linux-imx

/*

 * Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver

 *

 * Copyright 2012 Analog Devices Inc.

 * Author: Lars-Peter Clausen <lars@metafoo.de>

 *

 * Licensed under the GPL-2 or later.

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/delay.h>

#include <linux/i2c.h>

#include <linux/spi/spi.h>

#include <asm/unaligned.h>

​

#define SPI_XCOMM_SETTINGS_LEN_OFFSET       10

#define SPI_XCOMM_SETTINGS_3WIRE        BIT(6)

#define SPI_XCOMM_SETTINGS_CS_HIGH      BIT(5)

#define SPI_XCOMM_SETTINGS_SAMPLE_END       BIT(4)

#define SPI_XCOMM_SETTINGS_CPHA         BIT(3)

#define SPI_XCOMM_SETTINGS_CPOL         BIT(2)

#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK   0x3

#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64     0x2

#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16     0x1

#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4      0x0

​

#define SPI_XCOMM_CMD_UPDATE_CONFIG 0x03

#define SPI_XCOMM_CMD_WRITE     0x04

​

#define SPI_XCOMM_CLOCK 48000000

​

struct spi_xcomm {

    struct i2c_client *i2c;

​

    uint16_t settings;

    uint16_t chipselect;

​

    unsigned int current_speed;

​

    uint8_t buf[63];

};

​

static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)

{

    uint16_t settings;

    uint8_t *buf = spi_xcomm->buf;

​

    settings = spi_xcomm->settings;

    settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;

​

    buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;

    put_unaligned_be16(settings, &buf[1]);

    put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);

​

    return i2c_master_send(spi_xcomm->i2c, buf, 5);

}

​

static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,

    struct spi_device *spi, int is_active)

{

    unsigned long cs = spi->chip_select;

    uint16_t chipselect = spi_xcomm->chipselect;