/*
 * Copyright (c) 2013 Google, Inc
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <malloc.h>
#include <asm/gpio.h>
#include <linux/ctype.h>

DECLARE_GLOBAL_DATA_PTR;

/**
 * gpio_to_device() - Convert global GPIO number to device, number
 *
 * Convert the GPIO number to an entry in the list of GPIOs
 * or GPIO blocks registered with the GPIO controller. Returns
 * entry on success, NULL on error.
 *
 * @gpio:       The numeric representation of the GPIO
 * @desc:       Returns description (desc->flags will always be 0)
 * @return 0 if found, -ENOENT if not found
 */
static int gpio_to_device(unsigned int gpio, struct gpio_desc *desc)
{
        struct gpio_dev_priv *uc_priv;
        struct udevice *dev;
        int ret;

        for (ret = uclass_first_device(UCLASS_GPIO, &dev);
             dev;
             ret = uclass_next_device(&dev)) {
                uc_priv = dev_get_uclass_priv(dev);
                if (gpio >= uc_priv->gpio_base &&
                    gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
                        desc->dev = dev;
                        desc->offset = gpio - uc_priv->gpio_base;
                        desc->flags = 0;
                        return 0;
                }
        }

        /* No such GPIO */
        return ret ? ret : -ENOENT;
}

int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc)
{
        struct gpio_dev_priv *uc_priv = NULL;
        struct udevice *dev;
        ulong offset;
        int numeric;
        int ret;

        numeric = isdigit(*name) ? simple_strtoul(name, NULL, 10) : -1;
        for (ret = uclass_first_device(UCLASS_GPIO, &dev);
             dev;
             ret = uclass_next_device(&dev)) {
                int len;

                uc_priv = dev_get_uclass_priv(dev);
                if (numeric != -1) {
                        offset = numeric - uc_priv->gpio_base;
                        /* Allow GPIOs to be numbered from 0 */
                        if (offset >= 0 && offset < uc_priv->gpio_count)
                                break;
                }

                len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;

                if (!strncasecmp(name, uc_priv->bank_name, len)) {
                        if (!strict_strtoul(name + len, 10, &offset))
                                break;
                }
        }

        if (!dev)
                return ret ? ret : -EINVAL;

        desc->dev = dev;
        desc->offset = offset;

        return 0;
}

int gpio_lookup_name(const char *name, struct udevice **devp,
                     unsigned int *offsetp, unsigned int *gpiop)
{
        struct gpio_desc desc;
        int ret;

        if (devp)
                *devp = NULL;
        ret = dm_gpio_lookup_name(name, &desc);
        if (ret)
                return ret;

        if (devp)
                *devp = desc.dev;
        if (offsetp)
                *offsetp = desc.offset;
        if (gpiop) {
                struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(desc.dev);

                *gpiop = uc_priv->gpio_base + desc.offset;
        }

        return 0;
}

static int gpio_find_and_xlate(struct gpio_desc *desc,
                               struct fdtdec_phandle_args *args)
{
        struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);

        /* Use the first argument as the offset by default */
        if (args->args_count > 0)
                desc->offset = args->args[0];
        else
                desc->offset = -1;
        desc->flags = 0;

        return ops->xlate ? ops->xlate(desc->dev, desc, args) : 0;
}

int dm_gpio_request(struct gpio_desc *desc, const char *label)
{
        struct udevice *dev = desc->dev;
        struct gpio_dev_priv *uc_priv;
        char *str;
        int ret;

        uc_priv = dev_get_uclass_priv(dev);
        if (uc_priv->name[desc->offset])
                return -EBUSY;
        str = strdup(label);
        if (!str)
                return -ENOMEM;
        if (gpio_get_ops(dev)->request) {
                ret = gpio_get_ops(dev)->request(dev, desc->offset, label);
                if (ret) {
                        free(str);
                        return ret;
                }
        }
        uc_priv->name[desc->offset] = str;

        return 0;
}

static int dm_gpio_requestf(struct gpio_desc *desc, const char *fmt, ...)
{
        va_list args;
        char buf[40];

        va_start(args, fmt);
        vscnprintf(buf, sizeof(buf), fmt, args);
        va_end(args);
        return dm_gpio_request(desc, buf);
}

