linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * SuperH HSPI bus driver

 *

 * Copyright (C) 2011  Kuninori Morimoto

 *

 * Based on spi-sh.c:

 * Based on pxa2xx_spi.c:

 * Copyright (C) 2011 Renesas Solutions Corp.

 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs

 */

​

#include <linux/clk.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/timer.h>

#include <linux/delay.h>

#include <linux/list.h>

#include <linux/interrupt.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/io.h>

#include <linux/spi/spi.h>

#include <linux/spi/sh_hspi.h>

​

#define SPCR    0x00

#define SPSR    0x04

#define SPSCR   0x08

#define SPTBR   0x0C

#define SPRBR   0x10

#define SPCR2   0x14

​

/* SPSR */

#define RXFL    (1 << 2)

​

struct hspi_priv {

    void __iomem *addr;

    struct spi_controller *ctlr;

    struct device *dev;

    struct clk *clk;

};

​

/*

 *      basic function

 */

static void hspi_write(struct hspi_priv *hspi, int reg, u32 val)

{

    iowrite32(val, hspi->addr + reg);

}

​

static u32 hspi_read(struct hspi_priv *hspi, int reg)

{

    return ioread32(hspi->addr + reg);

}

​

static void hspi_bit_set(struct hspi_priv *hspi, int reg, u32 mask, u32 set)

{

    u32 val = hspi_read(hspi, reg);

​

    val &= ~mask;

    val |= set & mask;

​

    hspi_write(hspi, reg, val);

}

​

/*

 *      transfer function

 */

static int hspi_status_check_timeout(struct hspi_priv *hspi, u32 mask, u32 val)

{

    int t = 256;

​

    while (t--) {

        if ((mask & hspi_read(hspi, SPSR)) == val)

            return 0;

​

        udelay(10);

    }

​

    dev_err(hspi->dev, "timeout\n");

    return -ETIMEDOUT;

}

​

/*

 *      spi master function

 */

​

#define hspi_hw_cs_enable(hspi)     hspi_hw_cs_ctrl(hspi, 0)

#define hspi_hw_cs_disable(hspi)    hspi_hw_cs_ctrl(hspi, 1)

static void hspi_hw_cs_ctrl(struct hspi_priv *hspi, int hi)

{

    hspi_bit_set(hspi, SPSCR, (1 << 6), (hi) << 6);