[PATCH 0/7] Support ROHM BD127x0 hot-swap controllers

[PATCH 0/7] Support ROHM BD127x0 hot-swap controllers

[Matti Vaittinen]

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Support ROHM BD12780(A) and BD12790

The BD12780 and BD12780A hot-swap controllers are very similar to Analog
Devices ADM1278. There are only some minor differences in the registers.

The BD12790 is largely similar to the ADM1272, with slightly different
coefficients and minor register changes.

This series adds basic support for these ROHM ICs.

The last patch adds of_device_id table with entries for the newly added
controllers. This fixes the module auto-load on the test board with old
Debian user-space.

I have no idea if adding the of_device_id -entries for other ICs could
cause problems in some existing systems. Hence only new ICs were added
to the of_device_id tables.

---

Matti Vaittinen (7):
  dt-bindings: adm1275: ROHM BD12780 hot-swap controller
  doc: Add ROHM BD12780 and BD12780A
  hwmon: adm1275: Support ROHM BD12780
  dt-bindings: adm1275: ROHM BD12790 hot-swap controller
  doc: adm1275: Add ROHM BD12790
  hwmon: adm1275: Support ROHM BD12790
  hwmon: adm1275: Support module auto-loading

 .../bindings/hwmon/adi,adm1275.yaml           | 44 ++++++---
 Documentation/hwmon/adm1275.rst               | 24 +++++
 drivers/hwmon/pmbus/Kconfig                   |  4 +-
 drivers/hwmon/pmbus/adm1275.c                 | 91 +++++++++++++++++--
 4 files changed, 142 insertions(+), 21 deletions(-)


base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
-- 
2.54.0


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[PATCH 1/7] dt-bindings: adm1275: ROHM BD12780 hot-swap controller

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Support ROHM BD12780 and BD12780A hot-swap controllers, which are largely
compatible with the Analog Devices adm1278. Main difference between
the BD12780 and the BD12780A is, that the BD12780 has one I2C address
configuration pin more (ADDR3) than the BD12780A.

Introduce own compatibles for both variants but require the BD12780A to
always have the BD12780 as a fall-back.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 .../bindings/hwmon/adi,adm1275.yaml           | 39 +++++++++++++------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
index d6a7517f2a50..bc67510ef3ab 100644
--- a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
+++ b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
@@ -25,19 +25,35 @@ description: |
     https://www.silergy.com/
     download/downloadFile?id=5669&type=product&ftype=note
 
+  The BD12780 and BD12780A are hot-swap controllers from ROHM. They are
+  functionally compatible with the ADM1278. The main difference between
+  the BD12780A and the BD12780 is amount of configurable I2C addresses.
+
+  Datasheets:
+    https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780muv-lb-e.pdf
+    https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780amuv-lb-e.pdf
+
 properties:
   compatible:
-    enum:
-      - adi,adm1075
-      - adi,adm1272
-      - adi,adm1273
-      - adi,adm1275
-      - adi,adm1276
-      - adi,adm1278
-      - adi,adm1281
-      - adi,adm1293
-      - adi,adm1294
-      - silergy,mc09c
+    oneOf:
+      - items:
+          enum:
+            - adi,adm1075
+            - adi,adm1272
+            - adi,adm1273
+            - adi,adm1275
+            - adi,adm1276
+            - adi,adm1278
+            - adi,adm1281
+            - adi,adm1293
+            - adi,adm1294
+            - rohm,bd12780
+            - silergy,mc09c
+
+# Require BD12780 as a fall-back for BD12780A.
+      - items:
+          - const: rohm,bd12780a
+          - const: rohm,bd12780
 
   reg:
     maxItems: 1
@@ -104,6 +120,7 @@ allOf:
               - adi,adm1281
               - adi,adm1293
               - adi,adm1294
+              - rohm,bd12780
               - silergy,mc09c
     then:
       properties:
-- 
2.54.0


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[PATCH 2/7] doc: Add ROHM BD12780 and BD12780A

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Add the ROHM BD12780 and the BD12780A to the list of the ICs supported by
the adm1275 driver.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 Documentation/hwmon/adm1275.rst | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/hwmon/adm1275.rst b/Documentation/hwmon/adm1275.rst
index cf923f20fa52..8a793dd2b412 100644
--- a/Documentation/hwmon/adm1275.rst
+++ b/Documentation/hwmon/adm1275.rst
@@ -67,6 +67,22 @@ Supported chips:
 
     Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1293_1294.pdf
 
+  * ROHM Semiconductor BD12780
+
+    Prefix: 'bd12780'
+
+    Addresses scanned: -
+
+    Datasheet: https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780muv-lb-e.pdf
+
+  * ROHM Semiconductor BD12780A
+
+    Prefix: 'bd12780'
+
+    Addresses scanned: -
+
+    Datasheet: https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780amuv-lb-e.pdf
+
   * Silergy SQ24905C
 
     Prefix: 'mc09c'
-- 
2.54.0


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[PATCH 3/7] hwmon: adm1275: Support ROHM BD12780

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

ROHM BD12780 and BD12780A are hot-swap controllers. They are largely
similar to Analog Devices ADM1278. Besides the ID registers and some
added functionality, the BD12780 and BD12780A mark PMON_CONFIG bits
[15:14] as reserved. Hence TSFILT setting must be omitted on these ICs.

The BD12780 has 3 pins usable for configuring the I2C address. The
BD12780A lists the ADDR3-pin as "not connect".

Support ROHM BD12780 and BD12780A controllers.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 drivers/hwmon/pmbus/Kconfig   |  2 +-
 drivers/hwmon/pmbus/adm1275.c | 46 +++++++++++++++++++++++++++++------
 2 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 8f4bff375ecb..b3c27f3b2712 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -52,7 +52,7 @@ config SENSORS_ADM1275
 	help
 	  If you say yes here you get hardware monitoring support for Analog
 	  Devices ADM1075, ADM1272, ADM1273, ADM1275, ADM1276, ADM1278, ADM1281,
-	  ADM1293, ADM1294 and SQ24905C Hot-Swap Controller and
+	  ADM1293, ADM1294, ROHM BD12780, and SQ24905C Hot-Swap Controller and
 	  Digital Power Monitors.
 
