linux-imx

/*

 *  CLPS711X SPI bus driver

 *

 *  Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>

 *

 * 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.

 */

​

#include <linux/io.h>

#include <linux/clk.h>

#include <linux/gpio/consumer.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/mfd/syscon.h>

#include <linux/mfd/syscon/clps711x.h>

#include <linux/spi/spi.h>

​

#define DRIVER_NAME     "clps711x-spi"

​

#define SYNCIO_FRMLEN(x)    ((x) << 8)

#define SYNCIO_TXFRMEN      (1 << 14)

​

struct spi_clps711x_data {

    void __iomem        *syncio;

    struct regmap       *syscon;

    struct clk      *spi_clk;

​

    u8          *tx_buf;

    u8          *rx_buf;

    unsigned int        bpw;

    int         len;

};

​

static int spi_clps711x_prepare_message(struct spi_master *master,

                    struct spi_message *msg)

{

    struct spi_clps711x_data *hw = spi_master_get_devdata(master);

    struct spi_device *spi = msg->spi;

​

    /* Setup mode for transfer */

    return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,

                  (spi->mode & SPI_CPHA) ?

                  SYSCON3_ADCCKNSEN : 0);

}

​

static int spi_clps711x_transfer_one(struct spi_master *master,

                     struct spi_device *spi,

                     struct spi_transfer *xfer)

{

    struct spi_clps711x_data *hw = spi_master_get_devdata(master);

    u8 data;

​

    clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);

​

    hw->len = xfer->len;

    hw->bpw = xfer->bits_per_word;

    hw->tx_buf = (u8 *)xfer->tx_buf;

    hw->rx_buf = (u8 *)xfer->rx_buf;