// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2015  Masahiro Yamada <yamada.masahiro@socionext.com>
 */

#define LOG_CATEGORY UCLASS_PINCTRL

#include <common.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <dm/device_compat.h>
#include <linux/libfdt.h>
#include <linux/err.h>
#include <linux/list.h>
#include <dm.h>
#include <dm/lists.h>
#include <dm/pinctrl.h>
#include <dm/util.h>
#include <dm/of_access.h>

DECLARE_GLOBAL_DATA_PTR;

#if CONFIG_IS_ENABLED(PINCTRL_FULL)
/**
 * pinctrl_config_one() - apply pinctrl settings for a single node
 *
 * @config: pin configuration node
 * @return: 0 on success, or negative error code on failure
 */
static int pinctrl_config_one(struct udevice *config)
{
        struct udevice *pctldev;
        const struct pinctrl_ops *ops;

        pctldev = config;
        for (;;) {
                pctldev = dev_get_parent(pctldev);
                if (!pctldev) {
                        dev_err(config, "could not find pctldev\n");
                        return -EINVAL;
                }
                if (pctldev->uclass->uc_drv->id == UCLASS_PINCTRL)
                        break;
        }

        ops = pinctrl_get_ops(pctldev);
        return ops->set_state(pctldev, config);
}

/**
 * pinctrl_select_state_full() - full implementation of pinctrl_select_state
 *
 * @dev: peripheral device
 * @statename: state name, like "default"
 * @return: 0 on success, or negative error code on failure
 */
static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
{
        char propname[32]; /* long enough */
        const fdt32_t *list;
        uint32_t phandle;
        struct udevice *config;
        int state, size, i, ret;

        state = dev_read_stringlist_search(dev, "pinctrl-names", statename);
        if (state < 0) {
                char *end;
                /*
                 * If statename is not found in "pinctrl-names",
                 * assume statename is just the integer state ID.
                 */
                state = dectoul(statename, &end);
                if (*end)
                        return -EINVAL;
        }

        snprintf(propname, sizeof(propname), "pinctrl-%d", state);
        list = dev_read_prop(dev, propname, &size);
        if (!list)
                return -EINVAL;

        size /= sizeof(*list);
        for (i = 0; i < size; i++) {
                phandle = fdt32_to_cpu(*list++);
                ret = uclass_get_device_by_phandle_id(UCLASS_PINCONFIG, phandle,
                                                      &config);
                if (ret) {
                        dev_warn(dev, "%s: uclass_get_device_by_phandle_id: err=%d\n",
                                __func__, ret);
                        continue;
                }

                ret = pinctrl_config_one(config);
                if (ret) {
                        dev_warn(dev, "%s: pinctrl_config_one: err=%d\n",
                                __func__, ret);
                        continue;
                }
        }

        return 0;
}

/**
 * pinconfig_post_bind() - post binding for PINCONFIG uclass
 * Recursively bind its children as pinconfig devices.
 *
 * @dev: pinconfig device
 * @return: 0 on success, or negative error code on failure
 */
static int pinconfig_post_bind(struct udevice *dev)
{
        bool pre_reloc_only = !(gd->flags & GD_FLG_RELOC);
        const char *name;
        ofnode node;
        int ret;

        if (!dev_has_ofnode(dev))
                return 0;

        dev_for_each_subnode(node, dev) {
                if (pre_reloc_only &&
                    !ofnode_pre_reloc(node))
                        continue;
                /*
                 * If this node has "compatible" property, this is not
                 * a pin configuration node, but a normal device. skip.
                 */
                ofnode_get_property(node, "compatible", &ret);
                if (ret >= 0)
                        continue;
                /* If this node has "gpio-controller" property, skip */
                if (ofnode_read_bool(node, "gpio-controller"))
                        continue;

                if (ret != -FDT_ERR_NOTFOUND)
                        return ret;

                name = ofnode_get_name(node);
                if (!name)
                        return -EINVAL;
                ret = device_bind_driver_to_node(dev, "pinconfig", name,
                                                 node, NULL);
                if (ret)
                        return ret;
        }

        return 0;
}

UCLASS_DRIVER(pinconfig) = {
        .id = UCLASS_PINCONFIG,
#if CONFIG_IS_ENABLED(PINCONF_RECURSIVE)
        .post_bind = pinconfig_post_bind,
#endif
        .name = "pinconfig",
};

U_BOOT_DRIVER(pinconfig_generic) = {
        .name = "pinconfig",
        .id = UCLASS_PINCONFIG,
};

#else
static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
{
        return -ENODEV;
}

static int pinconfig_post_bind(struct udevice *dev)
{
        return 0;
}
#endif

static int
pinctrl_gpio_get_pinctrl_and_offset(struct udevice *dev, unsigned offset,
                                    struct udevice **pctldev,
                                    unsigned int *pin_selector)
{
        struct ofnode_phandle_args args;
        unsigned gpio_offset, pfc_base, pfc_pins;
        int ret;

        ret = dev_read_phandle_with_args(dev, "gpio-ranges", NULL, 3,
                                         0, &args);
        if (ret) {
                dev_dbg(dev, "%s: dev_read_phandle_with_args: err=%d\n",
                        __func__, ret);
                return ret;
        }

        ret = uclass_get_device_by_ofnode(UCLASS_PINCTRL,
                                          args.node, pctldev);
        if (ret) {
                dev_dbg(dev,
                        "%s: uclass_get_device_by_of_offset failed: err=%d\n",
                        __func__, ret);
                return ret;
        }

        gpio_offset = args.args[0];
        pfc_base = args.args[1];
        pfc_pins = args.args[2];

        if (offset < gpio_offset || offset > gpio_offset + pfc_pins) {
                dev_dbg(dev,
                        "%s: GPIO can not be mapped to pincontrol pin\n",
                        __func__);
                return -EINVAL;
        }