 	  This driver can also be built as a module. If so, the module will
diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index bc2a6a07dc3e..838b8827eb76 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -19,7 +19,7 @@
 #include "pmbus.h"
 
 enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
-	 adm1293, adm1294, sq24905c };
+	 adm1293, adm1294, bd12780, sq24905c };
 
 #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
 #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
@@ -47,6 +47,8 @@ enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
 #define ADM1278_VOUT_EN			BIT(1)
 
 #define ADM1278_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN | ADM1278_TSFILT)
+/* The BD12780 data sheets mark TSFILT bit as reserved. */
+#define BD12780_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
 
 #define ADM1293_IRANGE_25		0
 #define ADM1293_IRANGE_50		BIT(6)
@@ -487,6 +489,21 @@ static const struct i2c_device_id adm1275_id[] = {
 	{ "adm1281", adm1281 },
 	{ "adm1293", adm1293 },
 	{ "adm1294", adm1294 },
+	/*
+	 * The BD12780a is functionally identical to BD12780(*). Even the pmbus ID
+	 * register contents are same. When instantiated from the DT, it is required
+	 * to have the bd12780 as a fall-back. We still need the bd12780a ID here,
+	 * because the i2c_device_id is created from the first compatible, not from
+	 * the fall-back entry.
+	 * (*)Until proven to differ. I prefer having own compatible for these
+	 * variants for that day. Please note that even though the probe is called
+	 * based on the 'bd12780a' -entry, the ID is picked at probe based on the
+	 * pmbus register contents and not by DT entry. Thus, if the bd12780 and
+	 * bd12780a are found to require different handling, then this needs to be
+	 * changed, or bd12780a is handled as bd12780.
+	 */
+	{ "bd12780", bd12780 },
+	{ "bd12780a", /* driver data unused, see --^ */ },
 	{ "mc09c", sq24905c },
 	{ }
 };
@@ -494,12 +511,13 @@ MODULE_DEVICE_TABLE(i2c, adm1275_id);
 
 /* Enable VOUT & TEMP1 if not enabled (disabled by default) */
 static int adm1275_enable_vout_temp(struct adm1275_data *data,
-				    struct i2c_client *client, int config)
+				    struct i2c_client *client, int config,
+				    u16 defconfig)
 {
 	int ret;
 
-	if ((config & ADM1278_PMON_DEFCONFIG) != ADM1278_PMON_DEFCONFIG) {
-		config |= ADM1278_PMON_DEFCONFIG;
+	if ((config & defconfig) != defconfig) {
+		config |= defconfig;
 		ret = adm1275_write_pmon_config(data, client, config);
 		if (ret < 0) {
 			dev_err(&client->dev, "Failed to enable VOUT/TEMP1 monitoring\n");
@@ -535,7 +553,8 @@ static int adm1275_probe(struct i2c_client *client)
 		return ret;
 	}
 	if ((ret != 3 || strncmp(block_buffer, "ADI", 3)) &&
-	    (ret != 2 || strncmp(block_buffer, "SY", 2))) {
+	    (ret != 2 || strncmp(block_buffer, "SY", 2)) &&
+	    (ret != 4 || strncmp(block_buffer, "ROHM", 4))) {
 		dev_err(&client->dev, "Unsupported Manufacturer ID\n");
 		return -ENODEV;
 	}
@@ -562,7 +581,7 @@ static int adm1275_probe(struct i2c_client *client)
 	if (mid->driver_data == adm1272 || mid->driver_data == adm1273 ||
 	    mid->driver_data == adm1278 || mid->driver_data == adm1281 ||
 	    mid->driver_data == adm1293 || mid->driver_data == adm1294 ||
-	    mid->driver_data == sq24905c)
+	    mid->driver_data == bd12780 || mid->driver_data == sq24905c)
 		config_read_fn = i2c_smbus_read_word_data;
 	else
 		config_read_fn = i2c_smbus_read_byte_data;
@@ -666,7 +685,8 @@ static int adm1275_probe(struct i2c_client *client)
 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 
-		ret = adm1275_enable_vout_temp(data, client, config);
+		ret = adm1275_enable_vout_temp(data, client, config,
+					       ADM1278_PMON_DEFCONFIG);
 		if (ret)
 			return ret;
 
@@ -712,7 +732,16 @@ static int adm1275_probe(struct i2c_client *client)
 		break;
 	case adm1278:
 	case adm1281:
+	case bd12780:
 	case sq24905c:
+	{
+		u16 defconfig;
+
+		if (data->id == bd12780)
+			defconfig = BD12780_PMON_DEFCONFIG;
+		else
+			defconfig = ADM1278_PMON_DEFCONFIG;
+
 		data->have_vout = true;
 		data->have_pin_max = true;
 		data->have_temp_max = true;
@@ -728,13 +757,14 @@ static int adm1275_probe(struct i2c_client *client)
 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 
-		ret = adm1275_enable_vout_temp(data, client, config);
+		ret = adm1275_enable_vout_temp(data, client, config, defconfig);
 		if (ret)
 			return ret;
 
 		if (config & ADM1278_VIN_EN)
 			info->func[0] |= PMBUS_HAVE_VIN;
 		break;
+	}
 	case adm1293:
 	case adm1294:
 		data->have_iout_min = true;
-- 
2.54.0


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[PATCH 4/7] dt-bindings: adm1275: ROHM BD12790 hot-swap controller

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Support ROHM BD12790 hot-swap controller which is largely compatible
with the Analog Devices adm1272.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
index bc67510ef3ab..e231964a6706 100644
--- a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
+++ b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
@@ -33,6 +33,9 @@ description: |
     https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780muv-lb-e.pdf
     https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780amuv-lb-e.pdf
 
+  The BD12790 is a ROHM hot-swap controller,  functionally similar to the
+  ADM1272.
+
 properties:
   compatible:
     oneOf:
@@ -48,6 +51,7 @@ properties:
             - adi,adm1293
             - adi,adm1294
             - rohm,bd12780
+            - rohm,bd12790
             - silergy,mc09c
 
 # Require BD12780 as a fall-back for BD12780A.
@@ -104,6 +108,7 @@ allOf:
             enum:
               - adi,adm1272
               - adi,adm1273
+              - rohm,bd12790
     then:
       properties:
         adi,volt-curr-sample-average:
-- 
2.54.0


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[PATCH 5/7] doc: adm1275: Add ROHM BD12790

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Add the ROHM BD12790 to the list of the ICs supported by the adm1275
driver.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
I didn't find public data-sheet yet. I will add a link when one is
available.

 Documentation/hwmon/adm1275.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/hwmon/adm1275.rst b/Documentation/hwmon/adm1275.rst
index 8a793dd2b412..d8495be313b8 100644
--- a/Documentation/hwmon/adm1275.rst
+++ b/Documentation/hwmon/adm1275.rst
@@ -83,6 +83,14 @@ Supported chips:
 
     Datasheet: https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/power_switch/bd12780amuv-lb-e.pdf
 
+  * ROHM Semiconductor BD12790
+
+    Prefix: 'bd12790'
+
+    Addresses scanned: -
+
+    Datasheet: -
+
   * Silergy SQ24905C
 
     Prefix: 'mc09c'
-- 
2.54.0


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[PATCH 6/7] hwmon: adm1275: Support ROHM BD12790

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Add support for ROHM BD12790 hot-swap controller which is largely
similar to Analog Devices adm1272.