/**
 * gpio_request() - [COMPAT] Request GPIO
 * gpio:        GPIO number
 * label:       Name for the requested GPIO
 *
 * The label is copied and allocated so the caller does not need to keep
 * the pointer around.
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_request(unsigned gpio, const char *label)
{
        struct gpio_desc desc;
        int ret;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;

        return dm_gpio_request(&desc, label);
}

/**
 * gpio_requestf() - [COMPAT] Request GPIO
 * @gpio:       GPIO number
 * @fmt:        Format string for the requested GPIO
 * @...:        Arguments for the printf() format string
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_requestf(unsigned gpio, const char *fmt, ...)
{
        va_list args;
        char buf[40];

        va_start(args, fmt);
        vscnprintf(buf, sizeof(buf), fmt, args);
        va_end(args);
        return gpio_request(gpio, buf);
}

int _dm_gpio_free(struct udevice *dev, uint offset)
{
        struct gpio_dev_priv *uc_priv;
        int ret;

        uc_priv = dev_get_uclass_priv(dev);
        if (!uc_priv->name[offset])
                return -ENXIO;
        if (gpio_get_ops(dev)->free) {
                ret = gpio_get_ops(dev)->free(dev, offset);
                if (ret)
                        return ret;
        }

        free(uc_priv->name[offset]);
        uc_priv->name[offset] = NULL;

        return 0;
}

/**
 * gpio_free() - [COMPAT] Relinquish GPIO
 * gpio:        GPIO number
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_free(unsigned gpio)
{
        struct gpio_desc desc;
        int ret;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;

        return _dm_gpio_free(desc.dev, desc.offset);
}

static int check_reserved(struct gpio_desc *desc, const char *func)
{
        struct gpio_dev_priv *uc_priv;

        if (!dm_gpio_is_valid(desc))
                return -ENOENT;

        uc_priv = dev_get_uclass_priv(desc->dev);
        if (!uc_priv->name[desc->offset]) {
                printf("%s: %s: error: gpio %s%d not reserved\n",
                       desc->dev->name, func,
                       uc_priv->bank_name ? uc_priv->bank_name : "",
                       desc->offset);
                return -EBUSY;
        }

        return 0;
}

/**
 * gpio_direction_input() - [COMPAT] Set GPIO direction to input
 * gpio:        GPIO number
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_direction_input(unsigned gpio)
{
        struct gpio_desc desc;
        int ret;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;
        ret = check_reserved(&desc, "dir_input");
        if (ret)
                return ret;

        return gpio_get_ops(desc.dev)->direction_input(desc.dev, desc.offset);
}

/**
 * gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
 * gpio:        GPIO number
 * value:       Logical value to be set on the GPIO pin
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_direction_output(unsigned gpio, int value)
{
        struct gpio_desc desc;
        int ret;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;
        ret = check_reserved(&desc, "dir_output");
        if (ret)
                return ret;

        return gpio_get_ops(desc.dev)->direction_output(desc.dev,
                                                        desc.offset, value);
}

int dm_gpio_get_value(struct gpio_desc *desc)
{
        int value;
        int ret;

        ret = check_reserved(desc, "get_value");
        if (ret)
                return ret;

        value = gpio_get_ops(desc->dev)->get_value(desc->dev, desc->offset);

        return desc->flags & GPIOD_ACTIVE_LOW ? !value : value;
}

int dm_gpio_set_value(struct gpio_desc *desc, int value)
{
        int ret;

        ret = check_reserved(desc, "set_value");
        if (ret)
                return ret;

        if (desc->flags & GPIOD_ACTIVE_LOW)
                value = !value;
        gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value);
        return 0;
}

int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
{
        struct udevice *dev = desc->dev;
        struct dm_gpio_ops *ops = gpio_get_ops(dev);
        int ret;

        ret = check_reserved(desc, "set_dir");
        if (ret)
                return ret;

        if (flags & GPIOD_IS_OUT) {
                int value = flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;

                if (flags & GPIOD_ACTIVE_LOW)
                        value = !value;
                ret = ops->direction_output(dev, desc->offset, value);
        } else  if (flags & GPIOD_IS_IN) {
                ret = ops->direction_input(dev, desc->offset);
        }
        if (ret)
                return ret;
        /*
         * Update desc->flags here, so that GPIO_ACTIVE_LOW is honoured in
         * futures
         */
        desc->flags = flags;

        return 0;
}

int dm_gpio_set_dir(struct gpio_desc *desc)
{
        return dm_gpio_set_dir_flags(desc, desc->flags);
}

/**
 * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
 * gpio:        GPIO number
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns the value of the GPIO pin, or negative value
 * on error.
 */
int gpio_get_value(unsigned gpio)
{
        int ret;

        struct gpio_desc desc;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;
        return dm_gpio_get_value(&desc);
}

/**
 * gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
 * gpio:        GPIO number
 * value:       Logical value to be set on the GPIO pin.
 *
 * This function implements the API that's compatible with current
 * GPIO API used in U-Boot. The request is forwarded to particular
 * GPIO driver. Returns 0 on success, negative value on error.
 */
int gpio_set_value(unsigned gpio, int value)
{
        struct gpio_desc desc;
        int ret;

        ret = gpio_to_device(gpio, &desc);
        if (ret)
                return ret;
        return dm_gpio_set_value(&desc, value);
}

const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
{
        struct gpio_dev_priv *priv;

