[PATCH v4 0/7] hwmon: pmbus: add tps25990 efuse support

[PATCH v4 0/7] hwmon: pmbus: add tps25990 efuse support

[Jerome Brunet]

This patchset adds initial support for the Texas Instruments TPS25990
eFuse. The TPS25990 is an integrated, high-current circuit protection and
power management device. TPS25895 may be stacked on the TPS25990 for
higher currents.

This patchset provides basic telemetry support for the device.
On boot, the device is write protected. Limits can be changed in sysfs
if the write protection is removed using the introduced pmbus parameter.

Limits will be restored to the default value device on startup, unless
saved to NVM. Writing the NVM is not supported by the driver at the moment.

As part of this series, PMBus regulator support is improved to better
support write-protected devices.

Patch 3 depends on the regulator patchset available here [1].
This is a compilation dependency.

[1]: https://lore.kernel.org/r/20241008-regulator-ignored-data-v2-0-d1251e0ee507@baylibre.com

Changes in v4:
- Fix write protect value masking when initializing pmbus chips
- Add 2 more write protect forced mode (VOUT and OP)
- Move module parameter documentation to Documentation/hwmon/pmbus-core.rst
- Add pmbus flag documentation.
- Fix 0-day bitfield report.
- Link to v3: https://lore.kernel.org/r/20241024-tps25990-v3-0-b6a6e9d4b506@baylibre.com

Changes in v3:
- Ease application and Group with hwmon write protect patches from:
  https://lore.kernel.org/r/20240920-pmbus-wp-v1-0-d679ef31c483@baylibre.com
- Link to v2: https://lore.kernel.org/r/20240920-tps25990-v2-0-f3e39bce5173@baylibre.com

Changes in v2:
- Drop PGOOD command support
- Use micro-ohms for rimon property and better handle range.
- Adjust read/write callbacks to let PMBus core do the job by default
- Drop history reset specific properties and remap to the generic ones
- Drop debugfs write_protect property and remap to the generic register
- Link to v1: https://lore.kernel.org/r/20240909-tps25990-v1-0-39b37e43e795@baylibre.com

---
Jerome Brunet (7):
      hwmon: (pmbus) add documentation for existing flags
      hwmon: (pmbus/core) allow drivers to override WRITE_PROTECT
      hwmon: (pmbus/core) improve handling of write protected regulators
      hwmon: (pmbus/core) add wp module param
      hwmon: (pmbus/core) clear faults after setting smbalert mask
      dt-bindings: hwmon: pmbus: add ti tps25990 support
      hwmon: (pmbus/tps25990): add initial support

 .../bindings/hwmon/pmbus/ti,tps25990.yaml          |  83 ++++
 Documentation/hwmon/index.rst                      |   1 +
 Documentation/hwmon/pmbus-core.rst                 |  50 +++
 Documentation/hwmon/tps25990.rst                   | 148 +++++++
 MAINTAINERS                                        |   8 +
 drivers/hwmon/pmbus/Kconfig                        |  17 +
 drivers/hwmon/pmbus/Makefile                       |   1 +
 drivers/hwmon/pmbus/pmbus.h                        |   4 +
 drivers/hwmon/pmbus/pmbus_core.c                   |  95 ++++-
 drivers/hwmon/pmbus/tps25990.c                     | 428 +++++++++++++++++++++
 include/linux/pmbus.h                              |  14 +
 11 files changed, 840 insertions(+), 9 deletions(-)
---
base-commit: 516ddbfef736c843866a0b2db559ce89b40ce378
change-id: 20240909-tps25990-34c0cff2be06
prerequisite-change-id: 20240920-regulator-ignored-data-78e7a855643e:v2
prerequisite-patch-id: 468882ab023813ffe8a7eeb210d05b5177a1954a
prerequisite-patch-id: 2d88eb941437003c6ba1cebb09a352a65b94f358
prerequisite-patch-id: e64c06b721cda2e3c41a670251335d8a2a66a236

Best regards,
-- 
Jerome

[PATCH v4 1/7] hwmon: (pmbus) add documentation for existing flags

[Jerome Brunet]

PMBUS_NO_WRITE_PROTECT and PMBUS_USE_COEFFICIENTS_CMD flags have been added
to pmbus, but the corresponding documentation was not updated.

Update the documentation before adding new flags

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 Documentation/hwmon/pmbus-core.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
index 1eaf2b0158376812eaff1786d01b0f330c85eab8..686a00265bf71231c684afad6df41d6266303919 100644
--- a/Documentation/hwmon/pmbus-core.rst
+++ b/Documentation/hwmon/pmbus-core.rst
@@ -308,6 +308,10 @@ currently provides a flags field with four bits used::
 
 	#define PMBUS_READ_STATUS_AFTER_FAILED_CHECK	BIT(3)
 
+	#define PMBUS_NO_WRITE_PROTECT			BIT(4)
+
+	#define PMBUS_USE_COEFFICIENTS_CMD		BIT(5)
+
 	struct pmbus_platform_data {
 		u32 flags;              /* Device specific flags */
 
@@ -358,3 +362,14 @@ This can be done by reading a known register. By setting this flag the
 driver will try to read the STATUS register after each failed
 register check. This read may fail, but it will put the chip into a
 known state.
+
+PMBUS_NO_WRITE_PROTECT
+
+Some PMBus chips respond with invalid data when reading the WRITE_PROTECT
+register. For such chips, this flag should be set so that the PMBus core
+driver doesn't use the WRITE_PROTECT command to determine its behavior.
+
+PMBUS_USE_COEFFICIENTS_CMD
+
+When this flag is set the PMBus core driver will use the COEFFICIENTS
+register to initialize the coefficients for the direct mode format.

-- 
2.45.2

Re: [PATCH v4 1/7] hwmon: (pmbus) add documentation for existing flags

[Guenter Roeck]

On Tue, Nov 05, 2024 at 06:58:38PM +0100, Jerome Brunet wrote:
> PMBUS_NO_WRITE_PROTECT and PMBUS_USE_COEFFICIENTS_CMD flags have been added
> to pmbus, but the corresponding documentation was not updated.
> 
> Update the documentation before adding new flags
> 
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Applied.

Thanks,
Guenter

[PATCH v4 2/7] hwmon: (pmbus/core) allow drivers to override WRITE_PROTECT

[Jerome Brunet]

Use _pmbus_read_byte_data() rather than calling smbus directly to check
the write protection status. This give a chance to device implementing
write protection differently to report back on the actual write protection
status.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index ce7fd4ca9d89b0f0a02e6c99db391a7cfca924a8..085a4dc91d9bad3d2aacdd946b74a094ea9ae458 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2719,9 +2719,7 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 	 * limit registers need to be disabled.
 	 */
 	if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) {
-		pmbus_wait(client);
-		ret = i2c_smbus_read_byte_data(client, PMBUS_WRITE_PROTECT);
-		pmbus_update_ts(client, false);
+		ret = _pmbus_read_byte_data(client, 0xff, PMBUS_WRITE_PROTECT);
 
 		if (ret > 0 && (ret & PB_WP_ANY))
 			data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK;

-- 
2.45.2

Re: [PATCH v4 2/7] hwmon: (pmbus/core) allow drivers to override WRITE_PROTECT

[Guenter Roeck]

On Tue, Nov 05, 2024 at 06:58:39PM +0100, Jerome Brunet wrote:
> Use _pmbus_read_byte_data() rather than calling smbus directly to check
> the write protection status. This give a chance to device implementing
> write protection differently to report back on the actual write protection
> status.
> 
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Applied,

Thanks,
Guenter

[PATCH v4 3/7] hwmon: (pmbus/core) improve handling of write protected regulators

[Jerome Brunet]

Writing PMBus protected registers does succeed from the smbus perspective,
even if the write is ignored by the device and a communication fault is
raised. This fault will silently be caught and cleared by pmbus irq if one
has been registered.

