Nouveau - Apr 2017 - [PATCH v5 0/5] replace hwmon_device_register for hwmon_device_register_with_info

This v5 drops a check for attr_set.

Versions:

v1 -> v2:
        * Keep temp attrs as read only
v2 -> v3:
        * Code fix-ups: struct and string as const and add return within switch
        due to fallthrough
        * Add Signed-off-by to all commits
v3 -> v4:
        * Rever const to struct attribute. Kbuild complains.
v4 -> v5:
	* Drops a check for attr_set in "nouveau_temp_is_visible".

This patchseries replaces the deprecated hwmon_device_register function with the
new one hwmon_device_register_with_info.
It also does some cleanup.

Oscar Salvador (5):
  nouveau_hwmon: Add config for all sensors and their settings
  nouveau_hwmon: Add nouveau_hwmon_ops structure with
    .is_visible/.read_string
  nouveau_hwmon: Remove old code, add .write/.read operations
  nouveau_hwmon: Add support for auto_point attributes
  nouveau_hwmon: Change permissions to numeric

 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 953 +++++++++++++++++---------------
 1 file changed, 499 insertions(+), 454 deletions(-)

-- 
2.1.4

This is a preparation for the next patches. It just adds the sensors with
their possible configurable settings and then fills the struct
hwmon_channel_info
with all this information.

Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 72 +++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index 23b1670..24b40c5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -692,6 +692,78 @@ static const struct attribute_group hwmon_power_attrgroup =
{
 static const struct attribute_group hwmon_power_caps_attrgroup = {
 	.attrs = hwmon_power_caps_attributes,
 };
+
+static const u32 nouveau_config_chip[] = {
+	HWMON_C_UPDATE_INTERVAL,
+	0
+};
+
+static const u32 nouveau_config_in[] = {
+	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_LABEL,
+	0
+};
+
+static const u32 nouveau_config_temp[] = {
+	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
+	HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_EMERGENCY |
+	HWMON_T_EMERGENCY_HYST,
+	0
+};
+
+static const u32 nouveau_config_fan[] = {
+	HWMON_F_INPUT,
+	0
+};
+
+static const u32 nouveau_config_pwm[] = {
+	HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+	0
+};
+
+static const u32 nouveau_config_power[] = {
+	HWMON_P_INPUT | HWMON_P_CAP_MAX | HWMON_P_CRIT,
+	0
+};
+
+static const struct hwmon_channel_info nouveau_chip = {
+	.type = hwmon_chip,
+	.config = nouveau_config_chip,
+};
+
+static const struct hwmon_channel_info nouveau_temp = {
+	.type = hwmon_temp,
+	.config = nouveau_config_temp,
+};
+
+static const struct hwmon_channel_info nouveau_fan = {
+	.type = hwmon_fan,
+	.config = nouveau_config_fan,
+};
+
+static const struct hwmon_channel_info nouveau_in = {
+	.type = hwmon_in,
+	.config = nouveau_config_in,
+};
+
+static const struct hwmon_channel_info nouveau_pwm = {
+	.type = hwmon_pwm,
+	.config = nouveau_config_pwm,
+};
+
+static const struct hwmon_channel_info nouveau_power = {
+	.type = hwmon_power,
+	.config = nouveau_config_power,
+};
+
+static const struct hwmon_channel_info *nouveau_info[] = {
+	&nouveau_chip,
+	&nouveau_temp,
+	&nouveau_fan,
+	&nouveau_in,
+	&nouveau_pwm,
+	&nouveau_power,
+	NULL
+};
 #endif
 
 int
-- 
2.1.4

This patch introduces the nouveau_hwmon_ops structure, sets up
.is_visible and .read_string operations and adds all the functions
for these operations.
This is also a preparation for the next patches, where most of the
work is being done.
This code doesn't interacture with the old one.
It's just to make easier the review of all patches.

Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 170 ++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index 24b40c5..e8ea8d0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -764,6 +764,176 @@ static const struct hwmon_channel_info *nouveau_info[] = {
 	&nouveau_power,
 	NULL
 };
+
+static umode_t
+nouveau_chip_is_visible(const void *data, u32 attr, int channel)
+{
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_power_is_visible(const void *data, u32 attr, int channel)
+{
+	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
+	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
+
+	if (!iccsense)
+		return 0;
+
+	switch (attr) {
+	case hwmon_power_input:
+		if (iccsense->data_valid &&
+			!list_empty(&iccsense->rails))
+			return 0444;
+		return 0;
+	case hwmon_power_max:
+		if (iccsense->power_w_max)
+			return 0444;
+		return 0;
+	case hwmon_power_crit:
+		if (iccsense->power_w_crit)
+			return 0444;
+		return 0;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_temp_is_visible(const void *data, u32 attr, int channel)
+{
+	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
+	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
+
+	if (therm &&
+		therm->attr_get &&
+		nvkm_therm_temp_get(therm) < 0)
+		return 0;
+
+	switch (attr) {
+	case hwmon_temp_input:
+	case hwmon_temp_max:
+	case hwmon_temp_max_hyst:
+	case hwmon_temp_crit:
+	case hwmon_temp_crit_hyst:
+	case hwmon_temp_emergency:
+	case hwmon_temp_emergency_hyst:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_pwm_is_visible(const void *data, u32 attr, int channel)
+{
+	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
+	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
+
+	if (therm &&
+		therm->attr_get &&
+		therm->fan_get &&
+		therm->fan_get(therm) < 0)
+		return 0;
+
+	switch (attr) {
+	case hwmon_pwm_enable:
+	case hwmon_pwm_input:
+		return 0644;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_input_is_visible(const void *data, u32 attr, int channel)
+{
+	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
+	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
+
+	if (!volt || nvkm_volt_get(volt) < 0)
+		return 0;
+
+	switch (attr) {
+	case hwmon_in_input:
+	case hwmon_in_label:
+	case hwmon_in_min:
+	case hwmon_in_max:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_fan_is_visible(const void *data, u32 attr, int channel)
+{
+	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
+	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
+
+	if (!therm || !therm->attr_get || nvkm_therm_fan_sense(therm) < 0)
+		return 0;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static umode_t
+nouveau_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
+								int channel)
+{
+	switch (type) {
+	case hwmon_chip:
+		return nouveau_chip_is_visible(data, attr, channel);
+	case hwmon_temp:
+		return nouveau_temp_is_visible(data, attr, channel);
+	case hwmon_fan:
+		return nouveau_fan_is_visible(data, attr, channel);
+	case hwmon_in:
+		return nouveau_input_is_visible(data, attr, channel);
+	case hwmon_pwm:
+		return nouveau_pwm_is_visible(data, attr, channel);
+	case hwmon_power:
+		return nouveau_power_is_visible(data, attr, channel);
+	default:
+		return 0;
+	}
+}
+
+static const char input_label[] = "GPU core";
+
+static int
+nouveau_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+							int channel, char **buf)
+{
+	if (type == hwmon_in && attr == hwmon_in_label) {
+		*buf = input_label;
+		return 0;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops nouveau_hwmon_ops = {
+	.is_visible = nouveau_is_visible,
+	.read = NULL,
+	.read_string = nouveau_read_string,
+	.write = NULL,
+};
+
+static const struct hwmon_chip_info nouveau_chip_info = {
+	.ops = &nouveau_hwmon_ops,
+	.info = nouveau_info,
+};
 #endif
 
 int
-- 
2.1.4

This patch removes old code related to the old api and transforms the
functions for the new api. It also adds the .write and .read operations.

Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 722 +++++++++++---------------------
 1 file changed, 249 insertions(+), 473 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index e8ea8d0..4db65fb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -38,21 +38,17 @@
 #include <nvkm/subdev/volt.h>
 
 #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
-static ssize_t
-nouveau_hwmon_show_temp(struct device *d, struct device_attribute *a, char
*buf)
+static int
+nouveau_hwmon_show_temp(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
 	int temp = nvkm_therm_temp_get(therm);
 
 	if (temp < 0)
 		return temp;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", temp * 1000);
+	return (temp * 1000);
 }
-static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, nouveau_hwmon_show_temp,
-						  NULL, 0);
 
 static ssize_t
 nouveau_hwmon_show_temp1_auto_point1_pwm(struct device *d,
@@ -129,312 +125,100 @@ static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst,
S_IRUGO | S_IWUSR,
 			  nouveau_hwmon_temp1_auto_point1_temp_hyst,
 			  nouveau_hwmon_set_temp1_auto_point1_temp_hyst, 0);
 
-static ssize_t
-nouveau_hwmon_max_temp(struct device *d, struct device_attribute *a, char *buf)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK) * 1000);
-}
-static ssize_t
-nouveau_hwmon_set_max_temp(struct device *d, struct device_attribute *a,
-						const char *buf, size_t count)
+static int
+nouveau_hwmon_max_temp(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
 
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
-
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK, value / 1000);
-
-	return count;
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK) * 1000;
 }
-static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, nouveau_hwmon_max_temp,
-						  nouveau_hwmon_set_max_temp,
-						  0);
 
