ACPI 5.0+ spec defines a generic mode of communication
between the OS and a platform such as the BMC. This medium
(PCC) is typically used by CPPC (ACPI CPU Performance management),
RAS (ACPI reliability protocol) and MPST (ACPI Memory power
states).

This patch adds PCC support as a Mailbox Controller. As of
ACPI v5.1 there is no provision for clients to lookup mailbox
controllers in a way that Linux expects. e.g. in DT the clients
can list the mailboxes they can associate with in the DT binding
and then provide a unique index to lookup a channel within a mailbox.
Since the ACPI spec doesn't have anything similar, we introduce a
mailbox controller specific API so that when the client calls it,
we know to lookup in the context of a specific controller. This
also helps in keeping a consistent interface across DT and ACPI
for such drivers.

This patch implements basic PCC support using the ACPI v5.1
structures. IRQ mode support will be provided as follow up patches.
Signed-off-by: NAshwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: NMark Brown <broonie@kernel.org>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJassi Brar <jaswinder.singh@linaro.org>

Introduce common framework for client/protocol drivers and
controller drivers of Inter-Processor-Communication (IPC).

Client driver developers should have a look at
 include/linux/mailbox_client.h to understand the part of
the API exposed to client drivers.
Similarly controller driver developers should have a look
at include/linux/mailbox_controller.h
Reviewed-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NJassi Brar <jaswinder.singh@linaro.org>

There is no need for a separate common OMAP mailbox module
now that the OMAP1 mailbox driver has been removed. So,
consolidate the two individual OMAP mailbox modules into a
single driver. This streamlines the driver for converting
to mailbox framework.

The following are the main changes:
- collapse mailbox-omap2.c into omap-mailbox.c
- remove omap_mbox_ops and replace the ops calls with
  the equivalent functionality.
- simplify the sub-mailbox startup/shutdown functionality,
  the one-time operations are moved into probe, and the
  pm_runtime_get_sync and pm_runtime_put_sync can be invoked
  without using a configuration counter.
- move all definitions from private omap_mbox.h into the
  source code, and eliminate this internal header.
- rename some variables that used the omap2_mbox prefix with
  a generic omap_mbox prefix.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

There are no existing users for OMAP1 mailbox driver
in kernel. Commit ab6f7751 "Removing dead OMAP_DSP"
has cleaned up all the dead code related to the only
possible user, including the creation of the mailbox
platform device.

Remove this stale driver so that the OMAP mailbox
driver can be simplified and streamlined better for
converting to mailbox framework.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Acked-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NTony Lindgren <tony@atomide.com>

The mailbox hardware (in OMAP) uses a queued mailbox interrupt
mechanism that provides a communication channel between processors
through a set of registers and their associated interrupt signals
by sending and receiving messages.

The OMAP mailbox framework/driver code is moved to be under
drivers/mailbox, in preparation for adapting to a common mailbox
driver framework. This allows the build for OMAP mailbox to be
enabled (it was disabled during the multi-platform support).

As part of the migration from plat and mach code:
- Kconfig symbols have been renamed to build OMAP1 or OMAP2+ drivers.
- mailbox.h under plat-omap/plat/include has been split into a public
  and private header files. The public header has only the API related
  functions and types.
- The module name mailbox.ko from plat-omap is changed to
  omap-mailbox.ko
- The module name mailbox_mach.ko from mach-omapX is changed as
    mailbox_omap1.ko for OMAP1
    mailbox_omap2.ko for OMAP2+

Cc: Tony Lindgren <tony@atomide.com>
[gregkh@linuxfoundation.org: ack for staging part]
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NOmar Ramirez Luna <omar.ramirez@copitl.com>
Signed-off-by: NSuman Anna <s-anna@ti.com>

The pl320 IPC allows for interprocessor communication between the
highbank A9 and the EnergyCore Management Engine. The pl320 implements
a straightforward mailbox protocol.
Signed-off-by: NMark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>