Always call _pmbus_read_byte() instead of pmbus_read_byte() in PMBus core
driver. With this change, device specific read functions can be implemented for
all registers.

Since the device specific read_byte function is now always called, we need to be
more careful with page validations. Only fail if the passed page number is larger
than 0, since -1 means "current page".
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: NRobert Coulson <robert.coulson@ericsson.com>

EINVAL was over-used in the code. Replace it with more appropriate errors.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: NRobert Coulson <robert.coulson@ericsson.com>

Driver remove functions have an error return value, but rarely return an error
in practice. If a driver does return an error from its remove function, the
driver won't be unloaded and is expected to stay alive.

pmbus_do_remove() is defined as returning an int, but always returns 0 (no
error). Calling code passes that return value on to high level driver
remove functions, but does not evaluate it and removes driver data even if
pmbus_do_remove() returned an error (which it in practice never does). Even if
this code could never cause a real problem, it is nevertheless conceptually
wrong.

To reduce confusion and simplify the code, change pmbus_do_remove() to be a void
function, and have PMBus client drivers always return zero in their driver
remove functions.
Reported-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Acked-by: NJean Delvare <khali@linux-fr.org>

Rewrite the loop walking the id array during probe. The new code is
better adapted to a null-terminated array, and is also clearer and
more efficient than the original.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

Since the number of PMBus drivers is getting large, move them into
directory drivers/hwmon/pmbus to improve readability and scalability.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: NRobert Coulson <robert.coulson@ericsson.com>

Hardware monitoring support for TI UCD90120, UCD90124, UCD9090, and UCD90910
Sequencer and System Health Controllers.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: NTom Grennan <tom.grennan@ericsson.com>