[PATCH 0/5] hwmon: pmbus: Add support for MPM82504 and MPM3695-10

[PATCH 0/5] hwmon: pmbus: Add support for MPM82504 and MPM3695-10

[Pawel Dembicki]

This series extends the hwmon PMBus driver for the MPS MPQ8785 to support
two additional Monolithic Power Systems devices: the MPM82504 and
MPM3695-10.

The driver is restructured to support multiple devices using device tree
matching. It also introduces an optional "voltage-scale-loop"
property to configure the VOUT_SCALE_LOOP PMBus register, which adjusts
reported output voltages depending on the external feedback divider.

Device tree bindings are updated accordingly.

Changes have been tested on hardware with device-tree based matching
using both the MPM82504 and MPM3695-10.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>

Pawel Dembicki (5):
  hwmon: pmbus: mpq8785: Prepare driver for multiple device support
  hwmon: pmbus: mpq8785: Add support for MPM82504
  hwmon: pmbus: mpq8785: Add support for MPM3695
  hwmon: pmbus: mpq8785: Implement voltage scale loop configuration
  dt-bindings: hwmon: Add bindings for mpq8785 driver

 .../bindings/hwmon/pmbus/mps,mpq8785.yaml     | 54 ++++++++++++++++
 Documentation/hwmon/mpq8785.rst               | 29 +++++++--
 drivers/hwmon/pmbus/mpq8785.c                 | 61 ++++++++++++++++---
 3 files changed, 131 insertions(+), 13 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml

-- 
2.43.0

[PATCH 1/5] hwmon: pmbus: mpq8785: Prepare driver for multiple device support

[Pawel Dembicki]

Refactor the driver to support multiple Monolithic Power Systems devices.
Introduce chip ID handling based on device tree matching.

No functional changes intended.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 drivers/hwmon/pmbus/mpq8785.c | 38 +++++++++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index 331c274ca892..00ec21b081cb 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -8,6 +8,8 @@
 #include <linux/of_device.h>
 #include "pmbus.h"
 
+enum chips { mpq8785 };
+
 static int mpq8785_identify(struct i2c_client *client,
 			    struct pmbus_driver_info *info)
 {
@@ -53,26 +55,46 @@ static struct pmbus_driver_info mpq8785_info = {
 		PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
-	.identify = mpq8785_identify,
-};
-
-static int mpq8785_probe(struct i2c_client *client)
-{
-	return pmbus_do_probe(client, &mpq8785_info);
 };
 
 static const struct i2c_device_id mpq8785_id[] = {
-	{ "mpq8785" },
+	{ "mpq8785", mpq8785 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, mpq8785_id);
 
 static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
-	{ .compatible = "mps,mpq8785" },
+	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mpq8785_of_match);
 
+static int mpq8785_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct pmbus_driver_info *info;
+	enum chips chip_id;
+
+	info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	if (dev->of_node)
+		chip_id = (uintptr_t)of_device_get_match_data(dev);
+	else
+		chip_id = i2c_match_id(mpq8785_id, client)->driver_data;
+
+	switch (chip_id) {
+	case mpq8785:
+		info->identify = mpq8785_identify;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return pmbus_do_probe(client, info);
+};
+
 static struct i2c_driver mpq8785_driver = {
 	.driver = {
 		   .name = "mpq8785",
-- 
2.43.0

[PATCH 2/5] hwmon: pmbus: mpq8785: Add support for MPM82504

[Pawel Dembicki]

Add support for the Monolithic Power Systems MPM82504 digital voltage
regulator. MPM82504 uses PMBus direct format for voltage output.

Tested with device tree based matching.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 Documentation/hwmon/mpq8785.rst | 20 +++++++++++++++-----
 drivers/hwmon/pmbus/mpq8785.c   | 12 +++++++++++-
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/Documentation/hwmon/mpq8785.rst b/Documentation/hwmon/mpq8785.rst
index bf8176b87086..be228ee58ce2 100644
--- a/Documentation/hwmon/mpq8785.rst
+++ b/Documentation/hwmon/mpq8785.rst
@@ -6,6 +6,7 @@ Kernel driver mpq8785
 Supported chips:
 
   * MPS MPQ8785
+  * MPS MPM82504
 
     Prefix: 'mpq8785'
 
@@ -20,21 +21,30 @@ buck converter. The MPQ8785 offers a very compact solution that achieves up to
 wide input supply range. The MPQ8785 operates at high efficiency over a wide
 output current load range.
 
