[PATCH v3 0/3] hwmon: powr1220: add powr104 support

[PATCH v3 0/3] hwmon: powr1220: add powr104 support

[michaelsh]

From: Michael Shych <michaelsh@nvidia.com>

This patchset adds support for Lattice POWR1014 power management device

Michael Shych (3):
  hwmon: powr1220: Cosmetic changes
  hwmon: powr1220: Upgrade driver to support hwmon info infrastructure
  hwmon: powr1220: Add support for Lattice's POWR1014 power manager IC

 drivers/hwmon/powr1220.c | 235 +++++++++++++++++++++++------------------------
 1 file changed, 116 insertions(+), 119 deletions(-)

-- 
2.14.1

[PATCH v3 1/3] hwmon: powr1220: Cosmetic changes

[michaelsh]

From: Michael Shych <michaelsh@nvidia.com>

Update code alignments.

Signed-off-by: Michael Shych <michaelsh@nvidia.com>
---
 drivers/hwmon/powr1220.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
index 9e086338dcba..542e4a7b0234 100644
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -111,7 +111,7 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 	mutex_lock(&data->update_lock);
 
 	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
-			!data->adc_valid[ch_num]) {
+	    !data->adc_valid[ch_num]) {
 		/*
 		 * figure out if we need to use the attenuator for
 		 * high inputs or inputs that we don't yet have a measurement
@@ -119,12 +119,12 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 		 * max reading.
 		 */
 		if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
-				data->adc_maxes[ch_num] == 0)
+		    data->adc_maxes[ch_num] == 0)
 			adc_range = 1 << 4;
 
 		/* set the attenuator and mux */
 		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
-				adc_range | ch_num);
+						   adc_range | ch_num);
 		if (result)
 			goto exit;
 
-- 
2.14.1

[PATCH v3 2/3] hwmon: powr1220: Upgrade driver to support hwmon info infrastructure

[michaelsh]

From: Michael Shych <michaelsh@nvidia.com>

Reduce code by using devm_hwmon_device_register_with_groups() API by
devm_hwmon_device_register_with_info() API.
The motivation is to reduce code and to allow easy support for similar
devices by the same driver.

Signed-off-by: Michael Shych <michaelsh@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
---
v2->v3
Fixes according to Guenter Roeck notes.
1. Don't change usleep instead udelay.
2. Move code aligments to separate patch.
---
 drivers/hwmon/powr1220.c | 207 +++++++++++++++++++++--------------------------
 1 file changed, 92 insertions(+), 115 deletions(-)

diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
index 542e4a7b0234..1d4e005977b6 100644
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -167,135 +167,109 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 	return result;
 }
 
-/* Shows the voltage associated with the specified ADC channel */
-static ssize_t powr1220_voltage_show(struct device *dev,
-				     struct device_attribute *dev_attr,
-				     char *buf)
+static umode_t
+powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32
+		    attr, int channel)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
-	int adc_val = powr1220_read_adc(dev, attr->index);
-
-	if (adc_val < 0)
-		return adc_val;
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+		case hwmon_in_highest:
+		case hwmon_in_label:
+			return 0444;
+		default:
+			break;
+		}
+
+	default:
+		break;
+	}
 
-	return sprintf(buf, "%d\n", adc_val);
+	return 0;
 }
 
-/* Shows the maximum setting associated with the specified ADC channel */
-static ssize_t powr1220_max_show(struct device *dev,
-				 struct device_attribute *dev_attr, char *buf)
+static int
+powr1220_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+		     int channel, const char **str)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
-	struct powr1220_data *data = dev_get_drvdata(dev);
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_label:
+			*str = input_names[channel];
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
 
-	return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
+	return -EOPNOTSUPP;
 }
 
-/* Shows the label associated with the specified ADC channel */
-static ssize_t powr1220_label_show(struct device *dev,
-				   struct device_attribute *dev_attr,
-				   char *buf)
+static int
+powr1220_read(struct device *dev, enum hwmon_sensor_types type, u32
+	      attr, int channel, long *val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct powr1220_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			ret = powr1220_read_adc(dev, channel);
+			if (ret < 0)
+				return ret;
+			*val = ret;
+			break;
+		case hwmon_in_highest:
+			*val = data->adc_maxes[channel];
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+}
 