        /* Must be called on an active device */
        priv = dev_get_uclass_priv(dev);
        assert(priv);

        *bit_count = priv->gpio_count;
        return priv->bank_name;
}

static const char * const gpio_function[GPIOF_COUNT] = {
        "input",
        "output",
        "unused",
        "unknown",
        "func",
};

int get_function(struct udevice *dev, int offset, bool skip_unused,
                 const char **namep)
{
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
        struct dm_gpio_ops *ops = gpio_get_ops(dev);

        BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
        if (!device_active(dev))
                return -ENODEV;
        if (offset < 0 || offset >= uc_priv->gpio_count)
                return -EINVAL;
        if (namep)
                *namep = uc_priv->name[offset];
        if (skip_unused && !uc_priv->name[offset])
                return GPIOF_UNUSED;
        if (ops->get_function) {
                int ret;

                ret = ops->get_function(dev, offset);
                if (ret < 0)
                        return ret;
                if (ret >= ARRAY_SIZE(gpio_function))
                        return -ENODATA;
                return ret;
        }

        return GPIOF_UNKNOWN;
}

int gpio_get_function(struct udevice *dev, int offset, const char **namep)
{
        return get_function(dev, offset, true, namep);
}

int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep)
{
        return get_function(dev, offset, false, namep);
}

int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize)
{
        struct dm_gpio_ops *ops = gpio_get_ops(dev);
        struct gpio_dev_priv *priv;
        char *str = buf;
        int func;
        int ret;
        int len;

        BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));

        *buf = 0;
        priv = dev_get_uclass_priv(dev);
        ret = gpio_get_raw_function(dev, offset, NULL);
        if (ret < 0)
                return ret;
        func = ret;
        len = snprintf(str, buffsize, "%s%d: %s",
                       priv->bank_name ? priv->bank_name : "",
                       offset, gpio_function[func]);
        if (func == GPIOF_INPUT || func == GPIOF_OUTPUT ||
            func == GPIOF_UNUSED) {
                const char *label;
                bool used;

                ret = ops->get_value(dev, offset);
                if (ret < 0)
                        return ret;
                used = gpio_get_function(dev, offset, &label) != GPIOF_UNUSED;
                snprintf(str + len, buffsize - len, ": %d [%c]%s%s",
                         ret,
                         used ? 'x' : ' ',
                         used ? " " : "",
                         label ? label : "");
        }

        return 0;
}

int gpio_claim_vector(const int *gpio_num_array, const char *fmt)
{
        int i, ret;
        int gpio;

        for (i = 0; i < 32; i++) {
                gpio = gpio_num_array[i];
                if (gpio == -1)
                        break;
                ret = gpio_requestf(gpio, fmt, i);
                if (ret)
                        goto err;
                ret = gpio_direction_input(gpio);
                if (ret) {
                        gpio_free(gpio);
                        goto err;
                }
        }

        return 0;
err:
        for (i--; i >= 0; i--)
                gpio_free(gpio_num_array[i]);

        return ret;
}

/*
 * get a number comprised of multiple GPIO values. gpio_num_array points to
 * the array of gpio pin numbers to scan, terminated by -1.
 */
int gpio_get_values_as_int(const int *gpio_list)
{
        int gpio;
        unsigned bitmask = 1;
        unsigned vector = 0;
        int ret;

        while (bitmask &&
               ((gpio = *gpio_list++) != -1)) {
                ret = gpio_get_value(gpio);
                if (ret < 0)
                        return ret;
                else if (ret)
                        vector |= bitmask;
                bitmask <<= 1;
        }

        return vector;
}

static int _gpio_request_by_name_nodev(const void *blob, int node,
                                       const char *list_name, int index,
                                       struct gpio_desc *desc, int flags,
                                       bool add_index)
{
        struct fdtdec_phandle_args args;
        int ret;

        desc->dev = NULL;
        desc->offset = 0;
        ret = fdtdec_parse_phandle_with_args(blob, node, list_name,
                                             "#gpio-cells", 0, index, &args);
        if (ret) {
                debug("%s: fdtdec_parse_phandle_with_args failed\n", __func__);
                goto err;
        }

        ret = uclass_get_device_by_of_offset(UCLASS_GPIO, args.node,
                                             &desc->dev);
        if (ret) {
                debug("%s: uclass_get_device_by_of_offset failed\n", __func__);
                goto err;
        }
        ret = gpio_find_and_xlate(desc, &args);
        if (ret) {
                debug("%s: gpio_find_and_xlate failed\n", __func__);
                goto err;
        }
        ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
                               fdt_get_name(blob, node, NULL),
                               list_name, index);
        if (ret) {
                debug("%s: dm_gpio_requestf failed\n", __func__);
                goto err;
        }
        ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
        if (ret) {
                debug("%s: dm_gpio_set_dir failed\n", __func__);
                goto err;
        }

