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

#include <common.h>
#include <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>

DECLARE_GLOBAL_DATA_PTR;

int pinctrl_decode_pin_config(const void *blob, int node)
{
        int flags = 0;

        if (fdtdec_get_bool(blob, node, "bias-pull-up"))
                flags |= 1 << PIN_CONFIG_BIAS_PULL_UP;
        else if (fdtdec_get_bool(blob, node, "bias-pull-down"))
                flags |= 1 << PIN_CONFIG_BIAS_PULL_DOWN;

        return flags;
}

#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)
{
        const void *fdt = gd->fdt_blob;
        int node = dev_of_offset(dev);
        char propname[32]; /* long enough */
        const fdt32_t *list;
        uint32_t phandle;
        int config_node;
        struct udevice *config;
        int state, size, i, ret;

        state = fdt_stringlist_search(fdt, node, "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 = simple_strtoul(statename, &end, 10);
                if (*end)
                        return -EINVAL;
        }

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

        size /= sizeof(*list);
        for (i = 0; i < size; i++) {
                phandle = fdt32_to_cpu(*list++);

                config_node = fdt_node_offset_by_phandle(fdt, phandle);
                if (config_node < 0) {
                        dev_err(dev, "prop %s index %d invalid phandle\n",
                                propname, i);
                        return -EINVAL;
                }
                ret = uclass_get_device_by_of_offset(UCLASS_PINCONFIG,
                                                     config_node, &config);
                if (ret)
                        return ret;

                ret = pinctrl_config_one(config);
                if (ret)
                        return ret;
        }

        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;

        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 (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,
        .post_bind = pinconfig_post_bind,
        .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

/**
 * 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 simplicity, assume the first device of PINCTRL uclass
         * is the correct one.  This is most likely OK as there is
         * usually only one pinctrl device on the system.
         */
        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)
{
        /*
         * 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);
}

/**
 * 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 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,
        .post_bind = pinctrl_post_bind,
        .flags = DM_UC_FLAG_SEQ_ALIAS,
        .name = "pinctrl",
};