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");
118