diff mbox series

[v3] drm/i915/hwmon: expose fan speed

Message ID 20240807123018.827506-1-raag.jadav@intel.com (mailing list archive)
State Handled Elsewhere
Headers show
Series [v3] drm/i915/hwmon: expose fan speed | expand

Commit Message

Raag Jadav Aug. 7, 2024, 12:30 p.m. UTC 
Add hwmon support for fan1_input attribute, which will expose fan speed
in RPM. With this in place we can monitor fan speed using lm-sensors tool.

$ sensors
i915-pci-0300
Adapter: PCI adapter
in0:         653.00 mV
fan1:        3833 RPM
power1:           N/A  (max =  43.00 W)
energy1:      32.02 kJ

v3:
- Declare rotations as "long" and drop redundant casting
- Change date and version in ABI documentation
- Add commenter name in changelog (Riana)

v2:
- Add mutex protection
- Handle overflow
- Add ABI documentation
- Aesthetic adjustments (Riana)

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
---
 .../ABI/testing/sysfs-driver-intel-i915-hwmon |  8 ++
 drivers/gpu/drm/i915/gt/intel_gt_regs.h       |  2 +
 drivers/gpu/drm/i915/i915_hwmon.c             | 88 +++++++++++++++++++
 3 files changed, 98 insertions(+)

Comments

Andi Shyti Aug. 7, 2024, 1:24 p.m. UTC | #1 
Hi Raag,

> +static umode_t
> +hwm_fan_is_visible(const struct hwm_drvdata *ddat, u32 attr)
> +{
> +	struct i915_hwmon *hwmon = ddat->hwmon;
> +
> +	switch (attr) {
> +	case hwmon_fan_input:
> +		return i915_mmio_reg_valid(hwmon->rg.fan_speed) ? 0444 : 0;
> +	default:
> +		return 0;
> +	}

Why do we need switch case here?
Why can't this function become a single "return " line?

> +}
> +
> +static int
> +hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val)
> +{
> +	struct i915_hwmon *hwmon = ddat->hwmon;
> +	struct hwm_fan_info *fi = &ddat->fi;
> +	u32 reg_val, pulses, time, time_now;
> +	intel_wakeref_t wakeref;
> +	long rotations;
> +	int ret = 0;
> +
> +	switch (attr) {
> +	case hwmon_fan_input:
> +		with_intel_runtime_pm(ddat->uncore->rpm, wakeref) {
> +			mutex_lock(&hwmon->hwmon_lock);
> +
> +			reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.fan_speed);
> +			time_now = jiffies_to_msecs(jiffies);
> +
> +			/* Handle overflow */
> +			if (reg_val >= fi->reg_val_prev)
> +				pulses = reg_val - fi->reg_val_prev;
> +			else
> +				pulses = UINT_MAX - fi->reg_val_prev + reg_val;
> +
> +			/*
> +			 * HW register value is accumulated count of pulses from
> +			 * PWM fan with the scale of 2 pulses per rotation.
> +			 */
> +			rotations = pulses >> 1;
> +			time = time_now - fi->time_prev;
> +
> +			if (unlikely(!time)) {
> +				ret = -EAGAIN;
> +				mutex_unlock(&hwmon->hwmon_lock);
> +				break;
> +			}
> +
> +			/* Convert to minutes for calculating RPM */
> +			*val = DIV_ROUND_UP(rotations * (60 * MSEC_PER_SEC), time);
> +
> +			fi->reg_val_prev = reg_val;
> +			fi->time_prev = time_now;
> +
> +			mutex_unlock(&hwmon->hwmon_lock);
> +		}
> +		return ret;
> +	default:
> +		return -EOPNOTSUPP;
> +	}

same here, can we make this function:

if (attr != hwmon_fan_input)
	return -EOPNOTSUPP;

and then save all the indentation.

Are we expecting more cases here?

Andi
Raag Jadav Aug. 8, 2024, 4:42 a.m. UTC | #2 
On Wed, Aug 07, 2024 at 02:24:27PM +0100, Andi Shyti wrote:
> Hi Raag,
> 
> > +static umode_t
> > +hwm_fan_is_visible(const struct hwm_drvdata *ddat, u32 attr)
> > +{
> > +	struct i915_hwmon *hwmon = ddat->hwmon;
> > +
> > +	switch (attr) {
> > +	case hwmon_fan_input:
> > +		return i915_mmio_reg_valid(hwmon->rg.fan_speed) ? 0444 : 0;
> > +	default:
> > +		return 0;
> > +	}
> 
> Why do we need switch case here?

