1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * GPD Pocket fan controller driver
4 *
5 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
6 */
7
8#include <linux/acpi.h>
9#include <linux/devm-helpers.h>
10#include <linux/gpio/consumer.h>
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/platform_device.h>
14#include <linux/power_supply.h>
15#include <linux/thermal.h>
16#include <linux/workqueue.h>
17
18#define MAX_SPEED 3
19
20#define TEMP_LIMIT0_DEFAULT 55000
21#define TEMP_LIMIT1_DEFAULT 60000
22#define TEMP_LIMIT2_DEFAULT 65000
23
24#define HYSTERESIS_DEFAULT 3000
25
26#define SPEED_ON_AC_DEFAULT 2
27
28static int temp_limits[3] = {
29 TEMP_LIMIT0_DEFAULT, TEMP_LIMIT1_DEFAULT, TEMP_LIMIT2_DEFAULT,
30};
31module_param_array(temp_limits, int, NULL, 0444);
32MODULE_PARM_DESC(temp_limits,
33 "Millicelsius values above which the fan speed increases");
34
35static int hysteresis = HYSTERESIS_DEFAULT;
36module_param(hysteresis, int, 0444);
37MODULE_PARM_DESC(hysteresis,
38 "Hysteresis in millicelsius before lowering the fan speed");
39
40static int speed_on_ac = SPEED_ON_AC_DEFAULT;
41module_param(speed_on_ac, int, 0444);
42MODULE_PARM_DESC(speed_on_ac,
43 "minimum fan speed to allow when system is powered by AC");
44
45struct gpd_pocket_fan_data {
46 struct device *dev;
47 struct thermal_zone_device *dts0;
48 struct thermal_zone_device *dts1;
49 struct gpio_desc *gpio0;
50 struct gpio_desc *gpio1;
51 struct delayed_work work;
52 int last_speed;
53};
54
55static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
56{
57 if (speed == fan->last_speed)
58 return;
59
60 gpiod_direction_output(desc: fan->gpio0, value: !!(speed & 1));
61 gpiod_direction_output(desc: fan->gpio1, value: !!(speed & 2));
62
63 fan->last_speed = speed;
64}
65
66static int gpd_pocket_fan_min_speed(void)
67{
68 if (power_supply_is_system_supplied())
69 return speed_on_ac;
70 else
71 return 0;
72}
73
74static void gpd_pocket_fan_worker(struct work_struct *work)
75{
76 struct gpd_pocket_fan_data *fan =
77 container_of(work, struct gpd_pocket_fan_data, work.work);
78 int t0, t1, temp, speed, min_speed, i;
79
80 if (thermal_zone_get_temp(tz: fan->dts0, temp: &t0) ||
81 thermal_zone_get_temp(tz: fan->dts1, temp: &t1)) {
82 dev_warn(fan->dev, "Error getting temperature\n");
83 speed = MAX_SPEED;
84 goto set_speed;
85 }
86
87 temp = max(t0, t1);
88
89 speed = fan->last_speed;
90 min_speed = gpd_pocket_fan_min_speed();
91
92 /* Determine minimum speed */
93 for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
94 if (temp < temp_limits[i])
95 break;
96 }
97 if (speed < i)
98 speed = i;
99
100 /* Use hysteresis before lowering speed again */
101 for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
102 if (temp <= (temp_limits[i] - hysteresis))
103 break;
104 }
105 if (speed > i)
106 speed = i;
107
108 if (fan->last_speed <= 0 && speed)
109 speed = MAX_SPEED; /* kick start motor */
110
111set_speed:
112 gpd_pocket_fan_set_speed(fan, speed);
113
114 /* When mostly idle (low temp/speed), slow down the poll interval. */
115 queue_delayed_work(wq: system_wq, dwork: &fan->work,
116 delay: msecs_to_jiffies(m: 4000 / (speed + 1)));
117}
118
119static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan)
120{
