1 /* 2 * INT3406 thermal driver for display participant device 3 * 4 * Copyright (C) 2016, Intel Corporation 5 * Authors: Aaron Lu <aaron.lu@intel.com> 6 * 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. 10 * 11 */ 12 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> 19 20 #define INT3406_BRIGHTNESS_LIMITS_CHANGED 0x80 21 22 struct int3406_thermal_data { 23 int upper_limit; 24 int lower_limit; 25 acpi_handle handle; 26 struct acpi_video_device_brightness *br; 27 struct backlight_device *raw_bd; 28 struct thermal_cooling_device *cooling_dev; 29 }; 30 31 /* 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." 36 * 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 40 */ 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) 43 44 static int 45 int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev, 46 unsigned long *state) 47 { 48 struct int3406_thermal_data *d = cooling_dev->devdata; 49 50 *state = d->upper_limit - d->lower_limit; 51 return 0; 52 } 53 54 static int 55 int3406_thermal_set_cur_state(struct thermal_cooling_device *cooling_dev, 56 unsigned long state) 57 { 58 struct int3406_thermal_data *d = cooling_dev->devdata; 59 int acpi_level, raw_level; 60 61 if (state > d->upper_limit - d->lower_limit) 62 return -EINVAL; 63 64 acpi_level = d->br->levels[d->upper_limit - state]; 65 66 raw_level = ACPI_TO_RAW(acpi_level, d); 67 68 return backlight_device_set_brightness(d->raw_bd, raw_level); 69 } 70 71 static int 72 int3406_thermal_get_cur_state(struct thermal_cooling_device *cooling_dev, 73 unsigned long *state) 74 { 75 struct int3406_thermal_data *d = cooling_dev->devdata; 76 int acpi_level; 77 int index; 78 79 acpi_level = RAW_TO_ACPI(d->raw_bd->props.brightness, d); 80 81 /* 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 84 * right above it. 85 */ 86 for (index = d->lower_limit; index < d->upper_limit; index++) { 87 if (acpi_level <= d->br->levels[index]) 88 break; 89 } 90 91 *state = d->upper_limit - index; 92 return 0; 93 } 94 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, 99 }; 100 101 static int int3406_thermal_get_index(int *array, int nr, int value) 102 { 103 int i; 104 105 for (i = 2; i < nr; i++) { 106 if (array[i] == value) 107 break; 108 } 109 return i == nr ? -ENOENT : i; 110 } 111 112 static void int3406_thermal_get_limit(struct int3406_thermal_data *d) 113 { 114 acpi_status status; 115 unsigned long long lower_limit, upper_limit; 116 117 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); 121 122 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); 126 127 /* 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; 130 } 131 132 static void int3406_notify(acpi_handle handle, u32 event, void *data) 133 { 134 if (event == INT3406_BRIGHTNESS_LIMITS_CHANGED) 135 int3406_thermal_get_limit(data); 136 } 137 138 static int int3406_thermal_probe(struct platform_device *pdev) 139 { 140 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); 141 struct int3406_thermal_data *d; 142 struct backlight_device *bd; 143 int ret; 144 145 if (!ACPI_HANDLE(&pdev->dev)) 146 return -ENODEV; 147 148 d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL); 149 if (!d) 150 return -ENOMEM; 151 d->handle = ACPI_HANDLE(&pdev->dev); 152 153 bd = backlight_device_get_by_type(BACKLIGHT_RAW); 154 if (!bd) 155 return -ENODEV; 156 d->raw_bd = bd; 157 158 ret = acpi_video_get_levels(ACPI_COMPANION(&pdev->dev), &d->br, NULL); 159 if (ret) 160 return ret; 161 162 int3406_thermal_get_limit(d); 163 164 d->cooling_dev = thermal_cooling_device_register(acpi_device_bid(adev), 165 d, &video_cooling_ops); 166 if (IS_ERR(d->cooling_dev)) 167 goto err; 168 169 ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY, 170 int3406_notify, d); 171 if (ret) 172 goto err_cdev; 173 174 platform_set_drvdata(pdev, d); 175 176 return 0; 177 178 err_cdev: 179 thermal_cooling_device_unregister(d->cooling_dev); 180 err: 181 kfree(d->br); 182 return -ENODEV; 183 } 184 185 static int int3406_thermal_remove(struct platform_device *pdev) 186 { 187 struct int3406_thermal_data *d = platform_get_drvdata(pdev); 188 189 thermal_cooling_device_unregister(d->cooling_dev); 190 kfree(d->br); 191 return 0; 192 } 193 194 static const struct acpi_device_id int3406_thermal_match[] = { 195 {"INT3406", 0}, 196 {} 197 }; 198 199 MODULE_DEVICE_TABLE(acpi, int3406_thermal_match); 200 201 static struct platform_driver int3406_thermal_driver = { 202 .probe = int3406_thermal_probe, 203 .remove = int3406_thermal_remove, 204 .driver = { 205 .name = "int3406 thermal", 206 .acpi_match_table = int3406_thermal_match, 207 }, 208 }; 209 210 module_platform_driver(int3406_thermal_driver); 211 212 MODULE_DESCRIPTION("INT3406 Thermal driver"); 213 MODULE_LICENSE("GPL v2"); 214