The BD12790 uses the same selectable 60V/100V voltage ranges and
15mV/30mV current-sense ranges as the ADM1272, and the same VRANGE
(bit 5) and IRANGE (bit 0) layout in PMON_CONFIG. It therefore uses
a dedicated coefficient table that mirrors adm1272_coefficients, with
the following differences derived from BD12790 datasheet Table 1 (p.18):
- power 60V/30mV: m=17560 (vs. 17561)
- power 100V/30mV: m=10536 (vs. 10535)
- temperature: b=31880 (vs. 31871, reflecting T[11:0] = 4.2*T + 3188)

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Assisted-by: GitHub Copilot:claude-sonnet-4.6

---
Originally this patch was AI-generated. I did pretty much re-write the
probe changes by hand, and also fixed some of the coefficient math
afterwards :/ But yeah, this one was AI "assisted". :)

 drivers/hwmon/pmbus/Kconfig   |  4 +--
 drivers/hwmon/pmbus/adm1275.c | 53 +++++++++++++++++++++++++++++------
 2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index b3c27f3b2712..6ebc01e26db3 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -52,8 +52,8 @@ config SENSORS_ADM1275
 	help
 	  If you say yes here you get hardware monitoring support for Analog
 	  Devices ADM1075, ADM1272, ADM1273, ADM1275, ADM1276, ADM1278, ADM1281,
-	  ADM1293, ADM1294, ROHM BD12780, and SQ24905C Hot-Swap Controller and
-	  Digital Power Monitors.
+	  ADM1293, ADM1294, ROHM BD12780, ROHM BD12790, and SQ24905C
+	  Hot-Swap Controller and Digital Power Monitors.
 
 	  This driver can also be built as a module. If so, the module will
 	  be called adm1275.
diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index 838b8827eb76..9e21dd4083e9 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -19,7 +19,7 @@
 #include "pmbus.h"
 
 enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
-	 adm1293, adm1294, bd12780, sq24905c };
+	 adm1293, adm1294, bd12780, bd12790, sq24905c };
 
 #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
 #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
@@ -47,8 +47,8 @@ enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
 #define ADM1278_VOUT_EN			BIT(1)
 
 #define ADM1278_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN | ADM1278_TSFILT)
-/* The BD12780 data sheets mark TSFILT bit as reserved. */
-#define BD12780_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
+/* The BD127x0 data sheets mark TSFILT bit as reserved. */
+#define BD127X0_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
 
 #define ADM1293_IRANGE_25		0
 #define ADM1293_IRANGE_50		BIT(6)
@@ -136,6 +136,30 @@ static const struct coefficients adm1272_coefficients[] = {
 
 };
 
+/*
+ * BD12790 coefficients derived from preliminary datasheet, Table 1 (p.18)
+ * and the PMBus direct-format relationship X = (Y * 10^(-R) - b) / m.
+ *
+ * Voltage: V[V] = 14.77e-3 * code (60V) / 24.62e-3 * code (100V)
+ *   -> m = 6770, R=-2 / m = 4062, R=-2
+ * Current: code = I[A] * RS * 132802.1 + 2048 (15mV) / * 66401.06 + 2048 (30mV)
+ *   -> m = 1328, b = 2048 * 10^(-R) = 20480, R=-1 / m = 664, same b and R
+ * Power: code = k * RS * PIN, k = 35119.94 / 17559.97 / 21071.44 / 10535.72
+ *   -> m = round(k / 10^(-R)), R=-2 for 60V/15mV, R=-3 for the other three
+ * Temperature: code = 4.2 * T + 3188 -> m = 42, b = 3188 * 10 = 31880, R=-1
+ */
+static const struct coefficients bd12790_coefficients[] = {
+	[0] = { 6770, 0, -2 },		/* voltage, vrange 60V */
+	[1] = { 4062, 0, -2 },		/* voltage, vrange 100V */
+	[2] = { 1328, 20480, -1 },	/* current, vsense range 15mV */
+	[3] = { 664, 20480, -1 },	/* current, vsense range 30mV */
+	[4] = { 3512, 0, -2 },		/* power, vrange 60V, irange 15mV */
+	[5] = { 21071, 0, -3 },		/* power, vrange 100V, irange 15mV */
+	[6] = { 17560, 0, -3 },		/* power, vrange 60V, irange 30mV */
+	[7] = { 10536, 0, -3 },		/* power, vrange 100V, irange 30mV */
+	[8] = { 42, 31880, -1 },	/* temperature */
+};
+
 static const struct coefficients adm1275_coefficients[] = {
 	[0] = { 19199, 0, -2 },		/* voltage, vrange set */
 	[1] = { 6720, 0, -1 },		/* voltage, vrange not set */
@@ -504,6 +528,7 @@ static const struct i2c_device_id adm1275_id[] = {
 	 */
 	{ "bd12780", bd12780 },
 	{ "bd12780a", /* driver data unused, see --^ */ },
+	{ "bd12790", bd12790 },
 	{ "mc09c", sq24905c },
 	{ }
 };
@@ -581,7 +606,8 @@ static int adm1275_probe(struct i2c_client *client)
 	if (mid->driver_data == adm1272 || mid->driver_data == adm1273 ||
 	    mid->driver_data == adm1278 || mid->driver_data == adm1281 ||
 	    mid->driver_data == adm1293 || mid->driver_data == adm1294 ||
-	    mid->driver_data == bd12780 || mid->driver_data == sq24905c)
+	    mid->driver_data == bd12780 || mid->driver_data == bd12790 ||
+	    mid->driver_data == sq24905c)
 		config_read_fn = i2c_smbus_read_word_data;
 	else
 		config_read_fn = i2c_smbus_read_byte_data;
@@ -655,12 +681,23 @@ static int adm1275_probe(struct i2c_client *client)
 		break;
 	case adm1272:
 	case adm1273:
+	case bd12790:
+	{
+		u16 defconfig;
+
 		data->have_vout = true;
 		data->have_pin_max = true;
 		data->have_temp_max = true;
 		data->have_power_sampling = true;
 
-		coefficients = adm1272_coefficients;
+		if (data->id == bd12790) {
+			coefficients = bd12790_coefficients;
+			defconfig = BD127X0_PMON_DEFCONFIG;
+		} else {
+			coefficients = adm1272_coefficients;
+			defconfig = ADM1278_PMON_DEFCONFIG;
+		}
+
 		vindex = (config & ADM1275_VRANGE) ? 1 : 0;
 		cindex = (config & ADM1272_IRANGE) ? 3 : 2;
 		/* pindex depends on the combination of the above */
@@ -685,14 +722,14 @@ static int adm1275_probe(struct i2c_client *client)
 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 
-		ret = adm1275_enable_vout_temp(data, client, config,
-					       ADM1278_PMON_DEFCONFIG);
+		ret = adm1275_enable_vout_temp(data, client, config, defconfig);
 		if (ret)
 			return ret;
 
 		if (config & ADM1278_VIN_EN)
 			info->func[0] |= PMBUS_HAVE_VIN;
 		break;
+	}
 	case adm1275:
 		if (device_config & ADM1275_IOUT_WARN2_SELECT)
 			data->have_oc_fault = true;
@@ -738,7 +775,7 @@ static int adm1275_probe(struct i2c_client *client)
 		u16 defconfig;
 
 		if (data->id == bd12780)
-			defconfig = BD12780_PMON_DEFCONFIG;
+			defconfig = BD127X0_PMON_DEFCONFIG;
 		else
 			defconfig = ADM1278_PMON_DEFCONFIG;
 
