209 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * INT3406 thermal driver for display participant device4 *5 * Copyright (C) 2016, Intel Corporation6 * Authors: Aaron Lu <aaron.lu@intel.com>7 */8 9#include <linux/module.h>10#include <linux/platform_device.h>11#include <linux/acpi.h>12#include <linux/backlight.h>13#include <linux/thermal.h>14#include <acpi/video.h>15 16#define INT3406_BRIGHTNESS_LIMITS_CHANGED 0x8017 18struct int3406_thermal_data {19 int upper_limit;20 int lower_limit;21 acpi_handle handle;22 struct acpi_video_device_brightness *br;23 struct backlight_device *raw_bd;24 struct thermal_cooling_device *cooling_dev;25};26 27/*28 * According to the ACPI spec,29 * "Each brightness level is represented by a number between 0 and 100,30 * and can be thought of as a percentage. For example, 50 can be 50%31 * power consumption or 50% brightness, as defined by the OEM."32 *33 * As int3406 device uses this value to communicate with the native34 * graphics driver, we make the assumption that it represents35 * the percentage of brightness only36 */37#define ACPI_TO_RAW(v, d) (d->raw_bd->props.max_brightness * v / 100)38#define RAW_TO_ACPI(v, d) (v * 100 / d->raw_bd->props.max_brightness)39 40static int41int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev,42 unsigned long *state)43{44 struct int3406_thermal_data *d = cooling_dev->devdata;45 46 *state = d->upper_limit - d->lower_limit;47 return 0;48}49 50static int51int3406_thermal_set_cur_state(struct thermal_cooling_device *cooling_dev,52 unsigned long state)53{54 struct int3406_thermal_data *d = cooling_dev->devdata;55 int acpi_level, raw_level;56 57 if (state > d->upper_limit - d->lower_limit)58 return -EINVAL;59 60 acpi_level = d->br->levels[d->upper_limit - state];61 62 raw_level = ACPI_TO_RAW(acpi_level, d);63 64 return backlight_device_set_brightness(d->raw_bd, raw_level);65}66 67static int68int3406_thermal_get_cur_state(struct thermal_cooling_device *cooling_dev,69 unsigned long *state)70{71 struct int3406_thermal_data *d = cooling_dev->devdata;72 int acpi_level;73 int index;74 75 acpi_level = RAW_TO_ACPI(d->raw_bd->props.brightness, d);76 77 /*78 * There is no 1:1 mapping between the firmware interface level79 * with the raw interface level, we will have to find one that is80 * right above it.81 */82 for (index = d->lower_limit; index < d->upper_limit; index++) {83 if (acpi_level <= d->br->levels[index])84 break;85 }86 87 *state = d->upper_limit - index;88 return 0;89}90 91static const struct thermal_cooling_device_ops video_cooling_ops = {92 .get_max_state = int3406_thermal_get_max_state,93 .get_cur_state = int3406_thermal_get_cur_state,94 .set_cur_state = int3406_thermal_set_cur_state,95};96 97static int int3406_thermal_get_index(int *array, int nr, int value)98{99 int i;100 101 for (i = 2; i < nr; i++) {102 if (array[i] == value)103 break;104 }105 return i == nr ? -ENOENT : i;106}107 108static void int3406_thermal_get_limit(struct int3406_thermal_data *d)109{110 acpi_status status;111 unsigned long long lower_limit, upper_limit;112 113 status = acpi_evaluate_integer(d->handle, "DDDL", NULL, &lower_limit);114 if (ACPI_SUCCESS(status))115 d->lower_limit = int3406_thermal_get_index(d->br->levels,116 d->br->count, lower_limit);117 118 status = acpi_evaluate_integer(d->handle, "DDPC", NULL, &upper_limit);119 if (ACPI_SUCCESS(status))120 d->upper_limit = int3406_thermal_get_index(d->br->levels,121 d->br->count, upper_limit);122 123 /* lower_limit and upper_limit should be always set */124 d->lower_limit = d->lower_limit > 0 ? d->lower_limit : 2;125 d->upper_limit = d->upper_limit > 0 ? d->upper_limit : d->br->count - 1;126}127 128static void int3406_notify(acpi_handle handle, u32 event, void *data)129{130 if (event == INT3406_BRIGHTNESS_LIMITS_CHANGED)131 int3406_thermal_get_limit(data);132}133 134static int int3406_thermal_probe(struct platform_device *pdev)135{136 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);137 struct int3406_thermal_data *d;138 struct backlight_device *bd;139 int ret;140 141 if (!ACPI_HANDLE(&pdev->dev))142 return -ENODEV;143 144 d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL);145 if (!d)146 return -ENOMEM;147 d->handle = ACPI_HANDLE(&pdev->dev);148 149 bd = backlight_device_get_by_type(BACKLIGHT_RAW);150 if (!bd)151 return -ENODEV;152 d->raw_bd = bd;153 154 ret = acpi_video_get_levels(ACPI_COMPANION(&pdev->dev), &d->br, NULL);155 if (ret)156 return ret;157 158 int3406_thermal_get_limit(d);159 160 d->cooling_dev = thermal_cooling_device_register(acpi_device_bid(adev),161 d, &video_cooling_ops);162 if (IS_ERR(d->cooling_dev))163 goto err;164 165 ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,166 int3406_notify, d);167 if (ret)168 goto err_cdev;169 170 platform_set_drvdata(pdev, d);171 172 return 0;173 174err_cdev:175 thermal_cooling_device_unregister(d->cooling_dev);176err:177 kfree(d->br);178 return -ENODEV;179}180 181static void int3406_thermal_remove(struct platform_device *pdev)182{183 struct int3406_thermal_data *d = platform_get_drvdata(pdev);184 185 thermal_cooling_device_unregister(d->cooling_dev);186 kfree(d->br);187}188 189static const struct acpi_device_id int3406_thermal_match[] = {190 {"INT3406", 0},191 {}192};193 194MODULE_DEVICE_TABLE(acpi, int3406_thermal_match);195 196static struct platform_driver int3406_thermal_driver = {197 .probe = int3406_thermal_probe,198 .remove_new = int3406_thermal_remove,199 .driver = {200 .name = "int3406 thermal",201 .acpi_match_table = int3406_thermal_match,202 },203};204 205module_platform_driver(int3406_thermal_driver);206 207MODULE_DESCRIPTION("INT3406 Thermal driver");208MODULE_LICENSE("GPL v2");209