[PATCH v2 0/3] hwmon: (pmbus/max34440): Bug fixes and supporting new device

[PATCH v2 0/3] hwmon: (pmbus/max34440): Bug fixes and supporting new device

[Alexis Czezar Torreno]

This series fixes register access issues in MAX34451/ADPM devices and adds
support for newer MAX34451 variants and the MAX34452 device.

The first patch addresses an issue where the driver attempts to access
unsupported registers on MAX34451 and ADPM devices, causing CML errors and
triggering ALERT. 
NOTE: Patch already applied to hwmon branch as a fix. It was suggested I
could simply carry this for the meantime to easily submit new versions
of patch 2 and 3 which are dependent of patch 1.

The second patch adds support for the newer MAX34451ETNA8+ silicon revision
which uses different direct format coefficients for voltage and current
measurements.

The third patch introduces support for the MAX34452, a 16-channel voltage/
current monitor that shares a similar architecture with MAX34451.

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
Changes in v2:
- Patch 1/3:
    - Accepted and applied in hwmon. As per suggestion, carried this
      over to simplify submission of patch 2 and 3 as dependency exist.
- Patch 2/3:
    - Replaced ETNA8+ revision check from == to >= for future proofing
- Patch 3/3: 
    - Added MAX34452 to unsupported register check
    - Added explicit MAX34451 id check in ETNA6+ feature detection to
      prevent applying to MAX34452.
- Link to v1: https://lore.kernel.org/r/20260716-max34451_fixes-v1-0-a941b27eaecb@analog.com

---
Alexis Czezar Torreno (2):
      hwmon: (pmbus/max34440): block unsupported VIN and IIN limit registers
      hwmon: (pmbus/max34440): add support for newer version of max34451

Carlos Jones Jr (1):
      hwmon: (pmbus/max34440): Add support for MAX34452

 Documentation/hwmon/max34440.rst |  26 ++++---
 drivers/hwmon/pmbus/Kconfig      |   5 +-
 drivers/hwmon/pmbus/max34440.c   | 152 ++++++++++++++++++++++++++++++++++++---
 3 files changed, 163 insertions(+), 20 deletions(-)
---
base-commit: ec5dac32f359168b90f5361a4de16dbf7f258031
change-id: 20260716-max34451_fixes-788edb623116

Best regards,
-- 
Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

[PATCH v2 1/3] hwmon: (pmbus/max34440): block unsupported VIN and IIN limit registers

[Alexis Czezar Torreno]

MAX34451 and ADPM chips do not support standard PMBus VIN/IIN limit
registers, manufacturer specific min/max registers, or undercurrent
or undertemperature fault limits. STATUS_BYTE and STATUS_OTHER are also
not available. Accessing these non-existent registers during driver
initialization triggers a CML error and asserts ALERT. Handled by
blocking these functions during read/write.

