xref: /linux/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c (revision 0e2b2a76278153d1ac312b0691cb65dabb9aef3e)
1 /*
2  * Copyright 2012 The Nouveau community
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Martin Peres
23  */
24 #include "priv.h"
25 
26 #include <subdev/gpio.h>
27 #include <subdev/timer.h>
28 
29 struct nvkm_fantog {
30 	struct nvkm_fan base;
31 	struct nvkm_alarm alarm;
32 	spinlock_t lock;
33 	u32 period_us;
34 	u32 percent;
35 	struct dcb_gpio_func func;
36 };
37 
38 static void
39 nvkm_fantog_update(struct nvkm_fantog *fan, int percent)
40 {
41 	struct nvkm_therm *therm = fan->base.parent;
42 	struct nvkm_device *device = therm->subdev.device;
43 	struct nvkm_timer *tmr = device->timer;
44 	struct nvkm_gpio *gpio = device->gpio;
45 	unsigned long flags;
46 	int duty;
47 
48 	spin_lock_irqsave(&fan->lock, flags);
49 	if (percent < 0)
50 		percent = fan->percent;
51 	fan->percent = percent;
52 
53 	duty = !nvkm_gpio_get(gpio, 0, DCB_GPIO_FAN, 0xff);
54 	nvkm_gpio_set(gpio, 0, DCB_GPIO_FAN, 0xff, duty);
55 
56 	if (percent != (duty * 100)) {
57 		u64 next_change = (percent * fan->period_us) / 100;
58 		if (!duty)
59 			next_change = fan->period_us - next_change;
60 		nvkm_timer_alarm(tmr, next_change * 1000, &fan->alarm);
61 	}
62 	spin_unlock_irqrestore(&fan->lock, flags);
63 }
64 
65 static void
66 nvkm_fantog_alarm(struct nvkm_alarm *alarm)
67 {
68 	struct nvkm_fantog *fan =
69 	       container_of(alarm, struct nvkm_fantog, alarm);
70 	nvkm_fantog_update(fan, -1);
71 }
72 
73 static int
74 nvkm_fantog_get(struct nvkm_therm *therm)
75 {
76 	struct nvkm_fantog *fan = (void *)therm->fan;
77 	return fan->percent;
78 }
79 
80 static int
81 nvkm_fantog_set(struct nvkm_therm *therm, int percent)
82 {
83 	struct nvkm_fantog *fan = (void *)therm->fan;
84 	if (therm->func->pwm_ctrl)
85 		therm->func->pwm_ctrl(therm, fan->func.line, false);
86 	nvkm_fantog_update(fan, percent);
87 	return 0;
88 }
89 
90 int
91 nvkm_fantog_create(struct nvkm_therm *therm, struct dcb_gpio_func *func)
92 {
93 	struct nvkm_fantog *fan;
94 	int ret;
95 
96 	if (therm->func->pwm_ctrl) {
97 		ret = therm->func->pwm_ctrl(therm, func->line, false);
98 		if (ret)
99 			return ret;
100 	}
101 
102 	fan = kzalloc(sizeof(*fan), GFP_KERNEL);
103 	if (!fan)
104 		return -ENOMEM;
105 
106 	therm->fan = &fan->base;
107 	fan->base.type = "toggle";
108 	fan->base.get = nvkm_fantog_get;
109 	fan->base.set = nvkm_fantog_set;
110 	nvkm_alarm_init(&fan->alarm, nvkm_fantog_alarm);
111 	fan->period_us = 100000; /* 10Hz */
112 	fan->percent = 100;
113 	fan->func = *func;
114 	spin_lock_init(&fan->lock);
115 	return 0;
116 }
117