+The MPM82504 is a quad 25A, scalable, fully integrated power module with a PMBus
+interface. The device offers a complete power solution that achieves up to 25A
+per output channel. The MPM82504 has four output channels that can be paralleled
+to provide 50A, 75A, or 100A of output current for flexible configurations.
+The device can also operate in parallel with the MPM3695-100 and additional
+MPM82504 devices to provide a higher output current. The MPM82504 operates
+at high efficiency across a wide load range.
+
 The PMBus interface provides converter configurations and key parameters
 monitoring.
 
-The MPQ8785 adopts MPS's proprietary multi-phase digital constant-on-time (MCOT)
+The devices adopts MPS's proprietary multi-phase digital constant-on-time (MCOT)
 control, which provides fast transient response and eases loop stabilization.
-The MCOT scheme also allows multiple MPQ8785 devices to be connected in parallel
-with excellent current sharing and phase interleaving for high-current
+The MCOT scheme also allows multiple devices or chennels to be connected in
+parallel with excellent current sharing and phase interleaving for high-current
 applications.
 
 Fully integrated protection features include over-current protection (OCP),
 over-voltage protection (OVP), under-voltage protection (UVP), and
 over-temperature protection (OTP).
 
-The MPQ8785 requires a minimal number of readily available, standard external
-components, and is available in a TLGA (5mmx6mm) package.
+All supported modules require a minimal number of readily available, standard
+external components. The MPQ8785 is available in a TLGA (5mmx6mm) package
+and the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package.
 
 Device compliant with:
 
diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index 00ec21b081cb..7ee201550554 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -8,7 +8,7 @@
 #include <linux/of_device.h>
 #include "pmbus.h"
 
-enum chips { mpq8785 };
+enum chips { mpq8785, mpm82504 };
 
 static int mpq8785_identify(struct i2c_client *client,
 			    struct pmbus_driver_info *info)
@@ -59,12 +59,14 @@ static struct pmbus_driver_info mpq8785_info = {
 
 static const struct i2c_device_id mpq8785_id[] = {
 	{ "mpq8785", mpq8785 },
+	{ "mpm82504", mpm82504 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, mpq8785_id);
 
 static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
 	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
+	{ .compatible = "mps,mpm82504", .data = (void *)mpm82504 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mpq8785_of_match);
@@ -87,6 +89,14 @@ static int mpq8785_probe(struct i2c_client *client)
 	switch (chip_id) {
 	case mpq8785:
 		info->identify = mpq8785_identify;
+
+		break;
+	case mpm82504:
+		info->format[PSC_VOLTAGE_OUT] = direct;
+		info->m[PSC_VOLTAGE_OUT] = 8;
+		info->b[PSC_VOLTAGE_OUT] = 0;
+		info->R[PSC_VOLTAGE_OUT] = 2;
+
 		break;
 	default:
 		return -ENODEV;
-- 
2.43.0

Re: [PATCH 2/5] hwmon: pmbus: mpq8785: Add support for MPM82504

[Guenter Roeck]