-	return sprintf(buf, "%s\n", input_names[attr->index]);
+	return 0;
 }
 
-static SENSOR_DEVICE_ATTR_RO(in0_input, powr1220_voltage, VMON1);
-static SENSOR_DEVICE_ATTR_RO(in1_input, powr1220_voltage, VMON2);
-static SENSOR_DEVICE_ATTR_RO(in2_input, powr1220_voltage, VMON3);
-static SENSOR_DEVICE_ATTR_RO(in3_input, powr1220_voltage, VMON4);
-static SENSOR_DEVICE_ATTR_RO(in4_input, powr1220_voltage, VMON5);
-static SENSOR_DEVICE_ATTR_RO(in5_input, powr1220_voltage, VMON6);
-static SENSOR_DEVICE_ATTR_RO(in6_input, powr1220_voltage, VMON7);
-static SENSOR_DEVICE_ATTR_RO(in7_input, powr1220_voltage, VMON8);
-static SENSOR_DEVICE_ATTR_RO(in8_input, powr1220_voltage, VMON9);
-static SENSOR_DEVICE_ATTR_RO(in9_input, powr1220_voltage, VMON10);
-static SENSOR_DEVICE_ATTR_RO(in10_input, powr1220_voltage, VMON11);
-static SENSOR_DEVICE_ATTR_RO(in11_input, powr1220_voltage, VMON12);
-static SENSOR_DEVICE_ATTR_RO(in12_input, powr1220_voltage, VCCA);
-static SENSOR_DEVICE_ATTR_RO(in13_input, powr1220_voltage, VCCINP);
-
-static SENSOR_DEVICE_ATTR_RO(in0_highest, powr1220_max, VMON1);
-static SENSOR_DEVICE_ATTR_RO(in1_highest, powr1220_max, VMON2);
-static SENSOR_DEVICE_ATTR_RO(in2_highest, powr1220_max, VMON3);
-static SENSOR_DEVICE_ATTR_RO(in3_highest, powr1220_max, VMON4);
-static SENSOR_DEVICE_ATTR_RO(in4_highest, powr1220_max, VMON5);
-static SENSOR_DEVICE_ATTR_RO(in5_highest, powr1220_max, VMON6);
-static SENSOR_DEVICE_ATTR_RO(in6_highest, powr1220_max, VMON7);
-static SENSOR_DEVICE_ATTR_RO(in7_highest, powr1220_max, VMON8);
-static SENSOR_DEVICE_ATTR_RO(in8_highest, powr1220_max, VMON9);
-static SENSOR_DEVICE_ATTR_RO(in9_highest, powr1220_max, VMON10);
-static SENSOR_DEVICE_ATTR_RO(in10_highest, powr1220_max, VMON11);
-static SENSOR_DEVICE_ATTR_RO(in11_highest, powr1220_max, VMON12);
-static SENSOR_DEVICE_ATTR_RO(in12_highest, powr1220_max, VCCA);
-static SENSOR_DEVICE_ATTR_RO(in13_highest, powr1220_max, VCCINP);
-
-static SENSOR_DEVICE_ATTR_RO(in0_label, powr1220_label, VMON1);
-static SENSOR_DEVICE_ATTR_RO(in1_label, powr1220_label, VMON2);
-static SENSOR_DEVICE_ATTR_RO(in2_label, powr1220_label, VMON3);
-static SENSOR_DEVICE_ATTR_RO(in3_label, powr1220_label, VMON4);
-static SENSOR_DEVICE_ATTR_RO(in4_label, powr1220_label, VMON5);
-static SENSOR_DEVICE_ATTR_RO(in5_label, powr1220_label, VMON6);
-static SENSOR_DEVICE_ATTR_RO(in6_label, powr1220_label, VMON7);
-static SENSOR_DEVICE_ATTR_RO(in7_label, powr1220_label, VMON8);
