A number of drivers in drivers/gpio return -ENODEV when confronted with
missing setup parameters such as the platform data. However, returning
-ENODEV causes the driver layer to silently ignore the driver as it
assumes the probe did not find anything and was only speculative.
To make life easier to discern why a driver is not being attached, change
to returning -EINVAL, which is a better description of the fact that the
driver data was not valid.
Also add a set of dev_dbg() statements to the error paths to provide an
better explanation of the error as there may be more that one point in the
driver.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the I2C external GPIO expander drivers register themselves at
subsys_initcall() time when they're statically linked.
SOC-integrated GPIOs are available starting very early -- early in
arch_initcall() at latest, but often even before initcalls start to run --
so this improves consistency, so more subsystems can rely on GPIOs in
their own subsys_initcall() code.
(This isn't a theoretical problem. This is one of several patches needed
to resolve oopsing observed when statically linking kernels on a DaVinci
EVM. Its pcf857x GPIOs needed to be available well before some other
drivers initialized.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a driver supporting a family of I2C port expanders from Maxim,
which includes the MAX7319 and MAX7320-7327 chips.
[dbrownell@users.sourceforge.net: minor fixes]
Signed-off-by: Jack Ren <jack.ren@marvell.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