This means that the regulator call may return succeed although the
operation was ignored.

With this change, the operation which are not supported will be properly
flagged as such and the regulator framework won't even try to execute them.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 Documentation/hwmon/pmbus-core.rst | 14 ++++++++++
 drivers/hwmon/pmbus/pmbus.h        |  4 +++
 drivers/hwmon/pmbus/pmbus_core.c   | 52 +++++++++++++++++++++++++++++++++-----
 include/linux/pmbus.h              | 14 ++++++++++
 4 files changed, 78 insertions(+), 6 deletions(-)

diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
index 686a00265bf71231c684afad6df41d6266303919..0a251960f8910ffb121d82b45e729d06f98424ef 100644
--- a/Documentation/hwmon/pmbus-core.rst
+++ b/Documentation/hwmon/pmbus-core.rst
@@ -312,6 +312,10 @@ currently provides a flags field with four bits used::
 
 	#define PMBUS_USE_COEFFICIENTS_CMD		BIT(5)
 
+	#define PMBUS_OP_PROTECTED			BIT(6)
+
+	#define PMBUS_VOUT_PROTECTED			BIT(7)
+
 	struct pmbus_platform_data {
 		u32 flags;              /* Device specific flags */
 
@@ -373,3 +377,13 @@ PMBUS_USE_COEFFICIENTS_CMD
 
 When this flag is set the PMBus core driver will use the COEFFICIENTS
 register to initialize the coefficients for the direct mode format.
+
+PMBUS_OP_PROTECTED
+
+Set if the chip OPERATION command is protected and protection is not
+determined by the standard WRITE_PROTECT command.
+
+PMBUS_VOUT_PROTECTED
+
+Set if the chip VOUT_COMMAND command is protected and protection is not
+determined by the standard WRITE_PROTECT command.
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d605412a3173b95041524285ad1fde52fb64ce5a..ddb19c9726d62416244f83603b92d81d82e64891 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -487,6 +487,8 @@ struct pmbus_driver_info {
 /* Regulator ops */
 
 extern const struct regulator_ops pmbus_regulator_ops;
+int pmbus_regulator_init_cb(struct regulator_dev *rdev,
+			    struct regulator_config *config);
 
 /* Macros for filling in array of struct regulator_desc */
 #define PMBUS_REGULATOR_STEP(_name, _id, _voltages, _step, _min_uV)  \
@@ -501,6 +503,7 @@ extern const struct regulator_ops pmbus_regulator_ops;
 		.n_voltages = _voltages,			\
 		.uV_step = _step,				\
 		.min_uV = _min_uV,				\
+		.init_cb = pmbus_regulator_init_cb,		\
 	}
 
 #define PMBUS_REGULATOR(_name, _id)   PMBUS_REGULATOR_STEP(_name, _id, 0, 0, 0)
@@ -516,6 +519,7 @@ extern const struct regulator_ops pmbus_regulator_ops;
 		.n_voltages = _voltages,			\
 		.uV_step = _step,				\
 		.min_uV = _min_uV,				\
+		.init_cb = pmbus_regulator_init_cb,		\
 	}
 
 #define PMBUS_REGULATOR_ONE(_name)   PMBUS_REGULATOR_STEP_ONE(_name, 0, 0, 0)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 085a4dc91d9bad3d2aacdd946b74a094ea9ae458..51348803ff842c442c711338bab928a54b4d0d9a 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2665,6 +2665,30 @@ static void pmbus_remove_pec(void *dev)
 	device_remove_file(dev, &dev_attr_pec);
 }
 
+static void pmbus_init_wp(struct i2c_client *client, struct pmbus_data *data)
+{
+	int ret;
+
+	ret = _pmbus_read_byte_data(client, 0xff, PMBUS_WRITE_PROTECT);
+	if (ret < 0)
+		return;
+
+	switch (ret & PB_WP_ANY) {
+	case PB_WP_ALL:
+		data->flags |= PMBUS_OP_PROTECTED;
+		fallthrough;
+	case PB_WP_OP:
+		data->flags |= PMBUS_VOUT_PROTECTED;
+		fallthrough;
+	case PB_WP_VOUT:
+		data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK;
+		break;
+
+	default:
+		break;
+	}
+}
+
 static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 			     struct pmbus_driver_info *info)
 {
@@ -2718,12 +2742,8 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 	 * faults, and we should not try it. Also, in that case, writes into
 	 * limit registers need to be disabled.
 	 */
-	if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) {
-		ret = _pmbus_read_byte_data(client, 0xff, PMBUS_WRITE_PROTECT);
-
-		if (ret > 0 && (ret & PB_WP_ANY))
-			data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK;
-	}
+	if (!(data->flags & PMBUS_NO_WRITE_PROTECT))
+		pmbus_init_wp(client, data);
 
 	ret = i2c_smbus_read_byte_data(client, PMBUS_REVISION);
 	if (ret >= 0)
@@ -3183,8 +3203,12 @@ static int pmbus_regulator_list_voltage(struct regulator_dev *rdev,
 {
 	struct device *dev = rdev_get_dev(rdev);
 	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct pmbus_data *data = i2c_get_clientdata(client);
 	int val, low, high;
 
+	if (data->flags & PMBUS_VOUT_PROTECTED)
+		return 0;
+
 	if (selector >= rdev->desc->n_voltages ||
 	    selector < rdev->desc->linear_min_sel)
 		return -EINVAL;
@@ -3219,6 +3243,22 @@ const struct regulator_ops pmbus_regulator_ops = {
 };
 EXPORT_SYMBOL_NS_GPL(pmbus_regulator_ops, PMBUS);
 
+int pmbus_regulator_init_cb(struct regulator_dev *rdev,
+			    struct regulator_config *config)
+{
+	struct pmbus_data *data = config->driver_data;
+	struct regulation_constraints *constraints = rdev->constraints;
+
+	if (data->flags & PMBUS_OP_PROTECTED)
+		constraints->valid_ops_mask &= ~REGULATOR_CHANGE_STATUS;
+
+	if (data->flags & PMBUS_VOUT_PROTECTED)
+		constraints->valid_ops_mask &= ~REGULATOR_CHANGE_VOLTAGE;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(pmbus_regulator_init_cb, PMBUS);
+
 static int pmbus_regulator_register(struct pmbus_data *data)
 {
 	struct device *dev = data->dev;
diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h
index fa9f08164c365a541ee1c6480bafd8c3a8f98138..884040e1383bf41d2eb3b6de72c40e2650178dc6 100644
--- a/include/linux/pmbus.h
+++ b/include/linux/pmbus.h
@@ -73,6 +73,20 @@
  */
 #define PMBUS_USE_COEFFICIENTS_CMD		BIT(5)
 
+/*
+ * PMBUS_OP_PROTECTED
+ * Set if the chip OPERATION command is protected and protection is not
+ * determined by the standard WRITE_PROTECT command.
+ */
+#define PMBUS_OP_PROTECTED			BIT(6)
+
+/*
+ * PMBUS_VOUT_PROTECTED
+ * Set if the chip VOUT_COMMAND command is protected and protection is not
+ * determined by the standard WRITE_PROTECT command.
+ */
+#define PMBUS_VOUT_PROTECTED			BIT(7)
+
 struct pmbus_platform_data {
 	u32 flags;		/* Device specific flags */
 

-- 
2.45.2

[PATCH v4 4/7] hwmon: (pmbus/core) add wp module param

[Jerome Brunet]

Add a module parameter to force the write protection mode of pmbus chips.