-- 
2.54.0


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[PATCH 7/7] hwmon: adm1275: Support module auto-loading

[Matti Vaittinen]

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From: Matti Vaittinen <mazziesaccount@gmail.com>

Populating the spi_device_id -table is not enough to make the
driver module automatically load when device-tree node for the bd12780
is parsed at boot.

Adding the of_device_id tables causes the driver module to be
automatically load at boot. Testing has been done with rather old Debian
system.

When inspecting the generated module-aliases with the insmod, following
entries seem to be the difference:

alias:          of:N*T*Crohm,bd12780C*
alias:          of:N*T*Crohm,bd12780

I suspect these are required for the module loading to work.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>

---

I did not add of_device_ids for other supported ICs as I can't verify it
doesn't cause side-effects. Please let me know if you think those IDs
should be added as well. I would be glad if I got more educated opinion
on adding the of-IDs :) (I can squash this to 3/7 and 6/7 in next
revision, and add own patch for adding of-IDs for other ICs if
required).

---
 drivers/hwmon/pmbus/adm1275.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index 9e21dd4083e9..c27bb0e49354 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -927,9 +927,17 @@ static int adm1275_probe(struct i2c_client *client)
 	return pmbus_do_probe(client, info);
 }
 
+static const struct of_device_id adm1275_of_match[] = {
+	{ .compatible = "rohm,bd12780", },
+	{ .compatible = "rohm,bd12790", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, adm1275_of_match);
+
 static struct i2c_driver adm1275_driver = {
 	.driver = {
 		   .name = "adm1275",
+		   .of_match_table = adm1275_of_match,
 		   },
 	.probe = adm1275_probe,
 	.id_table = adm1275_id,
-- 
2.54.0


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Re: [PATCH 7/7] hwmon: adm1275: Support module auto-loading

[Guenter Roeck]

On 6/15/26 23:47, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> Populating the spi_device_id -table is not enough to make the
> driver module automatically load when device-tree node for the bd12780
> is parsed at boot.
> 
> Adding the of_device_id tables causes the driver module to be
> automatically load at boot. Testing has been done with rather old Debian
> system.
> 
> When inspecting the generated module-aliases with the insmod, following
> entries seem to be the difference:
> 
> alias:          of:N*T*Crohm,bd12780C*
> alias:          of:N*T*Crohm,bd12780
> 
> I suspect these are required for the module loading to work.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> ---
> 
> I did not add of_device_ids for other supported ICs as I can't verify it
> doesn't cause side-effects. Please let me know if you think those IDs
> should be added as well. I would be glad if I got more educated opinion
> on adding the of-IDs :) (I can squash this to 3/7 and 6/7 in next
> revision, and add own patch for adding of-IDs for other ICs if
> required).
> 

I don't know what those side effects might be. I am much more concerned
about side effects of having some of the devices in adm1275_of_match
and some in adm1275_id. So, yes, please add a patch to provide
adm1275_of_match for all chips supported by the driver.

Thanks,
Guenter

> ---
>   drivers/hwmon/pmbus/adm1275.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index 9e21dd4083e9..c27bb0e49354 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -927,9 +927,17 @@ static int adm1275_probe(struct i2c_client *client)
>   	return pmbus_do_probe(client, info);
>   }
>   
> +static const struct of_device_id adm1275_of_match[] = {
> +	{ .compatible = "rohm,bd12780", },
> +	{ .compatible = "rohm,bd12790", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, adm1275_of_match);
> +
>   static struct i2c_driver adm1275_driver = {
>   	.driver = {
>   		   .name = "adm1275",
> +		   .of_match_table = adm1275_of_match,
>   		   },
>   	.probe = adm1275_probe,
>   	.id_table = adm1275_id,

Re: [PATCH 6/7] hwmon: adm1275: Support ROHM BD12790

[Guenter Roeck]