Fixes: 7a001dbab4ad ("hwmon: (pmbus/max34440) Add support for MAX34451.")
Fixes: 629cf8f6c23a ("hwmon: (pmbus/max34440) Add support for ADPM12160")
Fixes: 2e0b52f1ae88 ("hwmon: (pmbus/max34440): add support adpm12200")
Fixes: 479bfeba2eb6 ("hwmon: (pmbus/max34440): add support adpm12250")
Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
Link: https://lore.kernel.org/r/20260716-max34451_fixes-v1-1-a941b27eaecb@analog.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/pmbus/max34440.c | 80 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/drivers/hwmon/pmbus/max34440.c b/drivers/hwmon/pmbus/max34440.c
index 74876d2207fbe4014b8b54a9fd9682370fc3bbed..e56057e9273c1639bddbaf4e665ea159f1d7c3ed 100644
--- a/drivers/hwmon/pmbus/max34440.c
+++ b/drivers/hwmon/pmbus/max34440.c
@@ -88,6 +88,33 @@ static int max34440_read_word_data(struct i2c_client *client, int page,
 		ret = pmbus_read_word_data(client, page, phase,
 					   data->iout_oc_warn_limit);
 		break;
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+	case PMBUS_VIN_OV_WARN_LIMIT:
+	case PMBUS_VIN_UV_WARN_LIMIT:
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_MFR_VIN_MIN:
+	case PMBUS_MFR_VIN_MAX:
+	case PMBUS_IIN_OC_WARN_LIMIT:
+	case PMBUS_IIN_OC_FAULT_LIMIT:
+	case PMBUS_MFR_IIN_MAX:
+	case PMBUS_MFR_VOUT_MIN:
+	case PMBUS_MFR_VOUT_MAX:
+	case PMBUS_IOUT_UC_FAULT_LIMIT:
+	case PMBUS_MFR_IOUT_MAX:
+	case PMBUS_UT_WARN_LIMIT:
+	case PMBUS_UT_FAULT_LIMIT:
+	case PMBUS_MFR_MAX_TEMP_1:
+		/*
+		 * MAX34451/ADPM family do not support VIN/IIN limit registers,
+		 * manufacturer-specific min/max registers, or undercurrent/
+		 * undertemperature fault limits. Accessing these triggers CML
+		 * error and asserts ALERT.
+		 */
+		if (data->id == max34451 || data->id == adpm12160 ||
+		    data->id == adpm12200 || data->id == adpm12250)
+			return -ENXIO;
+		ret = -ENODATA;
+		break;
 	case PMBUS_VIRT_READ_VOUT_MIN:
 		ret = pmbus_read_word_data(client, page, phase,
 					   MAX34440_MFR_VOUT_MIN);
@@ -244,6 +271,51 @@ static int max34440_read_byte_data(struct i2c_client *client, int page, int reg)
 	return ret;
 }
 
+static int max34451_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	const struct max34440_data *data = to_max34440_data(info);
+
+	switch (reg) {
+	case PMBUS_STATUS_BYTE:
+	case PMBUS_STATUS_OTHER:
+		/*
+		 * MAX34451/ADPM family do not support STATUS_BYTE or
+		 * STATUS_OTHER registers. Accessing them triggers CML
+		 * error and asserts ALERT.
+		 */
+		if (data->id == max34451 || data->id == adpm12160 ||
+		    data->id == adpm12200 || data->id == adpm12250)
+			return -ENXIO;
+		return -ENODATA;
+	default:
+		return -ENODATA;
+	}
+}
+
+static int max34451_write_byte_data(struct i2c_client *client, int page,
+				    int reg, u8 byte)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	const struct max34440_data *data = to_max34440_data(info);
+
+	switch (reg) {
+	case PMBUS_STATUS_BYTE:
+	case PMBUS_STATUS_OTHER:
+		/*
+		 * MAX34451/ADPM family do not support STATUS_BYTE or
+		 * STATUS_OTHER registers. Writing to them triggers CML
+		 * error and asserts ALERT.
+		 */
+		if (data->id == max34451 || data->id == adpm12160 ||
+		    data->id == adpm12200 || data->id == adpm12250)
+			return -ENXIO;
+		return -ENODATA;
+	default:
+		return -ENODATA;
+	}
+}
+
 static int max34451_set_supported_funcs(struct i2c_client *client,
 					 struct max34440_data *data)
 {
@@ -363,7 +435,9 @@ static struct pmbus_driver_info max34440_info[] = {
 		.func[9] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT,
 		.func[10] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT,
 		.func[18] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.read_byte_data = max34451_read_byte_data,
 		.read_word_data = max34440_read_word_data,
+		.write_byte_data = max34451_write_byte_data,
 		.write_word_data = max34440_write_word_data,
 	},
 	[adpm12200] = {
@@ -399,7 +473,9 @@ static struct pmbus_driver_info max34440_info[] = {
 		.func[10] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT,
 		.func[14] = PMBUS_HAVE_IOUT,
 		.func[18] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.read_byte_data = max34451_read_byte_data,
 		.read_word_data = max34440_read_word_data,
+		.write_byte_data = max34451_write_byte_data,
 		.write_word_data = max34440_write_word_data,
 	},
 	[adpm12250] = {
@@ -433,7 +509,9 @@ static struct pmbus_driver_info max34440_info[] = {
 		.func[10] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT,
 		.func[14] = PMBUS_HAVE_IOUT,
 		.func[18] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.read_byte_data = max34451_read_byte_data,
 		.read_word_data = max34440_read_word_data,
+		.write_byte_data = max34451_write_byte_data,
 		.write_word_data = max34440_write_word_data,
 	},
 	[max34440] = {
@@ -581,7 +659,9 @@ static struct pmbus_driver_info max34440_info[] = {
 		.func[18] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
 		.func[19] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
 		.func[20] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.read_byte_data = max34451_read_byte_data,
 		.read_word_data = max34440_read_word_data,
+		.write_byte_data = max34451_write_byte_data,
 		.write_word_data = max34440_write_word_data,
 		.page_change_delay = MAX34440_PAGE_CHANGE_DELAY,
 	},