4 protections modes are provided to start with:
* 0: Remove the write protection
* 1: Disable all writes except to the WRITE_PROTECT, OPERATION,
     PAGE, ON_OFF_CONFIG and VOUT_COMMAND commands
* 2: Disable all writes except to the WRITE_PROTECT, OPERATION and
     PAGE commands
* 3: Disable all writes except to the WRITE_PROTECT command

Of course, if the parameter is not provided, the default write protection
status of the pmbus chips is left untouched.

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 Documentation/hwmon/pmbus-core.rst | 21 +++++++++++++++++++++
 drivers/hwmon/pmbus/pmbus_core.c   | 29 +++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
index 0a251960f8910ffb121d82b45e729d06f98424ef..fdfb237731486ce9977b337586333d28f7419d1d 100644
--- a/Documentation/hwmon/pmbus-core.rst
+++ b/Documentation/hwmon/pmbus-core.rst
@@ -387,3 +387,24 @@ PMBUS_VOUT_PROTECTED
 
 Set if the chip VOUT_COMMAND command is protected and protection is not
 determined by the standard WRITE_PROTECT command.
+
+Module parameter
+----------------
+
+pmbus_core.wp: PMBus write protect forced mode
+
+PMBus may come up with a variety of write protection configuration.
+'pmbus_core.wp' may be used if a particular write protection is necessary.
+The ability to actually alter the protection may also depend on the chip
+so the actual runtime write protection configuration may differ from
+the requested one. pmbus_core currently support the following value:
+
+* 0: write protection removed.
+* 1: Disable all writes except to the WRITE_PROTECT, OPERATION,
+  PAGE, ON_OFF_CONFIG and VOUT_COMMAND commands.
+* 2: Disable all writes except to the WRITE_PROTECT, OPERATION and
+  PAGE commands.
+* 3: Disable all writes except to the WRITE_PROTECT command. Note that
+  protection should include the PAGE register. This may be problematic
+  for multi-page chips, if the chips strictly follows the PMBus
+  specification, preventing the chip from changing the active page.
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 51348803ff842c442c711338bab928a54b4d0d9a..d355e3fb0d6b7bea392c7dd5551a1c904a05f21b 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -31,6 +31,9 @@
 #define PMBUS_ATTR_ALLOC_SIZE	32
 #define PMBUS_NAME_SIZE		24
 
+static int wp = -1;
+module_param(wp, int, 0444);
+
 struct pmbus_sensor {
 	struct pmbus_sensor *next;
 	char name[PMBUS_NAME_SIZE];	/* sysfs sensor name */
@@ -2669,6 +2672,32 @@ static void pmbus_init_wp(struct i2c_client *client, struct pmbus_data *data)
 {
 	int ret;
 
+	switch (wp) {
+	case 0:
+		_pmbus_write_byte_data(client, 0xff,
+				       PMBUS_WRITE_PROTECT, 0);
+		break;
+
+	case 1:
+		_pmbus_write_byte_data(client, 0xff,
+				       PMBUS_WRITE_PROTECT, PB_WP_VOUT);
+		break;
+
+	case 2:
+		_pmbus_write_byte_data(client, 0xff,
+				       PMBUS_WRITE_PROTECT, PB_WP_OP);
+		break;
+
+	case 3:
+		_pmbus_write_byte_data(client, 0xff,
+				       PMBUS_WRITE_PROTECT, PB_WP_ALL);
+		break;
+
+	default:
+		/* Ignore the other values */
+		break;
+	}
+
 	ret = _pmbus_read_byte_data(client, 0xff, PMBUS_WRITE_PROTECT);
 	if (ret < 0)
 		return;

-- 
2.45.2

[PATCH v4 5/7] hwmon: (pmbus/core) clear faults after setting smbalert mask

[Jerome Brunet]

pmbus_write_smbalert_mask() ignores the errors if the chip can't set
smbalert mask the standard way. It is not necessarily a problem for the irq
support if the chip is otherwise properly setup but it may leave an
uncleared fault behind.

pmbus_core will pick the fault on the next register_check(). The register
check will fails regardless of the actual register support by the chip.

This leads to missing attributes or debugfs entries for chips that should
provide them.

We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.

Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
avoid the problem.

Suggested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index d355e3fb0d6b7bea392c7dd5551a1c904a05f21b..55167e195e2a22154ae8fee693169d6f0829ffca 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3346,7 +3346,17 @@ static int pmbus_regulator_notify(struct pmbus_data *data, int page, int event)
 
 static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
 {
-	return _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+	int ret;
+
+	ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+
+	/*
+	 * Clear fault systematically in case writing PMBUS_SMBALERT_MASK
+	 * is not supported by the chip.
+	 */
+	pmbus_clear_fault_page(client, page);
+
+	return ret;
 }
 
 static irqreturn_t pmbus_fault_handler(int irq, void *pdata)

-- 
2.45.2

Re: [PATCH v4 5/7] hwmon: (pmbus/core) clear faults after setting smbalert mask

[Guenter Roeck]

On Tue, Nov 05, 2024 at 06:58:42PM +0100, Jerome Brunet wrote:
> pmbus_write_smbalert_mask() ignores the errors if the chip can't set
> smbalert mask the standard way. It is not necessarily a problem for the irq
> support if the chip is otherwise properly setup but it may leave an
> uncleared fault behind.
> 
> pmbus_core will pick the fault on the next register_check(). The register
> check will fails regardless of the actual register support by the chip.
> 
> This leads to missing attributes or debugfs entries for chips that should
> provide them.
> 
> We cannot rely on register_check() as PMBUS_SMBALERT_MASK may be read-only.
> 
> Unconditionally clear the page fault after setting PMBUS_SMBALERT_MASK to
> avoid the problem.
> 
> Suggested-by: Guenter Roeck <linux@roeck-us.net>
> Fixes: 221819ca4c36 ("hwmon: (pmbus/core) Add interrupt support")
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Applied.

Thanks,
Guenter

[PATCH v4 6/7] dt-bindings: hwmon: pmbus: add ti tps25990 support

[Jerome Brunet]