-static SENSOR_DEVICE_ATTR_RO(in8_label, powr1220_label, VMON9);
-static SENSOR_DEVICE_ATTR_RO(in9_label, powr1220_label, VMON10);
-static SENSOR_DEVICE_ATTR_RO(in10_label, powr1220_label, VMON11);
-static SENSOR_DEVICE_ATTR_RO(in11_label, powr1220_label, VMON12);
-static SENSOR_DEVICE_ATTR_RO(in12_label, powr1220_label, VCCA);
-static SENSOR_DEVICE_ATTR_RO(in13_label, powr1220_label, VCCINP);
-
-static struct attribute *powr1220_attrs[] = {
-	&sensor_dev_attr_in0_input.dev_attr.attr,
-	&sensor_dev_attr_in1_input.dev_attr.attr,
-	&sensor_dev_attr_in2_input.dev_attr.attr,
-	&sensor_dev_attr_in3_input.dev_attr.attr,
-	&sensor_dev_attr_in4_input.dev_attr.attr,
-	&sensor_dev_attr_in5_input.dev_attr.attr,
-	&sensor_dev_attr_in6_input.dev_attr.attr,
-	&sensor_dev_attr_in7_input.dev_attr.attr,
-	&sensor_dev_attr_in8_input.dev_attr.attr,
-	&sensor_dev_attr_in9_input.dev_attr.attr,
-	&sensor_dev_attr_in10_input.dev_attr.attr,
-	&sensor_dev_attr_in11_input.dev_attr.attr,
-	&sensor_dev_attr_in12_input.dev_attr.attr,
-	&sensor_dev_attr_in13_input.dev_attr.attr,
-
-	&sensor_dev_attr_in0_highest.dev_attr.attr,
-	&sensor_dev_attr_in1_highest.dev_attr.attr,
-	&sensor_dev_attr_in2_highest.dev_attr.attr,
-	&sensor_dev_attr_in3_highest.dev_attr.attr,
-	&sensor_dev_attr_in4_highest.dev_attr.attr,
-	&sensor_dev_attr_in5_highest.dev_attr.attr,
-	&sensor_dev_attr_in6_highest.dev_attr.attr,
-	&sensor_dev_attr_in7_highest.dev_attr.attr,
-	&sensor_dev_attr_in8_highest.dev_attr.attr,
-	&sensor_dev_attr_in9_highest.dev_attr.attr,
-	&sensor_dev_attr_in10_highest.dev_attr.attr,
-	&sensor_dev_attr_in11_highest.dev_attr.attr,
-	&sensor_dev_attr_in12_highest.dev_attr.attr,
-	&sensor_dev_attr_in13_highest.dev_attr.attr,
-
-	&sensor_dev_attr_in0_label.dev_attr.attr,
-	&sensor_dev_attr_in1_label.dev_attr.attr,
-	&sensor_dev_attr_in2_label.dev_attr.attr,
-	&sensor_dev_attr_in3_label.dev_attr.attr,
-	&sensor_dev_attr_in4_label.dev_attr.attr,
-	&sensor_dev_attr_in5_label.dev_attr.attr,
-	&sensor_dev_attr_in6_label.dev_attr.attr,
-	&sensor_dev_attr_in7_label.dev_attr.attr,
-	&sensor_dev_attr_in8_label.dev_attr.attr,
-	&sensor_dev_attr_in9_label.dev_attr.attr,
-	&sensor_dev_attr_in10_label.dev_attr.attr,
-	&sensor_dev_attr_in11_label.dev_attr.attr,
-	&sensor_dev_attr_in12_label.dev_attr.attr,
-	&sensor_dev_attr_in13_label.dev_attr.attr,
+static const struct hwmon_channel_info *powr1220_info[] = {
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL),
 