        offset -= gpio_offset;
        offset += pfc_base;
        *pin_selector = offset;

        return 0;
}

/**
 * pinctrl_gpio_request() - request a single pin to be used as GPIO
 *
 * @dev: GPIO peripheral device
 * @offset: the GPIO pin offset from the GPIO controller
 * @return: 0 on success, or negative error code on failure
 */
int pinctrl_gpio_request(struct udevice *dev, unsigned offset)
{
        const struct pinctrl_ops *ops;
        struct udevice *pctldev;
        unsigned int pin_selector;
        int ret;

        ret = pinctrl_gpio_get_pinctrl_and_offset(dev, offset,
                                                  &pctldev, &pin_selector);
        if (ret)
                return ret;

        ops = pinctrl_get_ops(pctldev);
        assert(ops);
        if (!ops->gpio_request_enable)
                return -ENOSYS;

        return ops->gpio_request_enable(pctldev, pin_selector);
}

/**
 * pinctrl_gpio_free() - free a single pin used as GPIO
 *
 * @dev: GPIO peripheral device
 * @offset: the GPIO pin offset from the GPIO controller
 * @return: 0 on success, or negative error code on failure
 */
int pinctrl_gpio_free(struct udevice *dev, unsigned offset)
{
        const struct pinctrl_ops *ops;
        struct udevice *pctldev;
        unsigned int pin_selector;
        int ret;

        ret = pinctrl_gpio_get_pinctrl_and_offset(dev, offset,
                                                  &pctldev, &pin_selector);
        if (ret)
                return ret;

        ops = pinctrl_get_ops(pctldev);
        assert(ops);
        if (!ops->gpio_disable_free)
                return -ENOSYS;

        return ops->gpio_disable_free(pctldev, pin_selector);
}

/**
 * pinctrl_select_state_simple() - simple implementation of pinctrl_select_state
 *
 * @dev: peripheral device
 * @return: 0 on success, or negative error code on failure
 */
static int pinctrl_select_state_simple(struct udevice *dev)
{
        struct udevice *pctldev;
        struct pinctrl_ops *ops;
        int ret;

        /*
         * For most system, there is only one pincontroller device. But in
         * case of multiple pincontroller devices, probe the one with sequence
         * number 0 (defined by alias) to avoid race condition.
         */
        ret = uclass_get_device_by_seq(UCLASS_PINCTRL, 0, &pctldev);
        if (ret)
                /* if not found, get the first one */
                ret = uclass_get_device(UCLASS_PINCTRL, 0, &pctldev);
        if (ret)
                return ret;

        ops = pinctrl_get_ops(pctldev);
        if (!ops->set_state_simple) {
                dev_dbg(dev, "set_state_simple op missing\n");
                return -ENOSYS;
        }

        return ops->set_state_simple(pctldev, dev);
}

int pinctrl_select_state(struct udevice *dev, const char *statename)
{
        /*
         * Some device which is logical like mmc.blk, do not have
         * a valid ofnode.
         */
        if (!dev_has_ofnode(dev))
                return 0;
        /*
         * Try full-implemented pinctrl first.
         * If it fails or is not implemented, try simple one.
         */
        if (pinctrl_select_state_full(dev, statename))
                return pinctrl_select_state_simple(dev);

        return 0;
}

int pinctrl_request(struct udevice *dev, int func, int flags)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->request)
                return -ENOSYS;

        return ops->request(dev, func, flags);
}

int pinctrl_request_noflags(struct udevice *dev, int func)
{
        return pinctrl_request(dev, func, 0);
}

int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->get_periph_id)
                return -ENOSYS;

        return ops->get_periph_id(dev, periph);
}

int pinctrl_get_gpio_mux(struct udevice *dev, int banknum, int index)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->get_gpio_mux)
                return -ENOSYS;

        return ops->get_gpio_mux(dev, banknum, index);
}

int pinctrl_get_pins_count(struct udevice *dev)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->get_pins_count)
                return -ENOSYS;

        return ops->get_pins_count(dev);
}

int pinctrl_get_pin_name(struct udevice *dev, int selector, char *buf,
                         int size)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->get_pin_name)
                return -ENOSYS;

        snprintf(buf, size, ops->get_pin_name(dev, selector));

        return 0;
}

int pinctrl_get_pin_muxing(struct udevice *dev, int selector, char *buf,
                           int size)
{
        struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops->get_pin_muxing)
                return -ENOSYS;

        return ops->get_pin_muxing(dev, selector, buf, size);
}

/**
 * pinconfig_post_bind() - post binding for PINCTRL uclass
 * Recursively bind child nodes as pinconfig devices in case of full pinctrl.
 *
 * @dev: pinctrl device
 * @return: 0 on success, or negative error code on failure
 */
static int __maybe_unused pinctrl_post_bind(struct udevice *dev)
{
        const struct pinctrl_ops *ops = pinctrl_get_ops(dev);

        if (!ops) {
                dev_dbg(dev, "ops is not set.  Do not bind.\n");
                return -EINVAL;
        }

        /*
         * If set_state callback is set, we assume this pinctrl driver is the
         * full implementation.  In this case, its child nodes should be bound
         * so that peripheral devices can easily search in parent devices
         * during later DT-parsing.
         */
        if (ops->set_state)
                return pinconfig_post_bind(dev);

        return 0;
}

UCLASS_DRIVER(pinctrl) = {
        .id = UCLASS_PINCTRL,
#if CONFIG_IS_ENABLED(OF_REAL)
        .post_bind = pinctrl_post_bind,
#endif
        .flags = DM_UC_FLAG_SEQ_ALIAS,
        .name = "pinctrl",
};