On 6/15/26 23:44, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> Add support for ROHM BD12790 hot-swap controller which is largely
> similar to Analog Devices adm1272.
> 
> The BD12790 uses the same selectable 60V/100V voltage ranges and
> 15mV/30mV current-sense ranges as the ADM1272, and the same VRANGE
> (bit 5) and IRANGE (bit 0) layout in PMON_CONFIG. It therefore uses
> a dedicated coefficient table that mirrors adm1272_coefficients, with
> the following differences derived from BD12790 datasheet Table 1 (p.18):
> - power 60V/30mV: m=17560 (vs. 17561)
> - power 100V/30mV: m=10536 (vs. 10535)
> - temperature: b=31880 (vs. 31871, reflecting T[11:0] = 4.2*T + 3188)
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Assisted-by: GitHub Copilot:claude-sonnet-4.6
> 
> ---
> Originally this patch was AI-generated. I did pretty much re-write the
> probe changes by hand, and also fixed some of the coefficient math
> afterwards :/ But yeah, this one was AI "assisted". :)
> 
>   drivers/hwmon/pmbus/Kconfig   |  4 +--
>   drivers/hwmon/pmbus/adm1275.c | 53 +++++++++++++++++++++++++++++------
>   2 files changed, 47 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index b3c27f3b2712..6ebc01e26db3 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -52,8 +52,8 @@ config SENSORS_ADM1275
>   	help
>   	  If you say yes here you get hardware monitoring support for Analog
>   	  Devices ADM1075, ADM1272, ADM1273, ADM1275, ADM1276, ADM1278, ADM1281,
> -	  ADM1293, ADM1294, ROHM BD12780, and SQ24905C Hot-Swap Controller and
> -	  Digital Power Monitors.
> +	  ADM1293, ADM1294, ROHM BD12780, ROHM BD12790, and SQ24905C
> +	  Hot-Swap Controller and Digital Power Monitors.
>   
>   	  This driver can also be built as a module. If so, the module will
>   	  be called adm1275.
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index 838b8827eb76..9e21dd4083e9 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -19,7 +19,7 @@
>   #include "pmbus.h"
>   
>   enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
> -	 adm1293, adm1294, bd12780, sq24905c };
> +	 adm1293, adm1294, bd12780, bd12790, sq24905c };
>   
>   #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
>   #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
> @@ -47,8 +47,8 @@ enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
>   #define ADM1278_VOUT_EN			BIT(1)
>   
>   #define ADM1278_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN | ADM1278_TSFILT)
> -/* The BD12780 data sheets mark TSFILT bit as reserved. */
> -#define BD12780_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
> +/* The BD127x0 data sheets mark TSFILT bit as reserved. */
> +#define BD127X0_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
>   
>   #define ADM1293_IRANGE_25		0
>   #define ADM1293_IRANGE_50		BIT(6)
> @@ -136,6 +136,30 @@ static const struct coefficients adm1272_coefficients[] = {
>   
>   };
>   
> +/*
> + * BD12790 coefficients derived from preliminary datasheet, Table 1 (p.18)
> + * and the PMBus direct-format relationship X = (Y * 10^(-R) - b) / m.
> + *
> + * Voltage: V[V] = 14.77e-3 * code (60V) / 24.62e-3 * code (100V)
> + *   -> m = 6770, R=-2 / m = 4062, R=-2
> + * Current: code = I[A] * RS * 132802.1 + 2048 (15mV) / * 66401.06 + 2048 (30mV)
> + *   -> m = 1328, b = 2048 * 10^(-R) = 20480, R=-1 / m = 664, same b and R
> + * Power: code = k * RS * PIN, k = 35119.94 / 17559.97 / 21071.44 / 10535.72
> + *   -> m = round(k / 10^(-R)), R=-2 for 60V/15mV, R=-3 for the other three
> + * Temperature: code = 4.2 * T + 3188 -> m = 42, b = 3188 * 10 = 31880, R=-1
> + */
> +static const struct coefficients bd12790_coefficients[] = {
> +	[0] = { 6770, 0, -2 },		/* voltage, vrange 60V */
> +	[1] = { 4062, 0, -2 },		/* voltage, vrange 100V */
> +	[2] = { 1328, 20480, -1 },	/* current, vsense range 15mV */
> +	[3] = { 664, 20480, -1 },	/* current, vsense range 30mV */
> +	[4] = { 3512, 0, -2 },		/* power, vrange 60V, irange 15mV */
> +	[5] = { 21071, 0, -3 },		/* power, vrange 100V, irange 15mV */
> +	[6] = { 17560, 0, -3 },		/* power, vrange 60V, irange 30mV */
> +	[7] = { 10536, 0, -3 },		/* power, vrange 100V, irange 30mV */
> +	[8] = { 42, 31880, -1 },	/* temperature */
> +};
> +
>   static const struct coefficients adm1275_coefficients[] = {
>   	[0] = { 19199, 0, -2 },		/* voltage, vrange set */
>   	[1] = { 6720, 0, -1 },		/* voltage, vrange not set */
> @@ -504,6 +528,7 @@ static const struct i2c_device_id adm1275_id[] = {
>   	 */
>   	{ "bd12780", bd12780 },
>   	{ "bd12780a", /* driver data unused, see --^ */ },
> +	{ "bd12790", bd12790 },
>   	{ "mc09c", sq24905c },
>   	{ }
>   };
> @@ -581,7 +606,8 @@ static int adm1275_probe(struct i2c_client *client)
>   	if (mid->driver_data == adm1272 || mid->driver_data == adm1273 ||
>   	    mid->driver_data == adm1278 || mid->driver_data == adm1281 ||
>   	    mid->driver_data == adm1293 || mid->driver_data == adm1294 ||
> -	    mid->driver_data == bd12780 || mid->driver_data == sq24905c)
> +	    mid->driver_data == bd12780 || mid->driver_data == bd12790 ||
> +	    mid->driver_data == sq24905c)
>   		config_read_fn = i2c_smbus_read_word_data;
>   	else
>   		config_read_fn = i2c_smbus_read_byte_data;
> @@ -655,12 +681,23 @@ static int adm1275_probe(struct i2c_client *client)
>   		break;
>   	case adm1272:
>   	case adm1273:
> +	case bd12790:

Please don't overload the existing case statements.
Just add separate case statements for the new chips.

Thanks,
Guenter

> +	{
> +		u16 defconfig;
> +
>   		data->have_vout = true;
>   		data->have_pin_max = true;
>   		data->have_temp_max = true;
>   		data->have_power_sampling = true;
>   
> -		coefficients = adm1272_coefficients;
> +		if (data->id == bd12790) {
> +			coefficients = bd12790_coefficients;
> +			defconfig = BD127X0_PMON_DEFCONFIG;
> +		} else {
> +			coefficients = adm1272_coefficients;
> +			defconfig = ADM1278_PMON_DEFCONFIG;
> +		}
> +
>   		vindex = (config & ADM1275_VRANGE) ? 1 : 0;
>   		cindex = (config & ADM1272_IRANGE) ? 3 : 2;
>   		/* pindex depends on the combination of the above */
> @@ -685,14 +722,14 @@ static int adm1275_probe(struct i2c_client *client)
>   			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
>   			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
>   
> -		ret = adm1275_enable_vout_temp(data, client, config,
> -					       ADM1278_PMON_DEFCONFIG);
> +		ret = adm1275_enable_vout_temp(data, client, config, defconfig);
>   		if (ret)
>   			return ret;
>   
>   		if (config & ADM1278_VIN_EN)
>   			info->func[0] |= PMBUS_HAVE_VIN;
>   		break;
> +	}
>   	case adm1275:
>   		if (device_config & ADM1275_IOUT_WARN2_SELECT)
>   			data->have_oc_fault = true;
> @@ -738,7 +775,7 @@ static int adm1275_probe(struct i2c_client *client)
>   		u16 defconfig;
>   
>   		if (data->id == bd12780)
> -			defconfig = BD12780_PMON_DEFCONFIG;
> +			defconfig = BD127X0_PMON_DEFCONFIG;
>   		else
>   			defconfig = ADM1278_PMON_DEFCONFIG;
>   

Re: [PATCH 3/7] hwmon: adm1275: Support ROHM BD12780

[Guenter Roeck]

