fantog.c

  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
 29struct 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
 38static void
 39nvkm_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
 65static void
 66nvkm_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
 73static int
 74nvkm_fantog_get(struct nvkm_therm *therm)
 75{
 76	struct nvkm_fantog *fan = (void *)therm->fan;
 77	return fan->percent;
 78}
 79
 80static int
 81nvkm_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
 90int
 91nvkm_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}