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 upper_limit_index;
25 int lower_limit;
26 int lower_limit_index;
27 acpi_handle handle;
28 struct acpi_video_device_brightness *br;
29 struct backlight_device *raw_bd;
30 struct thermal_cooling_device *cooling_dev;
31 };
32
int3406_thermal_to_raw(int level,struct int3406_thermal_data * d)33 static int int3406_thermal_to_raw(int level, struct int3406_thermal_data *d)
34 {
35 int max_level = d->br->levels[d->br->count - 1];
36 int raw_max = d->raw_bd->props.max_brightness;
37
38 return level * raw_max / max_level;
39 }
40
int3406_thermal_to_acpi(int level,struct int3406_thermal_data * d)41 static int int3406_thermal_to_acpi(int level, struct int3406_thermal_data *d)
42 {
43 int raw_max = d->raw_bd->props.max_brightness;
44 int max_level = d->br->levels[d->br->count - 1];
45
46 return level * max_level / raw_max;
47 }
48
49 static int
int3406_thermal_get_max_state(struct thermal_cooling_device * cooling_dev,unsigned long * state)50 int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev,
51 unsigned long *state)
52 {
53 struct int3406_thermal_data *d = cooling_dev->devdata;
54 int index = d->lower_limit_index ? d->lower_limit_index : 2;
55
56 *state = d->br->count - 1 - index;
57 return 0;
58 }
59
60 static int
int3406_thermal_set_cur_state(struct thermal_cooling_device * cooling_dev,unsigned long state)61 int3406_thermal_set_cur_state(struct thermal_cooling_device *cooling_dev,
62 unsigned long state)
63 {
64 struct int3406_thermal_data *d = cooling_dev->devdata;
65 int level, raw_level;
66
67 if (state > d->br->count - 3)
68 return -EINVAL;
69
70 state = d->br->count - 1 - state;
71 level = d->br->levels[state];
72
73 if ((d->upper_limit && level > d->upper_limit) ||
74 (d->lower_limit && level < d->lower_limit))
75 return -EINVAL;
76
77 raw_level = int3406_thermal_to_raw(level, d);
78 return backlight_device_set_brightness(d->raw_bd, raw_level);
79 }
80
81 static int
int3406_thermal_get_cur_state(struct thermal_cooling_device * cooling_dev,unsigned long * state)82 int3406_thermal_get_cur_state(struct thermal_cooling_device *cooling_dev,
83 unsigned long *state)
84 {
85 struct int3406_thermal_data *d = cooling_dev->devdata;
86 int raw_level, level, i;
87 int *levels = d->br->levels;
88
89 raw_level = d->raw_bd->props.brightness;
90 level = int3406_thermal_to_acpi(raw_level, d);
91
92 /*
93 * There is no 1:1 mapping between the firmware interface level with the
94 * raw interface level, we will have to find one that is close enough.
95 */
96 for (i = 2; i < d->br->count; i++) {
97 if (level < levels[i]) {
98 if (i == 2)
99 break;
100 if ((level - levels[i - 1]) < (levels[i] - level))
101 i--;
102 break;
103 }
104 }
105
106 *state = d->br->count - 1 - i;
107 return 0;
108 }
109
110 static const struct thermal_cooling_device_ops video_cooling_ops = {
111 .get_max_state = int3406_thermal_get_max_state,
112 .get_cur_state = int3406_thermal_get_cur_state,
113 .set_cur_state = int3406_thermal_set_cur_state,
114 };
115
int3406_thermal_get_index(int * array,int nr,int value)116 static int int3406_thermal_get_index(int *array, int nr, int value)
117 {
118 int i;
119
120 for (i = 0; i < nr; i++) {
121 if (array[i] == value)
122 break;
123 }
124 return i == nr ? -ENOENT : i;
125 }
126
int3406_thermal_get_limit(struct int3406_thermal_data * d)127 static void int3406_thermal_get_limit(struct int3406_thermal_data *d)
128 {
129 acpi_status status;
130 unsigned long long lower_limit, upper_limit;
131 int index;
132
133 status = acpi_evaluate_integer(d->handle, "DDDL", NULL, &lower_limit);
134 if (ACPI_SUCCESS(status)) {
135 index = int3406_thermal_get_index(d->br->levels, d->br->count,
136 lower_limit);
137 if (index > 0) {
138 d->lower_limit = (int)lower_limit;
139 d->lower_limit_index = index;
140 }
141 }
142
143 status = acpi_evaluate_integer(d->handle, "DDPC", NULL, &upper_limit);
144 if (ACPI_SUCCESS(status)) {
145 index = int3406_thermal_get_index(d->br->levels, d->br->count,
146 upper_limit);
147 if (index > 0) {
148 d->upper_limit = (int)upper_limit;
149 d->upper_limit_index = index;
150 }
151 }
152 }
153
int3406_notify(acpi_handle handle,u32 event,void * data)154 static void int3406_notify(acpi_handle handle, u32 event, void *data)
155 {
156 if (event == INT3406_BRIGHTNESS_LIMITS_CHANGED)
157 int3406_thermal_get_limit(data);
158 }
159
int3406_thermal_probe(struct platform_device * pdev)160 static int int3406_thermal_probe(struct platform_device *pdev)
161 {
162 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
163 struct int3406_thermal_data *d;
164 struct backlight_device *bd;
165 int ret;
166
167 if (!ACPI_HANDLE(&pdev->dev))
168 return -ENODEV;
169
170 d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL);
171 if (!d)
172 return -ENOMEM;
173 d->handle = ACPI_HANDLE(&pdev->dev);
174
175 bd = backlight_device_get_by_type(BACKLIGHT_RAW);
176 if (!bd)
177 return -ENODEV;
178 d->raw_bd = bd;
179
180 ret = acpi_video_get_levels(ACPI_COMPANION(&pdev->dev), &d->br, NULL);
181 if (ret)
182 return ret;
183
184 int3406_thermal_get_limit(d);
185
186 d->cooling_dev = thermal_cooling_device_register(acpi_device_bid(adev),
187 d, &video_cooling_ops);
188 if (IS_ERR(d->cooling_dev))
189 goto err;
190
191 ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
192 int3406_notify, d);
193 if (ret)
194 goto err_cdev;
195
196 platform_set_drvdata(pdev, d);
197
198 return 0;
199
200 err_cdev:
201 thermal_cooling_device_unregister(d->cooling_dev);
202 err:
203 kfree(d->br);
204 return -ENODEV;
205 }
206
int3406_thermal_remove(struct platform_device * pdev)207 static int int3406_thermal_remove(struct platform_device *pdev)
208 {
209 struct int3406_thermal_data *d = platform_get_drvdata(pdev);
210
211 thermal_cooling_device_unregister(d->cooling_dev);
212 kfree(d->br);
213 return 0;
214 }
215
216 static const struct acpi_device_id int3406_thermal_match[] = {
217 {"INT3406", 0},
218 {}
219 };
220
221 MODULE_DEVICE_TABLE(acpi, int3406_thermal_match);
222
223 static struct platform_driver int3406_thermal_driver = {
224 .probe = int3406_thermal_probe,
225 .remove = int3406_thermal_remove,
226 .driver = {
227 .name = "int3406 thermal",
228 .acpi_match_table = int3406_thermal_match,
229 },
230 };
231
232 module_platform_driver(int3406_thermal_driver);
233
234 MODULE_DESCRIPTION("INT3406 Thermal driver");
235 MODULE_LICENSE("GPL v2");
236