2 * INT3406 thermal driver for display participant device
4 * Copyright (C) 2016, Intel Corporation
5 * Authors: Aaron Lu <aaron.lu@intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/acpi.h>
16 #include <linux/backlight.h>
17 #include <linux/thermal.h>
18 #include <acpi/video.h>
20 #define INT3406_BRIGHTNESS_LIMITS_CHANGED 0x80
22 struct int3406_thermal_data {
26 struct acpi_video_device_brightness *br;
27 struct backlight_device *raw_bd;
28 struct thermal_cooling_device *cooling_dev;
32 * According to the ACPI spec,
33 * "Each brightness level is represented by a number between 0 and 100,
34 * and can be thought of as a percentage. For example, 50 can be 50%
35 * power consumption or 50% brightness, as defined by the OEM."
37 * As int3406 device uses this value to communicate with the native
38 * graphics driver, we make the assumption that it represents
39 * the percentage of brightness only
41 #define ACPI_TO_RAW(v, d) (d->raw_bd->props.max_brightness * v / 100)
42 #define RAW_TO_ACPI(v, d) (v * 100 / d->raw_bd->props.max_brightness)
45 int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev,
48 struct int3406_thermal_data *d = cooling_dev->devdata;
50 *state = d->upper_limit - d->lower_limit;
55 int3406_thermal_set_cur_state(struct thermal_cooling_device *cooling_dev,
58 struct int3406_thermal_data *d = cooling_dev->devdata;
59 int acpi_level, raw_level;
61 if (state > d->upper_limit - d->lower_limit)
64 acpi_level = d->br->levels[d->upper_limit - state];
66 raw_level = ACPI_TO_RAW(acpi_level, d);
68 return backlight_device_set_brightness(d->raw_bd, raw_level);
72 int3406_thermal_get_cur_state(struct thermal_cooling_device *cooling_dev,
75 struct int3406_thermal_data *d = cooling_dev->devdata;
79 acpi_level = RAW_TO_ACPI(d->raw_bd->props.brightness, d);
82 * There is no 1:1 mapping between the firmware interface level
83 * with the raw interface level, we will have to find one that is
86 for (index = d->lower_limit; index < d->upper_limit; index++) {
87 if (acpi_level <= d->br->levels[index])
91 *state = d->upper_limit - index;
95 static const struct thermal_cooling_device_ops video_cooling_ops = {
96 .get_max_state = int3406_thermal_get_max_state,
97 .get_cur_state = int3406_thermal_get_cur_state,
98 .set_cur_state = int3406_thermal_set_cur_state,
101 static int int3406_thermal_get_index(int *array, int nr, int value)
105 for (i = 2; i < nr; i++) {
106 if (array[i] == value)
109 return i == nr ? -ENOENT : i;
112 static void int3406_thermal_get_limit(struct int3406_thermal_data *d)
115 unsigned long long lower_limit, upper_limit;
117 status = acpi_evaluate_integer(d->handle, "DDDL", NULL, &lower_limit);
118 if (ACPI_SUCCESS(status))
119 d->lower_limit = int3406_thermal_get_index(d->br->levels,
120 d->br->count, lower_limit);
122 status = acpi_evaluate_integer(d->handle, "DDPC", NULL, &upper_limit);
123 if (ACPI_SUCCESS(status))
124 d->upper_limit = int3406_thermal_get_index(d->br->levels,
125 d->br->count, upper_limit);
127 /* lower_limit and upper_limit should be always set */
128 d->lower_limit = d->lower_limit > 0 ? d->lower_limit : 2;
129 d->upper_limit = d->upper_limit > 0 ? d->upper_limit : d->br->count - 1;
132 static void int3406_notify(acpi_handle handle, u32 event, void *data)
134 if (event == INT3406_BRIGHTNESS_LIMITS_CHANGED)
135 int3406_thermal_get_limit(data);
138 static int int3406_thermal_probe(struct platform_device *pdev)
140 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
141 struct int3406_thermal_data *d;
142 struct backlight_device *bd;
145 if (!ACPI_HANDLE(&pdev->dev))
148 d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL);
151 d->handle = ACPI_HANDLE(&pdev->dev);
153 bd = backlight_device_get_by_type(BACKLIGHT_RAW);
158 ret = acpi_video_get_levels(ACPI_COMPANION(&pdev->dev), &d->br, NULL);
162 int3406_thermal_get_limit(d);
164 d->cooling_dev = thermal_cooling_device_register(acpi_device_bid(adev),
165 d, &video_cooling_ops);
166 if (IS_ERR(d->cooling_dev))
169 ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
174 platform_set_drvdata(pdev, d);
179 thermal_cooling_device_unregister(d->cooling_dev);
185 static int int3406_thermal_remove(struct platform_device *pdev)
187 struct int3406_thermal_data *d = platform_get_drvdata(pdev);
189 thermal_cooling_device_unregister(d->cooling_dev);
194 static const struct acpi_device_id int3406_thermal_match[] = {
199 MODULE_DEVICE_TABLE(acpi, int3406_thermal_match);
201 static struct platform_driver int3406_thermal_driver = {
202 .probe = int3406_thermal_probe,
203 .remove = int3406_thermal_remove,
205 .name = "int3406 thermal",
206 .acpi_match_table = int3406_thermal_match,
210 module_platform_driver(int3406_thermal_driver);
212 MODULE_DESCRIPTION("INT3406 Thermal driver");
213 MODULE_LICENSE("GPL v2");