This allows the ssbi module to be autoloaded on boot.

Cc: David Brown <davidb@codeaurora.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDavid Brown <davidb@codeaurora.org>

Although the SSBI sub is currently only used on MSM SoCs, it is still
a bus in its own right.  Remove this msm_ prefix from the driver and
it's symbols.  Clients can now refer directly to ssbi_write() and
ssbi_read().
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove some unhelpful error logs.  This also removes the necessity of
having a pointer back to the struct device within the ssbi-specific
structure
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With device tree, and deferred probe, it is no longer necessary to
make sure that the ssbi bus driver is initialized very early.  Restore
to a regular module_init().
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The ssbi driver uses a busywait loop to read its status register.  Add
a comment explaining the timing of the device itself so that future
developers can better understand this delay, and possibly diagnose any
problems.
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The SSBI bus is exclusive to the Qualcomm MSM targets, and all SoCs
using it will be using device tree.  Convert this driver to indentify
with device tree.

This makes the bus probing a good bit simpler, since the attaching of
child nodes can be represented directly in the devicetree, rather than
having to be inferred by name.
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

msm_ssbi_remove is referenced with __exit_p, but not declared with
__exit.  This causes a warning when the driver is not built as a
module:

drivers/ssbi/ssbi.c:341:23: warning: 'msm_ssbi_remove' defined but not used [-Wunused-function]

The remove is needed for unbinding to work, even if not compiled as a
module, so just remove it.
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

SSBI is the Qualcomm single-wire serial bus interface used to connect
the MSM devices to the PMIC and other devices.

Since SSBI only supports a single slave, the driver gets the name of the
slave device passed in from the board file through the master device's
platform data.

SSBI registers pretty early (postcore), so that the PMIC can come up
before the board init. This is useful if the board init requires the
use of gpios that are connected through the PMIC.

Based on a patch by Dima Zavin <dima@android.com> that can be found at:
http://android.git.kernel.org/?p=kernel/msm.git;a=commitdiff;h=eb060bac4

This patch adds PMIC Arbiter support for the MSM8660. The PMIC Arbiter
is a hardware wrapper around the SSBI 2.0 controller that is designed to
overcome concurrency issues and security limitations.  A controller_type
field is added to the platform data to specify the type of the SSBI
controller (1.0, 2.0, or PMIC Arbiter).

[davidb@codeaurora.org:
 I've moved this driver into drivers/ssbi/ and added an include for
 linux/module.h so that it will compile]
Signed-off-by: NKenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>