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Commit 20fcfe17 authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (pmbus) Add comments explaining internal driver API return values 



Return values for functions reading/writing manufacturer specific registers are
poorly explained. Add comments to improve documentation.

Signed-off-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
Acked-by: default avatarJean Delvare <khali@linux-fr.org>
parent 363a12a4

drivers/hwmon/pmbus/pmbus.h

+16 −2
Original line number Original line Diff line number Diff line
@@ -134,8 +134,16 @@ 
 * Semantics:

 * Semantics:

 * Virtual registers are all word size.

 * Virtual registers are all word size.

 * READ registers are read-only; writes are either ignored or return an error.

 * READ registers are read-only; writes are either ignored or return an error.

 * RESET registers are read/write. Reading returns zero (used for detection),

 * RESET registers are read/write. Reading reset registers returns zero

 * writing any value causes the associated history to be reset.

 * (used for detection), writing any value causes the associated history to be

 * reset.

 * Virtual registers have to be handled in device specific driver code. Chip

 * driver code returns non-negative register values if a virtual register is

 * supported, or a negative error code if not. The chip driver may return

 * -ENODATA or any other error code in this case, though an error code other

 * than -ENODATA is handled more efficiently and thus preferred. Either case,

 * the calling PMBus core code will abort if the chip driver returns an error

 * code when reading or writing virtual registers.

 */

 */

#define PMBUS_VIRT_BASE			0x100

#define PMBUS_VIRT_BASE			0x100

#define PMBUS_VIRT_READ_TEMP_MIN	(PMBUS_VIRT_BASE + 0)

#define PMBUS_VIRT_READ_TEMP_MIN	(PMBUS_VIRT_BASE + 0)
@@ -320,6 +328,12 @@ struct pmbus_driver_info { 
	 * The following functions map manufacturing specific register values

	 * The following functions map manufacturing specific register values

	 * to PMBus standard register values. Specify only if mapping is

	 * to PMBus standard register values. Specify only if mapping is

	 * necessary.

	 * necessary.

	 * Functions return the register value (read) or zero (write) if

	 * successful. A return value of -ENODATA indicates that there is no

	 * manufacturer specific register, but that a standard PMBus register

	 * may exist. Any other negative return value indicates that the

	 * register does not exist, and that no attempt should be made to read

	 * the standard register.

	 */

	 */

	int (*read_byte_data)(struct i2c_client *client, int page, int reg);

	int (*read_byte_data)(struct i2c_client *client, int page, int reg);

	int (*read_word_data)(struct i2c_client *client, int page, int reg);

	int (*read_word_data)(struct i2c_client *client, int page, int reg);