// SPDX-License-Identifier: GPL-2.0+

/*
 * PC-Engines APUv2/APUv3 board platform driver
 * for GPIO buttons and LEDs
 *
 * Copyright (C) 2018 metux IT consult
 * Author: Enrico Weigelt <info@metux.net>
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/dmi.h>
#include <linux/err.h>
#include <linux/gpio/machine.h>
#include <linux/gpio/property.h>
#include <linux/input-event-codes.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/platform_data/gpio/gpio-amd-fch.h>

/*
 * NOTE: this driver only supports APUv2/3 - not APUv1, as this one
 * has completely different register layouts.
 */

/* Register mappings */
#define APU2_GPIO_REG_LED1		AMD_FCH_GPIO_REG_GPIO57
#define APU2_GPIO_REG_LED2		AMD_FCH_GPIO_REG_GPIO58
#define APU2_GPIO_REG_LED3		AMD_FCH_GPIO_REG_GPIO59_DEVSLP1
#define APU2_GPIO_REG_MODESW		AMD_FCH_GPIO_REG_GPIO32_GE1
#define APU2_GPIO_REG_SIMSWAP		AMD_FCH_GPIO_REG_GPIO33_GE2
#define APU2_GPIO_REG_MPCIE2		AMD_FCH_GPIO_REG_GPIO55_DEVSLP0
#define APU2_GPIO_REG_MPCIE3		AMD_FCH_GPIO_REG_GPIO51

/* Order in which the GPIO lines are defined in the register list */
#define APU2_GPIO_LINE_LED1		0
#define APU2_GPIO_LINE_LED2		1
#define APU2_GPIO_LINE_LED3		2
#define APU2_GPIO_LINE_MODESW		3
#define APU2_GPIO_LINE_SIMSWAP		4
#define APU2_GPIO_LINE_MPCIE2		5
#define APU2_GPIO_LINE_MPCIE3		6

/* GPIO device */

static int apu2_gpio_regs[] = {
	[APU2_GPIO_LINE_LED1]		= APU2_GPIO_REG_LED1,
	[APU2_GPIO_LINE_LED2]		= APU2_GPIO_REG_LED2,
	[APU2_GPIO_LINE_LED3]		= APU2_GPIO_REG_LED3,
	[APU2_GPIO_LINE_MODESW]		= APU2_GPIO_REG_MODESW,
	[APU2_GPIO_LINE_SIMSWAP]	= APU2_GPIO_REG_SIMSWAP,
	[APU2_GPIO_LINE_MPCIE2]		= APU2_GPIO_REG_MPCIE2,
	[APU2_GPIO_LINE_MPCIE3]		= APU2_GPIO_REG_MPCIE3,
};

static const char * const apu2_gpio_names[] = {
	[APU2_GPIO_LINE_LED1]		= "front-led1",
	[APU2_GPIO_LINE_LED2]		= "front-led2",
	[APU2_GPIO_LINE_LED3]		= "front-led3",
	[APU2_GPIO_LINE_MODESW]		= "front-button",
	[APU2_GPIO_LINE_SIMSWAP]	= "simswap",
	[APU2_GPIO_LINE_MPCIE2]		= "mpcie2_reset",
	[APU2_GPIO_LINE_MPCIE3]		= "mpcie3_reset",
};

static const struct amd_fch_gpio_pdata board_apu2 = {
	.gpio_num	= ARRAY_SIZE(apu2_gpio_regs),
	.gpio_reg	= apu2_gpio_regs,
	.gpio_names	= apu2_gpio_names,
};

static const struct software_node apu2_gpiochip_node = {
	.name = AMD_FCH_GPIO_DRIVER_NAME,
};

/* GPIO LEDs device */
static const struct software_node apu2_leds_node = {
	.name = "apu2-leds",
};

static const struct property_entry apu2_led1_props[] = {
	PROPERTY_ENTRY_STRING("label", "apu:green:1"),
	PROPERTY_ENTRY_GPIO("gpios", &apu2_gpiochip_node,
			    APU2_GPIO_LINE_LED1, GPIO_ACTIVE_LOW),
	{ }
};

static const struct software_node apu2_led1_swnode = {
	.name = "led-1",
	.parent = &apu2_leds_node,
	.properties = apu2_led1_props,
};

static const struct property_entry apu2_led2_props[] = {
	PROPERTY_ENTRY_STRING("label", "apu:green:2"),
	PROPERTY_ENTRY_GPIO("gpios", &apu2_gpiochip_node,
			    APU2_GPIO_LINE_LED2, GPIO_ACTIVE_LOW),
	{ }
};

static const struct software_node apu2_led2_swnode = {
	.name = "led-2",
	.parent = &apu2_leds_node,
	.properties = apu2_led2_props,
};

static const struct property_entry apu2_led3_props[] = {
	PROPERTY_ENTRY_STRING("label", "apu:green:3"),
	PROPERTY_ENTRY_GPIO("gpios", &apu2_gpiochip_node,
			    APU2_GPIO_LINE_LED3, GPIO_ACTIVE_LOW),
	{ }
};

static const struct software_node apu2_led3_swnode = {
	.name = "led-3",
	.parent = &apu2_leds_node,
	.properties = apu2_led3_props,
};

