/*
 * Copyright (c) 2009 Wind River Systems, Inc.
 * Tom Rix <Tom.Rix@windriver.com>
 *
 * SPDX-License-Identifier:     GPL-2.0
 *
 * This work is derived from the linux 2.6.27 kernel source
 * To fetch, use the kernel repository
 * git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
 * Use the v2.6.27 tag.
 *
 * Below is the original's header including its copyright
 *
 *  linux/arch/arm/plat-omap/gpio.c
 *
 * Support functions for OMAP GPIO
 *
 * Copyright (C) 2003-2005 Nokia Corporation
 * Written by Juha Yrjölä <juha.yrjola@nokia.com>
 */
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <malloc.h>

DECLARE_GLOBAL_DATA_PTR;

#define OMAP_GPIO_DIR_OUT       0
#define OMAP_GPIO_DIR_IN        1

#ifdef CONFIG_DM_GPIO

#define GPIO_PER_BANK                   32

struct gpio_bank {
        /* TODO(sjg@chromium.org): Can we use a struct here? */
        void *base;     /* address of registers in physical memory */
};

#endif

static inline int get_gpio_index(int gpio)
{
        return gpio & 0x1f;
}

int gpio_is_valid(int gpio)
{
        return (gpio >= 0) && (gpio < OMAP_MAX_GPIO);
}

static void _set_gpio_direction(const struct gpio_bank *bank, int gpio,
                                int is_input)
{
        void *reg = bank->base;
        u32 l;

        reg += OMAP_GPIO_OE;

        l = __raw_readl(reg);
        if (is_input)
                l |= 1 << gpio;
        else
                l &= ~(1 << gpio);
        __raw_writel(l, reg);
}

/**
 * Get the direction of the GPIO by reading the GPIO_OE register
 * corresponding to the specified bank.
 */
static int _get_gpio_direction(const struct gpio_bank *bank, int gpio)
{
        void *reg = bank->base;
        u32 v;

        reg += OMAP_GPIO_OE;

        v = __raw_readl(reg);

        if (v & (1 << gpio))
                return OMAP_GPIO_DIR_IN;
        else
                return OMAP_GPIO_DIR_OUT;
}

static void _set_gpio_dataout(const struct gpio_bank *bank, int gpio,
                                int enable)
{
        void *reg = bank->base;
        u32 l = 0;

        if (enable)
                reg += OMAP_GPIO_SETDATAOUT;
        else
                reg += OMAP_GPIO_CLEARDATAOUT;

        l = 1 << gpio;
        __raw_writel(l, reg);
}

static int _get_gpio_value(const struct gpio_bank *bank, int gpio)
{
        void *reg = bank->base;
        int input;

        input = _get_gpio_direction(bank, gpio);
        switch (input) {
        case OMAP_GPIO_DIR_IN:
                reg += OMAP_GPIO_DATAIN;
                break;
        case OMAP_GPIO_DIR_OUT:
                reg += OMAP_GPIO_DATAOUT;
                break;
        default:
                return -1;
        }

        return (__raw_readl(reg) & (1 << gpio)) != 0;
}

#ifndef CONFIG_DM_GPIO

static inline const struct gpio_bank *get_gpio_bank(int gpio)
{
        return &omap_gpio_bank[gpio >> 5];
}

static int check_gpio(int gpio)
{
        if (!gpio_is_valid(gpio)) {
                printf("ERROR : check_gpio: invalid GPIO %d\n", gpio);
                return -1;
        }
        return 0;
}

/**
 * Set value of the specified gpio
 */
int gpio_set_value(unsigned gpio, int value)
{
        const struct gpio_bank *bank;

        if (check_gpio(gpio) < 0)
                return -1;
        bank = get_gpio_bank(gpio);
        _set_gpio_dataout(bank, get_gpio_index(gpio), value);

        return 0;
}

/**
 * Get value of the specified gpio
 */
int gpio_get_value(unsigned gpio)
{
        const struct gpio_bank *bank;

        if (check_gpio(gpio) < 0)
                return -1;
        bank = get_gpio_bank(gpio);

        return _get_gpio_value(bank, get_gpio_index(gpio));
}

/**
 * Set gpio direction as input
 */
int gpio_direction_input(unsigned gpio)
{
        const struct gpio_bank *bank;

        if (check_gpio(gpio) < 0)
                return -1;

        bank = get_gpio_bank(gpio);
        _set_gpio_direction(bank, get_gpio_index(gpio), 1);

        return 0;
}

/**
 * Set gpio direction as output
 */
int gpio_direction_output(unsigned gpio, int value)
{
        const struct gpio_bank *bank;

        if (check_gpio(gpio) < 0)
                return -1;

        bank = get_gpio_bank(gpio);
        _set_gpio_dataout(bank, get_gpio_index(gpio), value);
        _set_gpio_direction(bank, get_gpio_index(gpio), 0);

        return 0;
}

/**
 * Request a gpio before using it.
 *
 * NOTE: Argument 'label' is unused.
 */
int gpio_request(unsigned gpio, const char *label)
{
        if (check_gpio(gpio) < 0)
                return -1;

        return 0;
}

/**
 * Reset and free the gpio after using it.
 */
int gpio_free(unsigned gpio)
{
        return 0;
}