-- 
2.34.1

[PATCH v2 2/3] hwmon: (pmbus/max34440): add support for newer version of max34451

[Alexis Czezar Torreno]

The MAX34451 released a newer version called max34451etna8+.
This simply changes the direct format coefficients

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
 drivers/hwmon/pmbus/max34440.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/pmbus/max34440.c b/drivers/hwmon/pmbus/max34440.c
index e56057e9273c1639bddbaf4e665ea159f1d7c3ed..81514727565f29c7251fe93f049cdd6b0f214f81 100644
--- a/drivers/hwmon/pmbus/max34440.c
+++ b/drivers/hwmon/pmbus/max34440.c
@@ -59,6 +59,7 @@ enum chips {
 #define MAX34440_IOUT_OC_FAULT_LIMIT	0x4A
 
 #define MAX34451ETNA6_MFR_REV		0x0012
+#define MAX34451ETNA8_MFR_REV		0x0014
 
 #define MAX34451_MFR_CHANNEL_CONFIG	0xe4
 #define MAX34451_MFR_CHANNEL_CONFIG_SEL_MASK	0x3f
@@ -343,12 +344,24 @@ static int max34451_set_supported_funcs(struct i2c_client *client,
 		max34451_na6 = true;
 		data->info.format[PSC_VOLTAGE_IN] = direct;
 		data->info.format[PSC_CURRENT_IN] = direct;
-		data->info.m[PSC_VOLTAGE_IN] = 1;
+
 		data->info.b[PSC_VOLTAGE_IN] = 0;
-		data->info.R[PSC_VOLTAGE_IN] = 3;
-		data->info.m[PSC_CURRENT_IN] = 1;
 		data->info.b[PSC_CURRENT_IN] = 0;
-		data->info.R[PSC_CURRENT_IN] = 2;
+		if (rv >= MAX34451ETNA8_MFR_REV) {
+			data->info.m[PSC_VOLTAGE_IN] = 125;
+			data->info.R[PSC_VOLTAGE_IN] = 0;
+			data->info.m[PSC_VOLTAGE_OUT] = 125;
+			data->info.R[PSC_VOLTAGE_OUT] = 0;
+			data->info.m[PSC_CURRENT_IN] = 250;
+			data->info.R[PSC_CURRENT_IN] = -1;
+			data->info.m[PSC_CURRENT_OUT] = 250;
+			data->info.R[PSC_CURRENT_OUT] = -1;
+		} else {
+			data->info.m[PSC_VOLTAGE_IN] = 1;
+			data->info.R[PSC_VOLTAGE_IN] = 3;
+			data->info.m[PSC_CURRENT_IN] = 1;
+			data->info.R[PSC_CURRENT_IN] = 2;
+		}
 		data->iout_oc_fault_limit = PMBUS_IOUT_OC_FAULT_LIMIT;
 		data->iout_oc_warn_limit = PMBUS_IOUT_OC_WARN_LIMIT;
 	}

-- 
2.34.1

[PATCH v2 3/3] hwmon: (pmbus/max34440): Add support for MAX34452

[Alexis Czezar Torreno]

From: Carlos Jones Jr <carlosjr.jones@analog.com>

Add support for Maxim MAX34452 PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer. The device is similar to MAX34451
and shares the same configuration function.