On 4/28/25 15:13, Pawel Dembicki wrote:
> Add support for the Monolithic Power Systems MPM82504 digital voltage
> regulator. MPM82504 uses PMBus direct format for voltage output.
> 
> Tested with device tree based matching.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>   Documentation/hwmon/mpq8785.rst | 20 +++++++++++++++-----
>   drivers/hwmon/pmbus/mpq8785.c   | 12 +++++++++++-
>   2 files changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/hwmon/mpq8785.rst b/Documentation/hwmon/mpq8785.rst
> index bf8176b87086..be228ee58ce2 100644
> --- a/Documentation/hwmon/mpq8785.rst
> +++ b/Documentation/hwmon/mpq8785.rst
> @@ -6,6 +6,7 @@ Kernel driver mpq8785
>   Supported chips:
>   
>     * MPS MPQ8785
> +  * MPS MPM82504
>   
>       Prefix: 'mpq8785'
>   
> @@ -20,21 +21,30 @@ buck converter. The MPQ8785 offers a very compact solution that achieves up to
>   wide input supply range. The MPQ8785 operates at high efficiency over a wide
>   output current load range.
>   
> +The MPM82504 is a quad 25A, scalable, fully integrated power module with a PMBus
> +interface. The device offers a complete power solution that achieves up to 25A
> +per output channel. The MPM82504 has four output channels that can be paralleled
> +to provide 50A, 75A, or 100A of output current for flexible configurations.
> +The device can also operate in parallel with the MPM3695-100 and additional
> +MPM82504 devices to provide a higher output current. The MPM82504 operates
> +at high efficiency across a wide load range.
> +
>   The PMBus interface provides converter configurations and key parameters
>   monitoring.
>   
> -The MPQ8785 adopts MPS's proprietary multi-phase digital constant-on-time (MCOT)
> +The devices adopts MPS's proprietary multi-phase digital constant-on-time (MCOT)
>   control, which provides fast transient response and eases loop stabilization.
> -The MCOT scheme also allows multiple MPQ8785 devices to be connected in parallel
> -with excellent current sharing and phase interleaving for high-current
> +The MCOT scheme also allows multiple devices or chennels to be connected in
> +parallel with excellent current sharing and phase interleaving for high-current
>   applications.
>   
>   Fully integrated protection features include over-current protection (OCP),
>   over-voltage protection (OVP), under-voltage protection (UVP), and
>   over-temperature protection (OTP).
>   
> -The MPQ8785 requires a minimal number of readily available, standard external
> -components, and is available in a TLGA (5mmx6mm) package.
> +All supported modules require a minimal number of readily available, standard
> +external components. The MPQ8785 is available in a TLGA (5mmx6mm) package
> +and the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package.
>   
>   Device compliant with:
>   
> diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
> index 00ec21b081cb..7ee201550554 100644
> --- a/drivers/hwmon/pmbus/mpq8785.c
> +++ b/drivers/hwmon/pmbus/mpq8785.c
> @@ -8,7 +8,7 @@
>   #include <linux/of_device.h>
>   #include "pmbus.h"
>   
> -enum chips { mpq8785 };
> +enum chips { mpq8785, mpm82504 };
>   
>   static int mpq8785_identify(struct i2c_client *client,
>   			    struct pmbus_driver_info *info)
> @@ -59,12 +59,14 @@ static struct pmbus_driver_info mpq8785_info = {
>   
>   static const struct i2c_device_id mpq8785_id[] = {
>   	{ "mpq8785", mpq8785 },
> +	{ "mpm82504", mpm82504 },
>   	{ },
>   };
>   MODULE_DEVICE_TABLE(i2c, mpq8785_id);
>   
>   static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
>   	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
> +	{ .compatible = "mps,mpm82504", .data = (void *)mpm82504 },
>   	{}
>   };
>   MODULE_DEVICE_TABLE(of, mpq8785_of_match);
> @@ -87,6 +89,14 @@ static int mpq8785_probe(struct i2c_client *client)
>   	switch (chip_id) {
>   	case mpq8785:
>   		info->identify = mpq8785_identify;
> +
Please drop this extra empty line.

> +		break;
> +	case mpm82504:
> +		info->format[PSC_VOLTAGE_OUT] = direct;
> +		info->m[PSC_VOLTAGE_OUT] = 8;
> +		info->b[PSC_VOLTAGE_OUT] = 0;
> +		info->R[PSC_VOLTAGE_OUT] = 2;
> +
Same here.

>   		break;
>   	default:
>   		return -ENODEV;

[PATCH 3/5] hwmon: pmbus: mpq8785: Add support for MPM3695

[Pawel Dembicki]

Add support for the Monolithic Power Systems MPM3695 device.
The device is PMBus compliant and shares characteristics with the
MPM82504.