Add DT binding for the Texas Instruments TPS25990 eFuse

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 .../bindings/hwmon/pmbus/ti,tps25990.yaml          | 83 ++++++++++++++++++++++
 MAINTAINERS                                        |  6 ++
 2 files changed, 89 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..f4115870e4509425e88c913f350789ffc8d396c2
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml
@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/pmbus/ti,tps25990.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments TPS25990 Stackable eFuse
+
+maintainers:
+  - Jerome Brunet <jbrunet@baylibre.com>
+
+description:
+  The TI TPS25990 is an integrated, high-current circuit
+  protection and power management device with PMBUS interface
+
+properties:
+  compatible:
+    const: ti,tps25990
+
+  reg:
+    maxItems: 1
+
+  ti,rimon-micro-ohms:
+    description:
+      micro Ohms value of the resistance installed between the Imon pin
+      and the ground reference.
+
+  interrupts:
+    description: PMBUS SMB Alert Interrupt.
+    maxItems: 1
+
+  regulators:
+    type: object
+    description:
+      list of regulators provided by this controller.
+
+    properties:
+      vout:
+        $ref: /schemas/regulator/regulator.yaml#
+        type: object
+        unevaluatedProperties: false
+
+      gpdac1:
+        $ref: /schemas/regulator/regulator.yaml#
+        type: object
+        unevaluatedProperties: false
+
+      gpdac2:
+        $ref: /schemas/regulator/regulator.yaml#
+        type: object
+        unevaluatedProperties: false
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - ti,rimon-micro-ohms
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        hw-monitor@46 {
+            compatible = "ti,tps25990";
+            reg = <0x46>;
+
+            interrupt-parent = <&gpio>;
+            interrupts = <42 IRQ_TYPE_LEVEL_LOW>;
+            ti,rimon-micro-ohms = <1370000000>;
+
+            regulators {
+                cpu0_vout: vout {
+                    regulator-name = "main_cpu0";
+                };
+            };
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 1b56b163f1219b73085cb5a45b130e2c96a2cb2b..4f21d7d2ce992f14d8c533f0c8742edb22a0db3f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22811,6 +22811,12 @@ F:	include/linux/dma/k3-udma-glue.h
 F:	include/linux/dma/ti-cppi5.h
 X:	drivers/dma/ti/cppi41.c
 
+TEXAS INSTRUMENTS TPS25990 HARDWARE MONITOR DRIVER
+M:	Jerome Brunet <jbrunet@baylibre.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml
+
 TEXAS INSTRUMENTS TPS23861 PoE PSE DRIVER
 M:	Robert Marko <robert.marko@sartura.hr>
 M:	Luka Perkov <luka.perkov@sartura.hr>

-- 
2.45.2

Re: [PATCH v4 6/7] dt-bindings: hwmon: pmbus: add ti tps25990 support

[Guenter Roeck]

On Tue, Nov 05, 2024 at 06:58:43PM +0100, Jerome Brunet wrote:
> Add DT binding for the Texas Instruments TPS25990 eFuse
> 
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Applied.

Thanks,
Guenter

[PATCH v4 7/7] hwmon: (pmbus/tps25990): add initial support

[Jerome Brunet]

Add initial support for the Texas Instruments TPS25990 eFuse.
This adds the basic PMBUS telemetry support for the device.

Tested-by: Vaishnav Achath <vaishnav.a@ti.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 Documentation/hwmon/index.rst    |   1 +
 Documentation/hwmon/tps25990.rst | 148 ++++++++++++++
 MAINTAINERS                      |   2 +
 drivers/hwmon/pmbus/Kconfig      |  17 ++
 drivers/hwmon/pmbus/Makefile     |   1 +
 drivers/hwmon/pmbus/tps25990.c   | 428 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 597 insertions(+)

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 55f1111594b2e9ada4a881e5d4d8884f33256d1f..1a3cb0a59f7210b8a5e972a8015658b983834cd2 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -236,6 +236,7 @@ Hardware Monitoring Kernel Drivers
    tmp464
    tmp513
    tps23861
+   tps25990
    tps40422
    tps53679
    tps546d24
diff --git a/Documentation/hwmon/tps25990.rst b/Documentation/hwmon/tps25990.rst
new file mode 100644
index 0000000000000000000000000000000000000000..ed9e74d43e2c2f070d3abe987d93bcdfcf2162ec
--- /dev/null
+++ b/Documentation/hwmon/tps25990.rst
@@ -0,0 +1,148 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver tps25990
+======================
+
+Supported chips:
+
+  * TI TPS25990
+
+    Prefix: 'tps25990'
+
+  * Datasheet
+
+    Publicly available at Texas Instruments website: https://www.ti.com/lit/gpn/tps25990
+
+Author:
+
+	Jerome Brunet <jbrunet@baylibre.com>
+
+Description
+-----------
+
+This driver implements support for TI TPS25990 eFuse.
+This is an integrated, high-current circuit protection and power
+management device with PMBUS interface
+
+Device compliant with:
+
+- PMBus rev 1.3 interface.
+
+Device supports direct format for reading input voltages,
+output voltage, input current, input power and temperature.
+
+Due to the specificities of the chip, all history reset attributes
+are tied together. Resetting the history of a sensor, resets the
+history of all the sensors.
+
+The driver exports the following attributes via the 'sysfs' files
+for input current:
+
+**curr1_average**
+
+**curr1_crit**
+
+**curr1_crit_alarm**
+
+**curr1_highest**
+
+**curr1_input**
+
+**curr1_label**
+
+**curr1_max**
+
+**curr1_max_alarm**
+
+**curr1_reset_history**
+
+The driver provides the following attributes for main input voltage:
+
+**in1_average**
+
+**in1_crit**
+
+**in1_crit_alarm**
+
+**in1_highest**
+
+**in1_input**
+
+**in1_label**
+
+**in1_lcrit**
+
+**in1_lcrit_alarm**
+
+**in1_lowest**
+
+**in1_max**
+
+**in1_max_alarm**
+
+**in1_min**
+
+**in1_min_alarm**
+
+**in1_reset_history**
+
+The driver provides the following attributes for auxiliary input voltage:
+
+**in2_input**
+
+**in2_label**
+
+The driver provides the following attributes for output voltage:
+
+**in3_average**
+
+**in3_input**
+
+**in3_label**
+
+**in3_lowest**
+
+**in3_min**
+
+**in3_min_alarm**
+
+**in3_reset_history**
+
+The driver provides the following attributes for input power:
+
+**power1_alarm**
+
+**power1_average**
+
+**power1_input**
+
+**power1_input_highest**
+
+**power1_label**
+
+**power1_max**
+
+**power1_reset_history**
+
+The driver provides the following attributes for temperature:
+
+**temp1_average**
+
+**temp1_crit**
+
+**temp1_crit_alarm**
+
+**temp1_highest**
+
+**temp1_input**
+
+**temp1_max**
+
+**temp1_max_alarm**
+
+**temp1_reset_history**
+
+The driver provides the following attributes for sampling:
+
+**samples**
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 4f21d7d2ce992f14d8c533f0c8742edb22a0db3f..10a65cd5c84e56cf876ee5eb06336b5bc8ff991c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22816,6 +22816,8 @@ M:	Jerome Brunet <jbrunet@baylibre.com>
 L:	linux-hwmon@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml
+F:	Documentation/hwmon/tps25990.rst
+F:	drivers/hwmon/pmbus/tps25990.c
 
 TEXAS INSTRUMENTS TPS23861 PoE PSE DRIVER
 M:	Robert Marko <robert.marko@sartura.hr>
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index f6d3528419536a68011d67a4a239c0cba1bbf475..22418a05ced0c4d7025a243134f231c54c741371 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -510,6 +510,23 @@ config SENSORS_TDA38640_REGULATOR
 	  If you say yes here you get regulator support for Infineon
 	  TDA38640 as regulator.
 
