linux-imx

#include <linux/amba/bus.h>

#include <linux/amba/clcd.h>

#include <linux/gpio/consumer.h>

#include <linux/of.h>

#include <linux/of_graph.h>

#include <linux/delay.h>

#include <linux/bitops.h>

#include <linux/mfd/syscon.h>

#include <linux/regmap.h>

​

#include "amba-clcd-nomadik.h"

​

static struct gpio_desc *grestb;

static struct gpio_desc *scen;

static struct gpio_desc *scl;

static struct gpio_desc *sda;

​

static u8 tpg110_readwrite_reg(bool write, u8 address, u8 outval)

{

    int i;

    u8 inval = 0;

​

    /* Assert SCEN */

    gpiod_set_value_cansleep(scen, 1);

    ndelay(150);

    /* Hammer out the address */

    for (i = 5; i >= 0; i--) {

        if (address & BIT(i))

            gpiod_set_value_cansleep(sda, 1);

        else

            gpiod_set_value_cansleep(sda, 0);

        ndelay(150);

        /* Send an SCL pulse */

        gpiod_set_value_cansleep(scl, 1);

        ndelay(160);

        gpiod_set_value_cansleep(scl, 0);

        ndelay(160);

    }

​

    if (write) {

        /* WRITE */

        gpiod_set_value_cansleep(sda, 0);

    } else {

        /* READ */

        gpiod_set_value_cansleep(sda, 1);

    }

    ndelay(150);

    /* Send an SCL pulse */

    gpiod_set_value_cansleep(scl, 1);

    ndelay(160);

    gpiod_set_value_cansleep(scl, 0);

    ndelay(160);

​

    if (!write)

        /* HiZ turn-around cycle */

        gpiod_direction_input(sda);

    ndelay(150);

    /* Send an SCL pulse */

    gpiod_set_value_cansleep(scl, 1);

    ndelay(160);

    gpiod_set_value_cansleep(scl, 0);

    ndelay(160);

​

    /* Hammer in/out the data */

    for (i = 7; i >= 0; i--) {

        int value;

​

        if (write) {

            value = !!(outval & BIT(i));

            gpiod_set_value_cansleep(sda, value);

        } else {

            value = gpiod_get_value(sda);

            if (value)

                inval |= BIT(i);

        }

        ndelay(150);

        /* Send an SCL pulse */

        gpiod_set_value_cansleep(scl, 1);

        ndelay(160);

        gpiod_set_value_cansleep(scl, 0);

        ndelay(160);

    }

​

    gpiod_direction_output(sda, 0);

    /* Deassert SCEN */

    gpiod_set_value_cansleep(scen, 0);

    /* Satisfies SCEN pulse width */

    udelay(1);

​

    return inval;

}

​