Tested with device tree based matching.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 Documentation/hwmon/mpq8785.rst | 13 +++++++++++--
 drivers/hwmon/pmbus/mpq8785.c   |  5 ++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Documentation/hwmon/mpq8785.rst b/Documentation/hwmon/mpq8785.rst
index be228ee58ce2..20d43b8bba97 100644
--- a/Documentation/hwmon/mpq8785.rst
+++ b/Documentation/hwmon/mpq8785.rst
@@ -7,6 +7,7 @@ Supported chips:
 
   * MPS MPQ8785
   * MPS MPM82504
+  * MPS MPM3695-10
 
     Prefix: 'mpq8785'
 
@@ -29,6 +30,13 @@ The device can also operate in parallel with the MPM3695-100 and additional
 MPM82504 devices to provide a higher output current. The MPM82504 operates
 at high efficiency across a wide load range.
 
+The MPM3695-10 is a scalable, ultra-thin, fully integrated power module with
+a PMBus interface. It offers a complete power solution that achieves up to
+10A of output current with excellent load and line regulation across a wide
+input voltage range. The device’s 2mm height enables it to be placed on the
+backside of a PCB for space optimization. It operates at high efficiency over
+a wide load range, and can be paralleled to deliver higher current.
+
 The PMBus interface provides converter configurations and key parameters
 monitoring.
 
@@ -43,8 +51,9 @@ over-voltage protection (OVP), under-voltage protection (UVP), and
 over-temperature protection (OTP).
 
 All supported modules require a minimal number of readily available, standard
-external components. The MPQ8785 is available in a TLGA (5mmx6mm) package
-and the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package.
+external components. The MPQ8785 is available in a TLGA (5mmx6mm) package,
+the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package and the MPM3695-10
+is available in an LGA-45 (8mmx8mmx2mm) package.
 
 Device compliant with:
 
diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index 7ee201550554..e6a643856f08 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -8,7 +8,7 @@
 #include <linux/of_device.h>
 #include "pmbus.h"
 
-enum chips { mpq8785, mpm82504 };
+enum chips { mpq8785, mpm82504, mpm3695_10 };
 
 static int mpq8785_identify(struct i2c_client *client,
 			    struct pmbus_driver_info *info)
@@ -60,6 +60,7 @@ static struct pmbus_driver_info mpq8785_info = {
 static const struct i2c_device_id mpq8785_id[] = {
 	{ "mpq8785", mpq8785 },
 	{ "mpm82504", mpm82504 },
+	{ "mpm3695-10", mpm3695_10 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, mpq8785_id);
@@ -67,6 +68,7 @@ MODULE_DEVICE_TABLE(i2c, mpq8785_id);
 static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
 	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
 	{ .compatible = "mps,mpm82504", .data = (void *)mpm82504 },
+	{ .compatible = "mps,mpm3695-10", .data = (void *)mpm3695_10 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mpq8785_of_match);
@@ -92,6 +94,7 @@ static int mpq8785_probe(struct i2c_client *client)
 
 		break;
 	case mpm82504:
+	case mpm3695_10:
 		info->format[PSC_VOLTAGE_OUT] = direct;
 		info->m[PSC_VOLTAGE_OUT] = 8;
 		info->b[PSC_VOLTAGE_OUT] = 0;
-- 
2.43.0

Re: [PATCH 3/5] hwmon: pmbus: mpq8785: Add support for MPM3695

[Guenter Roeck]

On 4/28/25 15:13, Pawel Dembicki wrote:
> Add support for the Monolithic Power Systems MPM3695 device.
> The device is PMBus compliant and shares characteristics with the
> MPM82504.
> 
> Tested with device tree based matching.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>   Documentation/hwmon/mpq8785.rst | 13 +++++++++++--
>   drivers/hwmon/pmbus/mpq8785.c   |  5 ++++-
>   2 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/hwmon/mpq8785.rst b/Documentation/hwmon/mpq8785.rst
> index be228ee58ce2..20d43b8bba97 100644
> --- a/Documentation/hwmon/mpq8785.rst
> +++ b/Documentation/hwmon/mpq8785.rst
> @@ -7,6 +7,7 @@ Supported chips:
>   
>     * MPS MPQ8785
>     * MPS MPM82504
> +  * MPS MPM3695-10

Why the restriction to the -10 variant ? I found four variante (-10, -20, -25, and -100).
Unless I am missing something they all use the same parameters.