+config SENSORS_TPS25990
+	tristate "TI TPS25990"
+	help
+	  If you say yes here you get hardware monitoring support for TI
+	  TPS25990.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called tps25990.
+
+config SENSORS_TPS25990_REGULATOR
+	bool "Regulator support for TPS25990 and compatibles"
+	depends on SENSORS_TPS25990 && REGULATOR
+	default SENSORS_TPS25990
+	help
+	  If you say yes here you get regulator support for Texas Instruments
+	  TPS25990.
+
 config SENSORS_TPS40422
 	tristate "TI TPS40422"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index d00bcc758b97200b80158e33b0ac41e6e5ac3231..3d3183f8d2a7060eb513f54f4f0a78ba37c09393 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
 obj-$(CONFIG_SENSORS_Q54SJ108A2)	+= q54sj108a2.o
 obj-$(CONFIG_SENSORS_STPDDC60)	+= stpddc60.o
 obj-$(CONFIG_SENSORS_TDA38640)	+= tda38640.o
+obj-$(CONFIG_SENSORS_TPS25990)	+= tps25990.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
 obj-$(CONFIG_SENSORS_TPS546D24)	+= tps546d24.o
diff --git a/drivers/hwmon/pmbus/tps25990.c b/drivers/hwmon/pmbus/tps25990.c
new file mode 100644
index 0000000000000000000000000000000000000000..db59638f6c626f2467b859f023523276cfb6c3a5
--- /dev/null
+++ b/drivers/hwmon/pmbus/tps25990.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2024 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/bitfield.h>
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "pmbus.h"
+
+#define TPS25990_READ_VAUX		0xd0
+#define TPS25990_READ_VIN_MIN		0xd1
+#define TPS25990_READ_VIN_PEAK		0xd2
+#define TPS25990_READ_IIN_PEAK		0xd4
+#define TPS25990_READ_PIN_PEAK		0xd5
+#define TPS25990_READ_TEMP_AVG		0xd6
+#define TPS25990_READ_TEMP_PEAK		0xd7
+#define TPS25990_READ_VOUT_MIN		0xda
+#define TPS25990_READ_VIN_AVG		0xdc
+#define TPS25990_READ_VOUT_AVG		0xdd
+#define TPS25990_READ_IIN_AVG		0xde
+#define TPS25990_READ_PIN_AVG		0xdf
+#define TPS25990_VIREF			0xe0
+#define TPS25990_PK_MIN_AVG		0xea
+#define  PK_MIN_AVG_RST_PEAK		BIT(7)
+#define  PK_MIN_AVG_RST_AVG		BIT(6)
+#define  PK_MIN_AVG_RST_MIN		BIT(5)
+#define  PK_MIN_AVG_AVG_CNT		GENMASK(2, 0)
+#define TPS25990_MFR_WRITE_PROTECT	0xf8
+#define  TPS25990_UNLOCKED		BIT(7)
+
+#define TPS25990_8B_SHIFT		2
+#define TPS25990_VIN_OVF_NUM		525100
+#define TPS25990_VIN_OVF_DIV		10163
+#define TPS25990_VIN_OVF_OFF		155
+#define TPS25990_IIN_OCF_NUM		953800
+#define TPS25990_IIN_OCF_DIV		129278
+#define TPS25990_IIN_OCF_OFF		157
+
+#define PK_MIN_AVG_RST_MASK		(PK_MIN_AVG_RST_PEAK | \
+					 PK_MIN_AVG_RST_AVG  | \
+					 PK_MIN_AVG_RST_MIN)
+
+/*
+ * Arbitrary default Rimon value: 1kOhm
+ * This correspond to an overcurrent limit of 55A, close to the specified limit
+ * of un-stacked TPS25990 and makes further calculation easier to setup in
+ * sensor.conf, if necessary
+ */
+#define TPS25990_DEFAULT_RIMON		1000000000
+
+static void tps25990_set_m(int *m, u32 rimon)
+{
+	u64 val = ((u64)*m) * rimon;
+
+	/* Make sure m fits the s32 type */
+	*m = DIV_ROUND_CLOSEST_ULL(val, 1000000);
+}
+
+static int tps25990_mfr_write_protect_set(struct i2c_client *client,
+					  u8 protect)
+{
+	/*
+	 * The chip has a single protection mode, set it regardless of
+	 * the specific protection requested
+	 */
+	return pmbus_write_byte_data(client, -1, TPS25990_MFR_WRITE_PROTECT,
+				     protect ? 0x0 : 0xa2);
+}
+
+static int tps25990_mfr_write_protect_get(struct i2c_client *client)
+{
+	int ret = pmbus_read_byte_data(client, -1, TPS25990_MFR_WRITE_PROTECT);
+
+	if (ret < 0)
+		return ret;
+
+	return (ret & TPS25990_UNLOCKED) ? 0 : PB_WP_ALL;
+}
+
+static int tps25990_read_word_data(struct i2c_client *client,
+				   int page, int phase, int reg)
+{
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIRT_READ_VIN_MAX:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VIN_PEAK);
+		break;
+
+	case PMBUS_VIRT_READ_VIN_MIN:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VIN_MIN);
+		break;
+
+	case PMBUS_VIRT_READ_VIN_AVG:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VIN_AVG);
+		break;
+
+	case PMBUS_VIRT_READ_VOUT_MIN:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VOUT_MIN);
+		break;
+
+	case PMBUS_VIRT_READ_VOUT_AVG:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VOUT_AVG);
+		break;
+
+	case PMBUS_VIRT_READ_IIN_AVG:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_IIN_AVG);
+		break;
+
+	case PMBUS_VIRT_READ_IIN_MAX:
+		return TPS25990_READ_IIN_PEAK;
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_IIN_PEAK);
+		break;
+
+	case PMBUS_VIRT_READ_TEMP_AVG:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_TEMP_AVG);
+		break;
+
+	case PMBUS_VIRT_READ_TEMP_MAX:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_TEMP_PEAK);
+		break;
+
+	case PMBUS_VIRT_READ_PIN_AVG:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_PIN_AVG);
+		break;
+
+	case PMBUS_VIRT_READ_PIN_MAX:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_PIN_PEAK);
+		break;
+
+	case PMBUS_VIRT_READ_VMON:
+		ret = pmbus_read_word_data(client, page, phase,
+					   TPS25990_READ_VAUX);
+		break;
+
+	case PMBUS_VIN_UV_WARN_LIMIT:
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_VIN_OV_WARN_LIMIT:
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+	case PMBUS_IIN_OC_WARN_LIMIT:
+	case PMBUS_OT_WARN_LIMIT:
+	case PMBUS_OT_FAULT_LIMIT:
+	case PMBUS_PIN_OP_WARN_LIMIT:
+		/*
+		 * These registers provide an 8 bits value instead of a
+		 * 10bits one. Just shifting twice the register value is
+		 * enough to make the sensor type conversion work, even
+		 * if the datasheet provides different m, b and R for
+		 * those.
+		 */
+		ret = pmbus_read_word_data(client, page, phase, reg);
+		if (ret < 0)
+			break;
+		ret <<= TPS25990_8B_SHIFT;
+		break;
+
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+		ret = pmbus_read_word_data(client, page, phase, reg);
+		if (ret < 0)
+			break;
+		ret = DIV_ROUND_CLOSEST(ret * TPS25990_VIN_OVF_NUM,
+					TPS25990_VIN_OVF_DIV);
+		ret += TPS25990_VIN_OVF_OFF;
+		break;
+
+	case PMBUS_IIN_OC_FAULT_LIMIT:
+		/*
+		 * VIREF directly sets the over-current limit at which the eFuse
+		 * will turn the FET off and trigger a fault. Expose it through
+		 * this generic property instead of a manufacturer specific one.
+		 */
+		ret = pmbus_read_byte_data(client, page, TPS25990_VIREF);
+		if (ret < 0)
+			break;
+		ret = DIV_ROUND_CLOSEST(ret * TPS25990_IIN_OCF_NUM,
+					TPS25990_IIN_OCF_DIV);
+		ret += TPS25990_IIN_OCF_OFF;
+		break;
+
+	case PMBUS_VIRT_SAMPLES:
+		ret = pmbus_read_byte_data(client, page, TPS25990_PK_MIN_AVG);
+		if (ret < 0)
+			break;
+		ret = 1 << FIELD_GET(PK_MIN_AVG_AVG_CNT, ret);
+		break;
+
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+	case PMBUS_VIRT_RESET_VIN_HISTORY:
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+	case PMBUS_VIRT_RESET_PIN_HISTORY:
+	case PMBUS_VIRT_RESET_VOUT_HISTORY:
+		ret = 0;
+		break;
+
+	default:
+		ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+static int tps25990_write_word_data(struct i2c_client *client,
+				    int page, int reg, u16 value)
+{
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VIN_UV_WARN_LIMIT:
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_VIN_OV_WARN_LIMIT:
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+	case PMBUS_IIN_OC_WARN_LIMIT:
+	case PMBUS_OT_WARN_LIMIT:
+	case PMBUS_OT_FAULT_LIMIT:
+	case PMBUS_PIN_OP_WARN_LIMIT:
+		value >>= TPS25990_8B_SHIFT;
+		value = clamp_val(value, 0, 0xff);
+		ret = pmbus_write_word_data(client, page, reg, value);
+		break;
+
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+		value -= TPS25990_VIN_OVF_OFF;
+		value = DIV_ROUND_CLOSEST(((unsigned int)value) * TPS25990_VIN_OVF_DIV,
+					  TPS25990_VIN_OVF_NUM);
+		value = clamp_val(value, 0, 0xf);
+		ret = pmbus_write_word_data(client, page, reg, value);
+		break;
+
+	case PMBUS_IIN_OC_FAULT_LIMIT:
+		value -= TPS25990_IIN_OCF_OFF;
+		value = DIV_ROUND_CLOSEST(((unsigned int)value) * TPS25990_IIN_OCF_DIV,
+					  TPS25990_IIN_OCF_NUM);
+		value = clamp_val(value, 0, 0x3f);
+		ret = pmbus_write_byte_data(client, page, TPS25990_VIREF, value);
+		break;
+
+	case PMBUS_VIRT_SAMPLES:
+		value = clamp_val(value, 1, 1 << PK_MIN_AVG_AVG_CNT);
+		value = ilog2(value);
+		ret = pmbus_update_byte_data(client, page, TPS25990_PK_MIN_AVG,
+					     PK_MIN_AVG_AVG_CNT,
+					     FIELD_PREP(PK_MIN_AVG_AVG_CNT, value));
+		break;
+
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+	case PMBUS_VIRT_RESET_VIN_HISTORY:
+	case PMBUS_VIRT_RESET_IIN_HISTORY:
+	case PMBUS_VIRT_RESET_PIN_HISTORY:
+	case PMBUS_VIRT_RESET_VOUT_HISTORY:
+		/*
+		 * TPS25990 has history resets based on MIN/AVG/PEAK instead of per
+		 * sensor type. Exposing this quirk in hwmon is not desirable so
+		 * reset MIN, AVG and PEAK together. Even is there effectively only
+		 * one reset, which resets everything, expose the 5 entries so
+		 * userspace is not required map a sensor type to another to trigger
+		 * a reset
+		 */
+		ret = pmbus_update_byte_data(client, 0, TPS25990_PK_MIN_AVG,
+					     PK_MIN_AVG_RST_MASK,
+					     PK_MIN_AVG_RST_MASK);
+		break;
+
+	default:
+		ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+static int tps25990_read_byte_data(struct i2c_client *client,
+				   int page, int reg)
+{
+	int ret;
+
+	switch (reg) {
+	case PMBUS_WRITE_PROTECT:
+		ret = tps25990_mfr_write_protect_get(client);
+		break;
+
+	default:
+		ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+static int tps25990_write_byte_data(struct i2c_client *client,
+				    int page, int reg, u8 byte)
+{
+	int ret;
+
+	switch (reg) {
+	case PMBUS_WRITE_PROTECT:
+		ret = tps25990_mfr_write_protect_set(client, byte);
+		break;
+
+	default:
+		ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+#if IS_ENABLED(CONFIG_SENSORS_TPS25990_REGULATOR)
+static const struct regulator_desc tps25990_reg_desc[] = {
+	PMBUS_REGULATOR_ONE("vout"),
+};
+#endif
+
+static const struct pmbus_driver_info tps25990_base_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = direct,
+	.m[PSC_VOLTAGE_IN] = 5251,
+	.b[PSC_VOLTAGE_IN] = 0,
+	.R[PSC_VOLTAGE_IN] = -2,
+	.format[PSC_VOLTAGE_OUT] = direct,
+	.m[PSC_VOLTAGE_OUT] = 5251,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = -2,
+	.format[PSC_TEMPERATURE] = direct,
+	.m[PSC_TEMPERATURE] = 140,
+	.b[PSC_TEMPERATURE] = 32100,
+	.R[PSC_TEMPERATURE] = -2,
+	/*
+	 * Current and Power measurement depends on the ohm value
+	 * of Rimon. m is multiplied by 1000 below to have an integer
+	 * and -3 is added to R to compensate.
+	 */
+	.format[PSC_CURRENT_IN] = direct,
+	.m[PSC_CURRENT_IN] = 9538,
+	.b[PSC_CURRENT_IN] = 0,
+	.R[PSC_CURRENT_IN] = -6,
+	.format[PSC_POWER] = direct,
+	.m[PSC_POWER] = 4901,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = -7,
+	.func[0] = (PMBUS_HAVE_VIN |
+		    PMBUS_HAVE_VOUT |
+		    PMBUS_HAVE_VMON |
+		    PMBUS_HAVE_IIN |
+		    PMBUS_HAVE_PIN |
+		    PMBUS_HAVE_TEMP |
+		    PMBUS_HAVE_STATUS_VOUT |
+		    PMBUS_HAVE_STATUS_IOUT |
+		    PMBUS_HAVE_STATUS_INPUT |
+		    PMBUS_HAVE_STATUS_TEMP |
+		    PMBUS_HAVE_SAMPLES),
+	.read_word_data = tps25990_read_word_data,
+	.write_word_data = tps25990_write_word_data,
+	.read_byte_data = tps25990_read_byte_data,
+	.write_byte_data = tps25990_write_byte_data,
+
+#if IS_ENABLED(CONFIG_SENSORS_TPS25990_REGULATOR)
+	.reg_desc = tps25990_reg_desc,
+	.num_regulators = ARRAY_SIZE(tps25990_reg_desc),
+#endif
+};
+
+static const struct i2c_device_id tps25990_i2c_id[] = {
+	{ "tps25990" },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, tps25990_i2c_id);
+
+static const struct of_device_id tps25990_of_match[] = {
+	{ .compatible = "ti,tps25990" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, tps25990_of_match);
+
+static int tps25990_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct pmbus_driver_info *info;
+	u32 rimon = TPS25990_DEFAULT_RIMON;
+	int ret;
+
+	ret = device_property_read_u32(dev, "ti,rimon-micro-ohms", &rimon);
+	if (ret < 0 && ret != -EINVAL)
+		return dev_err_probe(dev, ret, "failed to get rimon\n");
+
+	info = devm_kmemdup(dev, &tps25990_base_info, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	/* Adapt the current and power scale for each instance */
+	tps25990_set_m(&info->m[PSC_CURRENT_IN], rimon);
+	tps25990_set_m(&info->m[PSC_POWER], rimon);
+
+	return pmbus_do_probe(client, info);
+}
+
+static struct i2c_driver tps25990_driver = {
+	.driver = {
+		.name = "tps25990",
+		.of_match_table = tps25990_of_match,
+	},
+	.probe = tps25990_probe,
+	.id_table = tps25990_i2c_id,
+};
+module_i2c_driver(tps25990_driver);
+
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_DESCRIPTION("PMBUS driver for TPS25990 eFuse");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);