/* GPIO keyboard device */
static const struct property_entry apu2_keys_props[] = {
	PROPERTY_ENTRY_U32("poll-interval", 100),
	{ }
};

static const struct software_node apu2_keys_node = {
	.name = "apu2-keys",
	.properties = apu2_keys_props,
};

static const struct property_entry apu2_front_button_props[] = {
	PROPERTY_ENTRY_STRING("label", "front button"),
	PROPERTY_ENTRY_U32("linux,code", KEY_RESTART),
	PROPERTY_ENTRY_GPIO("gpios", &apu2_gpiochip_node,
			    APU2_GPIO_LINE_MODESW, GPIO_ACTIVE_LOW),
	PROPERTY_ENTRY_U32("debounce-interval", 10),
	{ }
};

static const struct software_node apu2_front_button_swnode = {
	.name = "front-button",
	.parent = &apu2_keys_node,
	.properties = apu2_front_button_props,
};

static const struct software_node *apu2_swnodes[] = {
	&apu2_gpiochip_node,
	/* LEDs nodes */
	&apu2_leds_node,
	&apu2_led1_swnode,
	&apu2_led2_swnode,
	&apu2_led3_swnode,
	/* Keys nodes */
	&apu2_keys_node,
	&apu2_front_button_swnode,
	NULL
};

/* Board setup */

/* Note: matching works on string prefix, so "apu2" must come before "apu" */
static const struct dmi_system_id apu_gpio_dmi_table[] __initconst = {

	/* APU2 w/ legacy BIOS < 4.0.8 */
	{
		.ident		= "apu2",
		.matches	= {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "APU2")
		},
		.driver_data	= (void *)&board_apu2,
	},
	/* APU2 w/ legacy BIOS >= 4.0.8 */
	{
		.ident		= "apu2",
		.matches	= {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "apu2")
		},
		.driver_data	= (void *)&board_apu2,
	},
	/* APU2 w/ mainline BIOS */
	{
		.ident		= "apu2",
		.matches	= {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "PC Engines apu2")
		},
		.driver_data	= (void *)&board_apu2,
	},

	/* APU3 w/ legacy BIOS < 4.0.8 */
	{
		.ident		= "apu3",
		.matches	= {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "APU3")
		},
		.driver_data = (void *)&board_apu2,
	},
	/* APU3 w/ legacy BIOS >= 4.0.8 */
	{
		.ident       = "apu3",
		.matches     = {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "apu3")
		},
		.driver_data = (void *)&board_apu2,
	},
	/* APU3 w/ mainline BIOS */
	{
		.ident       = "apu3",
		.matches     = {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "PC Engines apu3")
		},
		.driver_data = (void *)&board_apu2,
	},
	/* APU4 w/ legacy BIOS < 4.0.8 */
	{
		.ident        = "apu4",
		.matches    = {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "APU4")
		},
		.driver_data = (void *)&board_apu2,
	},
	/* APU4 w/ legacy BIOS >= 4.0.8 */
	{
		.ident       = "apu4",
		.matches     = {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "apu4")
		},
		.driver_data = (void *)&board_apu2,
	},
	/* APU4 w/ mainline BIOS */
	{
		.ident       = "apu4",
		.matches     = {
			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
			DMI_MATCH(DMI_BOARD_NAME, "PC Engines apu4")
		},
		.driver_data = (void *)&board_apu2,
	},
	{}
};

static struct platform_device *apu_gpio_pdev;
static struct platform_device *apu_leds_pdev;
static struct platform_device *apu_keys_pdev;

static struct platform_device * __init apu_create_pdev(const char *name,
						       const void *data, size_t size,
						       const struct software_node *swnode)
{
	struct platform_device_info pdev_info = {
		.name = name,
		.id = PLATFORM_DEVID_NONE,
		.data = data,
		.size_data = size,
		.fwnode = software_node_fwnode(swnode),
	};
	struct platform_device *pdev;
	int err;

	pdev = platform_device_register_full(&pdev_info);

	err = PTR_ERR_OR_ZERO(pdev);
	if (err)
		pr_err("failed registering %s: %d\n", name, err);

	return pdev;
}

static int __init apu_board_init(void)
{
	const struct dmi_system_id *id;
	int err;

	id = dmi_first_match(apu_gpio_dmi_table);
	if (!id) {
		pr_err("failed to detect APU board via DMI\n");
		return -ENODEV;
	}

	err = software_node_register_node_group(apu2_swnodes);
	if (err) {
		pr_err("failed to register software nodes: %d\n", err);
		return err;
	}

	apu_gpio_pdev = apu_create_pdev(AMD_FCH_GPIO_DRIVER_NAME,
					id->driver_data, sizeof(struct amd_fch_gpio_pdata), NULL);
	err = PTR_ERR_OR_ZERO(apu_gpio_pdev);
	if (err)
		goto err_unregister_swnodes;

	apu_leds_pdev = apu_create_pdev("leds-gpio", NULL, 0, &apu2_leds_node);
	err = PTR_ERR_OR_ZERO(apu_leds_pdev);
	if (err)
		goto err_unregister_gpio;

	apu_keys_pdev = apu_create_pdev("gpio-keys-polled", NULL, 0, &apu2_keys_node);
	err = PTR_ERR_OR_ZERO(apu_keys_pdev);
	if (err)
		goto err_unregister_leds;

	return 0;

err_unregister_leds:
	platform_device_unregister(apu_leds_pdev);
err_unregister_gpio:
	platform_device_unregister(apu_gpio_pdev);
err_unregister_swnodes:
	software_node_unregister_node_group(apu2_swnodes);
	return err;
}

static void __exit apu_board_exit(void)
{
	platform_device_unregister(apu_keys_pdev);
	platform_device_unregister(apu_leds_pdev);
	platform_device_unregister(apu_gpio_pdev);
	software_node_unregister_node_group(apu2_swnodes);
}

module_init(apu_board_init);
module_exit(apu_board_exit);

MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>");
MODULE_DESCRIPTION("PC Engines APUv2/APUv3 board GPIO/LEDs/keys driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(dmi, apu_gpio_dmi_table);
MODULE_SOFTDEP("pre: platform:" AMD_FCH_GPIO_DRIVER_NAME " platform:leds-gpio platform:gpio_keys_polled");