-static ssize_t
-nouveau_hwmon_max_temp_hyst(struct device *d, struct device_attribute *a,
-			    char *buf)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST) * 1000);
-}
-static ssize_t
-nouveau_hwmon_set_max_temp_hyst(struct device *d, struct device_attribute *a,
-						const char *buf, size_t count)
+static int
+nouveau_hwmon_max_temp_hyst(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
-
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
 
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST,
-			value / 1000);
-
-	return count;
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST) * 1000;
 }
-static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
-			  nouveau_hwmon_max_temp_hyst,
-			  nouveau_hwmon_set_max_temp_hyst, 0);
-
-static ssize_t
-nouveau_hwmon_critical_temp(struct device *d, struct device_attribute *a,
-							char *buf)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL) * 1000);
-}
-static ssize_t
-nouveau_hwmon_set_critical_temp(struct device *d, struct device_attribute *a,
-							    const char *buf,
-								size_t count)
+static int
+nouveau_hwmon_critical_temp(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
-
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
-
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_CRITICAL, value / 1000);
 
-	return count;
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL) * 1000;
 }
-static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
-						nouveau_hwmon_critical_temp,
-						nouveau_hwmon_set_critical_temp,
-						0);
 
-static ssize_t
-nouveau_hwmon_critical_temp_hyst(struct device *d, struct device_attribute *a,
-							char *buf)
+static int
+nouveau_hwmon_critical_temp_hyst(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST) * 1000);
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST) * 1000;
 }
-static ssize_t
-nouveau_hwmon_set_critical_temp_hyst(struct device *d,
-				     struct device_attribute *a,
-				     const char *buf,
-				     size_t count)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
 
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
-
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST,
-			value / 1000);
-
-	return count;
-}
-static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
-			  nouveau_hwmon_critical_temp_hyst,
-			  nouveau_hwmon_set_critical_temp_hyst, 0);
-static ssize_t
-nouveau_hwmon_emergency_temp(struct device *d, struct device_attribute *a,
-							char *buf)
+static int
+nouveau_hwmon_emergency_temp(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN) * 1000);
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN) * 1000;
 }
-static ssize_t
-nouveau_hwmon_set_emergency_temp(struct device *d, struct device_attribute *a,
-							    const char *buf,
-								size_t count)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
 
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
-
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN, value / 1000);
-
-	return count;
-}
-static SENSOR_DEVICE_ATTR(temp1_emergency, S_IRUGO | S_IWUSR,
-					nouveau_hwmon_emergency_temp,
-					nouveau_hwmon_set_emergency_temp,
-					0);
-
-static ssize_t
-nouveau_hwmon_emergency_temp_hyst(struct device *d, struct device_attribute *a,
-							char *buf)
-{
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-
-	return snprintf(buf, PAGE_SIZE, "%d\n",
-	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST) * 1000);
-}
-static ssize_t
-nouveau_hwmon_set_emergency_temp_hyst(struct device *d,
-				      struct device_attribute *a,
-				      const char *buf,
-				      size_t count)
+static int
+nouveau_hwmon_emergency_temp_hyst(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
-
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return count;
-
-	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST,
-			value / 1000);
 
-	return count;
-}
-static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO | S_IWUSR,
-					nouveau_hwmon_emergency_temp_hyst,
-					nouveau_hwmon_set_emergency_temp_hyst,
-					0);
-
-static ssize_t nouveau_hwmon_show_name(struct device *dev,
-				      struct device_attribute *attr,
-				      char *buf)
-{
-	return sprintf(buf, "nouveau\n");
+	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST) * 1000;
 }
-static SENSOR_DEVICE_ATTR(name, S_IRUGO, nouveau_hwmon_show_name, NULL, 0);
 
-static ssize_t nouveau_hwmon_show_update_rate(struct device *dev,
-				      struct device_attribute *attr,
-				      char *buf)
+static int
+nouveau_hwmon_show_update_rate(struct nouveau_drm *drm)
 {
-	return sprintf(buf, "1000\n");
+	return 1000;
 }
-static SENSOR_DEVICE_ATTR(update_rate, S_IRUGO,
-						nouveau_hwmon_show_update_rate,
-						NULL, 0);
 
-static ssize_t
-nouveau_hwmon_show_fan1_input(struct device *d, struct device_attribute *attr,
-			      char *buf)
+static int
+nouveau_hwmon_show_fan1_input(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
nvkm_therm_fan_sense(therm));
+	return nvkm_therm_fan_sense(therm);
 }
-static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, nouveau_hwmon_show_fan1_input,
-			  NULL, 0);
 
- static ssize_t
-nouveau_hwmon_get_pwm1_enable(struct device *d,
-			   struct device_attribute *a, char *buf)
+static int
+nouveau_hwmon_get_pwm1_enable(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	int ret;
 
-	ret = therm->attr_get(therm, NVKM_THERM_ATTR_FAN_MODE);
-	if (ret < 0)
-		return ret;
-
-	return sprintf(buf, "%i\n", ret);
+	return therm->attr_get(therm, NVKM_THERM_ATTR_FAN_MODE);
 }
 
-static ssize_t
-nouveau_hwmon_set_pwm1_enable(struct device *d, struct device_attribute *a,
-			   const char *buf, size_t count)
+static int
+nouveau_hwmon_set_pwm1_enable(struct nouveau_drm *drm, long value)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	long value;
-	int ret;
 
-	ret = kstrtol(buf, 10, &value);
-	if (ret)
-		return ret;
-
-	ret = therm->attr_set(therm, NVKM_THERM_ATTR_FAN_MODE, value);
-	if (ret)
-		return ret;
-	else
-		return count;
+	return therm->attr_set(therm, NVKM_THERM_ATTR_FAN_MODE, value);
 }
-static SENSOR_DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
-			  nouveau_hwmon_get_pwm1_enable,
-			  nouveau_hwmon_set_pwm1_enable, 0);
 
-static ssize_t
-nouveau_hwmon_get_pwm1(struct device *d, struct device_attribute *a, char *buf)
+static int
+nouveau_hwmon_get_pwm1(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	int ret;
-
-	ret = therm->fan_get(therm);
-	if (ret < 0)
-		return ret;
 
-	return sprintf(buf, "%i\n", ret);
+	return therm->fan_get(therm);
 }
 
-static ssize_t
-nouveau_hwmon_set_pwm1(struct device *d, struct device_attribute *a,
-		       const char *buf, size_t count)
+static int
+nouveau_hwmon_set_pwm1(struct nouveau_drm *drm, long value)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	int ret = -ENODEV;
-	long value;
-
-	if (kstrtol(buf, 10, &value) == -EINVAL)
-		return -EINVAL;
-
-	ret = therm->fan_set(therm, value);
-	if (ret)
-		return ret;
 
-	return count;
+	return therm->fan_set(therm, value);
 }
 
-static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR,
-			  nouveau_hwmon_get_pwm1,
-			  nouveau_hwmon_set_pwm1, 0);
-
 static ssize_t
 nouveau_hwmon_get_pwm1_min(struct device *d,
 			   struct device_attribute *a, char *buf)
@@ -515,12 +299,9 @@ static SENSOR_DEVICE_ATTR(pwm1_max, S_IRUGO | S_IWUSR,
 			  nouveau_hwmon_get_pwm1_max,
 			  nouveau_hwmon_set_pwm1_max, 0);
 
-static ssize_t
-nouveau_hwmon_get_in0_input(struct device *d,
-			    struct device_attribute *a, char *buf)
+static int
+nouveau_hwmon_get_in0_input(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
 	int ret;
 
@@ -528,170 +309,54 @@ nouveau_hwmon_get_in0_input(struct device *d,
 	if (ret < 0)
 		return ret;
 
-	return sprintf(buf, "%i\n", ret / 1000);
+	return (ret / 1000);
 }
 
-static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO,
-			  nouveau_hwmon_get_in0_input, NULL, 0);
-
-static ssize_t
-nouveau_hwmon_get_in0_min(struct device *d,
-			    struct device_attribute *a, char *buf)
+static int
+nouveau_hwmon_get_in0_min(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
 
 	if (!volt || !volt->min_uv)
 		return -ENODEV;
 
-	return sprintf(buf, "%i\n", volt->min_uv / 1000);
+	return (volt->min_uv / 1000);
 }
 
-static SENSOR_DEVICE_ATTR(in0_min, S_IRUGO,
-			  nouveau_hwmon_get_in0_min, NULL, 0);
-
-static ssize_t
-nouveau_hwmon_get_in0_max(struct device *d,
-			    struct device_attribute *a, char *buf)
+static int
+nouveau_hwmon_get_in0_max(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
 
 	if (!volt || !volt->max_uv)
 		return -ENODEV;
 
-	return sprintf(buf, "%i\n", volt->max_uv / 1000);
-}
-
-static SENSOR_DEVICE_ATTR(in0_max, S_IRUGO,
-			  nouveau_hwmon_get_in0_max, NULL, 0);
-
-static ssize_t
-nouveau_hwmon_get_in0_label(struct device *d,
-			    struct device_attribute *a, char *buf)
-{
-	return sprintf(buf, "GPU core\n");
+	return (volt->max_uv / 1000);
 }
 
-static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO,
-			  nouveau_hwmon_get_in0_label, NULL, 0);
-
-static ssize_t
-nouveau_hwmon_get_power1_input(struct device *d, struct device_attribute *a,
-			       char *buf)
+static int
+nouveau_hwmon_get_power1_input(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
-	int result = nvkm_iccsense_read_all(iccsense);
 