121 fan->last_speed = -1;
122 mod_delayed_work(wq: system_wq, dwork: &fan->work, delay: 0);
123}
124
125static int gpd_pocket_fan_probe(struct platform_device *pdev)
126{
127 struct gpd_pocket_fan_data *fan;
128 int i, ret;
129
130 for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
131 if (temp_limits[i] < 20000 || temp_limits[i] > 90000) {
132 dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 20000 and 90000)\n",
133 temp_limits[i]);
134 temp_limits[0] = TEMP_LIMIT0_DEFAULT;
135 temp_limits[1] = TEMP_LIMIT1_DEFAULT;
136 temp_limits[2] = TEMP_LIMIT2_DEFAULT;
137 break;
138 }
139 }
140 if (hysteresis < 1000 || hysteresis > 10000) {
141 dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n",
142 hysteresis);
143 hysteresis = HYSTERESIS_DEFAULT;
144 }
145 if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) {
146 dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n",
147 speed_on_ac);
148 speed_on_ac = SPEED_ON_AC_DEFAULT;
149 }
150
151 fan = devm_kzalloc(dev: &pdev->dev, size: sizeof(*fan), GFP_KERNEL);
152 if (!fan)
153 return -ENOMEM;
154
155 fan->dev = &pdev->dev;
156 ret = devm_delayed_work_autocancel(dev: &pdev->dev, w: &fan->work,
157 worker: gpd_pocket_fan_worker);
158 if (ret)
159 return ret;
160
161 /* Note this returns a "weak" reference which we don't need to free */
162 fan->dts0 = thermal_zone_get_zone_by_name(name: "soc_dts0");
163 if (IS_ERR(ptr: fan->dts0))
164 return -EPROBE_DEFER;
165
166 fan->dts1 = thermal_zone_get_zone_by_name(name: "soc_dts1");
167 if (IS_ERR(ptr: fan->dts1))
168 return -EPROBE_DEFER;
169
170 fan->gpio0 = devm_gpiod_get_index(dev: fan->dev, NULL, idx: 0, flags: GPIOD_ASIS);
171 if (IS_ERR(ptr: fan->gpio0))
172 return PTR_ERR(ptr: fan->gpio0);
173
174 fan->gpio1 = devm_gpiod_get_index(dev: fan->dev, NULL, idx: 1, flags: GPIOD_ASIS);
175 if (IS_ERR(ptr: fan->gpio1))
176 return PTR_ERR(ptr: fan->gpio1);
177
178 gpd_pocket_fan_force_update(fan);
179
180 platform_set_drvdata(pdev, data: fan);
181 return 0;
182}
183
184#ifdef CONFIG_PM_SLEEP
185static int gpd_pocket_fan_suspend(struct device *dev)
186{
187 struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
188
189 cancel_delayed_work_sync(dwork: &fan->work);
190 gpd_pocket_fan_set_speed(fan, speed: gpd_pocket_fan_min_speed());
191 return 0;
192}
193
194static int gpd_pocket_fan_resume(struct device *dev)
195{
196 struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
197
198 gpd_pocket_fan_force_update(fan);
199 return 0;
200}
201#endif
202static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,
203 gpd_pocket_fan_suspend,
204 gpd_pocket_fan_resume);
205
206static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {
207 { "FAN02501" },
208 {},
209};
210MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);
211
212static struct platform_driver gpd_pocket_fan_driver = {
213 .probe = gpd_pocket_fan_probe,
214 .driver = {
215 .name = "gpd_pocket_fan",
216 .acpi_match_table = gpd_pocket_fan_acpi_match,
217 .pm = &gpd_pocket_fan_pm_ops,
218 },
219};
220
221module_platform_driver(gpd_pocket_fan_driver);
222MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
223MODULE_DESCRIPTION("GPD pocket fan driver");
224MODULE_LICENSE("GPL");
225

source code of linux/drivers/platform/x86/gpd-pocket-fan.c