On 6/15/26 23:36, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> ROHM BD12780 and BD12780A are hot-swap controllers. They are largely
> similar to Analog Devices ADM1278. Besides the ID registers and some
> added functionality, the BD12780 and BD12780A mark PMON_CONFIG bits
> [15:14] as reserved. Hence TSFILT setting must be omitted on these ICs.
> 
> The BD12780 has 3 pins usable for configuring the I2C address. The
> BD12780A lists the ADDR3-pin as "not connect".
> 
> Support ROHM BD12780 and BD12780A controllers.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> ---
>   drivers/hwmon/pmbus/Kconfig   |  2 +-
>   drivers/hwmon/pmbus/adm1275.c | 46 +++++++++++++++++++++++++++++------
>   2 files changed, 39 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 8f4bff375ecb..b3c27f3b2712 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -52,7 +52,7 @@ config SENSORS_ADM1275
>   	help
>   	  If you say yes here you get hardware monitoring support for Analog
>   	  Devices ADM1075, ADM1272, ADM1273, ADM1275, ADM1276, ADM1278, ADM1281,
> -	  ADM1293, ADM1294 and SQ24905C Hot-Swap Controller and
> +	  ADM1293, ADM1294, ROHM BD12780, and SQ24905C Hot-Swap Controller and
>   	  Digital Power Monitors.
>   
>   	  This driver can also be built as a module. If so, the module will
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index bc2a6a07dc3e..838b8827eb76 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -19,7 +19,7 @@
>   #include "pmbus.h"
>   
>   enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
> -	 adm1293, adm1294, sq24905c };
> +	 adm1293, adm1294, bd12780, sq24905c };
>   
>   #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
>   #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
> @@ -47,6 +47,8 @@ enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
>   #define ADM1278_VOUT_EN			BIT(1)
>   
>   #define ADM1278_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN | ADM1278_TSFILT)
> +/* The BD12780 data sheets mark TSFILT bit as reserved. */
> +#define BD12780_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
>   
>   #define ADM1293_IRANGE_25		0
>   #define ADM1293_IRANGE_50		BIT(6)
> @@ -487,6 +489,21 @@ static const struct i2c_device_id adm1275_id[] = {
>   	{ "adm1281", adm1281 },
>   	{ "adm1293", adm1293 },
>   	{ "adm1294", adm1294 },
> +	/*
> +	 * The BD12780a is functionally identical to BD12780(*). Even the pmbus ID
> +	 * register contents are same. When instantiated from the DT, it is required
> +	 * to have the bd12780 as a fall-back. We still need the bd12780a ID here,
> +	 * because the i2c_device_id is created from the first compatible, not from
> +	 * the fall-back entry.
> +	 * (*)Until proven to differ. I prefer having own compatible for these
> +	 * variants for that day. Please note that even though the probe is called
> +	 * based on the 'bd12780a' -entry, the ID is picked at probe based on the
> +	 * pmbus register contents and not by DT entry. Thus, if the bd12780 and
> +	 * bd12780a are found to require different handling, then this needs to be
> +	 * changed, or bd12780a is handled as bd12780.
> +	 */
> +	{ "bd12780", bd12780 },
> +	{ "bd12780a", /* driver data unused, see --^ */ },

We don't usually do that. There are various A/B/C variants for many chips,
and we just use the base name unless a difference is warranted. Either this
is needed, and driver data is needed as well, or it isn't. If it is not needed,
it should be dropped.

>   	{ "mc09c", sq24905c },
>   	{ }
>   };
> @@ -494,12 +511,13 @@ MODULE_DEVICE_TABLE(i2c, adm1275_id);
>   
>   /* Enable VOUT & TEMP1 if not enabled (disabled by default) */
>   static int adm1275_enable_vout_temp(struct adm1275_data *data,
> -				    struct i2c_client *client, int config)
> +				    struct i2c_client *client, int config,
> +				    u16 defconfig)
>   {
>   	int ret;
>   
> -	if ((config & ADM1278_PMON_DEFCONFIG) != ADM1278_PMON_DEFCONFIG) {
> -		config |= ADM1278_PMON_DEFCONFIG;
> +	if ((config & defconfig) != defconfig) {
> +		config |= defconfig;
>   		ret = adm1275_write_pmon_config(data, client, config);
>   		if (ret < 0) {
>   			dev_err(&client->dev, "Failed to enable VOUT/TEMP1 monitoring\n");
> @@ -535,7 +553,8 @@ static int adm1275_probe(struct i2c_client *client)
>   		return ret;
>   	}
>   	if ((ret != 3 || strncmp(block_buffer, "ADI", 3)) &&
> -	    (ret != 2 || strncmp(block_buffer, "SY", 2))) {
> +	    (ret != 2 || strncmp(block_buffer, "SY", 2)) &&
> +	    (ret != 4 || strncmp(block_buffer, "ROHM", 4))) {
>   		dev_err(&client->dev, "Unsupported Manufacturer ID\n");
>   		return -ENODEV;
>   	}
> @@ -562,7 +581,7 @@ static int adm1275_probe(struct i2c_client *client)
>   	if (mid->driver_data == adm1272 || mid->driver_data == adm1273 ||
>   	    mid->driver_data == adm1278 || mid->driver_data == adm1281 ||
>   	    mid->driver_data == adm1293 || mid->driver_data == adm1294 ||
> -	    mid->driver_data == sq24905c)
> +	    mid->driver_data == bd12780 || mid->driver_data == sq24905c)
>   		config_read_fn = i2c_smbus_read_word_data;
>   	else
>   		config_read_fn = i2c_smbus_read_byte_data;
> @@ -666,7 +685,8 @@ static int adm1275_probe(struct i2c_client *client)
>   			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
>   			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
>   
> -		ret = adm1275_enable_vout_temp(data, client, config);
> +		ret = adm1275_enable_vout_temp(data, client, config,
> +					       ADM1278_PMON_DEFCONFIG);
>   		if (ret)
>   			return ret;
>   
> @@ -712,7 +732,16 @@ static int adm1275_probe(struct i2c_client *client)
>   		break;
>   	case adm1278:
>   	case adm1281:
> +	case bd12780:
>   	case sq24905c:
> +	{
> +		u16 defconfig;
> +
> +		if (data->id == bd12780)
> +			defconfig = BD12780_PMON_DEFCONFIG;
> +		else
> +			defconfig = ADM1278_PMON_DEFCONFIG;
> +

Please add a separate case statement for the new chip
and do not overload existing chip data.

>   		data->have_vout = true;
>   		data->have_pin_max = true;
>   		data->have_temp_max = true;
> @@ -728,13 +757,14 @@ static int adm1275_probe(struct i2c_client *client)
>   			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
>   			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
>   
> -		ret = adm1275_enable_vout_temp(data, client, config);
> +		ret = adm1275_enable_vout_temp(data, client, config, defconfig);
>   		if (ret)
>   			return ret;
>   
>   		if (config & ADM1278_VIN_EN)
>   			info->func[0] |= PMBUS_HAVE_VIN;
>   		break;
> +	}
>   	case adm1293:
>   	case adm1294:
>   		data->have_iout_min = true;

Re: [PATCH 6/7] hwmon: adm1275: Support ROHM BD12790

[Guenter Roeck]

