// SPDX-License-Identifier: GPL-2.0
/* DSA driver for:
 * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch
 *
 * This driver takes control of the switch chip connected over CPU-attached
 * address bus and configures it to route packages around when connected to
 * a CPU port.
 *
 * Copyright (C) 2019 Pawel Dembicki <paweldembicki@gmail.com>
 * Based on vitesse-vsc-spi.c by:
 * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org>
 * Includes portions of code from the firmware uploader by:
 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include "vitesse-vsc73xx.h"

#define VSC73XX_CMD_PLATFORM_BLOCK_SHIFT                14
#define VSC73XX_CMD_PLATFORM_BLOCK_MASK                 0x7
#define VSC73XX_CMD_PLATFORM_SUBBLOCK_SHIFT             10
#define VSC73XX_CMD_PLATFORM_SUBBLOCK_MASK              0xf
#define VSC73XX_CMD_PLATFORM_REGISTER_SHIFT             2

/*
 * struct vsc73xx_platform - VSC73xx Platform state container
 */
struct vsc73xx_platform {
        struct platform_device  *pdev;
        void __iomem            *base_addr;
        struct vsc73xx          vsc;
};

static const struct vsc73xx_ops vsc73xx_platform_ops;

static u32 vsc73xx_make_addr(u8 block, u8 subblock, u8 reg)
{
        u32 ret;

        ret = (block & VSC73XX_CMD_PLATFORM_BLOCK_MASK)
            << VSC73XX_CMD_PLATFORM_BLOCK_SHIFT;
        ret |= (subblock & VSC73XX_CMD_PLATFORM_SUBBLOCK_MASK)
            << VSC73XX_CMD_PLATFORM_SUBBLOCK_SHIFT;
        ret |= reg << VSC73XX_CMD_PLATFORM_REGISTER_SHIFT;

        return ret;
}

static int vsc73xx_platform_read(struct vsc73xx *vsc, u8 block, u8 subblock,
                                 u8 reg, u32 *val)
{
        struct vsc73xx_platform *vsc_platform = vsc->priv;
        u32 offset;

        if (!vsc73xx_is_addr_valid(block, subblock))
                return -EINVAL;

        offset = vsc73xx_make_addr(block, subblock, reg);
        /* By default vsc73xx running in big-endian mode.
         * (See "Register Addressing" section 5.5.3 in the VSC7385 manual.)
         */
        *val = ioread32be(vsc_platform->base_addr + offset);

        return 0;
}

static int vsc73xx_platform_write(struct vsc73xx *vsc, u8 block, u8 subblock,
                                  u8 reg, u32 val)
{
        struct vsc73xx_platform *vsc_platform = vsc->priv;
        u32 offset;

        if (!vsc73xx_is_addr_valid(block, subblock))
                return -EINVAL;

        offset = vsc73xx_make_addr(block, subblock, reg);
        iowrite32be(val, vsc_platform->base_addr + offset);

        return 0;
}

static int vsc73xx_platform_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct vsc73xx_platform *vsc_platform;
        int ret;

        vsc_platform = devm_kzalloc(dev, sizeof(*vsc_platform), GFP_KERNEL);
        if (!vsc_platform)
                return -ENOMEM;

        platform_set_drvdata(pdev, vsc_platform);
        vsc_platform->pdev = pdev;
        vsc_platform->vsc.dev = dev;
        vsc_platform->vsc.priv = vsc_platform;
        vsc_platform->vsc.ops = &vsc73xx_platform_ops;

        /* obtain I/O memory space */
        vsc_platform->base_addr = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(vsc_platform->base_addr)) {
                dev_err(&pdev->dev, "cannot request I/O memory space\n");
                ret = -ENXIO;
                return ret;
        }

        return vsc73xx_probe(&vsc_platform->vsc);
}

static void vsc73xx_platform_remove(struct platform_device *pdev)
{
        struct vsc73xx_platform *vsc_platform = platform_get_drvdata(pdev);

        if (!vsc_platform)
                return;

        vsc73xx_remove(&vsc_platform->vsc);
}

static void vsc73xx_platform_shutdown(struct platform_device *pdev)
{
        struct vsc73xx_platform *vsc_platform = platform_get_drvdata(pdev);

        if (!vsc_platform)
                return;

        vsc73xx_shutdown(&vsc_platform->vsc);

        platform_set_drvdata(pdev, NULL);
}

static const struct vsc73xx_ops vsc73xx_platform_ops = {
        .read = vsc73xx_platform_read,
        .write = vsc73xx_platform_write,
};

static const struct of_device_id vsc73xx_of_match[] = {
        {
                .compatible = "vitesse,vsc7385",
        },
        {
                .compatible = "vitesse,vsc7388",
        },
        {
                .compatible = "vitesse,vsc7395",
        },
        {
                .compatible = "vitesse,vsc7398",
        },
        { },
};
MODULE_DEVICE_TABLE(of, vsc73xx_of_match);

static struct platform_driver vsc73xx_platform_driver = {
        .probe = vsc73xx_platform_probe,
        .remove = vsc73xx_platform_remove,
        .shutdown = vsc73xx_platform_shutdown,
        .driver = {
                .name = "vsc73xx-platform",
                .of_match_table = vsc73xx_of_match,
        },
};
module_platform_driver(vsc73xx_platform_driver);

MODULE_AUTHOR("Pawel Dembicki <paweldembicki@gmail.com>");
MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 Platform driver");
MODULE_LICENSE("GPL v2");