[2/3] hwmon: (pmbus) Add documentation for new flags
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Message ID 20210505183248.57082-3-erik.rosen@metormote.com
State New, archived
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Series
  • hwmon: (pmbus) Add support for additional Flex BMR converters to the pmbus driver
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Commit Message

Erik Rosen May 5, 2021, 6:32 p.m. UTC
Add documentation for the new pmbus flags PMBUS_WRITE_PROTECTED and
PMBUS_READ_STATUS_AFTER_FAILED_CHECK

Signed-off-by: Erik Rosen <erik.rosen@metormote.com>
---
 Documentation/hwmon/pmbus-core.rst | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

Comments

Guenter Roeck May 6, 2021, 4:04 a.m. UTC | #1
On 5/5/21 11:32 AM, Erik Rosen wrote:
> Add documentation for the new pmbus flags PMBUS_WRITE_PROTECTED and
> PMBUS_READ_STATUS_AFTER_FAILED_CHECK
> 
> Signed-off-by: Erik Rosen <erik.rosen@metormote.com>
> ---
>  Documentation/hwmon/pmbus-core.rst | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
> index 73e23ab42cc3..001c64f0f8c0 100644
> --- a/Documentation/hwmon/pmbus-core.rst
> +++ b/Documentation/hwmon/pmbus-core.rst
> @@ -289,9 +289,13 @@ PMBus driver platform data
>  ==========================
>  
>  PMBus platform data is defined in include/linux/pmbus.h. Platform data
> -currently only provides a flag field with a single bit used::
> +currently only provides a flag field with three bits used::
>  
> -	#define PMBUS_SKIP_STATUS_CHECK (1 << 0)
> +	#define PMBUS_SKIP_STATUS_CHECK  BIT(0)
> +
> +  #define PMBUS_WRITE_PROTECTED BIT(1)
> +
> +  #define PMBUS_READ_STATUS_AFTER_FAILED_CHECK  BIT(2)
>  
>  	struct pmbus_platform_data {
>  		u32 flags;              /* Device specific flags */
> @@ -315,3 +319,19 @@ status register must be disabled.
>  Some i2c controllers do not support single-byte commands (write commands with
>  no data, i2c_smbus_write_byte()). With such controllers, clearing the status
>  register is impossible, and the PMBUS_SKIP_STATUS_CHECK flag must be set.
> +
> +PMBUS_WRITE_PROTECTED
> +
> +Set if the chip is write protected and write protection is not determined
> +by the standard WRITE_PROTECT command.
> +
> +PMBUS_READ_STATUS_AFTER_FAILED_CHECK
> +  Read the STATUS register after each failed register check.
> +
> +Some PMBus chips end up in an undefined state when trying to read an
> +unsupported register. For such chips, it is necessary to reset the
> +chip pmbus controller to a known state after a failed register check.
> +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.
> \ No newline at end of file
> 

Formatting looks way off in this file. Please update to have
it look nice.

Thanks,
Guenter

Patch
diff mbox series

diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst
index 73e23ab42cc3..001c64f0f8c0 100644
--- a/Documentation/hwmon/pmbus-core.rst
+++ b/Documentation/hwmon/pmbus-core.rst
@@ -289,9 +289,13 @@  PMBus driver platform data
 ==========================
 
 PMBus platform data is defined in include/linux/pmbus.h. Platform data
-currently only provides a flag field with a single bit used::
+currently only provides a flag field with three bits used::
 
-	#define PMBUS_SKIP_STATUS_CHECK (1 << 0)
+	#define PMBUS_SKIP_STATUS_CHECK  BIT(0)
+
+  #define PMBUS_WRITE_PROTECTED BIT(1)
+
+  #define PMBUS_READ_STATUS_AFTER_FAILED_CHECK  BIT(2)
 
 	struct pmbus_platform_data {
 		u32 flags;              /* Device specific flags */
@@ -315,3 +319,19 @@  status register must be disabled.
 Some i2c controllers do not support single-byte commands (write commands with
 no data, i2c_smbus_write_byte()). With such controllers, clearing the status
 register is impossible, and the PMBUS_SKIP_STATUS_CHECK flag must be set.
+
+PMBUS_WRITE_PROTECTED
+
+Set if the chip is write protected and write protection is not determined
+by the standard WRITE_PROTECT command.
+
+PMBUS_READ_STATUS_AFTER_FAILED_CHECK
+  Read the STATUS register after each failed register check.
+
+Some PMBus chips end up in an undefined state when trying to read an
+unsupported register. For such chips, it is necessary to reset the
+chip pmbus controller to a known state after a failed register check.
+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.
\ No newline at end of file