// 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;
	struct resource *res = NULL;
	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 */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "cannot obtain I/O memory space\n");
		ret = -ENXIO;
		return ret;
	}

	vsc_platform->base_addr = devm_ioremap_resource(&pdev->dev, res);
	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 int vsc73xx_platform_remove(struct platform_device *pdev)
{
	struct vsc73xx_platform *vsc_platform = platform_get_drvdata(pdev);

	return vsc73xx_remove(&vsc_platform->vsc);
}

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,
	.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");