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>

The OMAP mailbox driver and its existing clients (remoteproc
for OMAP4+) are adapted to use the generic mailbox framework.

The main changes for the adaptation are:
  - The tasklet used for Tx is replaced with the state machine from
    the generic mailbox framework. The workqueue used for processing
    the received messages stays intact for minimizing the effects on
    the OMAP mailbox clients.
  - The existing exported client API, omap_mbox_get, omap_mbox_put and
    omap_mbox_send_msg are deleted, as the framework provides equivalent
    functionality. A OMAP-specific omap_mbox_request_channel is added
    though to support non-DT way of requesting mailboxes.
  - The OMAP mailbox driver is integrated with the mailbox framework
    through the proper implementations of mbox_chan_ops, except for
    .last_tx_done and .peek_data. The OMAP mailbox driver does not need
    these ops, as it is completely interrupt driven.
  - The OMAP mailbox driver uses a custom of_xlate controller ops that
    allows phandles for the pargs specifier instead of indexing to avoid
    any channel registration order dependencies.
  - The new framework does not support multiple clients operating on a
    single channel, so the reference counting logic is simplified.
  - The remoteproc driver (current client) is adapted to use the new API.
    The notifier callbacks used within this client is replaced with the
    regular callbacks from the newer framework.
  - The exported OMAP mailbox API are limited to omap_mbox_save_ctx,
    omap_mbox_restore_ctx, omap_mbox_enable_irq & omap_mbox_disable_irq,
    with the signature modified to take in the new mbox_chan handle instead
    of the OMAP specific omap_mbox handle. The first 2 will be removed when
    the OMAP mailbox driver is adapted to runtime_pm. The other exported
    API omap_mbox_request_channel will be removed once existing legacy
    users are converted to DT.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NJassi Brar <jaswinder.singh@linaro.org>

If the mailbox controller expects the payload is in place before
initiating the transmit, then it's impossible to reuse the list
maintained by core mailbox code currently. Maintaining another list
for sending the message in the controller seems totally unnecessary
as core mailbox library already provides that feature.

This patch introduces tx_prepare callback in mbox_client which
can be used by the core mailbox library before initiating the
transaction through mbox->ops->send_data. The client driver can
implement this callback to ensure the payload is copied to the
shared memory.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NJassi Brar <jaswinder.singh@linaro.org>

poll_txdone() will unconditionally re-arm the polling timer if there was
an active request, even if the active request completed and no other
requests were submitted.  This is fixed by:
 - only re-arming the timer if the controller reported that the current
   transmission has not completed, and,
 - moving the call to poll_txdone() into msg_submit() so that the
   controller gets polled (and the timer re-armed, if necessary) whenever
   a new message is submitted.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Reviewed-by: NThierry Reding <treding@nvidia.com>
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>

The patch 30058677 "ARM / highbank: add support for pl320 IPC"
added a pl320 IPC specific header file as a generic mailbox.h.
This file has been renamed appropriately to allow the
introduction of the generic mailbox API framework.
Acked-by: NMark Langsdorf <mark.langsdorf@calxeda.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSuman Anna <s-anna@ti.com>
Reviewed-by: NMark Brown <broonie@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Logic has been added to the OMAP2+ mailbox code to parse the
mailbox dt nodes and construct the different sub-mailboxes
associated with the instance. The DT representation of the
sub-mailbox devices is different from legacy platform data
representation to allow flexibility of interrupt configuration
between Tx and Rx fifos (to also possibly allow simplex devices
in the future). The DT representation gathers similar information
that was being passed previously through the platform data, except
for the interrupt type information, which is gathered through driver
compatible match data.

The non-DT support has to be maintained for now to not break
OMAP3 legacy boot, and the legacy-style code will be cleaned
up once OMAP3 is also converted to DT-boot only.

Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: NSuman Anna <s-anna@ti.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NTony Lindgren <tony@atomide.com>

A new structure, omap_mbox_device, is added to contain
the global variables pertinent to a mailbox h/w IP block.
This enables the support for having multiple instances of
the same h/w IP block in the SoC. This is in preparation
to support the DRA7 SoC, which is the first SoC in the OMAP
family to have multiple mailbox IP instances.

The changes include enhancements to the sub-mailbox registration
logic and mbox startup sequencing, removing the usage of single
global configuration variables for all h/w instances, and storing
the registered sub-mailboxes with the parent mailbox device
structure.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

The structure omap_mbox_priv is used previously to store arch
specific (OMAP1 vs OMAP2+) data, and is no longer required to be
maintained separately. Instead, absorb its elements into either
the sub-mailbox device structure, omap_mbox, or the individual
fifo descriptor structure, omap_mbox_fifo.

The newmsg_bit and notfull_bit used on Rx and Tx fifos respectively
are represented by the new intr_bit field in the fifo descriptor
structure. The interrupt configuration registers are also moved
into the fifo descriptor structure to allow the Rx and Tx fifos
to use different interrupt lines/users.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

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>

The OMAP mailbox IP has two different type of interrupt configuration
registers between OMAP4+ SoCs and OMAP2/3 SoCs. Simplify the current
interrupt configuration by using a single macro that translates the
two variants.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

The type definition omap_mbox_type_t used for distinguishing
OMAP1 from OMAP2+ mailboxes is no longer needed after the
removal of OMAP1 mailbox driver, and has therefore been
cleaned up. This cleanup also eliminates the need for the
polling logic used for checking the transmit readiness.
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>

Use the various devm_ interfaces to simplify the cleanup in
probe and remove functions in OMAP2+ mailbox driver.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

There is a bug in omap2_mbox_probe() where we try do:

		mbox->irq = platform_get_irq(pdev, info->irq_id);
		if (mbox->irq < 0) {

The problem is that mbox->irq is unsigned so the error handling doesn't
work.  I've changed it to a signed integer.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Suman Anna <s-anna@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Omar Ramirez Luna <omar.ramirez@copitl.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NSuman Anna <s-anna@ti.com>
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>

Avoids a section mismatch.
Signed-off-by: NMark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.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>