path: root/drivers/mfd/ab3100-core.c

/*
 * Copyright (C) 2007-2009 ST-Ericsson
 * License terms: GNU General Public License (GPL) version 2
 * Low-level core for exclusive access to the AB3100 IC on the I2C bus
 * and some basic chip-configuration.
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 */

#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/mfd/ab3100.h>

/* These are the only registers inside AB3100 used in this main file */

/* Interrupt event registers */
#define AB3100_EVENTA1		0x21
#define AB3100_EVENTA2		0x22
#define AB3100_EVENTA3		0x23

/* AB3100 DAC converter registers */
#define AB3100_DIS		0x00
#define AB3100_D0C		0x01
#define AB3100_D1C		0x02
#define AB3100_D2C		0x03
#define AB3100_D3C		0x04

/* Chip ID register */
#define AB3100_CID		0x20

/* AB3100 interrupt registers */
#define AB3100_IMRA1		0x24
#define AB3100_IMRA2		0x25
#define AB3100_IMRA3		0x26
#define AB3100_IMRB1		0x2B
#define AB3100_IMRB2		0x2C
#define AB3100_IMRB3		0x2D

/* System Power Monitoring and control registers */
#define AB3100_MCA		0x2E
#define AB3100_MCB		0x2F

/* SIM power up */
#define AB3100_SUP		0x50

/*
 * I2C communication
 *
 * The AB3100 is usually assigned address 0x48 (7-bit)
 * The chip is defined in the platform i2c_board_data section.
 */

u8 ab3100_get_chip_type(struct ab3100 *ab3100)
{
	u8 chip = ABUNKNOWN;

	switch (ab3100->chip_id & 0xf0) {
	case  0xa0:
		chip = AB3000;
		break;
	case  0xc0:
		chip = AB3100;
		break;
	}
	return chip;
}
EXPORT_SYMBOL(ab3100_get_chip_type);

int ab3100_set_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 regval)
{
	u8 regandval[2] = {reg, regval};
	int err;

	err = mutex_lock_interruptible(&ab3100->access_mutex);
	if (err)
		return err;

	/*
	 * A two-byte write message with the first byte containing the register
	 * number and the second byte containing the value to be written
	 * effectively sets a register in the AB3100.
	 */
	err = i2c_master_send(ab3100->i2c_client, regandval, 2);
	if (err < 0) {
		dev_err(ab3100->dev,
			"write error (write register): %d\n",
			err);
	} else if (err != 2) {
		dev_err(ab3100->dev,
			"write error (write register) "
			"%d bytes transferred (expected 2)\n",
			err);
		err = -EIO;
	} else {
		/* All is well */
		err = 0;
	}
	mutex_unlock(&ab3100->access_mutex);
	return err;
}
EXPORT_SYMBOL(ab3100_set_register_interruptible);


/*
 * The test registers exist at an I2C bus address up one
 * from the ordinary base. They are not supposed to be used
 * in production code, but sometimes you have to do that
 * anyway. It's currently only used from this file so declare
 * it static and do not export.
 */
static int ab3100_set_test_register_interruptible(struct ab3100 *ab3100,
				    u8 reg, u8 regval)
{
	u8 regandval[2] = {reg, regval};
	int err;

	err = mutex_lock_interruptible(&ab3100->access_mutex);
	if (err)
		return err;

	err = i2c_master_send(ab3100->testreg_client, regandval, 2);
	if (err < 0) {
		dev_err(ab3100->dev,
			"write error (write test register): %d\n",
			err);
	} else if (err != 2) {
		dev_err(ab3100->dev,
			"write error (write test register) "
			"%d bytes transferred (expected 2)\n",
			err);
		err = -EIO;
	} else {
		/* All is well */
		err = 0;
	}
	mutex_unlock(&ab3100->access_mutex);

	return err;
}


int ab3100_get_register_interruptible(struct ab3100 *ab3100, u8 reg, u8 *regval)
{
	int err;

	err = mutex_lock_interruptible(&ab3100->access_mutex);
	if (err)
		return err;

	/*
	 * AB3100 require an I2C "stop" command between each message, else
	 * it will not work. The only way of achieveing this with the
	 * message transport layer is to send the read and write messages
	 * separately.
	 */
	err = i2c_master_send(ab3100->i2c_client, &reg, 1);
	if (err < 0) {
		dev_err(ab3100->dev,
			"write error (send register address): %d\n",
			err);
		goto get_reg_out_unlock;
	} else if (err != 1) {
		dev_err(ab3100->dev,
			"write error (send register address) "
			"%d bytes transferred (expected 1)\n",
			err);
		err = -EIO;
		goto get_reg_out_unlock;
	} else {
		/* All is well */
		err = 0;
	}

	err = i2c_master_recv(ab3100->i2c_client, regval, 1);
	if (err < 0) {
		dev_err(ab3100->dev,
			"write error (read register): %d\n",
			err);
		goto get_reg_out_unlock;
	} else if (err != 1) {
		dev_err(ab3100->dev,
			"write error (read register) "
			"%d bytes transferred (expected 1)\n",
			err);
		err = -EI