On 6/15/26 23:44, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> Add support for ROHM BD12790 hot-swap controller which is largely
> similar to Analog Devices adm1272.
> 
> The BD12790 uses the same selectable 60V/100V voltage ranges and
> 15mV/30mV current-sense ranges as the ADM1272, and the same VRANGE
> (bit 5) and IRANGE (bit 0) layout in PMON_CONFIG. It therefore uses
> a dedicated coefficient table that mirrors adm1272_coefficients, with
> the following differences derived from BD12790 datasheet Table 1 (p.18):
> - power 60V/30mV: m=17560 (vs. 17561)
> - power 100V/30mV: m=10536 (vs. 10535)
> - temperature: b=31880 (vs. 31871, reflecting T[11:0] = 4.2*T + 3188)
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Assisted-by: GitHub Copilot:claude-sonnet-4.6
> 
> ---
> Originally this patch was AI-generated. I did pretty much re-write the
> probe changes by hand, and also fixed some of the coefficient math
> afterwards :/ But yeah, this one was AI "assisted". :)
> 
>   drivers/hwmon/pmbus/Kconfig   |  4 +--
>   drivers/hwmon/pmbus/adm1275.c | 53 +++++++++++++++++++++++++++++------
>   2 files changed, 47 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index b3c27f3b2712..6ebc01e26db3 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -52,8 +52,8 @@ config SENSORS_ADM1275
>   	help
>   	  If you say yes here you get hardware monitoring support for Analog
>   	  Devices ADM1075, ADM1272, ADM1273, ADM1275, ADM1276, ADM1278, ADM1281,
> -	  ADM1293, ADM1294, ROHM BD12780, and SQ24905C Hot-Swap Controller and
> -	  Digital Power Monitors.
> +	  ADM1293, ADM1294, ROHM BD12780, ROHM BD12790, and SQ24905C
> +	  Hot-Swap Controller and Digital Power Monitors.
>   
>   	  This driver can also be built as a module. If so, the module will
>   	  be called adm1275.
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index 838b8827eb76..9e21dd4083e9 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -19,7 +19,7 @@
>   #include "pmbus.h"
>   
>   enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
> -	 adm1293, adm1294, bd12780, sq24905c };
> +	 adm1293, adm1294, bd12780, bd12790, sq24905c };
>   
>   #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
>   #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
> @@ -47,8 +47,8 @@ enum chips { adm1075, adm1272, adm1273, adm1275, adm1276, adm1278, adm1281,
>   #define ADM1278_VOUT_EN			BIT(1)
>   
>   #define ADM1278_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN | ADM1278_TSFILT)
> -/* The BD12780 data sheets mark TSFILT bit as reserved. */
> -#define BD12780_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)
> +/* The BD127x0 data sheets mark TSFILT bit as reserved. */
> +#define BD127X0_PMON_DEFCONFIG		(ADM1278_VOUT_EN | ADM1278_TEMP1_EN)

Please don't use such placeholders. Just use BD12780_PMON_DEFCONFIG
for both chips, similar to how the defines for all other chips
are handled.

Thanks,
Guenter

Re: [PATCH 4/7] dt-bindings: adm1275: ROHM BD12790 hot-swap controller

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

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Re: [PATCH 3/7] hwmon: adm1275: Support ROHM BD12780

[Matti Vaittinen]

Thanks for taking the time to review this! Feedback is appreciated :)

On 16/06/2026 17:13, Guenter Roeck wrote:
> On 6/15/26 23:36, Matti Vaittinen wrote:
>> From: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> ROHM BD12780 and BD12780A are hot-swap controllers. They are largely
>> similar to Analog Devices ADM1278. Besides the ID registers and some
>> added functionality, the BD12780 and BD12780A mark PMON_CONFIG bits
>> [15:14] as reserved. Hence TSFILT setting must be omitted on these ICs.
>>
>> The BD12780 has 3 pins usable for configuring the I2C address. The
>> BD12780A lists the ADDR3-pin as "not connect".
>>
>> Support ROHM BD12780 and BD12780A controllers.
>>
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>> ---
>>   drivers/hwmon/pmbus/Kconfig   |  2 +-
>>   drivers/hwmon/pmbus/adm1275.c | 46 +++++++++++++++++++++++++++++------
>>   2 files changed, 39 insertions(+), 9 deletions(-)
>>

// snip

>> @@ -487,6 +489,21 @@ static const struct i2c_device_id adm1275_id[] = {
>>       { "adm1281", adm1281 },
>>       { "adm1293", adm1293 },
>>       { "adm1294", adm1294 },
>> +    /*
>> +     * The BD12780a is functionally identical to BD12780(*). Even the 
>> pmbus ID
>> +     * register contents are same. When instantiated from the DT, it 
>> is required
>> +     * to have the bd12780 as a fall-back. We still need the bd12780a 
>> ID here,
>> +     * because the i2c_device_id is created from the first 
>> compatible, not from
>> +     * the fall-back entry.
>> +     * (*)Until proven to differ. I prefer having own compatible for 
>> these
>> +     * variants for that day. Please note that even though the probe 
>> is called
>> +     * based on the 'bd12780a' -entry, the ID is picked at probe 
>> based on the
>> +     * pmbus register contents and not by DT entry. Thus, if the 
>> bd12780 and
>> +     * bd12780a are found to require different handling, then this 
>> needs to be
>> +     * changed, or bd12780a is handled as bd12780.
>> +     */
>> +    { "bd12780", bd12780 },
>> +    { "bd12780a", /* driver data unused, see --^ */ },
> 
> We don't usually do that. There are various A/B/C variants for many chips,
> and we just use the base name unless a difference is warranted. Either this
> is needed, and driver data is needed as well, or it isn't. If it is not 
> needed,
> it should be dropped.

At the moment the only difference I know is reduced amount of I2C slave 
addresses. This shouldn't be visible to this driver.

My problem is that I don't know for sure if we later notice something 
that requires differentiating. Thus I would like to have different DT 
compatibles (or other source of I2C IDs if those are used to instantiate 
the driver). If we don't do this, then we have problems if we later find 
out that these ICs require different handling as users because we can't 
differentiate these ICs if they are described with same compatible/I2C ID.

The "fun" thing is that both variants have exactly same MFR_MODEL and 
MFR_REVISION register contents. Thus, these ICs can't be differentiated 
by reading PMBus registers.

This is also why the driver data entry gets unused. The existing probe 
mechanism in this driver, scans the names in this ID list and compares 
it to the PMBus MFR_MODEL, and then picks-up the driver data to use. Now 
because BD12780 and BD12780A both have same MFR_MODEL, the scan in probe 
will always pick the same driver data entry, no matter what ID was 
matched by bus code. That's why I added the comment here.

If I drop the { "bd12780a", /* driver data unused, see --^ */ } -entry 
from the ID list and add the of_device_ids, then I think this problem is 
solved for the DT-platforms. As far as I understand, this would still 
cause any non DT platform to describe both variants as "bd12780", making 
it impossible to later differentiate ICs in the driver, right? I can do 
this, but for me it feels a bit like asking for problems...

My thinking was to have different IDs for these variants so hardware 
description could have different IDs for different ICs. Then, if we 
later need to differentiate these ICs, we still have an option to change 
the probe to trust the i2c_get_match_data() when PMBus indicates the 
bd12780.