Unless you have evidence that the chips are different enough to warrant separate entries,
just refer to the chip as MPM3695 and explain in the documentation that there are four
different variants.

Thanks,
Guenter

>   
>       Prefix: 'mpq8785'
>   
> @@ -29,6 +30,13 @@ The device can also operate in parallel with the MPM3695-100 and additional
>   MPM82504 devices to provide a higher output current. The MPM82504 operates
>   at high efficiency across a wide load range.
>   
> +The MPM3695-10 is a scalable, ultra-thin, fully integrated power module with
> +a PMBus interface. It offers a complete power solution that achieves up to
> +10A of output current with excellent load and line regulation across a wide
> +input voltage range. The device’s 2mm height enables it to be placed on the
> +backside of a PCB for space optimization. It operates at high efficiency over
> +a wide load range, and can be paralleled to deliver higher current.
> +
>   The PMBus interface provides converter configurations and key parameters
>   monitoring.
>   
> @@ -43,8 +51,9 @@ over-voltage protection (OVP), under-voltage protection (UVP), and
>   over-temperature protection (OTP).
>   
>   All supported modules require a minimal number of readily available, standard
> -external components. The MPQ8785 is available in a TLGA (5mmx6mm) package
> -and the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package.
> +external components. The MPQ8785 is available in a TLGA (5mmx6mm) package,
> +the MPM82504 is available in a BGA (15mmx30mmx5.18mm) package and the MPM3695-10
> +is available in an LGA-45 (8mmx8mmx2mm) package.
>   
>   Device compliant with:
>   
> diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
> index 7ee201550554..e6a643856f08 100644
> --- a/drivers/hwmon/pmbus/mpq8785.c
> +++ b/drivers/hwmon/pmbus/mpq8785.c
> @@ -8,7 +8,7 @@
>   #include <linux/of_device.h>
>   #include "pmbus.h"
>   
> -enum chips { mpq8785, mpm82504 };
> +enum chips { mpq8785, mpm82504, mpm3695_10 };
>   
>   static int mpq8785_identify(struct i2c_client *client,
>   			    struct pmbus_driver_info *info)
> @@ -60,6 +60,7 @@ static struct pmbus_driver_info mpq8785_info = {
>   static const struct i2c_device_id mpq8785_id[] = {
>   	{ "mpq8785", mpq8785 },
>   	{ "mpm82504", mpm82504 },
> +	{ "mpm3695-10", mpm3695_10 },
>   	{ },
>   };
>   MODULE_DEVICE_TABLE(i2c, mpq8785_id);
> @@ -67,6 +68,7 @@ MODULE_DEVICE_TABLE(i2c, mpq8785_id);
>   static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
>   	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
>   	{ .compatible = "mps,mpm82504", .data = (void *)mpm82504 },
> +	{ .compatible = "mps,mpm3695-10", .data = (void *)mpm3695_10 },
>   	{}
>   };
>   MODULE_DEVICE_TABLE(of, mpq8785_of_match);
> @@ -92,6 +94,7 @@ static int mpq8785_probe(struct i2c_client *client)
>   
>   		break;
>   	case mpm82504:
> +	case mpm3695_10:
>   		info->format[PSC_VOLTAGE_OUT] = direct;
>   		info->m[PSC_VOLTAGE_OUT] = 8;
>   		info->b[PSC_VOLTAGE_OUT] = 0;

[PATCH 4/5] hwmon: pmbus: mpq8785: Implement voltage scale loop configuration

[Pawel Dembicki]

Implement support for setting the VOUT_SCALE_LOOP PMBus register
based on an optional device tree property "voltage-scale-loop".

