linux-imx

/*

 * Copyright (C) ST-Ericsson SA 2010

 *

 * License Terms: GNU General Public License, version 2

 * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson

 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson

 */

​

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/gpio/driver.h>

#include <linux/of.h>

#include <linux/interrupt.h>

#include <linux/mfd/tc3589x.h>

#include <linux/bitops.h>

​

/*

 * These registers are modified under the irq bus lock and cached to avoid

 * unnecessary writes in bus_sync_unlock.

 */

enum { REG_IBE, REG_IEV, REG_IS, REG_IE };

​

#define CACHE_NR_REGS   4

#define CACHE_NR_BANKS  3

​

struct tc3589x_gpio {

    struct gpio_chip chip;

    struct tc3589x *tc3589x;

    struct device *dev;

    struct mutex irq_lock;

    /* Caches of interrupt control registers for bus_lock */

    u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];

    u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];

};

​

static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned int offset)

{

    struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);

    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;

    u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;

    u8 mask = BIT(offset % 8);

    int ret;

​

    ret = tc3589x_reg_read(tc3589x, reg);

    if (ret < 0)

        return ret;

​

    return !!(ret & mask);

}

​

static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned int offset, int val)

{

    struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);

    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;

    u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;

    unsigned int pos = offset % 8;

    u8 data[] = {val ? BIT(pos) : 0, BIT(pos)};

​

    tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);

}

​

static int tc3589x_gpio_direction_output(struct gpio_chip *chip,

                     unsigned int offset, int val)

{

    struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);

    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;

    u8 reg = TC3589x_GPIODIR0 + offset / 8;

    unsigned int pos = offset % 8;

​

    tc3589x_gpio_set(chip, offset, val);

​

    return tc3589x_set_bits(tc3589x, reg, BIT(pos), BIT(pos));

}

​

static int tc3589x_gpio_direction_input(struct gpio_chip *chip,

                    unsigned int offset)

{

    struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);

    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;

    u8 reg = TC3589x_GPIODIR0 + offset / 8;

    unsigned int pos = offset % 8;

​

    return tc3589x_set_bits(tc3589x, reg, BIT(pos), 0);

}

​

static int tc3589x_gpio_get_direction(struct gpio_chip *chip,

                      unsigned int offset)

{

    struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);

    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;

    u8 reg = TC3589x_GPIODIR0 + offset / 8;