The MAX34452 supports:
- 16 configurable voltage/current monitoring channels
- 5 temperature sensors (pages 16-20)
- Dynamic channel configuration via MFR_CHANNEL_CONFIG
- IOUT average monitoring

Signed-off-by: Carlos Jones Jr <carlosjr.jones@analog.com>
Co-Developed by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
 Documentation/hwmon/max34440.rst | 26 +++++++++-----
 drivers/hwmon/pmbus/Kconfig      |  5 +--
 drivers/hwmon/pmbus/max34440.c   | 75 ++++++++++++++++++++++++++++++----------
 3 files changed, 78 insertions(+), 28 deletions(-)

diff --git a/Documentation/hwmon/max34440.rst b/Documentation/hwmon/max34440.rst
index e7421f4dbf38fc1436bbaeba71d4461a00f8cefb..866f22b88e9b360ff54aa52807484bb3e859e56e 100644
--- a/Documentation/hwmon/max34440.rst
+++ b/Documentation/hwmon/max34440.rst
@@ -65,6 +65,16 @@ Supported chips:
 
     Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/max34451.pdf
 
+  * Maxim MAX34452
+
+    PMBus 16-Channel V/I Monitor and 12-Channel Sequencer/Marginer
+
+    Prefixes: 'max34452'
+
+    Addresses scanned: -
+
+    Datasheet: -
+
   * Maxim MAX34460
 
     PMBus 12-Channel Voltage Monitor & Sequencer
@@ -94,11 +104,11 @@ Description
 This driver supports multiple devices: hardware monitoring for Maxim MAX34440
 PMBus 6-Channel Power-Supply Manager, MAX34441 PMBus 5-Channel Power-Supply
 Manager and Intelligent Fan Controller, and MAX34446 PMBus Power-Supply Data
-Logger; PMBus Voltage Monitor and Sequencers for MAX34451, MAX34460, and
-MAX34461; PMBus DC/DC Power Module ADPM12160, ADPM12200, and ADPM12250. The
-MAX34451 supports monitoring voltage or current of 12 channels based on GIN
-pins. The MAX34460 supports 12 voltage channels, and the MAX34461 supports 16
-voltage channels. The ADPM12160, ADPM12200, and ADPM12250 also monitors both
+Logger; PMBus Voltage Monitor and Sequencers for MAX34451, MAX34452, MAX34460,
+and MAX34461; PMBus DC/DC Power Module ADPM12160, ADPM12200, and ADPM12250. The
+MAX34451 and MAX34452 support monitoring voltage or current of 16 channels based
+on GIN pins. The MAX34460 supports 12 voltage channels, and the MAX34461 supports
+16 voltage channels. The ADPM12160, ADPM12200, and ADPM12250 also monitor both
 input and output of voltage and current.
 
 The driver is a client driver to the core PMBus driver. Please see
@@ -171,7 +181,7 @@ curr[1-6]_crit		Critical maximum current. From IOUT_OC_FAULT_LIMIT
 			register.
 curr[1-6]_max_alarm	Current high alarm. From IOUT_OC_WARNING status.
 curr[1-6]_crit_alarm	Current critical high alarm. From IOUT_OC_FAULT status.
-curr[1-4]_average	Historical average current (MAX34446/34451 only).
+curr[1-4]_average	Historical average current (MAX34446/34451/34452 only).
 curr[1-6]_highest	Historical maximum current.
 curr[1-6]_reset_history	Write any value to reset history.
 ======================= ========================================================
@@ -223,7 +233,7 @@ temp[1-8]_reset_history	Write any value to reset history.
 