        return 0;
err:
        debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
              __func__, fdt_get_name(blob, node, NULL), list_name, index, ret);
        return ret;
}

int gpio_request_by_name_nodev(const void *blob, int node,
                               const char *list_name, int index,
                               struct gpio_desc *desc, int flags)
{
        return _gpio_request_by_name_nodev(blob, node, list_name, index, desc,
                                           flags, index > 0);
}

int gpio_request_by_name(struct udevice *dev,  const char *list_name, int index,
                         struct gpio_desc *desc, int flags)
{
        /*
         * This isn't ideal since we don't use dev->name in the debug()
         * calls in gpio_request_by_name(), but we can do this until
         * gpio_request_by_name_nodev() can be dropped.
         */
        return gpio_request_by_name_nodev(gd->fdt_blob, dev->of_offset,
                                          list_name, index, desc, flags);
}

int gpio_request_list_by_name_nodev(const void *blob, int node,
                                    const char *list_name,
                                    struct gpio_desc *desc, int max_count,
                                    int flags)
{
        int count;
        int ret;

        for (count = 0; count < max_count; count++) {
                ret = _gpio_request_by_name_nodev(blob, node, list_name, count,
                                                  &desc[count], flags, true);
                if (ret == -ENOENT)
                        break;
                else if (ret)
                        goto err;
        }

        /* We ran out of GPIOs in the list */
        return count;

err:
        gpio_free_list_nodev(desc, count - 1);

        return ret;
}

int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
                              struct gpio_desc *desc, int max_count,
                              int flags)
{
        /*
         * This isn't ideal since we don't use dev->name in the debug()
         * calls in gpio_request_by_name(), but we can do this until
         * gpio_request_list_by_name_nodev() can be dropped.
         */
        return gpio_request_list_by_name_nodev(gd->fdt_blob, dev->of_offset,
                                               list_name, desc, max_count,
                                               flags);
}

int gpio_get_list_count(struct udevice *dev, const char *list_name)
{
        int ret;

        ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
                                             list_name, "#gpio-cells", 0, -1,
                                             NULL);
        if (ret) {
                debug("%s: Node '%s', property '%s', GPIO count failed: %d\n",
                      __func__, dev->name, list_name, ret);
        }

        return ret;
}

int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc)
{
        /* For now, we don't do any checking of dev */
        return _dm_gpio_free(desc->dev, desc->offset);
}

int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count)
{
        int i;

        /* For now, we don't do any checking of dev */
        for (i = 0; i < count; i++)
                dm_gpio_free(dev, &desc[i]);

        return 0;
}

int gpio_free_list_nodev(struct gpio_desc *desc, int count)
{
        return gpio_free_list(NULL, desc, count);
}

/* We need to renumber the GPIOs when any driver is probed/removed */
static int gpio_renumber(struct udevice *removed_dev)
{
        struct gpio_dev_priv *uc_priv;
        struct udevice *dev;
        struct uclass *uc;
        unsigned base;
        int ret;

        ret = uclass_get(UCLASS_GPIO, &uc);
        if (ret)
                return ret;

        /* Ensure that we have a base for each bank */
        base = 0;
        uclass_foreach_dev(dev, uc) {
                if (device_active(dev) && dev != removed_dev) {
                        uc_priv = dev_get_uclass_priv(dev);
                        uc_priv->gpio_base = base;
                        base += uc_priv->gpio_count;
                }
        }

        return 0;
}

int gpio_get_number(struct gpio_desc *desc)
{
        struct udevice *dev = desc->dev;
        struct gpio_dev_priv *uc_priv;

        if (!dev)
                return -1;
        uc_priv = dev->uclass_priv;

        return uc_priv->gpio_base + desc->offset;
}

static int gpio_post_probe(struct udevice *dev)
{
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);

        uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
        if (!uc_priv->name)
                return -ENOMEM;

        return gpio_renumber(NULL);
}

static int gpio_pre_remove(struct udevice *dev)
{
        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
        int i;

        for (i = 0; i < uc_priv->gpio_count; i++) {
                if (uc_priv->name[i])
                        free(uc_priv->name[i]);
        }
        free(uc_priv->name);

        return gpio_renumber(dev);
}

UCLASS_DRIVER(gpio) = {
        .id             = UCLASS_GPIO,
        .name           = "gpio",
        .flags          = DM_UC_FLAG_SEQ_ALIAS,
        .post_probe     = gpio_post_probe,
        .pre_remove     = gpio_pre_remove,
        .per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
};