-	if (result < 0)
-		return result;
-
-	return sprintf(buf, "%i\n", result);
+	return nvkm_iccsense_read_all(iccsense);
 }
 
-static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO,
-			  nouveau_hwmon_get_power1_input, NULL, 0);
-
-static ssize_t
-nouveau_hwmon_get_power1_max(struct device *d, struct device_attribute *a,
-			     char *buf)
+static int
+nouveau_hwmon_get_power1_max(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
-	return sprintf(buf, "%i\n", iccsense->power_w_max);
-}
 
-static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO,
-			  nouveau_hwmon_get_power1_max, NULL, 0);
+	return iccsense->power_w_max;
+}
 
-static ssize_t
-nouveau_hwmon_get_power1_crit(struct device *d, struct device_attribute *a,
-			      char *buf)
+static int
+nouveau_hwmon_get_power1_crit(struct nouveau_drm *drm)
 {
-	struct drm_device *dev = dev_get_drvdata(d);
-	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
-	return sprintf(buf, "%i\n", iccsense->power_w_crit);
-}
-
-static SENSOR_DEVICE_ATTR(power1_crit, S_IRUGO,
-			  nouveau_hwmon_get_power1_crit, NULL, 0);
-
-static struct attribute *hwmon_default_attributes[] = {
-	&sensor_dev_attr_name.dev_attr.attr,
-	&sensor_dev_attr_update_rate.dev_attr.attr,
-	NULL
-};
-static struct attribute *hwmon_temp_attributes[] = {
-	&sensor_dev_attr_temp1_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_auto_point1_pwm.dev_attr.attr,
-	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
-	&sensor_dev_attr_temp1_auto_point1_temp_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_max.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_crit.dev_attr.attr,
-	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
-	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
-	NULL
-};
-static struct attribute *hwmon_fan_rpm_attributes[] = {
-	&sensor_dev_attr_fan1_input.dev_attr.attr,
-	NULL
-};
-static struct attribute *hwmon_pwm_fan_attributes[] = {
-	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
-	&sensor_dev_attr_pwm1.dev_attr.attr,
-	&sensor_dev_attr_pwm1_min.dev_attr.attr,
-	&sensor_dev_attr_pwm1_max.dev_attr.attr,
-	NULL
-};
-
-static struct attribute *hwmon_in0_attributes[] = {
-	&sensor_dev_attr_in0_input.dev_attr.attr,
-	&sensor_dev_attr_in0_min.dev_attr.attr,
-	&sensor_dev_attr_in0_max.dev_attr.attr,
-	&sensor_dev_attr_in0_label.dev_attr.attr,
-	NULL
-};
 
-static struct attribute *hwmon_power_attributes[] = {
-	&sensor_dev_attr_power1_input.dev_attr.attr,
-	NULL
-};
-
-static struct attribute *hwmon_power_caps_attributes[] = {
-	&sensor_dev_attr_power1_max.dev_attr.attr,
-	&sensor_dev_attr_power1_crit.dev_attr.attr,
-	NULL
-};
-
-static const struct attribute_group hwmon_default_attrgroup = {
-	.attrs = hwmon_default_attributes,
-};
-static const struct attribute_group hwmon_temp_attrgroup = {
-	.attrs = hwmon_temp_attributes,
-};
-static const struct attribute_group hwmon_fan_rpm_attrgroup = {
-	.attrs = hwmon_fan_rpm_attributes,
-};
-static const struct attribute_group hwmon_pwm_fan_attrgroup = {
-	.attrs = hwmon_pwm_fan_attributes,
-};
-static const struct attribute_group hwmon_in0_attrgroup = {
-	.attrs = hwmon_in0_attributes,
-};
-static const struct attribute_group hwmon_power_attrgroup = {
-	.attrs = hwmon_power_attributes,
-};
-static const struct attribute_group hwmon_power_caps_attrgroup = {
-	.attrs = hwmon_power_caps_attributes,
-};
+	return iccsense->power_w_crit;
+}
 
 static const u32 nouveau_config_chip[] = {
 	HWMON_C_UPDATE_INTERVAL,
@@ -887,6 +552,157 @@ nouveau_fan_is_visible(const void *data, u32 attr, int
channel)
 	}
 }
 
+static int
+nouveau_chip_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		*val = nouveau_hwmon_show_update_rate(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_temp_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_temp_input:
+		*val = nouveau_hwmon_show_temp(drm);
+		break;
+	case hwmon_temp_max:
+		*val = nouveau_hwmon_max_temp(drm);
+		break;
+	case hwmon_temp_max_hyst:
+		*val = nouveau_hwmon_max_temp_hyst(drm);
+		break;
+	case hwmon_temp_crit:
+		*val = nouveau_hwmon_critical_temp(drm);
+		break;
+	case hwmon_temp_crit_hyst:
+		*val = nouveau_hwmon_critical_temp_hyst(drm);
+		break;
+	case hwmon_temp_emergency:
+		*val = nouveau_hwmon_emergency_temp(drm);
+		break;
+	case hwmon_temp_emergency_hyst:
+		*val = nouveau_hwmon_emergency_temp_hyst(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_fan_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_fan_input:
+		*val = nouveau_hwmon_show_fan1_input(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_in_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_in_input:
+		*val = nouveau_hwmon_get_in0_input(drm);
+		break;
+	case hwmon_in_min:
+		*val = nouveau_hwmon_get_in0_min(drm);
+		break;
+	case hwmon_in_max:
+		*val = nouveau_hwmon_get_in0_max(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_pwm_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_pwm_enable:
+		*val = nouveau_hwmon_get_pwm1_enable(drm);
+		break;
+	case hwmon_pwm_input:
+		*val = nouveau_hwmon_get_pwm1(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_power_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_power_input:
+		*val = nouveau_hwmon_get_power1_input(drm);
+		break;
+	case hwmon_power_max:
+		*val = nouveau_hwmon_get_power1_max(drm);
+		break;
+	case hwmon_power_crit:
+		*val = nouveau_hwmon_get_power1_crit(drm);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+nouveau_pwm_write(struct device *dev, u32 attr, int channel, long val)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct nouveau_drm *drm = nouveau_drm(drm_dev);
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		return nouveau_hwmon_set_pwm1(drm, val);
+	case hwmon_pwm_enable:
+		return nouveau_hwmon_set_pwm1_enable(drm, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static umode_t
 nouveau_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
 								int channel)
@@ -923,11 +739,45 @@ nouveau_read_string(struct device *dev, enum
hwmon_sensor_types type, u32 attr,
 	return -EOPNOTSUPP;
 }
 
+static int
+nouveau_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+							int channel, long *val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return nouveau_chip_read(dev, attr, channel, val);
+	case hwmon_temp:
+		return nouveau_temp_read(dev, attr, channel, val);
+	case hwmon_fan:
+		return nouveau_fan_read(dev, attr, channel, val);
+	case hwmon_in:
+		return nouveau_in_read(dev, attr, channel, val);
+	case hwmon_pwm:
+		return nouveau_pwm_read(dev, attr, channel, val);
+	case hwmon_power:
+		return nouveau_power_read(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+nouveau_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+							int channel, long val)
+{
+	switch (type) {
+	case hwmon_pwm:
+		return nouveau_pwm_write(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct hwmon_ops nouveau_hwmon_ops = {
 	.is_visible = nouveau_is_visible,
-	.read = NULL,
+	.read = nouveau_read,
 	.read_string = nouveau_read_string,
-	.write = NULL,
+	.write = nouveau_write,
 };
 
 static const struct hwmon_chip_info nouveau_chip_info = {
@@ -942,8 +792,6 @@ nouveau_hwmon_init(struct drm_device *dev)
 #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
-	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
-	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
 	struct nouveau_hwmon *hwmon;
 	struct device *hwmon_dev;
 	int ret = 0;
@@ -953,79 +801,16 @@ nouveau_hwmon_init(struct drm_device *dev)
 		return -ENOMEM;
 	hwmon->dev = dev;
 