This allows the driver to provide the correct VOUT value depending
on the feedback voltage divider configuration for chips where the
bootloader does not configure the voltage scale.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 drivers/hwmon/pmbus/mpq8785.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index e6a643856f08..6e2325d7f37b 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -78,6 +78,8 @@ static int mpq8785_probe(struct i2c_client *client)
 	struct device *dev = &client->dev;
 	struct pmbus_driver_info *info;
 	enum chips chip_id;
+	u32 voltage_scale;
+	int ret;
 
 	info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
 	if (!info)
@@ -105,6 +107,14 @@ static int mpq8785_probe(struct i2c_client *client)
 		return -ENODEV;
 	}
 
+	if (!of_property_read_u32(dev->of_node, "voltage-scale-loop",
+				  &voltage_scale)) {
+		ret = i2c_smbus_write_word_data(client, PMBUS_VOUT_SCALE_LOOP,
+						voltage_scale);
+		if (ret)
+			return ret;
+	}
+
 	return pmbus_do_probe(client, info);
 };
 
-- 
2.43.0

Re: [PATCH 4/5] hwmon: pmbus: mpq8785: Implement voltage scale loop configuration

[Guenter Roeck]

On 4/28/25 15:13, Pawel Dembicki wrote:
> Implement support for setting the VOUT_SCALE_LOOP PMBus register
> based on an optional device tree property "voltage-scale-loop".
> 
> This allows the driver to provide the correct VOUT value depending
> on the feedback voltage divider configuration for chips where the
> bootloader does not configure the voltage scale.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>   drivers/hwmon/pmbus/mpq8785.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
> index e6a643856f08..6e2325d7f37b 100644
> --- a/drivers/hwmon/pmbus/mpq8785.c
> +++ b/drivers/hwmon/pmbus/mpq8785.c
> @@ -78,6 +78,8 @@ static int mpq8785_probe(struct i2c_client *client)
>   	struct device *dev = &client->dev;
>   	struct pmbus_driver_info *info;
>   	enum chips chip_id;
> +	u32 voltage_scale;
> +	int ret;
>   
>   	info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
>   	if (!info)
> @@ -105,6 +107,14 @@ static int mpq8785_probe(struct i2c_client *client)
>   		return -ENODEV;
>   	}
>   
> +	if (!of_property_read_u32(dev->of_node, "voltage-scale-loop",
> +				  &voltage_scale)) {
> +		ret = i2c_smbus_write_word_data(client, PMBUS_VOUT_SCALE_LOOP,
> +						voltage_scale);

Per PMBus specification this value can be in any supported scale.
Also, the chips do not support the full 16-bit value range. I see 10 bit for
mpq8785 and mpm3695, 7 bit for mp2853, and 12 bit for MPM82504. There will
have to be some device specific range check.

I don't understand the units. The devicetree document talks about
VOUT_SCALE_LOOP = VFB / VOUT * 1000, but I don't see how that translates
into chip values. For MPM82504, the datasheet says 1 LSB=2mV. For mpm3695
it is 0.001/LSB. I have no idea how that is supposed to translate to the
units suggested in the property patch.

Either case, I think the property needs to be something generic that is well
defined. Maybe "pmbus,voltage-scale-loop", but I really don't know what would
be acceptable for DT maintainers.

Guenter

[PATCH 5/5] dt-bindings: hwmon: Add bindings for mpq8785 driver

[Pawel Dembicki]

Add device tree bindings for Monolithic Power Systems MPQ8785, MPM82504
and MPM3695 PMBus-compliant voltage regulators.

These bindings also documents the optional "voltage-scale-loop" property.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 .../bindings/hwmon/pmbus/mps,mpq8785.yaml     | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
new file mode 100644
index 000000000000..e2a3958a61fa
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/pmbus/mps,mpq8785.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+allOf:
+  - $ref: /schemas/i2c/i2c-device.yaml#
+
+title: Monolithic Power Systems Multiphase Voltage Regulators with PMBus
+
+maintainers:
+  - Charles Hsu <ythsu0511@gmail.com>
+
+description: |
+  Monolithic Power Systems digital multiphase voltage regulators with PMBus.
+
+properties:
+  compatible:
+    enum:
+      - mps,mpq8785
+      - mps,mpm82504
+      - mps,mpm3695-10
+
+  reg:
+    maxItems: 1
+
+  voltage-scale-loop:
+    description:
+      Voltage scale factor for the VOUT_SCALE_LOOP register.
+      Value expressed in mili-units (1/1000th of a unit).
+      The simplest way to calculate it is
+      VOUT_SCALE_LOOP = VFB / VOUT * 1000
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      pmic@30 {
+        compatible = "mps,mpm82504";
+        reg = <0x30>;
+        voltage-scale-loop = <600>;
+      };
+    };
-- 
2.43.0