 .. note::
 
-   - MAX34451 supports attribute groups in[1-16] (or curr[1-16] based on
-     input pins) and temp[1-5].
+   - MAX34451 and MAX34452 support attribute groups in[1-16] (or curr[1-16]
+     based on input pins) and temp[1-5].
    - MAX34460 supports attribute groups in[1-12] and temp[1-5].
    - MAX34461 supports attribute groups in[1-16] and temp[1-5].
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index ca312be58ed5c46da2859db334a1abd69c6d3471..9b4bfdd003108e1846ff35e3f18ab408dd2cc76a 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -434,8 +434,9 @@ config SENSORS_MAX34440
 	tristate "Maxim MAX34440 and compatibles"
 	help
 	  If you say yes here you get hardware monitoring support for Maxim
-	  MAX34440, MAX34441, MAX34446, MAX34451, MAX34460, and MAX34461.
-	  Other compatible are ADPM12160, and ADPM12200.
+	  MAX34440, MAX34441, MAX34446, MAX34451, MAX34452, MAX34460, and
+	  MAX34461. Other compatible devices are ADPM12160, ADPM12200, and
+	  ADPM12250.
 
 	  This driver can also be built as a module. If so, the module will
 	  be called max34440.
diff --git a/drivers/hwmon/pmbus/max34440.c b/drivers/hwmon/pmbus/max34440.c
index 81514727565f29c7251fe93f049cdd6b0f214f81..866d25ae8971c49d3e296efb69fc486e5dbac668 100644
--- a/drivers/hwmon/pmbus/max34440.c
+++ b/drivers/hwmon/pmbus/max34440.c
@@ -23,6 +23,7 @@ enum chips {
 	max34441,
 	max34446,
 	max34451,
+	max34452,
 	max34460,
 	max34461,
 };
@@ -106,16 +107,21 @@ static int max34440_read_word_data(struct i2c_client *client, int page,
 	case PMBUS_UT_FAULT_LIMIT:
 	case PMBUS_MFR_MAX_TEMP_1:
 		/*
-		 * MAX34451/ADPM family do not support VIN/IIN limit registers,
-		 * manufacturer-specific min/max registers, or undercurrent/
-		 * undertemperature fault limits. Accessing these triggers CML
-		 * error and asserts ALERT.
+		 * MAX34451/MAX34452/ADPM family do not support VIN/IIN limit
+		 * registers, manufacturer-specific min/max registers, or
+		 * undercurrent/undertemperature fault limits. Accessing these
+		 * triggers CML error and asserts ALERT.
 		 */
-		if (data->id == max34451 || data->id == adpm12160 ||
-		    data->id == adpm12200 || data->id == adpm12250)
+		if (data->id == max34451 || data->id == max34452 ||
+		    data->id == adpm12160 || data->id == adpm12200 ||
+		    data->id == adpm12250)
 			return -ENXIO;
 		ret = -ENODATA;
 		break;
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+		if (data->id == max34452)
+			return -ENXIO;
+		return -ENODATA;
 	case PMBUS_VIRT_READ_VOUT_MIN:
 		ret = pmbus_read_word_data(client, page, phase,
 					   MAX34440_MFR_VOUT_MIN);
@@ -126,8 +132,8 @@ static int max34440_read_word_data(struct i2c_client *client, int page,
 		break;
 	case PMBUS_VIRT_READ_IOUT_AVG:
 		if (data->id != max34446 && data->id != max34451 &&
-		    data->id != adpm12160 && data->id != adpm12200 &&
-		    data->id != adpm12250)
+		    data->id != max34452 && data->id != adpm12160 &&
+		    data->id != adpm12200 && data->id != adpm12250)
 			return -ENXIO;
 		ret = pmbus_read_word_data(client, page, phase,
 					   MAX34446_MFR_IOUT_AVG);
@@ -192,6 +198,10 @@ static int max34440_write_word_data(struct i2c_client *client, int page,
 		ret = pmbus_write_word_data(client, page, data->iout_oc_warn_limit,
 					    word);
 		break;
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+		if (data->id == max34452)
+			return -ENXIO;
+		return -ENODATA;
 	case PMBUS_VIRT_RESET_POUT_HISTORY:
 		ret = pmbus_write_word_data(client, page,
 					    MAX34446_MFR_POUT_PEAK, 0);
@@ -212,8 +222,8 @@ static int max34440_write_word_data(struct i2c_client *client, int page,
 		ret = pmbus_write_word_data(client, page,
 					    MAX34440_MFR_IOUT_PEAK, 0);
 		if (!ret && (data->id == max34446 || data->id == max34451 ||
-			     data->id == adpm12160 || data->id == adpm12200 ||
-			     data->id == adpm12250))
+			     data->id == max34452 || data->id == adpm12160 ||
+			     data->id == adpm12200 || data->id == adpm12250))
 			ret = pmbus_write_word_data(client, page,
 					MAX34446_MFR_IOUT_AVG, 0);
 
@@ -281,12 +291,13 @@ static int max34451_read_byte_data(struct i2c_client *client, int page, int reg)
 	case PMBUS_STATUS_BYTE:
 	case PMBUS_STATUS_OTHER:
 		/*
-		 * MAX34451/ADPM family do not support STATUS_BYTE or
+		 * MAX34451/MAX34452/ADPM family do not support STATUS_BYTE or
 		 * STATUS_OTHER registers. Accessing them triggers CML
 		 * error and asserts ALERT.
 		 */
-		if (data->id == max34451 || data->id == adpm12160 ||
-		    data->id == adpm12200 || data->id == adpm12250)
+		if (data->id == max34451 || data->id == max34452 ||
+		    data->id == adpm12160 || data->id == adpm12200 ||
+		    data->id == adpm12250)
 			return -ENXIO;
 		return -ENODATA;
 	default:
@@ -304,12 +315,13 @@ static int max34451_write_byte_data(struct i2c_client *client, int page,
 	case PMBUS_STATUS_BYTE:
 	case PMBUS_STATUS_OTHER:
 		/*
-		 * MAX34451/ADPM family do not support STATUS_BYTE or
+		 * MAX34451/MAX34452/ADPM family do not support STATUS_BYTE or
 		 * STATUS_OTHER registers. Writing to them triggers CML
 		 * error and asserts ALERT.
 		 */
-		if (data->id == max34451 || data->id == adpm12160 ||
-		    data->id == adpm12200 || data->id == adpm12250)
+		if (data->id == max34451 || data->id == max34452 ||
+		    data->id == adpm12160 || data->id == adpm12200 ||
+		    data->id == adpm12250)
 			return -ENXIO;
 		return -ENODATA;
 	default:
@@ -340,7 +352,7 @@ static int max34451_set_supported_funcs(struct i2c_client *client,
 	if (rv < 0)
 		return rv;
 
-	if (rv >= MAX34451ETNA6_MFR_REV) {
+	if (data->id == max34451 && rv >= MAX34451ETNA6_MFR_REV) {
 		max34451_na6 = true;
 		data->info.format[PSC_VOLTAGE_IN] = direct;
 		data->info.format[PSC_CURRENT_IN] = direct;
@@ -678,6 +690,32 @@ static struct pmbus_driver_info max34440_info[] = {
 		.write_word_data = max34440_write_word_data,
 		.page_change_delay = MAX34440_PAGE_CHANGE_DELAY,
 	},
+	[max34452] = {
+		.pages = 21,
+		.format[PSC_VOLTAGE_OUT] = direct,
+		.format[PSC_TEMPERATURE] = direct,
+		.format[PSC_CURRENT_OUT] = direct,
+		.m[PSC_VOLTAGE_OUT] = 1,
+		.b[PSC_VOLTAGE_OUT] = 0,
+		.R[PSC_VOLTAGE_OUT] = 3,
+		.m[PSC_CURRENT_OUT] = 1,
+		.b[PSC_CURRENT_OUT] = 0,
+		.R[PSC_CURRENT_OUT] = 2,
+		.m[PSC_TEMPERATURE] = 1,
+		.b[PSC_TEMPERATURE] = 0,
+		.R[PSC_TEMPERATURE] = 2,
+		/* func 0-15 is set dynamically before probing */
+		.func[16] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.func[17] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.func[18] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.func[19] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.func[20] = PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+		.read_byte_data = max34451_read_byte_data,
+		.read_word_data = max34440_read_word_data,
+		.write_byte_data = max34451_write_byte_data,
+		.write_word_data = max34440_write_word_data,
+		.page_change_delay = MAX34440_PAGE_CHANGE_DELAY,
+	},
 	[max34460] = {
 		.pages = 18,
 		.format[PSC_VOLTAGE_OUT] = direct,
@@ -761,7 +799,7 @@ static int max34440_probe(struct i2c_client *client)
 	data->iout_oc_fault_limit = MAX34440_IOUT_OC_FAULT_LIMIT;
 	data->iout_oc_warn_limit = MAX34440_IOUT_OC_WARN_LIMIT;
 
-	if (data->id == max34451) {
+	if (data->id == max34451 || data->id == max34452) {
 		rv = max34451_set_supported_funcs(client, data);
 		if (rv)
 			return rv;
@@ -782,6 +820,7 @@ static const struct i2c_device_id max34440_id[] = {
 	{ .name = "max34441", .driver_data = max34441 },
 	{ .name = "max34446", .driver_data = max34446 },
 	{ .name = "max34451", .driver_data = max34451 },
+	{ .name = "max34452", .driver_data = max34452 },
 	{ .name = "max34460", .driver_data = max34460 },
 	{ .name = "max34461", .driver_data = max34461 },
 	{ }

-- 
2.34.1

Re: [PATCH v2 2/3] hwmon: (pmbus/max34440): add support for newer version of max34451

[sashiko-bot]

> The MAX34451 released a newer version called max34451etna8+.
> This simply changes the direct format coefficients
> 
> Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722-max34451_fixes-v2-0-bbddb18ec1d6@analog.com?part=2

Re: [PATCH v2 3/3] hwmon: (pmbus/max34440): Add support for MAX34452

[sashiko-bot]

> From: Carlos Jones Jr <carlosjr.jones@analog.com>
> 
> Add support for Maxim MAX34452 PMBus 16-Channel V/I Monitor and
> 12-Channel Sequencer/Marginer. The device is similar to MAX34451
> and shares the same configuration function.
> 
> The MAX34452 supports:
> - 16 configurable voltage/current monitoring channels
> - 5 temperature sensors (pages 16-20)
> - Dynamic channel configuration via MFR_CHANNEL_CONFIG
> - IOUT average monitoring
> 
> Signed-off-by: Carlos Jones Jr <carlosjr.jones@analog.com>
> Co-Developed by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722-max34451_fixes-v2-0-bbddb18ec1d6@analog.com?part=3

Re: [PATCH v2 1/3] hwmon: (pmbus/max34440): block unsupported VIN and IIN limit registers

[sashiko-bot]

> MAX34451 and ADPM chips do not support standard PMBus VIN/IIN limit
> registers, manufacturer specific min/max registers, or undercurrent
> or undertemperature fault limits. STATUS_BYTE and STATUS_OTHER are also
> not available. Accessing these non-existent registers during driver
> initialization triggers a CML error and asserts ALERT. Handled by
> blocking these functions during read/write.
> 
> Fixes: 7a001dbab4ad ("hwmon: (pmbus/max34440) Add support for MAX34451.")
> Fixes: 629cf8f6c23a ("hwmon: (pmbus/max34440) Add support for ADPM12160")
> Fixes: 2e0b52f1ae88 ("hwmon: (pmbus/max34440): add support adpm12200")
> Fixes: 479bfeba2eb6 ("hwmon: (pmbus/max34440): add support adpm12250")
> Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> Link: https://lore.kernel.org/r/20260716-max34451_fixes-v1-1-a941b27eaecb@analog.com
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722-max34451_fixes-v2-0-bbddb18ec1d6@analog.com?part=1