-	hwmon_dev = hwmon_device_register(dev->dev);
+	hwmon_dev = hwmon_device_register_with_info(dev->dev, "nouveau",
dev,
+						&nouveau_chip_info, NULL);
 	if (IS_ERR(hwmon_dev)) {
 		ret = PTR_ERR(hwmon_dev);
 		NV_ERROR(drm, "Unable to register hwmon device: %d\n", ret);
 		return ret;
 	}
-	dev_set_drvdata(hwmon_dev, dev);
-
-	/* set the default attributes */
-	ret = sysfs_create_group(&hwmon_dev->kobj,
&hwmon_default_attrgroup);
-	if (ret)
-		goto error;
-
-	if (therm && therm->attr_get && therm->attr_set) {
-		/* if the card has a working thermal sensor */
-		if (nvkm_therm_temp_get(therm) >= 0) {
-			ret = sysfs_create_group(&hwmon_dev->kobj,
&hwmon_temp_attrgroup);
-			if (ret)
-				goto error;
-		}
-
-		/* if the card has a pwm fan */
-		/*XXX: incorrect, need better detection for this, some boards have
-		 *     the gpio entries for pwm fan control even when there's no
-		 *     actual fan connected to it... therm table? */
-		if (therm->fan_get && therm->fan_get(therm) >= 0) {
-			ret = sysfs_create_group(&hwmon_dev->kobj,
-						 &hwmon_pwm_fan_attrgroup);
-			if (ret)
-				goto error;
-		}
-	}
-
-	/* if the card can read the fan rpm */
-	if (therm && nvkm_therm_fan_sense(therm) >= 0) {
-		ret = sysfs_create_group(&hwmon_dev->kobj,
-					 &hwmon_fan_rpm_attrgroup);
-		if (ret)
-			goto error;
-	}
-
-	if (volt && nvkm_volt_get(volt) >= 0) {
-		ret = sysfs_create_group(&hwmon_dev->kobj,
-					 &hwmon_in0_attrgroup);
-
-		if (ret)
-			goto error;
-	}
-
-	if (iccsense && iccsense->data_valid &&
!list_empty(&iccsense->rails)) {
-		ret = sysfs_create_group(&hwmon_dev->kobj,
-					 &hwmon_power_attrgroup);
-
-		if (ret)
-			goto error;
-
-		if (iccsense->power_w_max && iccsense->power_w_crit) {
-			ret = sysfs_create_group(&hwmon_dev->kobj,
-						 &hwmon_power_caps_attrgroup);
-			if (ret)
-				goto error;
-		}
-	}
 
 	hwmon->hwmon = hwmon_dev;
-
 	return 0;
-
-error:
-	NV_ERROR(drm, "Unable to create some hwmon sysfs files: %d\n", ret);
-	hwmon_device_unregister(hwmon_dev);
-	hwmon->hwmon = NULL;
-	return ret;
 #else
 	return 0;
 #endif
@@ -1037,17 +822,8 @@ nouveau_hwmon_fini(struct drm_device *dev)
 #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
 	struct nouveau_hwmon *hwmon = nouveau_hwmon(dev);
 
-	if (hwmon->hwmon) {
-		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_default_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj, &hwmon_temp_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_pwm_fan_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_fan_rpm_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj, &hwmon_in0_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_attrgroup);
-		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_caps_attrgroup);
-
+	if (hwmon->hwmon)
 		hwmon_device_unregister(hwmon->hwmon);
-	}
 
 	nouveau_drm(dev)->hwmon = NULL;
 	kfree(hwmon);
-- 
2.1.4

This patch creates a special group attributes for attrs like
"*auto_point*".
We check if we have support for them, and if we do, we gather them all in
an attribute_group's structure which is the parameter regarding special
groups
of hwmon_device_register_with_info.

Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index 4db65fb..9142779 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -358,6 +358,23 @@ nouveau_hwmon_get_power1_crit(struct nouveau_drm *drm)
 	return iccsense->power_w_crit;
 }
 
+static struct attribute *pwm_fan_sensor_attrs[] = {
+	&sensor_dev_attr_pwm1_min.dev_attr.attr,
+	&sensor_dev_attr_pwm1_max.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(pwm_fan_sensor);
+
+static struct attribute *temp1_auto_point_sensor_attrs[] = {
+	&sensor_dev_attr_temp1_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
+	&sensor_dev_attr_temp1_auto_point1_temp_hyst.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(temp1_auto_point_sensor);
+
+#define N_ATTR_GROUPS   3
+
 static const u32 nouveau_config_chip[] = {
 	HWMON_C_UPDATE_INTERVAL,
 	0
@@ -792,17 +809,27 @@ nouveau_hwmon_init(struct drm_device *dev)
 #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
+	const struct attribute_group *special_groups[N_ATTR_GROUPS];
 	struct nouveau_hwmon *hwmon;
 	struct device *hwmon_dev;
 	int ret = 0;
+	int i = 0;
 
 	hwmon = drm->hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
 	if (!hwmon)
 		return -ENOMEM;
 	hwmon->dev = dev;
 
+	if (therm && therm->attr_get && therm->attr_set) {
+		if (nvkm_therm_temp_get(therm) >= 0)
+			special_groups[i++] = &temp1_auto_point_sensor_group;
+		if (therm->fan_get && therm->fan_get(therm) >= 0)
+			special_groups[i++] = &pwm_fan_sensor_group;
+	}
+
+	special_groups[i] = 0;
 	hwmon_dev = hwmon_device_register_with_info(dev->dev, "nouveau",
dev,
-						&nouveau_chip_info, NULL);
+					&nouveau_chip_info, special_groups);
 	if (IS_ERR(hwmon_dev)) {
 		ret = PTR_ERR(hwmon_dev);
 		NV_ERROR(drm, "Unable to register hwmon device: %d\n", ret);
-- 
2.1.4

This patch replaces the symbolic permissions with the numeric ones,
and adds me to the authors too.

Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index 9142779..45b5c85 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -1,5 +1,6 @@
 /*
- * Copyright 2010 Red Hat Inc.
+ * Copyright 2010 Red Hat Inc. (Ben Skeggs)
+ * Copyright 2017 Oscar Salvador
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
"Software"),
@@ -19,7 +20,6 @@
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  *
- * Authors: Ben Skeggs
  */
 
 #ifdef CONFIG_ACPI
@@ -56,7 +56,7 @@ nouveau_hwmon_show_temp1_auto_point1_pwm(struct device *d,
 {
 	return snprintf(buf, PAGE_SIZE, "%d\n", 100);
 }
-static SENSOR_DEVICE_ATTR(temp1_auto_point1_pwm, S_IRUGO,
+static SENSOR_DEVICE_ATTR(temp1_auto_point1_pwm, 0444,
 			  nouveau_hwmon_show_temp1_auto_point1_pwm, NULL, 0);
 
 static ssize_t
@@ -88,7 +88,7 @@ nouveau_hwmon_set_temp1_auto_point1_temp(struct device *d,
 
 	return count;
 }
-static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp, S_IRUGO | S_IWUSR,
+static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp, 0644,
 			  nouveau_hwmon_temp1_auto_point1_temp,
 			  nouveau_hwmon_set_temp1_auto_point1_temp, 0);
 
@@ -121,7 +121,7 @@ nouveau_hwmon_set_temp1_auto_point1_temp_hyst(struct device
*d,
 
 	return count;
 }
-static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst, S_IRUGO | S_IWUSR,
+static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst, 0644,
 			  nouveau_hwmon_temp1_auto_point1_temp_hyst,
 			  nouveau_hwmon_set_temp1_auto_point1_temp_hyst, 0);
 
@@ -255,7 +255,7 @@ nouveau_hwmon_set_pwm1_min(struct device *d, struct
device_attribute *a,
 	return count;
 }
 
-static SENSOR_DEVICE_ATTR(pwm1_min, S_IRUGO | S_IWUSR,
+static SENSOR_DEVICE_ATTR(pwm1_min, 0644,
 			  nouveau_hwmon_get_pwm1_min,
 			  nouveau_hwmon_set_pwm1_min, 0);
 
@@ -295,7 +295,7 @@ nouveau_hwmon_set_pwm1_max(struct device *d, struct
device_attribute *a,
 	return count;
 }
 
-static SENSOR_DEVICE_ATTR(pwm1_max, S_IRUGO | S_IWUSR,
+static SENSOR_DEVICE_ATTR(pwm1_max, 0644,
 			  nouveau_hwmon_get_pwm1_max,
 			  nouveau_hwmon_set_pwm1_max, 0);
 
-- 
2.1.4

On 26/04/17 19:46, Oscar Salvador wrote:
> This patch introduces the nouveau_hwmon_ops structure, sets up
> .is_visible and .read_string operations and adds all the functions
> for these operations.
> This is also a preparation for the next patches, where most of the
> work is being done.
> This code doesn't interacture with the old one.
> It's just to make easier the review of all patches.
> 
> Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_hwmon.c | 170
++++++++++++++++++++++++++++++++
>  1 file changed, 170 insertions(+)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> index 24b40c5..e8ea8d0 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> @@ -764,6 +764,176 @@ static const struct hwmon_channel_info
*nouveau_info[] = {
>  	&nouveau_power,
>  	NULL
>  };
> +
> +static umode_t
> +nouveau_chip_is_visible(const void *data, u32 attr, int channel)
> +{
> +	switch (attr) {
> +	case hwmon_chip_update_interval:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_power_is_visible(const void *data, u32 attr, int channel)
> +{
> +	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
> +	struct nvkm_iccsense *iccsense =
nvxx_iccsense(&drm->client.device);
> +
> +	if (!iccsense)
> +		return 0;
> +
> +	switch (attr) {
> +	case hwmon_power_input:
> +		if (iccsense->data_valid &&
> +			!list_empty(&iccsense->rails))
Not sure if the kernel coding style would mandate !list_empty to be
aligned with the iccsense in the above line, but this is our coding
style at least.

Anyway, this condition has to be moved before the switch as we should
not expose power_max/crit if power_input is not exposed.