Re: [PATCH 5/5] dt-bindings: hwmon: Add bindings for mpq8785 driver

[Rob Herring (Arm)]

On Tue, 29 Apr 2025 00:13:35 +0200, Pawel Dembicki wrote:
> Add device tree bindings for Monolithic Power Systems MPQ8785, MPM82504
> and MPM3695 PMBus-compliant voltage regulators.
> 
> These bindings also documents the optional "voltage-scale-loop" property.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>  .../bindings/hwmon/pmbus/mps,mpq8785.yaml     | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Warning: Duplicate compatible "mps,mpq8785" found in schemas matching "$id":
	http://devicetree.org/schemas/hwmon/pmbus/mps,mpq8785.yaml#
	http://devicetree.org/schemas/trivial-devices.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.example.dtb: pmic@30 (mps,mpm82504): False schema does not allow {'compatible': ['mps,mpm82504'], 'reg': [[48]], 'voltage-scale-loop': 600, '$nodename': ['pmic@30']}
	from schema $id: http://devicetree.org/schemas/hwmon/pmbus/mps,mpq8785.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250428221420.2077697-6-paweldembicki@gmail.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 5/5] dt-bindings: hwmon: Add bindings for mpq8785 driver

[Krzysztof Kozlowski]

On Tue, Apr 29, 2025 at 12:13:35AM GMT, Pawel Dembicki wrote:
> Add device tree bindings for Monolithic Power Systems MPQ8785, MPM82504
> and MPM3695 PMBus-compliant voltage regulators.
> 
> These bindings also documents the optional "voltage-scale-loop" property.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>  .../bindings/hwmon/pmbus/mps,mpq8785.yaml     | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
> new file mode 100644
> index 000000000000..e2a3958a61fa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/mps,mpq8785.yaml
> @@ -0,0 +1,54 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +

Drop blank line.

> +$id: http://devicetree.org/schemas/hwmon/pmbus/mps,mpq8785.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +allOf:
> +  - $ref: /schemas/i2c/i2c-device.yaml#

From where did you take such code? Drop.

> +
> +title: Monolithic Power Systems Multiphase Voltage Regulators with PMBus
> +
> +maintainers:
> +  - Charles Hsu <ythsu0511@gmail.com>
> +
> +description: |

Drop |

> +  Monolithic Power Systems digital multiphase voltage regulators with PMBus.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - mps,mpq8785
> +      - mps,mpm82504
> +      - mps,mpm3695-10

Keep alphabetical order

> +
> +  reg:
> +    maxItems: 1
> +
> +  voltage-scale-loop:

Missing vendor prefix, missing tests, missing property unit suffix
(percent? bpp?)

Or this should be just output voltage in microvolts.

Best regards,
Krzysztof

Re: [PATCH 5/5] dt-bindings: hwmon: Add bindings for mpq8785 driver

[kernel test robot]

Hi Pawel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on groeck-staging/hwmon-next]
[also build test WARNING on linus/master v6.15-rc4 next-20250428]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Pawel-Dembicki/hwmon-pmbus-mpq8785-Prepare-driver-for-multiple-device-support/20250429-061658
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link:    https://lore.kernel.org/r/20250428221420.2077697-6-paweldembicki%40gmail.com
patch subject: [PATCH 5/5] dt-bindings: hwmon: Add bindings for mpq8785 driver
config: csky-randconfig-052-20250429 (https://download.01.org/0day-ci/archive/20250429/202504291853.nDOvzGEJ-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 11.5.0
dtschema version: 2025.3.dev21+ge6ea659
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250429/202504291853.nDOvzGEJ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504291853.nDOvzGEJ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> Warning: Duplicate compatible "mps,mpq8785" found in schemas matching "$id":
   	http://devicetree.org/schemas/trivial-devices.yaml#
   	http://devicetree.org/schemas/hwmon/pmbus/mps,mpq8785.yaml#

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki