remoteproc/omap: add a remoteproc driver for OMAP4

Add a remoteproc driver for OMAP4, so we can boot the dual-M3 and
and DSP subsystems.

Use the omap_device_* API to control the hardware state, and utilize
the OMAP mailbox to interrupt the remote processor when a new message
is pending (the mailbox payload is used to tell it which virtqueue was
the message placed in).

Conversely, when an inbound mailbox message arrives, tell the remoteproc
core which virtqueue is triggered.

Later we will also use the mailbox payload to signal omap-specific
events like remote crashes (which will be used to trigger remoteproc
recovery) and power management transitions. At that point we will also
extend the remoteproc core to support this.

Based on (but now quite far from) work done by Fernando Guzman Lugo
<fernando.lugo@ti.com> and Hari Kanigeri <h-kanigeri2@ti.com>.

Designed with Brian Swetland <swetland@google.com>.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index b250b15c0686..396c97a2661f 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -1,3 +1,24 @@
 # REMOTEPROC gets selected by whoever wants it
 config REMOTEPROC
         tristate
+
+config OMAP_REMOTEPROC
+        tristate "OMAP remoteproc support"
+        depends on ARCH_OMAP4
+        select OMAP_IOMMU
+        select REMOTEPROC
+        select OMAP_MBOX_FWK
+        select RPMSG
+        default m
+        help
+          Say y here to support OMAP's remote processors (dual M3
+          and DSP on OMAP4) via the remote processor framework.
+
+          Currently only supported on OMAP4.
+
+          Usually you want to say y here, in order to enable multimedia
+          use-cases to run on your platform (multimedia codecs are
+          offloaded to remote DSP processors using this framework).
+
+          It's safe to say n here if you're not interested in multimedia
+          offloading or just want a bare minimum kernel.