 	NULL
 };
 
-ATTRIBUTE_GROUPS(powr1220);
+static const struct hwmon_ops powr1220_hwmon_ops = {
+	.read = powr1220_read,
+	.read_string = powr1220_read_string,
+	.is_visible = powr1220_is_visible,
+};
+
+static const struct hwmon_chip_info powr1220_chip_info = {
+	.ops = &powr1220_hwmon_ops,
+	.info = powr1220_info,
+};
 
 static int powr1220_probe(struct i2c_client *client)
 {
@@ -312,8 +286,11 @@ static int powr1220_probe(struct i2c_client *client)
 	mutex_init(&data->update_lock);
 	data->client = client;
 
-	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
-			client->name, data, powr1220_groups);
+	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
+							 client->name,
+							 data,
+							 &powr1220_chip_info,
+							 NULL);
 
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
-- 
2.14.1

[PATCH v3 3/3] hwmon: powr1220: Add support for Lattice's POWR1014 power manager IC

[michaelsh]

From: Michael Shych <michaelsh@nvidia.com>

This patch adds support for Lattice's POWR1014 power manager IC.
Read access to all the ADCs on the chip are supported through
the "hwmon" "sysfs" files.

The main differences of POWR1014 compared to POWR1220 are
amount of VMON input lines: 10 on POWR1014 and 12 lines on POWR1220 and
number of output control signals: 14 on POWR1014 and 20 on POWR1220.

Signed-off-by: Michael Shych <michaelsh@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
---
v2->v3
Fixes according to Guenter Roeck notes
1. Correct commit notes.
2. Don't use usleep_range
3. Change devicenames in alphanumeric order.
4. Chanhge if statement
v1->v2
Fix added by Michael: Fix incorrect device id.
---
 drivers/hwmon/powr1220.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
index 1d4e005977b6..2a5e168a52a9 100644
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -22,6 +22,8 @@
 #define ADC_STEP_MV			2
 #define ADC_MAX_LOW_MEASUREMENT_MV	2000
 
+enum powr1xxx_chips { powr1014, powr1220 };
+
 enum powr1220_regs {
 	VMON_STATUS0,
 	VMON_STATUS1,
@@ -74,6 +76,7 @@ enum powr1220_adc_values {
 struct powr1220_data {
 	struct i2c_client *client;
 	struct mutex update_lock;
+	u8 max_channels;
 	bool adc_valid[MAX_POWR1220_ADC_VALUES];
 	 /* the next value is in jiffies */
 	unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
@@ -171,6 +174,11 @@ static umode_t
 powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32
 		    attr, int channel)
 {
+	struct powr1220_data *chip_data = (struct powr1220_data *)data;
+
+	if (channel >= chip_data->max_channels)
+		return 0;
+
 	switch (type) {
 	case hwmon_in:
 		switch (attr) {
@@ -271,6 +279,8 @@ static const struct hwmon_chip_info powr1220_chip_info = {
 	.info = powr1220_info,
 };
 
+static const struct i2c_device_id powr1220_ids[];
+
 static int powr1220_probe(struct i2c_client *client)
 {
 	struct powr1220_data *data;
@@ -283,6 +293,15 @@ static int powr1220_probe(struct i2c_client *client)
 	if (!data)
 		return -ENOMEM;
 
+	switch (i2c_match_id(powr1220_ids, client)->driver_data) {
+	case powr1014:
+		data->max_channels = 10;
+		break;
+	default:
+		data->max_channels = 12;
+		break;
+	}
+
 	mutex_init(&data->update_lock);
 	data->client = client;
 
@@ -296,7 +315,8 @@ static int powr1220_probe(struct i2c_client *client)
 }
 
 static const struct i2c_device_id powr1220_ids[] = {
-	{ "powr1220", 0, },
+	{ "powr1014", powr1014, },
+	{ "powr1220", powr1220, },
 	{ }
 };
 
-- 
2.14.1

Re: [PATCH v3 1/3] hwmon: powr1220: Cosmetic changes

[Guenter Roeck]

On Tue, Jan 18, 2022 at 09:56:09AM +0200, michaelsh@nvidia.com wrote:
> From: Michael Shych <michaelsh@nvidia.com>
> 
> Update code alignments.
> 
> Signed-off-by: Michael Shych <michaelsh@nvidia.com>

Applied.

Thanks,
Guenter

> ---
>  drivers/hwmon/powr1220.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
> index 9e086338dcba..542e4a7b0234 100644
> --- a/drivers/hwmon/powr1220.c
> +++ b/drivers/hwmon/powr1220.c
> @@ -111,7 +111,7 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
>  	mutex_lock(&data->update_lock);
>  
>  	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
> -			!data->adc_valid[ch_num]) {
> +	    !data->adc_valid[ch_num]) {
>  		/*
>  		 * figure out if we need to use the attenuator for
>  		 * high inputs or inputs that we don't yet have a measurement
> @@ -119,12 +119,12 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
>  		 * max reading.
>  		 */
>  		if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
> -				data->adc_maxes[ch_num] == 0)
> +		    data->adc_maxes[ch_num] == 0)
>  			adc_range = 1 << 4;
>  
>  		/* set the attenuator and mux */
>  		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
> -				adc_range | ch_num);
> +						   adc_range | ch_num);
>  		if (result)
>  			goto exit;
>  

