// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2021~2022 NXP
 *
 * The driver exports a standard gpiochip interface
 * to control the PIN resources on SCU domain.
 */

#include <linux/cleanup.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/firmware/imx/svc/rm.h>
#include <dt-bindings/firmware/imx/rsrc.h>

struct scu_gpio_priv {
        struct gpio_chip        chip;
        struct mutex            lock;
        struct device           *dev;
        struct imx_sc_ipc       *handle;
};

static unsigned int scu_rsrc_arr[] = {
        IMX_SC_R_BOARD_R0,
        IMX_SC_R_BOARD_R1,
        IMX_SC_R_BOARD_R2,
        IMX_SC_R_BOARD_R3,
        IMX_SC_R_BOARD_R4,
        IMX_SC_R_BOARD_R5,
        IMX_SC_R_BOARD_R6,
        IMX_SC_R_BOARD_R7,
};

static int imx_scu_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
        struct scu_gpio_priv *priv = gpiochip_get_data(chip);
        int level;
        int err;

        scoped_guard(mutex, &priv->lock) {
                /* to read PIN state via scu api */
                err = imx_sc_misc_get_control(priv->handle,
                                              scu_rsrc_arr[offset], 0, &level);
        }
        if (err) {
                dev_err(priv->dev, "SCU get failed: %d\n", err);
                return err;
        }

        return level;
}

static int imx_scu_gpio_set(struct gpio_chip *chip, unsigned int offset,
                            int value)
{
        struct scu_gpio_priv *priv = gpiochip_get_data(chip);
        int err;

        scoped_guard(mutex, &priv->lock) {
                /* to set PIN output level via scu api */
                err = imx_sc_misc_set_control(priv->handle,
                                              scu_rsrc_arr[offset], 0, value);
        }
        if (err)
                dev_err(priv->dev, "SCU set (%d) failed: %d\n",
                                scu_rsrc_arr[offset], err);

        return err;
}

static int imx_scu_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
        return GPIO_LINE_DIRECTION_OUT;
}

static int imx_scu_gpio_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct scu_gpio_priv *priv;
        struct gpio_chip *gc;
        int ret;

        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        ret = imx_scu_get_handle(&priv->handle);
        if (ret)
                return ret;

        priv->dev = dev;

        ret = devm_mutex_init(&pdev->dev, &priv->lock);
        if (ret)
                return ret;

        gc = &priv->chip;
        gc->base = -1;
        gc->parent = dev;
        gc->ngpio = ARRAY_SIZE(scu_rsrc_arr);
        gc->label = dev_name(dev);
        gc->get = imx_scu_gpio_get;
        gc->set = imx_scu_gpio_set;
        gc->get_direction = imx_scu_gpio_get_direction;

        platform_set_drvdata(pdev, priv);

        return devm_gpiochip_add_data(dev, gc, priv);
}

static const struct of_device_id imx_scu_gpio_dt_ids[] = {
        { .compatible = "fsl,imx8qxp-sc-gpio" },
        { /* sentinel */ }
};

static struct platform_driver imx_scu_gpio_driver = {
        .driver = {
                .name = "gpio-imx-scu",
                .of_match_table = imx_scu_gpio_dt_ids,
        },
        .probe = imx_scu_gpio_probe,
};

static int __init _imx_scu_gpio_init(void)
{
        return platform_driver_register(&imx_scu_gpio_driver);
}

subsys_initcall_sync(_imx_scu_gpio_init);

MODULE_AUTHOR("Shenwei Wang <shenwei.wang@nxp.com>");
MODULE_DESCRIPTION("NXP GPIO over IMX SCU API");