Just following the file conventions.

> Why can't this function become a single "return " line?
> 
> > +}
> > +
> > +static int
> > +hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val)
> > +{
> > +	struct i915_hwmon *hwmon = ddat->hwmon;
> > +	struct hwm_fan_info *fi = &ddat->fi;
> > +	u32 reg_val, pulses, time, time_now;
> > +	intel_wakeref_t wakeref;
> > +	long rotations;
> > +	int ret = 0;
> > +
> > +	switch (attr) {
> > +	case hwmon_fan_input:
> > +		with_intel_runtime_pm(ddat->uncore->rpm, wakeref) {
> > +			mutex_lock(&hwmon->hwmon_lock);
> > +
> > +			reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.fan_speed);
> > +			time_now = jiffies_to_msecs(jiffies);
> > +
> > +			/* Handle overflow */
> > +			if (reg_val >= fi->reg_val_prev)
> > +				pulses = reg_val - fi->reg_val_prev;
> > +			else
> > +				pulses = UINT_MAX - fi->reg_val_prev + reg_val;
> > +
> > +			/*
> > +			 * HW register value is accumulated count of pulses from
> > +			 * PWM fan with the scale of 2 pulses per rotation.
> > +			 */
> > +			rotations = pulses >> 1;
> > +			time = time_now - fi->time_prev;
> > +
> > +			if (unlikely(!time)) {
> > +				ret = -EAGAIN;
> > +				mutex_unlock(&hwmon->hwmon_lock);
> > +				break;
> > +			}
> > +
> > +			/* Convert to minutes for calculating RPM */
> > +			*val = DIV_ROUND_UP(rotations * (60 * MSEC_PER_SEC), time);
> > +
> > +			fi->reg_val_prev = reg_val;
> > +			fi->time_prev = time_now;
> > +
> > +			mutex_unlock(&hwmon->hwmon_lock);
> > +		}
> > +		return ret;
> > +	default:
> > +		return -EOPNOTSUPP;
> > +	}
> 
> same here, can we make this function:
> 
> if (attr != hwmon_fan_input)
> 	return -EOPNOTSUPP;
> 
> and then save all the indentation.

Makes sense for hwm_fan_read(). Let me try this.

> Are we expecting more cases here?

Not for now.

Raag
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
index 92fe7c5c5ac1..be4141a7522f 100644
--- a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
+++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
@@ -75,3 +75,11 @@  Description:	RO. Energy input of device or gt in microjoules.
 		for the gt.
 
 		Only supported for particular Intel i915 graphics platforms.
+
+What:		/sys/bus/pci/drivers/i915/.../hwmon/hwmon<i>/fan1_input
+Date:		November 2024
+KernelVersion:	6.12
+Contact:	intel-gfx@lists.freedesktop.org
+Description:	RO. Fan speed of device in RPM.
+
+		Only supported for particular Intel i915 graphics platforms.
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index e42b3a5d4e63..57a3c83d3655 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
@@ -1553,6 +1553,8 @@ 
 #define VLV_RENDER_C0_COUNT			_MMIO(0x138118)
 #define VLV_MEDIA_C0_COUNT			_MMIO(0x13811c)
 
+#define PCU_PWM_FAN_SPEED			_MMIO(0x138140)
+
 #define GEN12_RPSTAT1				_MMIO(0x1381b4)
 #define   GEN12_VOLTAGE_MASK			REG_GENMASK(10, 0)
 #define   GEN12_CAGF_MASK			REG_GENMASK(19, 11)
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 49db3e09826c..6b34cb146ea4 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -36,6 +36,7 @@  struct hwm_reg {
 	i915_reg_t pkg_rapl_limit;
 	i915_reg_t energy_status_all;
 	i915_reg_t energy_status_tile;
+	i915_reg_t fan_speed;
 };
 
 struct hwm_energy_info {
@@ -43,11 +44,17 @@  struct hwm_energy_info {
 	long accum_energy;			/* Accumulated energy for energy1_input */
 };
 
+struct hwm_fan_info {
+	u32 reg_val_prev;
+	u32 time_prev;
+};
+
 struct hwm_drvdata {
 	struct i915_hwmon *hwmon;
 	struct intel_uncore *uncore;
 	struct device *hwmon_dev;
 	struct hwm_energy_info ei;		/*  Energy info for energy1_input */
+	struct hwm_fan_info fi;			/*  Fan info for fan1_input */
 	char name[12];
 	int gt_n;
 	bool reset_in_progress;
@@ -276,6 +283,7 @@  static const struct hwmon_channel_info * const hwm_info[] = {
 	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX | HWMON_P_CRIT),
 	HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT),
 	HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT),
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
 	NULL
 };
 