-- 
2.45.2

Re: [PATCH v4 7/7] hwmon: (pmbus/tps25990): add initial support

[Guenter Roeck]

On Tue, Nov 05, 2024 at 06:58:44PM +0100, Jerome Brunet wrote:
> Add initial support for the Texas Instruments TPS25990 eFuse.
> This adds the basic PMBUS telemetry support for the device.
> 
> Tested-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  Documentation/hwmon/index.rst    |   1 +
>  Documentation/hwmon/tps25990.rst | 148 ++++++++++++++
>  MAINTAINERS                      |   2 +
>  drivers/hwmon/pmbus/Kconfig      |  17 ++
>  drivers/hwmon/pmbus/Makefile     |   1 +
>  drivers/hwmon/pmbus/tps25990.c   | 428 +++++++++++++++++++++++++++++++++++++++
>  6 files changed, 597 insertions(+)
> 
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index 55f1111594b2e9ada4a881e5d4d8884f33256d1f..1a3cb0a59f7210b8a5e972a8015658b983834cd2 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -236,6 +236,7 @@ Hardware Monitoring Kernel Drivers
>     tmp464
>     tmp513
>     tps23861
> +   tps25990
>     tps40422
>     tps53679
>     tps546d24
> diff --git a/Documentation/hwmon/tps25990.rst b/Documentation/hwmon/tps25990.rst
> new file mode 100644
> index 0000000000000000000000000000000000000000..ed9e74d43e2c2f070d3abe987d93bcdfcf2162ec
> --- /dev/null
> +++ b/Documentation/hwmon/tps25990.rst
> @@ -0,0 +1,148 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver tps25990
> +======================
> +
> +Supported chips:
> +
> +  * TI TPS25990
> +
> +    Prefix: 'tps25990'
> +
> +  * Datasheet
> +
> +    Publicly available at Texas Instruments website: https://www.ti.com/lit/gpn/tps25990
> +
> +Author:
> +
> +	Jerome Brunet <jbrunet@baylibre.com>
> +
> +Description
> +-----------
> +
> +This driver implements support for TI TPS25990 eFuse.
> +This is an integrated, high-current circuit protection and power
> +management device with PMBUS interface
> +
> +Device compliant with:
> +
> +- PMBus rev 1.3 interface.
> +
> +Device supports direct format for reading input voltages,
> +output voltage, input current, input power and temperature.
> +
> +Due to the specificities of the chip, all history reset attributes
> +are tied together. Resetting the history of a sensor, resets the
> +history of all the sensors.
> +
> +The driver exports the following attributes via the 'sysfs' files
> +for input current:
> +
> +**curr1_average**
> +
> +**curr1_crit**
> +
> +**curr1_crit_alarm**
> +
> +**curr1_highest**
> +
> +**curr1_input**
> +
> +**curr1_label**
> +
> +**curr1_max**
> +
> +**curr1_max_alarm**
> +
> +**curr1_reset_history**
> +
> +The driver provides the following attributes for main input voltage:
> +
> +**in1_average**
> +
> +**in1_crit**
> +
> +**in1_crit_alarm**
> +
> +**in1_highest**
> +
> +**in1_input**
> +
> +**in1_label**
> +
> +**in1_lcrit**
> +
> +**in1_lcrit_alarm**
> +
> +**in1_lowest**
> +
> +**in1_max**
> +
> +**in1_max_alarm**
> +
> +**in1_min**
> +
> +**in1_min_alarm**
> +
> +**in1_reset_history**
> +
> +The driver provides the following attributes for auxiliary input voltage:
> +
> +**in2_input**
> +
> +**in2_label**
> +
> +The driver provides the following attributes for output voltage:
> +
> +**in3_average**
> +
> +**in3_input**
> +
> +**in3_label**
> +
> +**in3_lowest**
> +
> +**in3_min**
> +
> +**in3_min_alarm**
> +
> +**in3_reset_history**
> +
> +The driver provides the following attributes for input power:
> +
> +**power1_alarm**
> +
> +**power1_average**
> +
> +**power1_input**
> +
> +**power1_input_highest**
> +
> +**power1_label**
> +
> +**power1_max**
> +
> +**power1_reset_history**
> +
> +The driver provides the following attributes for temperature:
> +
> +**temp1_average**
> +
> +**temp1_crit**
> +
> +**temp1_crit_alarm**
> +
> +**temp1_highest**
> +
> +**temp1_input**
> +
> +**temp1_max**
> +
> +**temp1_max_alarm**
> +
> +**temp1_reset_history**
> +
> +The driver provides the following attributes for sampling:
> +
> +**samples**
> +
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4f21d7d2ce992f14d8c533f0c8742edb22a0db3f..10a65cd5c84e56cf876ee5eb06336b5bc8ff991c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22816,6 +22816,8 @@ M:	Jerome Brunet <jbrunet@baylibre.com>
>  L:	linux-hwmon@vger.kernel.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/hwmon/pmbus/ti,tps25990.yaml
> +F:	Documentation/hwmon/tps25990.rst
> +F:	drivers/hwmon/pmbus/tps25990.c
>  
>  TEXAS INSTRUMENTS TPS23861 PoE PSE DRIVER
>  M:	Robert Marko <robert.marko@sartura.hr>
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index f6d3528419536a68011d67a4a239c0cba1bbf475..22418a05ced0c4d7025a243134f231c54c741371 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -510,6 +510,23 @@ config SENSORS_TDA38640_REGULATOR
>  	  If you say yes here you get regulator support for Infineon
>  	  TDA38640 as regulator.
>  
> +config SENSORS_TPS25990
> +	tristate "TI TPS25990"
> +	help
> +	  If you say yes here you get hardware monitoring support for TI
> +	  TPS25990.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called tps25990.
> +
> +config SENSORS_TPS25990_REGULATOR
> +	bool "Regulator support for TPS25990 and compatibles"
> +	depends on SENSORS_TPS25990 && REGULATOR
> +	default SENSORS_TPS25990
> +	help
> +	  If you say yes here you get regulator support for Texas Instruments
> +	  TPS25990.
> +
>  config SENSORS_TPS40422
>  	tristate "TI TPS40422"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index d00bcc758b97200b80158e33b0ac41e6e5ac3231..3d3183f8d2a7060eb513f54f4f0a78ba37c09393 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -51,6 +51,7 @@ obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
>  obj-$(CONFIG_SENSORS_Q54SJ108A2)	+= q54sj108a2.o
>  obj-$(CONFIG_SENSORS_STPDDC60)	+= stpddc60.o
>  obj-$(CONFIG_SENSORS_TDA38640)	+= tda38640.o
> +obj-$(CONFIG_SENSORS_TPS25990)	+= tps25990.o
>  obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
>  obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
>  obj-$(CONFIG_SENSORS_TPS546D24)	+= tps546d24.o
> diff --git a/drivers/hwmon/pmbus/tps25990.c b/drivers/hwmon/pmbus/tps25990.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..db59638f6c626f2467b859f023523276cfb6c3a5
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/tps25990.c
> @@ -0,0 +1,428 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (c) 2024 BayLibre, SAS.
> +// Author: Jerome Brunet <jbrunet@baylibre.com>
> +
> +#include <linux/bitfield.h>
> +#include <linux/debugfs.h>
> +#include <linux/err.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include "pmbus.h"
> +
> +#define TPS25990_READ_VAUX		0xd0
> +#define TPS25990_READ_VIN_MIN		0xd1
> +#define TPS25990_READ_VIN_PEAK		0xd2
> +#define TPS25990_READ_IIN_PEAK		0xd4
> +#define TPS25990_READ_PIN_PEAK		0xd5
> +#define TPS25990_READ_TEMP_AVG		0xd6
> +#define TPS25990_READ_TEMP_PEAK		0xd7
> +#define TPS25990_READ_VOUT_MIN		0xda
> +#define TPS25990_READ_VIN_AVG		0xdc
> +#define TPS25990_READ_VOUT_AVG		0xdd
> +#define TPS25990_READ_IIN_AVG		0xde
> +#define TPS25990_READ_PIN_AVG		0xdf
> +#define TPS25990_VIREF			0xe0
> +#define TPS25990_PK_MIN_AVG		0xea
> +#define  PK_MIN_AVG_RST_PEAK		BIT(7)
> +#define  PK_MIN_AVG_RST_AVG		BIT(6)
> +#define  PK_MIN_AVG_RST_MIN		BIT(5)
> +#define  PK_MIN_AVG_AVG_CNT		GENMASK(2, 0)
> +#define TPS25990_MFR_WRITE_PROTECT	0xf8
> +#define  TPS25990_UNLOCKED		BIT(7)
> +
> +#define TPS25990_8B_SHIFT		2
> +#define TPS25990_VIN_OVF_NUM		525100
> +#define TPS25990_VIN_OVF_DIV		10163
> +#define TPS25990_VIN_OVF_OFF		155
> +#define TPS25990_IIN_OCF_NUM		953800
> +#define TPS25990_IIN_OCF_DIV		129278
> +#define TPS25990_IIN_OCF_OFF		157
> +
> +#define PK_MIN_AVG_RST_MASK		(PK_MIN_AVG_RST_PEAK | \
> +					 PK_MIN_AVG_RST_AVG  | \
> +					 PK_MIN_AVG_RST_MIN)
> +
> +/*
> + * Arbitrary default Rimon value: 1kOhm
> + * This correspond to an overcurrent limit of 55A, close to the specified limit
> + * of un-stacked TPS25990 and makes further calculation easier to setup in
> + * sensor.conf, if necessary
> + */
> +#define TPS25990_DEFAULT_RIMON		1000000000
> +
> +static void tps25990_set_m(int *m, u32 rimon)
> +{
> +	u64 val = ((u64)*m) * rimon;
> +
> +	/* Make sure m fits the s32 type */
> +	*m = DIV_ROUND_CLOSEST_ULL(val, 1000000);
> +}
> +
> +static int tps25990_mfr_write_protect_set(struct i2c_client *client,
> +					  u8 protect)
> +{
> +	/*
> +	 * The chip has a single protection mode, set it regardless of
> +	 * the specific protection requested
> +	 */
> +	return pmbus_write_byte_data(client, -1, TPS25990_MFR_WRITE_PROTECT,
> +				     protect ? 0x0 : 0xa2);