Re: [PATCH v3 2/3] hwmon: powr1220: Upgrade driver to support hwmon info infrastructure

[Guenter Roeck]

On Tue, Jan 18, 2022 at 09:56:10AM +0200, michaelsh@nvidia.com wrote:
> From: Michael Shych <michaelsh@nvidia.com>
> 
> Reduce code by using devm_hwmon_device_register_with_groups() API by
> devm_hwmon_device_register_with_info() API.
> The motivation is to reduce code and to allow easy support for similar
> devices by the same driver.
> 
> Signed-off-by: Michael Shych <michaelsh@nvidia.com>
> Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>

Applied.

Thanks,
Guenter

Re: [PATCH v3 3/3] hwmon: powr1220: Add support for Lattice's POWR1014 power manager IC

[Guenter Roeck]

On Tue, Jan 18, 2022 at 09:56:11AM +0200, michaelsh@nvidia.com wrote:
> From: Michael Shych <michaelsh@nvidia.com>
> 
> This patch adds support for Lattice's POWR1014 power manager IC.
> Read access to all the ADCs on the chip are supported through
> the "hwmon" "sysfs" files.
> 
> The main differences of POWR1014 compared to POWR1220 are
> amount of VMON input lines: 10 on POWR1014 and 12 lines on POWR1220 and
> number of output control signals: 14 on POWR1014 and 20 on POWR1220.
> 
> Signed-off-by: Michael Shych <michaelsh@nvidia.com>
> Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>

Applied.

Thanks,
Guenter

> ---
> v2->v3
> Fixes according to Guenter Roeck notes
> 1. Correct commit notes.
> 2. Don't use usleep_range
> 3. Change devicenames in alphanumeric order.
> 4. Chanhge if statement
> v1->v2
> Fix added by Michael: Fix incorrect device id.
> ---
>  drivers/hwmon/powr1220.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
> index 1d4e005977b6..2a5e168a52a9 100644
> --- a/drivers/hwmon/powr1220.c
> +++ b/drivers/hwmon/powr1220.c
> @@ -22,6 +22,8 @@
>  #define ADC_STEP_MV			2
>  #define ADC_MAX_LOW_MEASUREMENT_MV	2000
>  
> +enum powr1xxx_chips { powr1014, powr1220 };
> +
>  enum powr1220_regs {
>  	VMON_STATUS0,
>  	VMON_STATUS1,
> @@ -74,6 +76,7 @@ enum powr1220_adc_values {
>  struct powr1220_data {
>  	struct i2c_client *client;
>  	struct mutex update_lock;
> +	u8 max_channels;
>  	bool adc_valid[MAX_POWR1220_ADC_VALUES];
>  	 /* the next value is in jiffies */
>  	unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
> @@ -171,6 +174,11 @@ static umode_t
>  powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32
>  		    attr, int channel)
>  {
> +	struct powr1220_data *chip_data = (struct powr1220_data *)data;
> +
> +	if (channel >= chip_data->max_channels)
> +		return 0;
> +
>  	switch (type) {
>  	case hwmon_in:
>  		switch (attr) {
> @@ -271,6 +279,8 @@ static const struct hwmon_chip_info powr1220_chip_info = {
>  	.info = powr1220_info,
>  };
>  
> +static const struct i2c_device_id powr1220_ids[];
> +
>  static int powr1220_probe(struct i2c_client *client)
>  {
>  	struct powr1220_data *data;
> @@ -283,6 +293,15 @@ static int powr1220_probe(struct i2c_client *client)
>  	if (!data)
>  		return -ENOMEM;
>  
> +	switch (i2c_match_id(powr1220_ids, client)->driver_data) {
> +	case powr1014:
> +		data->max_channels = 10;
> +		break;
> +	default:
> +		data->max_channels = 12;
> +		break;
> +	}
> +
>  	mutex_init(&data->update_lock);
>  	data->client = client;
>  
> @@ -296,7 +315,8 @@ static int powr1220_probe(struct i2c_client *client)
>  }
>  
>  static const struct i2c_device_id powr1220_ids[] = {
> -	{ "powr1220", 0, },
> +	{ "powr1014", powr1014, },
> +	{ "powr1220", powr1220, },
>  	{ }
>  };
>