drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
Extension
.c
Size
3257 bytes
Lines
117
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct nvkm_fantog {
	struct nvkm_fan base;
	struct nvkm_alarm alarm;
	spinlock_t lock;
	u32 period_us;
	u32 percent;
	struct dcb_gpio_func func;
};

static void
nvkm_fantog_update(struct nvkm_fantog *fan, int percent)
{
	struct nvkm_therm *therm = fan->base.parent;
	struct nvkm_device *device = therm->subdev.device;
	struct nvkm_timer *tmr = device->timer;
	struct nvkm_gpio *gpio = device->gpio;
	unsigned long flags;
	int duty;

	spin_lock_irqsave(&fan->lock, flags);
	if (percent < 0)
		percent = fan->percent;
	fan->percent = percent;

	duty = !nvkm_gpio_get(gpio, 0, DCB_GPIO_FAN, 0xff);
	nvkm_gpio_set(gpio, 0, DCB_GPIO_FAN, 0xff, duty);

	if (percent != (duty * 100)) {
		u64 next_change = (percent * fan->period_us) / 100;
		if (!duty)
			next_change = fan->period_us - next_change;
		nvkm_timer_alarm(tmr, next_change * 1000, &fan->alarm);
	}
	spin_unlock_irqrestore(&fan->lock, flags);
}

static void
nvkm_fantog_alarm(struct nvkm_alarm *alarm)
{
	struct nvkm_fantog *fan =
	       container_of(alarm, struct nvkm_fantog, alarm);
	nvkm_fantog_update(fan, -1);
}

static int
nvkm_fantog_get(struct nvkm_therm *therm)
{
	struct nvkm_fantog *fan = (void *)therm->fan;
	return fan->percent;
}

static int
nvkm_fantog_set(struct nvkm_therm *therm, int percent)
{
	struct nvkm_fantog *fan = (void *)therm->fan;
	if (therm->func->pwm_ctrl)
		therm->func->pwm_ctrl(therm, fan->func.line, false);
	nvkm_fantog_update(fan, percent);
	return 0;
}

int
nvkm_fantog_create(struct nvkm_therm *therm, struct dcb_gpio_func *func)
{
	struct nvkm_fantog *fan;
	int ret;

	if (therm->func->pwm_ctrl) {
		ret = therm->func->pwm_ctrl(therm, func->line, false);
		if (ret)
			return ret;
	}

	fan = kzalloc_obj(*fan);
	if (!fan)
		return -ENOMEM;

	therm->fan = &fan->base;
	fan->base.type = "toggle";
	fan->base.get = nvkm_fantog_get;
	fan->base.set = nvkm_fantog_set;
	nvkm_alarm_init(&fan->alarm, nvkm_fantog_alarm);
	fan->period_us = 100000; /* 10Hz */
	fan->percent = 100;
	fan->func = *func;
	spin_lock_init(&fan->lock);
	return 0;
}

Annotation

Implementation Notes