1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Driver for controlling LEDs for cameras connected to the Intel atomisp2
  4 * The main purpose of this driver is to turn off LEDs which are on at boot.
  5 *
  6 * Copyright (C) 2020 Hans de Goede <hdegoede@redhat.com>
  7 */
  8
  9#include <linux/dmi.h>
 10#include <linux/gpio/consumer.h>
 11#include <linux/gpio/machine.h>
 12#include <linux/leds.h>
 13#include <linux/module.h>
 14#include <linux/mod_devicetable.h>
 15#include <linux/platform_device.h>
 16#include <linux/workqueue.h>
 17
 18/* This must be leds-gpio as the leds-gpio driver binds to the name */
 19#define DEV_NAME		"leds-gpio"
 20
 21static const struct gpio_led atomisp2_leds[] = {
 22	{
 23		.name = "atomisp2::camera",
 24		.default_state  = LEDS_GPIO_DEFSTATE_OFF,
 25	},
 26};
 27
 28static const struct gpio_led_platform_data atomisp2_leds_pdata = {
 29	.num_leds	= ARRAY_SIZE(atomisp2_leds),
 30	.leds		= atomisp2_leds,
 31};
 32
 33static struct gpiod_lookup_table asus_t100ta_lookup = {
 34	.dev_id = DEV_NAME,
 35	.table = {
 36		GPIO_LOOKUP_IDX("INT33FC:02", 8, NULL, 0, GPIO_ACTIVE_HIGH),
 37		{ }
 38	}
 39};
 40
 41static struct gpiod_lookup_table asus_t100chi_lookup = {
 42	.dev_id = DEV_NAME,
 43	.table = {
 44		GPIO_LOOKUP_IDX("INT33FC:01", 24, NULL, 0, GPIO_ACTIVE_HIGH),
 45		{ }
 46	}
 47};
 48
 49static const struct dmi_system_id atomisp2_led_systems[] __initconst = {
 50	{
 51		.matches = {
 52			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 53			/* Non exact match to also match T100TAF */
 54			DMI_MATCH(DMI_PRODUCT_NAME, "T100TA"),
 55		},
 56		.driver_data = &asus_t100ta_lookup,
 57	},
 58	{
 59		.matches = {
 60			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 61			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T200TA"),
 62		},
 63		.driver_data = &asus_t100ta_lookup,
 64	},
 65	{
 66		.matches = {
 67			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 68			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100CHI"),
 69		},
 70		.driver_data = &asus_t100chi_lookup,
 71	},
 72	{} /* Terminating entry */
 73};
 74MODULE_DEVICE_TABLE(dmi, atomisp2_led_systems);
 75
 76static struct gpiod_lookup_table *gpio_lookup;
 77static struct platform_device *pdev;
 78
 79static int __init atomisp2_led_init(void)
 80{
 81	const struct dmi_system_id *system;
 82
 83	system = dmi_first_match(atomisp2_led_systems);
 84	if (!system)
 85		return -ENODEV;
 86
 87	gpio_lookup = system->driver_data;
 88	gpiod_add_lookup_table(gpio_lookup);
 89
 90	pdev = platform_device_register_resndata(NULL,
 91						 DEV_NAME, PLATFORM_DEVID_NONE,
 92						 NULL, 0, &atomisp2_leds_pdata,
 93						 sizeof(atomisp2_leds_pdata));
 94	if (IS_ERR(pdev))
 95		gpiod_remove_lookup_table(gpio_lookup);
 96
 97	return PTR_ERR_OR_ZERO(pdev);
 98}
 99
100static void __exit atomisp2_led_cleanup(void)
101{
102	platform_device_unregister(pdev);
103	gpiod_remove_lookup_table(gpio_lookup);
104}
105
106module_init(atomisp2_led_init);
107module_exit(atomisp2_led_cleanup);
108
109/*
110 * The ACPI INIT method from Asus WMI's code on the T100TA and T200TA turns the
111 * LED on (without the WMI interface allowing further control over the LED).
112 * Ensure we are loaded after asus-nb-wmi so that we turn the LED off again.
113 */
114MODULE_SOFTDEP("pre: asus_nb_wmi");
115MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
116MODULE_DESCRIPTION("Intel atomisp2 camera LED driver");
117MODULE_LICENSE("GPL");