tps65912-spi.c

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/*
 * tps65912-spi.c  --  SPI access for TI TPS65912x PMIC
 *
 * Copyright 2011 Texas Instruments Inc.
 *
 * Author: Margarita Olaya Cabrera <[email protected]>
 *
 *  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 driver is based on wm8350 implementation.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps65912.h>

static int tps65912_spi_write(struct tps65912 *tps65912, u8 addr,
                            int bytes, void *src)
{
    struct spi_device *spi = tps65912->control_data;
    u8 *data = (u8 *) src;
    int ret;
    /* bit 23 is the read/write bit */
    unsigned long spi_data = 1 << 23 | addr << 15 | *data;
    struct spi_transfer xfer;
    struct spi_message msg;
    u32 tx_buf, rx_buf;

    tx_buf = spi_data;
    rx_buf = 0;

    xfer.tx_buf = &tx_buf;
    xfer.rx_buf = NULL;
    xfer.len    = sizeof(unsigned long);
    xfer.bits_per_word = 24;

    spi_message_init(&msg);
    spi_message_add_tail(&xfer, &msg);

    ret = spi_sync(spi, &msg);
    return ret;
}

static int tps65912_spi_read(struct tps65912 *tps65912, u8 addr,
                            int bytes, void *dest)
{
    struct spi_device *spi = tps65912->control_data;
    /* bit 23 is the read/write bit */
    unsigned long spi_data = 0 << 23 | addr << 15;
    struct spi_transfer xfer;
    struct spi_message msg;
    int ret;
    u8 *data = (u8 *) dest;
    u32 tx_buf, rx_buf;

    tx_buf = spi_data;
    rx_buf = 0;

    xfer.tx_buf = &tx_buf;
    xfer.rx_buf = &rx_buf;
    xfer.len    = sizeof(unsigned long);
    xfer.bits_per_word = 24;

    spi_message_init(&msg);
    spi_message_add_tail(&xfer, &msg);

    if (spi == NULL)
        return 0;

    ret = spi_sync(spi, &msg);
    if (ret == 0)
        *data = (u8) (rx_buf & 0xFF);
    return ret;
}

static int __devinit tps65912_spi_probe(struct spi_device *spi)
{
    struct tps65912 *tps65912;

    tps65912 = kzalloc(sizeof(struct tps65912), GFP_KERNEL);
    if (tps65912 == NULL)
        return -ENOMEM;

    tps65912->dev = &spi->dev;
    tps65912->control_data = spi;
    tps65912->read = tps65912_spi_read;
    tps65912->write = tps65912_spi_write;

    spi_set_drvdata(spi, tps65912);

    return tps65912_device_init(tps65912);
}

static int __devexit tps65912_spi_remove(struct spi_device *spi)
{
    struct tps65912 *tps65912 = spi_get_drvdata(spi);

    tps65912_device_exit(tps65912);

    return 0;
}

static struct spi_driver tps65912_spi_driver = {
    .driver = {
        .name = "tps65912",
        .owner = THIS_MODULE,
    },
    .probe  = tps65912_spi_probe,
    .remove = __devexit_p(tps65912_spi_remove),
};

static int __init tps65912_spi_init(void)
{
    int ret;

    ret = spi_register_driver(&tps65912_spi_driver);
    if (ret != 0)
        pr_err("Failed to register TPS65912 SPI driver: %d\n", ret);

    return 0;
}
/* init early so consumer devices can complete system boot */
subsys_initcall(tps65912_spi_init);

static void __exit tps65912_spi_exit(void)
{
    spi_unregister_driver(&tps65912_spi_driver);
}
module_exit(tps65912_spi_exit);

MODULE_AUTHOR("Margarita Olaya  <[email protected]>");
MODULE_DESCRIPTION("SPI support for TPS65912 chip family mfd");
MODULE_LICENSE("GPL");