This however is some extra complexity, and I would like to add it to the 
probe only if it really is required.

But yeah, having an ID entry in the list and driver data not used even 
when the matching IC is found, is unusual and would have caught me off 
guard. Hence I added the (long) comment.

> 
>>       { "mc09c", sq24905c },
>>       { }
>>   };

// snip

>> @@ -712,7 +732,16 @@ static int adm1275_probe(struct i2c_client *client)
>>           break;
>>       case adm1278:
>>       case adm1281:
>> +    case bd12780:
>>       case sq24905c:
>> +    {
>> +        u16 defconfig;
>> +
>> +        if (data->id == bd12780)
>> +            defconfig = BD12780_PMON_DEFCONFIG;
>> +        else
>> +            defconfig = ADM1278_PMON_DEFCONFIG;
>> +
> 
> Please add a separate case statement for the new chip
> and do not overload existing chip data.

I originally did just that. I, however, was not happy with this as it 
resulted quite long own case this IC, which is almost identical to this 
other (adm1278, adm1281, sq24905c) case. I wanted the code to shout that 
the DB12780 is indeed (almost) identical to the adm1278. But yeah, I 
agree, having "if (foo)" in "switch (foo)" case can get confusing.

Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~

Re: [PATCH 6/7] hwmon: adm1275: Support ROHM BD12790

[Matti Vaittinen]

On 16/06/2026 17:08, Guenter Roeck wrote:
> On 6/15/26 23:44, Matti Vaittinen wrote:
>> From: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> Add support for ROHM BD12790 hot-swap controller which is largely
>> similar to Analog Devices adm1272.
>>
>> The BD12790 uses the same selectable 60V/100V voltage ranges and
>> 15mV/30mV current-sense ranges as the ADM1272, and the same VRANGE
>> (bit 5) and IRANGE (bit 0) layout in PMON_CONFIG. It therefore uses
>> a dedicated coefficient table that mirrors adm1272_coefficients, with
>> the following differences derived from BD12790 datasheet Table 1 (p.18):
>> - power 60V/30mV: m=17560 (vs. 17561)
>> - power 100V/30mV: m=10536 (vs. 10535)
>> - temperature: b=31880 (vs. 31871, reflecting T[11:0] = 4.2*T + 3188)
>>
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>> Assisted-by: GitHub Copilot:claude-sonnet-4.6
>>
>> ---
>> Originally this patch was AI-generated. I did pretty much re-write the
>> probe changes by hand, and also fixed some of the coefficient math
>> afterwards :/ But yeah, this one was AI "assisted". :)
>>
>>   drivers/hwmon/pmbus/Kconfig   |  4 +--
>>   drivers/hwmon/pmbus/adm1275.c | 53 +++++++++++++++++++++++++++++------
>>   2 files changed, 47 insertions(+), 10 deletions(-)

// snip

>> @@ -655,12 +681,23 @@ static int adm1275_probe(struct i2c_client *client)
>>           break;
>>       case adm1272:
>>       case adm1273:
>> +    case bd12790:
> 
> Please don't overload the existing case statements.
> Just add separate case statements for the new chips.
> 

Hmm. Ok, although, here, same as with the BD12780, I would like the code 
to clearly show that the BD12790 is very very similar to another IC 
(adm1272). When we have own case for it, this information gets kind of 
lost as these cases are a tad too long to easily spot the differences. 
If there are any ideas how to ease spotting this while having own cases 
- I am keen to hear.

Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~

Re: [PATCH 6/7] hwmon: adm1275: Support ROHM BD12790

[Matti Vaittinen]

On 16/06/2026 17:15, Guenter Roeck wrote:
> On 6/15/26 23:44, Matti Vaittinen wrote:
>> From: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> Add support for ROHM BD12790 hot-swap controller which is largely
>> similar to Analog Devices adm1272.
>>
>> The BD12790 uses the same selectable 60V/100V voltage ranges and
>> 15mV/30mV current-sense ranges as the ADM1272, and the same VRANGE
>> (bit 5) and IRANGE (bit 0) layout in PMON_CONFIG. It therefore uses
>> a dedicated coefficient table that mirrors adm1272_coefficients, with
>> the following differences derived from BD12790 datasheet Table 1 (p.18):
>> - power 60V/30mV: m=17560 (vs. 17561)
>> - power 100V/30mV: m=10536 (vs. 10535)
>> - temperature: b=31880 (vs. 31871, reflecting T[11:0] = 4.2*T + 3188)
>>
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>> Assisted-by: GitHub Copilot:claude-sonnet-4.6
>>
>> ---

// snip

>> -/* The BD12780 data sheets mark TSFILT bit as reserved. */
>> -#define BD12780_PMON_DEFCONFIG        (ADM1278_VOUT_EN | 
>> ADM1278_TEMP1_EN)
>> +/* The BD127x0 data sheets mark TSFILT bit as reserved. */
>> +#define BD127X0_PMON_DEFCONFIG        (ADM1278_VOUT_EN | 
>> ADM1278_TEMP1_EN)
> 
> Please don't use such placeholders. Just use BD12780_PMON_DEFCONFIG
> for both chips, similar to how the defines for all other chips
> are handled.

Ok, thanks.

Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~

Re: [PATCH 7/7] hwmon: adm1275: Support module auto-loading

[Matti Vaittinen]

On 16/06/2026 17:04, Guenter Roeck wrote:
> On 6/15/26 23:47, Matti Vaittinen wrote:
>> From: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> Populating the spi_device_id -table is not enough to make the
>> driver module automatically load when device-tree node for the bd12780
>> is parsed at boot.
>>
>> Adding the of_device_id tables causes the driver module to be
>> automatically load at boot. Testing has been done with rather old Debian
>> system.
>>
>> When inspecting the generated module-aliases with the insmod, following
>> entries seem to be the difference:
>>
>> alias:          of:N*T*Crohm,bd12780C*
>> alias:          of:N*T*Crohm,bd12780
>>
>> I suspect these are required for the module loading to work.
>>
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> ---
>>
>> I did not add of_device_ids for other supported ICs as I can't verify it
>> doesn't cause side-effects. Please let me know if you think those IDs
>> should be added as well. I would be glad if I got more educated opinion
>> on adding the of-IDs :) (I can squash this to 3/7 and 6/7 in next
>> revision, and add own patch for adding of-IDs for other ICs if
>> required).
>>
> 
> I don't know what those side effects might be. I am much more concerned
> about side effects of having some of the devices in adm1275_of_match
> and some in adm1275_id. So, yes, please add a patch to provide
> adm1275_of_match for all chips supported by the driver.
It's nice to have an opinion on this as I was really unsure what is the 
right way forward. Thanks for all the help this far. I'll do that in v2.

Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~