// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Copyright (C) 2012 ARM Limited
 */

#include <linux/gpio/driver.h>
#include <linux/gpio/generic.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/stat.h>

#define SYS_ID                  0x000
#define SYS_SW                  0x004
#define SYS_LED                 0x008
#define SYS_100HZ               0x024
#define SYS_FLAGSSET            0x030
#define SYS_FLAGSCLR            0x034
#define SYS_NVFLAGS             0x038
#define SYS_NVFLAGSSET          0x038
#define SYS_NVFLAGSCLR          0x03c
#define SYS_MCI                 0x048
#define SYS_FLASH               0x04c
#define SYS_CFGSW               0x058
#define SYS_24MHZ               0x05c
#define SYS_MISC                0x060
#define SYS_DMA                 0x064
#define SYS_PROCID0             0x084
#define SYS_PROCID1             0x088
#define SYS_CFGDATA             0x0a0
#define SYS_CFGCTRL             0x0a4
#define SYS_CFGSTAT             0x0a8

/* The sysreg block is just a random collection of various functions... */

static const struct property_entry vexpress_sysreg_sys_led_props[] = {
        PROPERTY_ENTRY_STRING("label", "sys_led"),
        PROPERTY_ENTRY_U32("ngpios", 8),
        { }
};

static const struct software_node vexpress_sysreg_sys_led_swnode = {
        .properties = vexpress_sysreg_sys_led_props,
};

static const struct property_entry vexpress_sysreg_sys_mci_props[] = {
        PROPERTY_ENTRY_STRING("label", "sys_mci"),
        PROPERTY_ENTRY_U32("ngpios", 2),
        { }
};

static const struct software_node vexpress_sysreg_sys_mci_swnode = {
        .properties = vexpress_sysreg_sys_mci_props,
};

static const struct property_entry vexpress_sysreg_sys_flash_props[] = {
        PROPERTY_ENTRY_STRING("label", "sys_flash"),
        PROPERTY_ENTRY_U32("ngpios", 1),
        { }
};

static const struct software_node vexpress_sysreg_sys_flash_swnode = {
        .properties = vexpress_sysreg_sys_flash_props,
};

static struct mfd_cell vexpress_sysreg_cells[] = {
        {
                .name = "basic-mmio-gpio",
                .of_compatible = "arm,vexpress-sysreg,sys_led",
                .num_resources = 1,
                .resources = &DEFINE_RES_MEM_NAMED(SYS_LED, 0x4, "dat"),
                .swnode = &vexpress_sysreg_sys_led_swnode,
        }, {
                .name = "basic-mmio-gpio",
                .of_compatible = "arm,vexpress-sysreg,sys_mci",
                .num_resources = 1,
                .resources = &DEFINE_RES_MEM_NAMED(SYS_MCI, 0x4, "dat"),
                .swnode = &vexpress_sysreg_sys_mci_swnode,
        }, {
                .name = "basic-mmio-gpio",
                .of_compatible = "arm,vexpress-sysreg,sys_flash",
                .num_resources = 1,
                .resources = &DEFINE_RES_MEM_NAMED(SYS_FLASH, 0x4, "dat"),
                .swnode = &vexpress_sysreg_sys_flash_swnode,
        }, {
                .name = "vexpress-syscfg",
                .num_resources = 1,
                .resources = &DEFINE_RES_MEM(SYS_MISC, 0x4c),
        }
};

static int vexpress_sysreg_probe(struct platform_device *pdev)
{
        struct gpio_generic_chip *mmc_gpio_chip;
        struct gpio_generic_chip_config config;
        struct resource *mem;
        void __iomem *base;
        int ret;

        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!mem)
                return -EINVAL;

        base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
        if (!base)
                return -ENOMEM;

        /*
         * Duplicated SYS_MCI pseudo-GPIO controller for compatibility with
         * older trees using sysreg node for MMC control lines.
         */
        mmc_gpio_chip = devm_kzalloc(&pdev->dev, sizeof(*mmc_gpio_chip),
                        GFP_KERNEL);
        if (!mmc_gpio_chip)
                return -ENOMEM;

        config = (struct gpio_generic_chip_config) {
                .dev = &pdev->dev,
                .sz = 4,
                .dat = base + SYS_MCI,
        };

        ret = gpio_generic_chip_init(mmc_gpio_chip, &config);
        if (ret)
                return ret;

        mmc_gpio_chip->gc.ngpio = 2;

        ret = devm_gpiochip_add_data(&pdev->dev, &mmc_gpio_chip->gc, NULL);
        if (ret)
                return ret;

        return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
                        vexpress_sysreg_cells,
                        ARRAY_SIZE(vexpress_sysreg_cells), mem, 0, NULL);
}

static const struct of_device_id vexpress_sysreg_match[] = {
        { .compatible = "arm,vexpress-sysreg", },
        {},
};
MODULE_DEVICE_TABLE(of, vexpress_sysreg_match);

static struct platform_driver vexpress_sysreg_driver = {
        .driver = {
                .name = "vexpress-sysreg",
                .of_match_table = vexpress_sysreg_match,
        },
        .probe = vexpress_sysreg_probe,
};

module_platform_driver(vexpress_sysreg_driver);
MODULE_DESCRIPTION("Versatile Express system registers driver");
MODULE_LICENSE("GPL v2");