drivers/platform/x86/intel_atomisp2_led.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for controlling LEDs for cameras connected to the Intel atomisp2
 * The main purpose of this driver is to turn off LEDs which are on at boot.
 *
 * Copyright (C) 2020 Hans de Goede <hdegoede@redhat.com>
 */

#include <linux/dmi.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>

/* This must be leds-gpio as the leds-gpio driver binds to the name */
#define DEV_NAME		"leds-gpio"

static const struct gpio_led atomisp2_leds[] = {
	{
		.name = "atomisp2::camera",
		.default_state  = LEDS_GPIO_DEFSTATE_OFF,
	},
};

static const struct gpio_led_platform_data atomisp2_leds_pdata = {
	.num_leds	= ARRAY_SIZE(atomisp2_leds),
	.leds		= atomisp2_leds,
};

static struct gpiod_lookup_table asus_t100ta_lookup = {
	.dev_id = DEV_NAME,
	.table = {
		GPIO_LOOKUP_IDX("INT33FC:02", 8, NULL, 0, GPIO_ACTIVE_HIGH),
		{ }
	}
};

static struct gpiod_lookup_table asus_t100chi_lookup = {
	.dev_id = DEV_NAME,
	.table = {
		GPIO_LOOKUP_IDX("INT33FC:01", 24, NULL, 0, GPIO_ACTIVE_HIGH),
		{ }
	}
};

static const struct dmi_system_id atomisp2_led_systems[] __initconst = {
	{
		.matches = {
			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100TA"),
		},
		.driver_data = &asus_t100ta_lookup,
	},
	{
		.matches = {
			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T200TA"),
		},
		.driver_data = &asus_t100ta_lookup,
	},
	{
		.matches = {
			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100CHI"),
		},
		.driver_data = &asus_t100chi_lookup,
	},
	{} /* Terminating entry */
};
MODULE_DEVICE_TABLE(dmi, atomisp2_led_systems);

static struct gpiod_lookup_table *gpio_lookup;
static struct platform_device *pdev;

static int __init atomisp2_led_init(void)
{
	const struct dmi_system_id *system;

	system = dmi_first_match(atomisp2_led_systems);
	if (!system)
		return -ENODEV;

	gpio_lookup = system->driver_data;
	gpiod_add_lookup_table(gpio_lookup);

	pdev = platform_device_register_resndata(NULL,
						 DEV_NAME, PLATFORM_DEVID_NONE,
						 NULL, 0, &atomisp2_leds_pdata,
						 sizeof(atomisp2_leds_pdata));
	if (IS_ERR(pdev))
		gpiod_remove_lookup_table(gpio_lookup);

	return PTR_ERR_OR_ZERO(pdev);
}

static void __exit atomisp2_led_cleanup(void)
{
	platform_device_unregister(pdev);
	gpiod_remove_lookup_table(gpio_lookup);
}

module_init(atomisp2_led_init);
module_exit(atomisp2_led_cleanup);

/*
 * The ACPI INIT method from Asus WMI's code on the T100TA and T200TA turns the
 * LED on (without the WMI interface allowing further control over the LED).
 * Ensure we are loaded after asus-nb-wmi so that we turn the LED off again.
 */
MODULE_SOFTDEP("pre: asus_nb_wmi");
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
MODULE_DESCRIPTION("Intel atomisp2 camera LED driver");
MODULE_LICENSE("GPL");