#else /* new driver model interface CONFIG_DM_GPIO */

/* set GPIO pin 'gpio' as an input */
static int omap_gpio_direction_input(struct udevice *dev, unsigned offset)
{
        struct gpio_bank *bank = dev_get_priv(dev);

        /* Configure GPIO direction as input. */
        _set_gpio_direction(bank, offset, 1);

        return 0;
}

/* set GPIO pin 'gpio' as an output, with polarity 'value' */
static int omap_gpio_direction_output(struct udevice *dev, unsigned offset,
                                       int value)
{
        struct gpio_bank *bank = dev_get_priv(dev);

        _set_gpio_dataout(bank, offset, value);
        _set_gpio_direction(bank, offset, 0);

        return 0;
}

/* read GPIO IN value of pin 'gpio' */
static int omap_gpio_get_value(struct udevice *dev, unsigned offset)
{
        struct gpio_bank *bank = dev_get_priv(dev);

        return _get_gpio_value(bank, offset);
}

/* write GPIO OUT value to pin 'gpio' */
static int omap_gpio_set_value(struct udevice *dev, unsigned offset,
                                 int value)
{
        struct gpio_bank *bank = dev_get_priv(dev);

        _set_gpio_dataout(bank, offset, value);

        return 0;
}

static int omap_gpio_get_function(struct udevice *dev, unsigned offset)
{
        struct gpio_bank *bank = dev_get_priv(dev);

        /* GPIOF_FUNC is not implemented yet */
        if (_get_gpio_direction(bank, offset) == OMAP_GPIO_DIR_OUT)
                return GPIOF_OUTPUT;
        else
                return GPIOF_INPUT;
}

static const struct dm_gpio_ops gpio_omap_ops = {
        .direction_input        = omap_gpio_direction_input,
        .direction_output       = omap_gpio_direction_output,
        .get_value              = omap_gpio_get_value,
        .set_value              = omap_gpio_set_value,
        .get_function           = omap_gpio_get_function,
};

static int omap_gpio_probe(struct udevice *dev)
{
        struct gpio_bank *bank = dev_get_priv(dev);
        struct omap_gpio_platdata *plat = dev_get_platdata(dev);
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);

        uc_priv->bank_name = plat->port_name;
        uc_priv->gpio_count = GPIO_PER_BANK;
        bank->base = (void *)plat->base;

        return 0;
}

static int omap_gpio_bind(struct udevice *dev)
{
        struct omap_gpio_platdata *plat = dev_get_platdata(dev);
        fdt_addr_t base_addr;

        if (plat)
                return 0;

        base_addr = devfdt_get_addr(dev);
        if (base_addr == FDT_ADDR_T_NONE)
                return -EINVAL;

        /*
        * TODO:
        * When every board is converted to driver model and DT is
        * supported, this can be done by auto-alloc feature, but
        * not using calloc to alloc memory for platdata.
        *
        * For example am33xx_gpio uses platform data rather than device tree.
        *
        * NOTE: DO NOT COPY this code if you are using device tree.
        */
        plat = calloc(1, sizeof(*plat));
        if (!plat)
                return -ENOMEM;

        plat->base = base_addr;
        plat->port_name = fdt_get_name(gd->fdt_blob, dev_of_offset(dev), NULL);
        dev->platdata = plat;

        return 0;
}

static const struct udevice_id omap_gpio_ids[] = {
        { .compatible = "ti,omap3-gpio" },
        { .compatible = "ti,omap4-gpio" },
        { .compatible = "ti,am4372-gpio" },
        { }
};

U_BOOT_DRIVER(gpio_omap) = {
        .name   = "gpio_omap",
        .id     = UCLASS_GPIO,
        .ops    = &gpio_omap_ops,
        .of_match = omap_gpio_ids,
        .bind   = omap_gpio_bind,
        .probe  = omap_gpio_probe,
        .priv_auto_alloc_size = sizeof(struct gpio_bank),
};

#endif /* CONFIG_DM_GPIO */