drivers/gpu/drm/nouveau/nvkm/subdev/therm/nv50.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/therm/nv50.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/therm/nv50.c
Extension
.c
Size
4877 bytes
Lines
177
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

if (nvkm_rd32(device, 0xc040) & 0x800000) {
			/* Use the HOST clock (100 MHz)
			* Where does this constant(2.4) comes from? */
			pwm_clock = (100000000 >> pwm_div) * 10 / 24;
		} else {
			/* Where does this constant(20) comes from? */
			pwm_clock = (device->crystal * 1000) >> pwm_div;
			pwm_clock /= 20;
		}
	} else {
		pwm_clock = (device->crystal * 1000) / 20;
	}

	return pwm_clock;
}

static void
nv50_sensor_setup(struct nvkm_therm *therm)
{
	struct nvkm_device *device = therm->subdev.device;
	nvkm_mask(device, 0x20010, 0x40000000, 0x0);
	mdelay(20); /* wait for the temperature to stabilize */
}

static int
nv50_temp_get(struct nvkm_therm *therm)
{
	struct nvkm_device *device = therm->subdev.device;
	struct nvbios_therm_sensor *sensor = &therm->bios_sensor;
	int core_temp;

	core_temp = nvkm_rd32(device, 0x20014) & 0x3fff;

	/* if the slope or the offset is unset, do no use the sensor */
	if (!sensor->slope_div || !sensor->slope_mult ||
	    !sensor->offset_num || !sensor->offset_den)
	    return -ENODEV;

	core_temp = core_temp * sensor->slope_mult / sensor->slope_div;
	core_temp = core_temp + sensor->offset_num / sensor->offset_den;
	core_temp = core_temp + sensor->offset_constant - 8;

	/* reserve negative temperatures for errors */
	if (core_temp < 0)
		core_temp = 0;

	return core_temp;
}

static void
nv50_therm_init(struct nvkm_therm *therm)
{
	nv50_sensor_setup(therm);
}

static const struct nvkm_therm_func
nv50_therm = {
	.init = nv50_therm_init,
	.intr = nv40_therm_intr,
	.pwm_ctrl = nv50_fan_pwm_ctrl,
	.pwm_get = nv50_fan_pwm_get,
	.pwm_set = nv50_fan_pwm_set,
	.pwm_clock = nv50_fan_pwm_clock,
	.temp_get = nv50_temp_get,
	.program_alarms = nvkm_therm_program_alarms_polling,
};

int
nv50_therm_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
	       struct nvkm_therm **ptherm)
{
	return nvkm_therm_new_(&nv50_therm, device, type, inst, ptherm);
}

Annotation

Implementation Notes