regmap-spi.c

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/*
 * Register map access API - SPI support
 *
 * Copyright 2011 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/init.h>
#include <linux/module.h>

static int regmap_spi_write(void *context, const void *data, size_t count)
{
    struct device *dev = context;
    struct spi_device *spi = to_spi_device(dev);

    return spi_write(spi, data, count);
}

static int regmap_spi_gather_write(void *context,
                   const void *reg, size_t reg_len,
                   const void *val, size_t val_len)
{
    struct device *dev = context;
    struct spi_device *spi = to_spi_device(dev);
    struct spi_message m;
    struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
                     { .tx_buf = val, .len = val_len, }, };

    spi_message_init(&m);
    spi_message_add_tail(&t[0], &m);
    spi_message_add_tail(&t[1], &m);

    return spi_sync(spi, &m);
}

static int regmap_spi_read(void *context,
               const void *reg, size_t reg_size,
               void *val, size_t val_size)
{
    struct device *dev = context;
    struct spi_device *spi = to_spi_device(dev);

    return spi_write_then_read(spi, reg, reg_size, val, val_size);
}

static struct regmap_bus regmap_spi = {
    .write = regmap_spi_write,
    .gather_write = regmap_spi_gather_write,
    .read = regmap_spi_read,
    .read_flag_mask = 0x80,
};

struct regmap *regmap_init_spi(struct spi_device *spi,
                   const struct regmap_config *config)
{
    return regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
}
EXPORT_SYMBOL_GPL(regmap_init_spi);

struct regmap *devm_regmap_init_spi(struct spi_device *spi,
                    const struct regmap_config *config)
{
    return devm_regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
}
EXPORT_SYMBOL_GPL(devm_regmap_init_spi);

MODULE_LICENSE("GPL");