After some thought, I think it would be better to reject all protect values
other than 0 (no write protection) and PB_WP_ALL because that is what the chip
supports. Something like

	if (protect & ~PB_WP_ALL)
		return -ENXIO;		// or -EINVAL ? Not really sure.

Thanks,
Guenter

Re: [PATCH v4 7/7] hwmon: (pmbus/tps25990): add initial support

[Jerome Brunet]

On Wed 06 Nov 2024 at 10:59, Guenter Roeck <linux@roeck-us.net> wrote:

>> +
>> +static int tps25990_mfr_write_protect_set(struct i2c_client *client,
>> +					  u8 protect)
>> +{
>> +	/*
>> +	 * The chip has a single protection mode, set it regardless of
>> +	 * the specific protection requested
>> +	 */
>> +	return pmbus_write_byte_data(client, -1, TPS25990_MFR_WRITE_PROTECT,
>> +				     protect ? 0x0 : 0xa2);
>
> After some thought, I think it would be better to reject all protect values
> other than 0 (no write protection) and PB_WP_ALL because that is what the chip
> supports. Something like

Since operation would not be allowed, it's maps the closest indeed.

>
> 	if (protect & ~PB_WP_ALL)
> 		return -ENXIO;		// or -EINVAL ? Not really sure.

The command is supported but the argument would not be, so -EINVAL seems
appropriate to me.

>
> Thanks,
> Guenter

-- 
Jerome

Re: [PATCH v4 0/7] hwmon: pmbus: add tps25990 efuse support

[Guenter Roeck]

On 11/5/24 09:58, Jerome Brunet wrote:
> This patchset adds initial support for the Texas Instruments TPS25990
> eFuse. The TPS25990 is an integrated, high-current circuit protection and
> power management device. TPS25895 may be stacked on the TPS25990 for
> higher currents.
> 
> This patchset provides basic telemetry support for the device.
> On boot, the device is write protected. Limits can be changed in sysfs
> if the write protection is removed using the introduced pmbus parameter.
> 
> Limits will be restored to the default value device on startup, unless
> saved to NVM. Writing the NVM is not supported by the driver at the moment.
> 
> As part of this series, PMBus regulator support is improved to better
> support write-protected devices.
> 
> Patch 3 depends on the regulator patchset available here [1].
> This is a compilation dependency.
> 

Unfortunately this means that I can not apply this and the following patch
until after the next commit window, which is unfortunate since patch 4
does not logically depend on patch 3. That also means that I can not apply
the last patch of the series since it depends on the ability to disable
write protect. Those patches will have to wait until after the next commit
window.

Guenter

Re: [PATCH v4 0/7] hwmon: pmbus: add tps25990 efuse support

[Jerome Brunet]

On Wed 06 Nov 2024 at 08:12, Guenter Roeck <linux@roeck-us.net> wrote:

> On 11/5/24 09:58, Jerome Brunet wrote:
>> This patchset adds initial support for the Texas Instruments TPS25990
>> eFuse. The TPS25990 is an integrated, high-current circuit protection and
>> power management device. TPS25895 may be stacked on the TPS25990 for
>> higher currents.
>> This patchset provides basic telemetry support for the device.
>> On boot, the device is write protected. Limits can be changed in sysfs
>> if the write protection is removed using the introduced pmbus parameter.
>> Limits will be restored to the default value device on startup, unless
>> saved to NVM. Writing the NVM is not supported by the driver at the moment.
>> As part of this series, PMBus regulator support is improved to better
>> support write-protected devices.
>> Patch 3 depends on the regulator patchset available here [1].
>> This is a compilation dependency.
>> 
>
> Unfortunately this means that I can not apply this and the following patch
> until after the next commit window, which is unfortunate since patch 4
> does not logically depend on patch 3. That also means that I can not apply
> the last patch of the series since it depends on the ability to disable
> write protect. Those patches will have to wait until after the next commit
> window.

These 2 patches where always gonna be touching the same part of the
code. Indeed 4 could have come before, I did not really think about it
TBH.

No problem waiting for -rc1. I'll rebase the remaining changes when it's
out and add the necessary change on patch 7.

Thanks for your support

>
> Guenter

-- 
Jerome