subdev/therm/fantog.c

0001 /*
0002  * Copyright 2012 The Nouveau community
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice shall be included in
0012  * all copies or substantial portions of the Software.
0013  *
0014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0017  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0018  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0019  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0020  * OTHER DEALINGS IN THE SOFTWARE.
0021  *
0022  * Authors: Martin Peres
0023  */
0024 #include "priv.h"
0025
0026 #include <subdev/gpio.h>
0027 #include <subdev/timer.h>
0028
0029 struct nvkm_fantog {
0030     struct nvkm_fan base;
0031     struct nvkm_alarm alarm;
0032     spinlock_t lock;
0033     u32 period_us;
0034     u32 percent;
0035     struct dcb_gpio_func func;
0036 };
0037
0038 static void
0039 nvkm_fantog_update(struct nvkm_fantog *fan, int percent)
0040 {
0041     struct nvkm_therm *therm = fan->base.parent;
0042     struct nvkm_device *device = therm->subdev.device;
0043     struct nvkm_timer *tmr = device->timer;
0044     struct nvkm_gpio *gpio = device->gpio;
0045     unsigned long flags;
0046     int duty;
0047
0048     spin_lock_irqsave(&fan->lock, flags);
0049     if (percent < 0)
0050         percent = fan->percent;
0051     fan->percent = percent;
0052
0053     duty = !nvkm_gpio_get(gpio, 0, DCB_GPIO_FAN, 0xff);
0054     nvkm_gpio_set(gpio, 0, DCB_GPIO_FAN, 0xff, duty);
0055
0056     if (percent != (duty * 100)) {
0057         u64 next_change = (percent * fan->period_us) / 100;
0058         if (!duty)
0059             next_change = fan->period_us - next_change;
0060         nvkm_timer_alarm(tmr, next_change * 1000, &fan->alarm);
0061     }
0062     spin_unlock_irqrestore(&fan->lock, flags);
0063 }
0064
0065 static void
0066 nvkm_fantog_alarm(struct nvkm_alarm *alarm)
0067 {
0068     struct nvkm_fantog *fan =
0069            container_of(alarm, struct nvkm_fantog, alarm);
0070     nvkm_fantog_update(fan, -1);
0071 }
0072
0073 static int
0074 nvkm_fantog_get(struct nvkm_therm *therm)
0075 {
0076     struct nvkm_fantog *fan = (void *)therm->fan;
0077     return fan->percent;
0078 }
0079
0080 static int
0081 nvkm_fantog_set(struct nvkm_therm *therm, int percent)
0082 {
0083     struct nvkm_fantog *fan = (void *)therm->fan;
0084     if (therm->func->pwm_ctrl)
0085         therm->func->pwm_ctrl(therm, fan->func.line, false);
0086     nvkm_fantog_update(fan, percent);
0087     return 0;
0088 }
0089
0090 int
0091 nvkm_fantog_create(struct nvkm_therm *therm, struct dcb_gpio_func *func)
0092 {
0093     struct nvkm_fantog *fan;
0094     int ret;
0095
0096     if (therm->func->pwm_ctrl) {
0097         ret = therm->func->pwm_ctrl(therm, func->line, false);
0098         if (ret)
0099             return ret;
0100     }
0101
0102     fan = kzalloc(sizeof(*fan), GFP_KERNEL);
0103     therm->fan = &fan->base;
0104     if (!fan)
0105         return -ENOMEM;
0106
0107     fan->base.type = "toggle";
0108     fan->base.get = nvkm_fantog_get;
0109     fan->base.set = nvkm_fantog_set;
0110     nvkm_alarm_init(&fan->alarm, nvkm_fantog_alarm);
0111     fan->period_us = 100000; /* 10Hz */
0112     fan->percent = 100;
0113     fan->func = *func;
0114     spin_lock_init(&fan->lock);
0115     return 0;
0116 }