Commit e5befc02 authored by Eddie James's avatar Eddie James Committed by Guenter Roeck
Browse files

hwmon: (pmbus) Add a PMBUS_NO_CAPABILITY platform data flag 



Some PMBus chips don't respond with valid data when reading the
CAPABILITY register. Add a flag that device drivers can set so
that the PMBus core driver doesn't use CAPABILITY to determine it's
behavior.

Signed-off-by: default avatarEddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20201222152640.27749-2-eajames@linux.ibm.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent c8d0d3fa

drivers/hwmon/pmbus/pmbus_core.c

+5 −3
Original line number Diff line number Diff line
@@ -2204,9 +2204,11 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, 
	}



	/* Enable PEC if the controller supports it */

	if (!(data->flags & PMBUS_NO_CAPABILITY)) {

		ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);

		if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))

			client->flags |= I2C_CLIENT_PEC;

	}



	/*

	 * Check if the chip is write protected. If it is, we can not clear

include/linux/pmbus.h

+9 −0
Original line number Diff line number Diff line
@@ -34,6 +34,15 @@ 
 */

#define PMBUS_WRITE_PROTECTED	BIT(1)



/*

 * PMBUS_NO_CAPABILITY

 *

 * Some PMBus chips don't respond with valid data when reading the CAPABILITY

 * register. For such chips, this flag should be set so that the PMBus core

 * driver doesn't use CAPABILITY to determine it's behavior.

 */

#define PMBUS_NO_CAPABILITY			BIT(2)



struct pmbus_platform_data {

	u32 flags;		/* Device specific flags */