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
21 static const struct gpio_led atomisp2_leds[] = {
22 {
23 .name = "atomisp2::camera",
24 .default_state = LEDS_GPIO_DEFSTATE_OFF,
25 },
26 };
27
28 static const struct gpio_led_platform_data atomisp2_leds_pdata = {
29 .num_leds = ARRAY_SIZE(atomisp2_leds),
30 .leds = atomisp2_leds,
31 };
32
33 static 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
41 static 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
49 static 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 };
74 MODULE_DEVICE_TABLE(dmi, atomisp2_led_systems);
75
76 static struct gpiod_lookup_table *gpio_lookup;
77 static struct platform_device *pdev;
78
atomisp2_led_init(void)79 static 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
atomisp2_led_cleanup(void)100 static void __exit atomisp2_led_cleanup(void)
101 {
102 platform_device_unregister(pdev);
103 gpiod_remove_lookup_table(gpio_lookup);
104 }
105
106 module_init(atomisp2_led_init);
107 module_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 */
114 MODULE_SOFTDEP("pre: asus_nb_wmi");
115 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
116 MODULE_DESCRIPTION("Intel atomisp2 camera LED driver");
117 MODULE_LICENSE("GPL");
118