@@ -613,6 +621,70 @@  hwm_curr_write(struct hwm_drvdata *ddat, u32 attr, long val)
 	}
 }
 
+static umode_t
+hwm_fan_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		return i915_mmio_reg_valid(hwmon->rg.fan_speed) ? 0444 : 0;
+	default:
+		return 0;
+	}
+}
+
+static int
+hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+	struct i915_hwmon *hwmon = ddat->hwmon;
+	struct hwm_fan_info *fi = &ddat->fi;
+	u32 reg_val, pulses, time, time_now;
+	intel_wakeref_t wakeref;
+	long rotations;
+	int ret = 0;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		with_intel_runtime_pm(ddat->uncore->rpm, wakeref) {
+			mutex_lock(&hwmon->hwmon_lock);
+
+			reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.fan_speed);
+			time_now = jiffies_to_msecs(jiffies);
+
+			/* Handle overflow */
+			if (reg_val >= fi->reg_val_prev)
+				pulses = reg_val - fi->reg_val_prev;
+			else
+				pulses = UINT_MAX - fi->reg_val_prev + reg_val;
+
+			/*
+			 * HW register value is accumulated count of pulses from
+			 * PWM fan with the scale of 2 pulses per rotation.
+			 */
+			rotations = pulses >> 1;
+			time = time_now - fi->time_prev;
+
+			if (unlikely(!time)) {
+				ret = -EAGAIN;
+				mutex_unlock(&hwmon->hwmon_lock);
+				break;
+			}
+
+			/* Convert to minutes for calculating RPM */
+			*val = DIV_ROUND_UP(rotations * (60 * MSEC_PER_SEC), time);
+
+			fi->reg_val_prev = reg_val;
+			fi->time_prev = time_now;
+
+			mutex_unlock(&hwmon->hwmon_lock);
+		}
+		return ret;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static umode_t
 hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 	       u32 attr, int channel)
@@ -628,6 +700,8 @@  hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 		return hwm_energy_is_visible(ddat, attr);
 	case hwmon_curr:
 		return hwm_curr_is_visible(ddat, attr);
+	case hwmon_fan:
+		return hwm_fan_is_visible(ddat, attr);
 	default:
 		return 0;
 	}
@@ -648,6 +722,8 @@  hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		return hwm_energy_read(ddat, attr, val);
 	case hwmon_curr:
 		return hwm_curr_read(ddat, attr, val);
+	case hwmon_fan:
+		return hwm_fan_read(ddat, attr, val);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -739,12 +815,14 @@  hwm_get_preregistration_info(struct drm_i915_private *i915)
 		hwmon->rg.pkg_rapl_limit = PCU_PACKAGE_RAPL_LIMIT;
 		hwmon->rg.energy_status_all = PCU_PACKAGE_ENERGY_STATUS;
 		hwmon->rg.energy_status_tile = INVALID_MMIO_REG;
+		hwmon->rg.fan_speed = PCU_PWM_FAN_SPEED;
 	} else {
 		hwmon->rg.pkg_power_sku_unit = INVALID_MMIO_REG;
 		hwmon->rg.pkg_power_sku = INVALID_MMIO_REG;
 		hwmon->rg.pkg_rapl_limit = INVALID_MMIO_REG;
 		hwmon->rg.energy_status_all = INVALID_MMIO_REG;
 		hwmon->rg.energy_status_tile = INVALID_MMIO_REG;
+		hwmon->rg.fan_speed = INVALID_MMIO_REG;
 	}
 
 	with_intel_runtime_pm(uncore->rpm, wakeref) {
@@ -755,6 +833,16 @@  hwm_get_preregistration_info(struct drm_i915_private *i915)
 		if (i915_mmio_reg_valid(hwmon->rg.pkg_power_sku_unit))
 			val_sku_unit = intel_uncore_read(uncore,
 							 hwmon->rg.pkg_power_sku_unit);
+
+		/*
+		 * Store the initial fan register value, so that we can use it for
+		 * initial fan speed calculation.
+		 */
+		if (i915_mmio_reg_valid(hwmon->rg.fan_speed)) {
+			ddat->fi.reg_val_prev = intel_uncore_read(uncore,
+								  hwmon->rg.fan_speed);
+			ddat->fi.time_prev = jiffies_to_msecs(jiffies);
+		}
 	}
 
 	hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, val_sku_unit);