struct cbus_host *host, unsigned data, unsigned len)
{ … }

/**
 * cbus_receive_bit - receives one bit from the bus
 * @host: the host we're using
 */
static int cbus_receive_bit(struct cbus_host *host)
{ … }

/**
 * cbus_receive_word - receives 16-bit word from the bus
 * @host: the host we're using
 */
static int cbus_receive_word(struct cbus_host *host)
{ … }

/**
 * cbus_transfer - transfers data over the bus
 * @host: the host we're using
 * @rw: read/write flag
 * @dev: device address
 * @reg: register address
 * @data: if @rw == I2C_SBUS_WRITE data to send otherwise 0
 */
static int cbus_transfer(struct cbus_host *host, char rw, unsigned dev,
			 unsigned reg, unsigned data)
{ … }

static int cbus_i2c_smbus_xfer(struct i2c_adapter	*adapter,
			       u16			addr,
			       unsigned short		flags,
			       char			read_write,
			       u8			command,
			       int			size,
			       union i2c_smbus_data	*data)
{ … }

static u32 cbus_i2c_func(struct i2c_adapter *adapter)
{ … }

static const struct i2c_algorithm cbus_i2c_algo = …;

static void cbus_i2c_remove(struct platform_device *pdev)
{ … }

static int cbus_i2c_probe(struct platform_device *pdev)
{ … }

#if defined(CONFIG_OF)
static const struct of_device_id i2c_cbus_dt_ids[] = …;
MODULE_DEVICE_TABLE(of, i2c_cbus_dt_ids);
#endif

static struct platform_driver cbus_i2c_driver = …;
module_platform_driver(…) …;

MODULE_ALIAS(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_AUTHOR(…) …;
MODULE_AUTHOR(…) …;
MODULE_AUTHOR(…) …;
MODULE_AUTHOR(…) …;
MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;