> +			return 0444;
> +		return 0;
> +	case hwmon_power_max:
> +		if (iccsense->power_w_max)
> +			return 0444;
> +		return 0;
> +	case hwmon_power_crit:
> +		if (iccsense->power_w_crit)
> +			return 0444;
> +		return 0;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_temp_is_visible(const void *data, u32 attr, int channel)
> +{
> +	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
> +	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> +
> +	if (therm &&
> +		therm->attr_get &&
> +		nvkm_therm_temp_get(therm) < 0)
> +		return 0;
You can also fold therm->attr_get on the same line as therm.
> +
> +	switch (attr) {
> +	case hwmon_temp_input:
> +	case hwmon_temp_max:
> +	case hwmon_temp_max_hyst:
> +	case hwmon_temp_crit:
> +	case hwmon_temp_crit_hyst:
> +	case hwmon_temp_emergency:
> +	case hwmon_temp_emergency_hyst:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_pwm_is_visible(const void *data, u32 attr, int channel)
> +{
> +	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
> +	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> +
> +	if (therm &&
> +		therm->attr_get &&
> +		therm->fan_get &&
> +		therm->fan_get(therm) < 0)
> +		return 0;
Same, please fold as much as you can in 80 characters ;)
> +
> +	switch (attr) {
> +	case hwmon_pwm_enable:
> +	case hwmon_pwm_input:
> +		return 0644;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_input_is_visible(const void *data, u32 attr, int channel)
> +{
> +	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
> +	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
> +
> +	if (!volt || nvkm_volt_get(volt) < 0)
> +		return 0;
> +
> +	switch (attr) {
> +	case hwmon_in_input:
> +	case hwmon_in_label:
> +	case hwmon_in_min:
> +	case hwmon_in_max:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_fan_is_visible(const void *data, u32 attr, int channel)
> +{
> +	struct nouveau_drm *drm = nouveau_drm((struct drm_device *)data);
> +	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> +
> +	if (!therm || !therm->attr_get || nvkm_therm_fan_sense(therm) < 0)
> +		return 0;
> +
> +	switch (attr) {
> +	case hwmon_fan_input:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static umode_t
> +nouveau_is_visible(const void *data, enum hwmon_sensor_types type, u32
attr,
> +								int channel)
Could you align 'int channel' with 'const void *data'?
> +{
> +	switch (type) {
> +	case hwmon_chip:
> +		return nouveau_chip_is_visible(data, attr, channel);
> +	case hwmon_temp:
> +		return nouveau_temp_is_visible(data, attr, channel);
> +	case hwmon_fan:
> +		return nouveau_fan_is_visible(data, attr, channel);
> +	case hwmon_in:
> +		return nouveau_input_is_visible(data, attr, channel);
> +	case hwmon_pwm:
> +		return nouveau_pwm_is_visible(data, attr, channel);
> +	case hwmon_power:
> +		return nouveau_power_is_visible(data, attr, channel);
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static const char input_label[] = "GPU core";
> +
> +static int
> +nouveau_read_string(struct device *dev, enum hwmon_sensor_types type, u32
attr,
> +							int channel, char **buf)
Same as above.
> +{
> +	if (type == hwmon_in && attr == hwmon_in_label) {
> +		*buf = input_label;
> +		return 0;
> +	}
> +
> +	return -EOPNOTSUPP;
> +}
> +
> +static const struct hwmon_ops nouveau_hwmon_ops = {
> +	.is_visible = nouveau_is_visible,
> +	.read = NULL,
> +	.read_string = nouveau_read_string,
> +	.write = NULL,
> +};
> +
> +static const struct hwmon_chip_info nouveau_chip_info = {
> +	.ops = &nouveau_hwmon_ops,
> +	.info = nouveau_info,
> +};
>  #endif
>  
>  int
>
With the power-related conditions and all the alignments fixed, patches
1-2 are:

Reviewed-by: Martin Peres <martin.peres at free.fr>

On 26/04/17 19:46, Oscar Salvador wrote:
> This patch removes old code related to the old api and transforms the
> functions for the new api. It also adds the .write and .read operations.
> 
> Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_hwmon.c | 722
+++++++++++---------------------
>  1 file changed, 249 insertions(+), 473 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> index e8ea8d0..4db65fb 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> @@ -38,21 +38,17 @@
>  #include <nvkm/subdev/volt.h>
>  
>  #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
> -static ssize_t
> -nouveau_hwmon_show_temp(struct device *d, struct device_attribute *a, char
*buf)
> +static int
> +nouveau_hwmon_show_temp(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
>  	int temp = nvkm_therm_temp_get(therm);
>  
>  	if (temp < 0)
>  		return temp;
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n", temp * 1000);
> +	return (temp * 1000);
>  }
> -static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, nouveau_hwmon_show_temp,
> -						  NULL, 0);
>  
>  static ssize_t
>  nouveau_hwmon_show_temp1_auto_point1_pwm(struct device *d,
> @@ -129,312 +125,100 @@ static
SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst, S_IRUGO | S_IWUSR,
>  			  nouveau_hwmon_temp1_auto_point1_temp_hyst,
>  			  nouveau_hwmon_set_temp1_auto_point1_temp_hyst, 0);
>  
> -static ssize_t
> -nouveau_hwmon_max_temp(struct device *d, struct device_attribute *a, char
*buf)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK) * 1000);
> -}
> -static ssize_t
> -nouveau_hwmon_set_max_temp(struct device *d, struct device_attribute *a,
> -						const char *buf, size_t count)
> +static int
> +nouveau_hwmon_max_temp(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
>  
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
> -
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK, value / 1000);
> -
> -	return count;
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK) * 1000;
>  }
> -static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
nouveau_hwmon_max_temp,
> -						  nouveau_hwmon_set_max_temp,
> -						  0);
>  
> -static ssize_t
> -nouveau_hwmon_max_temp_hyst(struct device *d, struct device_attribute *a,
> -			    char *buf)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST) * 1000);
> -}
> -static ssize_t
> -nouveau_hwmon_set_max_temp_hyst(struct device *d, struct device_attribute
*a,
> -						const char *buf, size_t count)
> +static int
> +nouveau_hwmon_max_temp_hyst(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
> -
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
>  
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST,
> -			value / 1000);
> -
> -	return count;
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_DOWN_CLK_HYST) *
1000;
>  }
> -static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
> -			  nouveau_hwmon_max_temp_hyst,
> -			  nouveau_hwmon_set_max_temp_hyst, 0);
> -
> -static ssize_t
> -nouveau_hwmon_critical_temp(struct device *d, struct device_attribute *a,
> -							char *buf)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL) * 1000);
> -}
> -static ssize_t
> -nouveau_hwmon_set_critical_temp(struct device *d, struct device_attribute
*a,
> -							    const char *buf,
> -								size_t count)
> +static int
> +nouveau_hwmon_critical_temp(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
> -
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
> -
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_CRITICAL, value / 1000);
>  
> -	return count;
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL) * 1000;
>  }
> -static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
> -						nouveau_hwmon_critical_temp,
> -						nouveau_hwmon_set_critical_temp,
> -						0);
>  
> -static ssize_t
> -nouveau_hwmon_critical_temp_hyst(struct device *d, struct device_attribute
*a,
> -							char *buf)
> +static int
> +nouveau_hwmon_critical_temp_hyst(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST) * 1000);
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST) *
1000;
>  }
> -static ssize_t
> -nouveau_hwmon_set_critical_temp_hyst(struct device *d,
> -				     struct device_attribute *a,
> -				     const char *buf,
> -				     size_t count)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
>  
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
> -
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_CRITICAL_HYST,
> -			value / 1000);
> -
> -	return count;
> -}
> -static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
> -			  nouveau_hwmon_critical_temp_hyst,
> -			  nouveau_hwmon_set_critical_temp_hyst, 0);
> -static ssize_t
> -nouveau_hwmon_emergency_temp(struct device *d, struct device_attribute *a,
> -							char *buf)
> +static int
> +nouveau_hwmon_emergency_temp(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	       therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN) * 1000);
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN) * 1000;
>  }
> -static ssize_t
> -nouveau_hwmon_set_emergency_temp(struct device *d, struct device_attribute
*a,
> -							    const char *buf,
> -								size_t count)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
>  
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
> -
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN, value / 1000);
> -
> -	return count;
> -}
> -static SENSOR_DEVICE_ATTR(temp1_emergency, S_IRUGO | S_IWUSR,
> -					nouveau_hwmon_emergency_temp,
> -					nouveau_hwmon_set_emergency_temp,
> -					0);
> -
> -static ssize_t
> -nouveau_hwmon_emergency_temp_hyst(struct device *d, struct
device_attribute *a,
> -							char *buf)
> -{
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
> -	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
> -	  therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST) * 1000);
> -}
> -static ssize_t
> -nouveau_hwmon_set_emergency_temp_hyst(struct device *d,
> -				      struct device_attribute *a,
> -				      const char *buf,
> -				      size_t count)
> +static int
> +nouveau_hwmon_emergency_temp_hyst(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
> -
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return count;
> -
> -	therm->attr_set(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST,
> -			value / 1000);
>  
> -	return count;
> -}
> -static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO | S_IWUSR,
> -					nouveau_hwmon_emergency_temp_hyst,
> -					nouveau_hwmon_set_emergency_temp_hyst,
> -					0);
> -
> -static ssize_t nouveau_hwmon_show_name(struct device *dev,
> -				      struct device_attribute *attr,
> -				      char *buf)
> -{
> -	return sprintf(buf, "nouveau\n");
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_THRS_SHUTDOWN_HYST) *
1000;
>  }
> -static SENSOR_DEVICE_ATTR(name, S_IRUGO, nouveau_hwmon_show_name, NULL,
0);
>  
> -static ssize_t nouveau_hwmon_show_update_rate(struct device *dev,
> -				      struct device_attribute *attr,
> -				      char *buf)
> +static int
> +nouveau_hwmon_show_update_rate(struct nouveau_drm *drm)
>  {
> -	return sprintf(buf, "1000\n");
> +	return 1000;
>  }
> -static SENSOR_DEVICE_ATTR(update_rate, S_IRUGO,
> -						nouveau_hwmon_show_update_rate,
> -						NULL, 0);
>  
> -static ssize_t
> -nouveau_hwmon_show_fan1_input(struct device *d, struct device_attribute
*attr,
> -			      char *buf)
> +static int
> +nouveau_hwmon_show_fan1_input(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n",
nvkm_therm_fan_sense(therm));
> +	return nvkm_therm_fan_sense(therm);
>  }
> -static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO,
nouveau_hwmon_show_fan1_input,
> -			  NULL, 0);
>  
> - static ssize_t
> -nouveau_hwmon_get_pwm1_enable(struct device *d,
> -			   struct device_attribute *a, char *buf)
> +static int
> +nouveau_hwmon_get_pwm1_enable(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	int ret;
>  
> -	ret = therm->attr_get(therm, NVKM_THERM_ATTR_FAN_MODE);
> -	if (ret < 0)
> -		return ret;
> -
> -	return sprintf(buf, "%i\n", ret);
> +	return therm->attr_get(therm, NVKM_THERM_ATTR_FAN_MODE);
>  }
>  
> -static ssize_t
> -nouveau_hwmon_set_pwm1_enable(struct device *d, struct device_attribute
*a,
> -			   const char *buf, size_t count)
> +static int
> +nouveau_hwmon_set_pwm1_enable(struct nouveau_drm *drm, long value)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	long value;
> -	int ret;
>  
> -	ret = kstrtol(buf, 10, &value);
> -	if (ret)
> -		return ret;
> -
> -	ret = therm->attr_set(therm, NVKM_THERM_ATTR_FAN_MODE, value);
> -	if (ret)
> -		return ret;
> -	else
> -		return count;
> +	return therm->attr_set(therm, NVKM_THERM_ATTR_FAN_MODE, value);
>  }
> -static SENSOR_DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
> -			  nouveau_hwmon_get_pwm1_enable,
> -			  nouveau_hwmon_set_pwm1_enable, 0);
>  
> -static ssize_t
> -nouveau_hwmon_get_pwm1(struct device *d, struct device_attribute *a, char
*buf)
> +static int
> +nouveau_hwmon_get_pwm1(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	int ret;
> -
> -	ret = therm->fan_get(therm);
> -	if (ret < 0)
> -		return ret;
>  
> -	return sprintf(buf, "%i\n", ret);
> +	return therm->fan_get(therm);
>  }
>  
> -static ssize_t
> -nouveau_hwmon_set_pwm1(struct device *d, struct device_attribute *a,
> -		       const char *buf, size_t count)
> +static int
> +nouveau_hwmon_set_pwm1(struct nouveau_drm *drm, long value)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	int ret = -ENODEV;
> -	long value;
> -
> -	if (kstrtol(buf, 10, &value) == -EINVAL)
> -		return -EINVAL;
> -
> -	ret = therm->fan_set(therm, value);
> -	if (ret)
> -		return ret;
>  
> -	return count;
> +	return therm->fan_set(therm, value);
>  }
>  
> -static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR,
> -			  nouveau_hwmon_get_pwm1,
> -			  nouveau_hwmon_set_pwm1, 0);
> -
>  static ssize_t
>  nouveau_hwmon_get_pwm1_min(struct device *d,
>  			   struct device_attribute *a, char *buf)
> @@ -515,12 +299,9 @@ static SENSOR_DEVICE_ATTR(pwm1_max, S_IRUGO | S_IWUSR,
>  			  nouveau_hwmon_get_pwm1_max,
>  			  nouveau_hwmon_set_pwm1_max, 0);
>  
> -static ssize_t
> -nouveau_hwmon_get_in0_input(struct device *d,
> -			    struct device_attribute *a, char *buf)
> +static int
> +nouveau_hwmon_get_in0_input(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
>  	int ret;
>  
> @@ -528,170 +309,54 @@ nouveau_hwmon_get_in0_input(struct device *d,
>  	if (ret < 0)
>  		return ret;
>  
> -	return sprintf(buf, "%i\n", ret / 1000);
> +	return (ret / 1000);
>  }
>  
> -static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO,
> -			  nouveau_hwmon_get_in0_input, NULL, 0);
> -
> -static ssize_t
> -nouveau_hwmon_get_in0_min(struct device *d,
> -			    struct device_attribute *a, char *buf)
> +static int
> +nouveau_hwmon_get_in0_min(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
>  
>  	if (!volt || !volt->min_uv)
>  		return -ENODEV;
>  
> -	return sprintf(buf, "%i\n", volt->min_uv / 1000);
> +	return (volt->min_uv / 1000);
>  }
>  
> -static SENSOR_DEVICE_ATTR(in0_min, S_IRUGO,
> -			  nouveau_hwmon_get_in0_min, NULL, 0);
> -
> -static ssize_t
> -nouveau_hwmon_get_in0_max(struct device *d,
> -			    struct device_attribute *a, char *buf)
> +static int
> +nouveau_hwmon_get_in0_max(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
>  
>  	if (!volt || !volt->max_uv)
>  		return -ENODEV;
>  
> -	return sprintf(buf, "%i\n", volt->max_uv / 1000);
> -}
> -
> -static SENSOR_DEVICE_ATTR(in0_max, S_IRUGO,
> -			  nouveau_hwmon_get_in0_max, NULL, 0);
> -
> -static ssize_t
> -nouveau_hwmon_get_in0_label(struct device *d,
> -			    struct device_attribute *a, char *buf)
> -{
> -	return sprintf(buf, "GPU core\n");
> +	return (volt->max_uv / 1000);
>  }
>  
> -static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO,
> -			  nouveau_hwmon_get_in0_label, NULL, 0);
> -
> -static ssize_t
> -nouveau_hwmon_get_power1_input(struct device *d, struct device_attribute
*a,
> -			       char *buf)
> +static int
> +nouveau_hwmon_get_power1_input(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_iccsense *iccsense =
nvxx_iccsense(&drm->client.device);
> -	int result = nvkm_iccsense_read_all(iccsense);
>  
> -	if (result < 0)
> -		return result;
> -
> -	return sprintf(buf, "%i\n", result);
> +	return nvkm_iccsense_read_all(iccsense);
>  }
>  
> -static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO,
> -			  nouveau_hwmon_get_power1_input, NULL, 0);
> -
> -static ssize_t
> -nouveau_hwmon_get_power1_max(struct device *d, struct device_attribute *a,
> -			     char *buf)
> +static int
> +nouveau_hwmon_get_power1_max(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_iccsense *iccsense =
nvxx_iccsense(&drm->client.device);
> -	return sprintf(buf, "%i\n", iccsense->power_w_max);
> -}
>  
> -static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO,
> -			  nouveau_hwmon_get_power1_max, NULL, 0);
> +	return iccsense->power_w_max;
> +}
>  
> -static ssize_t
> -nouveau_hwmon_get_power1_crit(struct device *d, struct device_attribute
*a,
> -			      char *buf)
> +static int
> +nouveau_hwmon_get_power1_crit(struct nouveau_drm *drm)
>  {
> -	struct drm_device *dev = dev_get_drvdata(d);
> -	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_iccsense *iccsense =
nvxx_iccsense(&drm->client.device);
> -	return sprintf(buf, "%i\n", iccsense->power_w_crit);
> -}
> -
> -static SENSOR_DEVICE_ATTR(power1_crit, S_IRUGO,
> -			  nouveau_hwmon_get_power1_crit, NULL, 0);
> -
> -static struct attribute *hwmon_default_attributes[] = {
> -	&sensor_dev_attr_name.dev_attr.attr,
> -	&sensor_dev_attr_update_rate.dev_attr.attr,
> -	NULL
> -};
> -static struct attribute *hwmon_temp_attributes[] = {
> -	&sensor_dev_attr_temp1_input.dev_attr.attr,
> -	&sensor_dev_attr_temp1_auto_point1_pwm.dev_attr.attr,
> -	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
> -	&sensor_dev_attr_temp1_auto_point1_temp_hyst.dev_attr.attr,
> -	&sensor_dev_attr_temp1_max.dev_attr.attr,
> -	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
> -	&sensor_dev_attr_temp1_crit.dev_attr.attr,
> -	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
> -	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
> -	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
> -	NULL
> -};
> -static struct attribute *hwmon_fan_rpm_attributes[] = {
> -	&sensor_dev_attr_fan1_input.dev_attr.attr,
> -	NULL
> -};
> -static struct attribute *hwmon_pwm_fan_attributes[] = {
> -	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
> -	&sensor_dev_attr_pwm1.dev_attr.attr,
> -	&sensor_dev_attr_pwm1_min.dev_attr.attr,
> -	&sensor_dev_attr_pwm1_max.dev_attr.attr,
> -	NULL
> -};
> -
> -static struct attribute *hwmon_in0_attributes[] = {
> -	&sensor_dev_attr_in0_input.dev_attr.attr,
> -	&sensor_dev_attr_in0_min.dev_attr.attr,
> -	&sensor_dev_attr_in0_max.dev_attr.attr,
> -	&sensor_dev_attr_in0_label.dev_attr.attr,
> -	NULL
> -};
>  
> -static struct attribute *hwmon_power_attributes[] = {
> -	&sensor_dev_attr_power1_input.dev_attr.attr,
> -	NULL
> -};
> -
> -static struct attribute *hwmon_power_caps_attributes[] = {
> -	&sensor_dev_attr_power1_max.dev_attr.attr,
> -	&sensor_dev_attr_power1_crit.dev_attr.attr,
> -	NULL
> -};
> -
> -static const struct attribute_group hwmon_default_attrgroup = {
> -	.attrs = hwmon_default_attributes,
> -};
> -static const struct attribute_group hwmon_temp_attrgroup = {
> -	.attrs = hwmon_temp_attributes,
> -};
> -static const struct attribute_group hwmon_fan_rpm_attrgroup = {
> -	.attrs = hwmon_fan_rpm_attributes,
> -};
> -static const struct attribute_group hwmon_pwm_fan_attrgroup = {
> -	.attrs = hwmon_pwm_fan_attributes,
> -};
> -static const struct attribute_group hwmon_in0_attrgroup = {
> -	.attrs = hwmon_in0_attributes,
> -};
> -static const struct attribute_group hwmon_power_attrgroup = {
> -	.attrs = hwmon_power_attributes,
> -};
> -static const struct attribute_group hwmon_power_caps_attrgroup = {
> -	.attrs = hwmon_power_caps_attributes,
> -};
> +	return iccsense->power_w_crit;
> +}
>  
>  static const u32 nouveau_config_chip[] = {
>  	HWMON_C_UPDATE_INTERVAL,
> @@ -887,6 +552,157 @@ nouveau_fan_is_visible(const void *data, u32 attr,
int channel)
>  	}
>  }
>  
> +static int
> +nouveau_chip_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_chip_update_interval:
> +		*val = nouveau_hwmon_show_update_rate(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_temp_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_temp_input:
> +		*val = nouveau_hwmon_show_temp(drm);
> +		break;
> +	case hwmon_temp_max:
> +		*val = nouveau_hwmon_max_temp(drm);
> +		break;
> +	case hwmon_temp_max_hyst:
> +		*val = nouveau_hwmon_max_temp_hyst(drm);
> +		break;
> +	case hwmon_temp_crit:
> +		*val = nouveau_hwmon_critical_temp(drm);
> +		break;
> +	case hwmon_temp_crit_hyst:
> +		*val = nouveau_hwmon_critical_temp_hyst(drm);
> +		break;
> +	case hwmon_temp_emergency:
> +		*val = nouveau_hwmon_emergency_temp(drm);
> +		break;
> +	case hwmon_temp_emergency_hyst:
> +		*val = nouveau_hwmon_emergency_temp_hyst(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_fan_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_fan_input:
> +		*val = nouveau_hwmon_show_fan1_input(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_in_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_in_input:
> +		*val = nouveau_hwmon_get_in0_input(drm);
> +		break;
> +	case hwmon_in_min:
> +		*val = nouveau_hwmon_get_in0_min(drm);
> +		break;
> +	case hwmon_in_max:
> +		*val = nouveau_hwmon_get_in0_max(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_pwm_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_pwm_enable:
> +		*val = nouveau_hwmon_get_pwm1_enable(drm);
> +		break;
> +	case hwmon_pwm_input:
> +		*val = nouveau_hwmon_get_pwm1(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_power_read(struct device *dev, u32 attr, int channel, long *val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
> +
> +	switch (attr) {
> +	case hwmon_power_input:
> +		*val = nouveau_hwmon_get_power1_input(drm);
> +		break;
> +	case hwmon_power_max:
> +		*val = nouveau_hwmon_get_power1_max(drm);
> +		break;
> +	case hwmon_power_crit:
> +		*val = nouveau_hwmon_get_power1_crit(drm);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +nouveau_pwm_write(struct device *dev, u32 attr, int channel, long val)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct nouveau_drm *drm = nouveau_drm(drm_dev);
	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
	if (!therm || therm->attr_set)
		return -EOPNOTSUPP;

