hwmon: (pmbus) add documentation for existing flags

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>
Message-ID: <20241105-tps25990-v4-1-0e312ac70b62@baylibre.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
index 1eaf2b015837..686a00265bf7 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.