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 | |
28 | static int temp_limits[3] = { |
29 | TEMP_LIMIT0_DEFAULT, TEMP_LIMIT1_DEFAULT, TEMP_LIMIT2_DEFAULT, |
30 | }; |
31 | module_param_array(temp_limits, int, NULL, 0444); |
32 | MODULE_PARM_DESC(temp_limits, |
33 | "Millicelsius values above which the fan speed increases" ); |
34 | |
35 | static int hysteresis = HYSTERESIS_DEFAULT; |
36 | module_param(hysteresis, int, 0444); |
37 | MODULE_PARM_DESC(hysteresis, |
38 | "Hysteresis in millicelsius before lowering the fan speed" ); |
39 | |
40 | static int speed_on_ac = SPEED_ON_AC_DEFAULT; |
41 | module_param(speed_on_ac, int, 0444); |
42 | MODULE_PARM_DESC(speed_on_ac, |
43 | "minimum fan speed to allow when system is powered by AC" ); |
44 | |
45 | struct 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 | |
55 | static 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 | |
66 | static 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 | |
74 | static 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 | |
111 | set_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 | |
119 | static 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 | |
125 | static 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 |
185 | static 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 | |
194 | static 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 |
202 | static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops, |
203 | gpd_pocket_fan_suspend, |
204 | gpd_pocket_fan_resume); |
205 | |
206 | static struct acpi_device_id gpd_pocket_fan_acpi_match[] = { |
207 | { "FAN02501" }, |
208 | {}, |
209 | }; |
210 | MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match); |
211 | |
212 | static 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 | |
221 | module_platform_driver(gpd_pocket_fan_driver); |
222 | MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com" ); |
223 | MODULE_DESCRIPTION("GPD pocket fan driver" ); |
224 | MODULE_LICENSE("GPL" ); |
225 | |