And since you already got the therm pointer, maybe you can drop
nouveau_hwmon_set_pwm1 and nouveau_hwmon_set_pwm1_enable entirely and
make the therm->fan_set/set_attr calls right here.
> +
> +	switch (attr) {
> +	case hwmon_pwm_input:
> +		return nouveau_hwmon_set_pwm1(drm, val);
> +	case hwmon_pwm_enable:
> +		return nouveau_hwmon_set_pwm1_enable(drm, val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
>  static umode_t
>  nouveau_is_visible(const void *data, enum hwmon_sensor_types type, u32
attr,
>  								int channel)
> @@ -923,11 +739,45 @@ nouveau_read_string(struct device *dev, enum
hwmon_sensor_types type, u32 attr,
>  	return -EOPNOTSUPP;
>  }
>  
> +static int
> +nouveau_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> +							int channel, long *val)
> +{
> +	switch (type) {
> +	case hwmon_chip:
> +		return nouveau_chip_read(dev, attr, channel, val);
> +	case hwmon_temp:
> +		return nouveau_temp_read(dev, attr, channel, val);
> +	case hwmon_fan:
> +		return nouveau_fan_read(dev, attr, channel, val);
> +	case hwmon_in:
> +		return nouveau_in_read(dev, attr, channel, val);
> +	case hwmon_pwm:
> +		return nouveau_pwm_read(dev, attr, channel, val);
> +	case hwmon_power:
> +		return nouveau_power_read(dev, attr, channel, val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int
> +nouveau_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> +							int channel, long val)
> +{
> +	switch (type) {
> +	case hwmon_pwm:
> +		return nouveau_pwm_write(dev, attr, channel, val);
Where did all the temperature-related writes go?

Some vbios have fucked up thermal values set by default, this is why we
allow users to override them through hwmon.

Could you expose _max, _max_hyst, _crit and _crit_hyst?
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
>  static const struct hwmon_ops nouveau_hwmon_ops = {
>  	.is_visible = nouveau_is_visible,
> -	.read = NULL,
> +	.read = nouveau_read,
>  	.read_string = nouveau_read_string,
> -	.write = NULL,
> +	.write = nouveau_write,
>  };
>  
>  static const struct hwmon_chip_info nouveau_chip_info = {
> @@ -942,8 +792,6 @@ nouveau_hwmon_init(struct drm_device *dev)
>  #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
>  	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> -	struct nvkm_volt *volt = nvxx_volt(&drm->client.device);
> -	struct nvkm_iccsense *iccsense =
nvxx_iccsense(&drm->client.device);
>  	struct nouveau_hwmon *hwmon;
>  	struct device *hwmon_dev;
>  	int ret = 0;
> @@ -953,79 +801,16 @@ nouveau_hwmon_init(struct drm_device *dev)
>  		return -ENOMEM;
>  	hwmon->dev = dev;
>  
> -	hwmon_dev = hwmon_device_register(dev->dev);
> +	hwmon_dev = hwmon_device_register_with_info(dev->dev,
"nouveau", dev,
> +						&nouveau_chip_info, NULL);
>  	if (IS_ERR(hwmon_dev)) {
>  		ret = PTR_ERR(hwmon_dev);
>  		NV_ERROR(drm, "Unable to register hwmon device: %d\n", ret);
>  		return ret;
>  	}
> -	dev_set_drvdata(hwmon_dev, dev);
> -
> -	/* set the default attributes */
> -	ret = sysfs_create_group(&hwmon_dev->kobj,
&hwmon_default_attrgroup);
> -	if (ret)
> -		goto error;
> -
> -	if (therm && therm->attr_get && therm->attr_set) {
> -		/* if the card has a working thermal sensor */
> -		if (nvkm_therm_temp_get(therm) >= 0) {
> -			ret = sysfs_create_group(&hwmon_dev->kobj,
&hwmon_temp_attrgroup);
> -			if (ret)
> -				goto error;
> -		}
> -
> -		/* if the card has a pwm fan */
> -		/*XXX: incorrect, need better detection for this, some boards have
> -		 *     the gpio entries for pwm fan control even when there's no
> -		 *     actual fan connected to it... therm table? */
> -		if (therm->fan_get && therm->fan_get(therm) >= 0) {
> -			ret = sysfs_create_group(&hwmon_dev->kobj,
> -						 &hwmon_pwm_fan_attrgroup);
> -			if (ret)
> -				goto error;
> -		}
> -	}
> -
> -	/* if the card can read the fan rpm */
> -	if (therm && nvkm_therm_fan_sense(therm) >= 0) {
> -		ret = sysfs_create_group(&hwmon_dev->kobj,
> -					 &hwmon_fan_rpm_attrgroup);
> -		if (ret)
> -			goto error;
> -	}
> -
> -	if (volt && nvkm_volt_get(volt) >= 0) {
> -		ret = sysfs_create_group(&hwmon_dev->kobj,
> -					 &hwmon_in0_attrgroup);
> -
> -		if (ret)
> -			goto error;
> -	}
> -
> -	if (iccsense && iccsense->data_valid &&
!list_empty(&iccsense->rails)) {
> -		ret = sysfs_create_group(&hwmon_dev->kobj,
> -					 &hwmon_power_attrgroup);
> -
> -		if (ret)
> -			goto error;
> -
> -		if (iccsense->power_w_max && iccsense->power_w_crit) {
> -			ret = sysfs_create_group(&hwmon_dev->kobj,
> -						 &hwmon_power_caps_attrgroup);
> -			if (ret)
> -				goto error;
> -		}
> -	}
>  
>  	hwmon->hwmon = hwmon_dev;
> -
>  	return 0;
> -
> -error:
> -	NV_ERROR(drm, "Unable to create some hwmon sysfs files: %d\n",
ret);
> -	hwmon_device_unregister(hwmon_dev);
> -	hwmon->hwmon = NULL;
> -	return ret;
>  #else
>  	return 0;
>  #endif
> @@ -1037,17 +822,8 @@ nouveau_hwmon_fini(struct drm_device *dev)
>  #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
>  	struct nouveau_hwmon *hwmon = nouveau_hwmon(dev);
>  
> -	if (hwmon->hwmon) {
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_default_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_temp_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_pwm_fan_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_fan_rpm_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_in0_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_attrgroup);
> -		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_caps_attrgroup);
> -
> +	if (hwmon->hwmon)
>  		hwmon_device_unregister(hwmon->hwmon);
> -	}
>  
>  	nouveau_drm(dev)->hwmon = NULL;
>  	kfree(hwmon);
> 
Thanks a lot, this patch makes a huge improvement in readability! With
the comments addressed, this patch is:

Reviewed-by: Martin Peres <martin.peres at free.fr>

The name of the patch is misleading since you also add support for
pwm1_min/max.

Could you add change the title to "nouveau/hwmon: expose the auto_point
and pwm_min/max attrs"? And while you are at it, please change every
commit title to nouveau/hwmon instead of nouveau_hwmon.

On 26/04/17 19:46, Oscar Salvador wrote:
> This patch creates a special group attributes for attrs like
"*auto_point*".
> We check if we have support for them, and if we do, we gather them all in
> an attribute_group's structure which is the parameter regarding special
groups
> of hwmon_device_register_with_info.
> 
> Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_hwmon.c | 29 ++++++++++++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> index 4db65fb..9142779 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> @@ -358,6 +358,23 @@ nouveau_hwmon_get_power1_crit(struct nouveau_drm *drm)
>  	return iccsense->power_w_crit;
>  }
>  
> +static struct attribute *pwm_fan_sensor_attrs[] = {
> +	&sensor_dev_attr_pwm1_min.dev_attr.attr,
> +	&sensor_dev_attr_pwm1_max.dev_attr.attr,
> +	NULL
> +};
> +ATTRIBUTE_GROUPS(pwm_fan_sensor);
> +
> +static struct attribute *temp1_auto_point_sensor_attrs[] = {
> +	&sensor_dev_attr_temp1_auto_point1_pwm.dev_attr.attr,
> +	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
> +	&sensor_dev_attr_temp1_auto_point1_temp_hyst.dev_attr.attr,
> +	NULL
> +};
> +ATTRIBUTE_GROUPS(temp1_auto_point_sensor);
> +
> +#define N_ATTR_GROUPS   3
> +
>  static const u32 nouveau_config_chip[] = {
>  	HWMON_C_UPDATE_INTERVAL,
>  	0
> @@ -792,17 +809,27 @@ nouveau_hwmon_init(struct drm_device *dev)
>  #if defined(CONFIG_HWMON) || (defined(MODULE) &&
defined(CONFIG_HWMON_MODULE))
>  	struct nouveau_drm *drm = nouveau_drm(dev);
>  	struct nvkm_therm *therm = nvxx_therm(&drm->client.device);
> +	const struct attribute_group *special_groups[N_ATTR_GROUPS];
>  	struct nouveau_hwmon *hwmon;
>  	struct device *hwmon_dev;
>  	int ret = 0;
> +	int i = 0;
>  
>  	hwmon = drm->hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
>  	if (!hwmon)
>  		return -ENOMEM;
>  	hwmon->dev = dev;
>  
> +	if (therm && therm->attr_get && therm->attr_set) {
> +		if (nvkm_therm_temp_get(therm) >= 0)
> +			special_groups[i++] = &temp1_auto_point_sensor_group;
> +		if (therm->fan_get && therm->fan_get(therm) >= 0)
> +			special_groups[i++] = &pwm_fan_sensor_group;
> +	}
> +
> +	special_groups[i] = 0;
>  	hwmon_dev = hwmon_device_register_with_info(dev->dev,
"nouveau", dev,
> -						&nouveau_chip_info, NULL);
> +					&nouveau_chip_info, special_groups);
Please align &nouveau_chip_info with dev->dev and split special_groups
on the following line.
>  	if (IS_ERR(hwmon_dev)) {
>  		ret = PTR_ERR(hwmon_dev);
>  		NV_ERROR(drm, "Unable to register hwmon device: %d\n", ret);
> 
This commit breaks bisectability, so Ben may have to squash it in the
previous one. Otherwise, this looks good to me:

Reviewed-by: Martin Peres <martin.peres at free.fr>

On 26/04/17 19:46, Oscar Salvador wrote:
> This patch replaces the symbolic permissions with the numeric ones,
> and adds me to the authors too.
> 
> Signed-off-by: Oscar Salvador <osalvador.vilardaga at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_hwmon.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> index 9142779..45b5c85 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
> @@ -1,5 +1,6 @@
>  /*
> - * Copyright 2010 Red Hat Inc.
> + * Copyright 2010 Red Hat Inc. (Ben Skeggs)
Please drop this change.
> + * Copyright 2017 Oscar Salvador
>   *
>   * Permission is hereby granted, free of charge, to any person obtaining a
>   * copy of this software and associated documentation files (the
"Software"),
> @@ -19,7 +20,6 @@
>   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>   * OTHER DEALINGS IN THE SOFTWARE.
>   *
> - * Authors: Ben Skeggs
You can't remove people as being the author of something. Just add
yourself if you care about this (I did not care to add my name when I
wrote in this file, because the git history makes more sense nowadays.

Otherwise, I have no strong opinions on this patch. I guess the numeric
representation is easier to read, so I will give you my R-b for this and
let others decide what to do:

Reviewed-by: Martin Peres <martin.peres at free.fr>
>   */
>  
>  #ifdef CONFIG_ACPI
> @@ -56,7 +56,7 @@ nouveau_hwmon_show_temp1_auto_point1_pwm(struct device
*d,
>  {
>  	return snprintf(buf, PAGE_SIZE, "%d\n", 100);
>  }
> -static SENSOR_DEVICE_ATTR(temp1_auto_point1_pwm, S_IRUGO,
> +static SENSOR_DEVICE_ATTR(temp1_auto_point1_pwm, 0444,
>  			  nouveau_hwmon_show_temp1_auto_point1_pwm, NULL, 0);
>  
>  static ssize_t
> @@ -88,7 +88,7 @@ nouveau_hwmon_set_temp1_auto_point1_temp(struct device
*d,
>  
>  	return count;
>  }
> -static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp, S_IRUGO | S_IWUSR,
> +static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp, 0644,
>  			  nouveau_hwmon_temp1_auto_point1_temp,
>  			  nouveau_hwmon_set_temp1_auto_point1_temp, 0);
>  
> @@ -121,7 +121,7 @@ nouveau_hwmon_set_temp1_auto_point1_temp_hyst(struct
device *d,
>  
>  	return count;
>  }
> -static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst, S_IRUGO | S_IWUSR,
> +static SENSOR_DEVICE_ATTR(temp1_auto_point1_temp_hyst, 0644,
>  			  nouveau_hwmon_temp1_auto_point1_temp_hyst,
>  			  nouveau_hwmon_set_temp1_auto_point1_temp_hyst, 0);
>  
> @@ -255,7 +255,7 @@ nouveau_hwmon_set_pwm1_min(struct device *d, struct
device_attribute *a,
>  	return count;
>  }
>  
> -static SENSOR_DEVICE_ATTR(pwm1_min, S_IRUGO | S_IWUSR,
> +static SENSOR_DEVICE_ATTR(pwm1_min, 0644,
>  			  nouveau_hwmon_get_pwm1_min,
>  			  nouveau_hwmon_set_pwm1_min, 0);
>  
> @@ -295,7 +295,7 @@ nouveau_hwmon_set_pwm1_max(struct device *d, struct
device_attribute *a,
>  	return count;
>  }
>  
> -static SENSOR_DEVICE_ATTR(pwm1_max, S_IRUGO | S_IWUSR,
> +static SENSOR_DEVICE_ATTR(pwm1_max, 0644,
>  			  nouveau_hwmon_get_pwm1_max,
>  			  nouveau_hwmon_set_pwm1_max, 0);
>  
>