misc: generic on-chip SRAM allocation driver
authorPhilipp Zabel <p.zabel@pengutronix.de>
Mon, 29 Apr 2013 23:17:12 +0000 (16:17 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 30 Apr 2013 01:28:13 +0000 (18:28 -0700)
commit4984c6f5e56c3e68922fd979347ba7aff385783b
tree7931e0e6dbb71d837a24638cebc62a5dbb38798b
parent9375db07adeaeea5f5ea7ca0463a8b371d71ddbb
misc: generic on-chip SRAM allocation driver

This driver requests and remaps a memory region as configured in the
device tree.  It serves memory from this region via the genalloc API.  It
optionally enables the SRAM clock.

Other drivers can retrieve the genalloc pool from a phandle pointing to
this drivers' device node in the device tree.

The allocation granularity is hard-coded to 32 bytes for now, to make the
SRAM driver useful for the 6502 remoteproc driver.  There is overhead for
bigger SRAMs, where only a much coarser allocation granularity is needed:
At 32 bytes minimum allocation size, a 256 KiB SRAM needs a 1 KiB bitmap
to track allocations.

[akpm@linux-foundation.org: fix Kconfig text, make sram_init static]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Shijie <shijie8@gmail.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/devicetree/bindings/misc/sram.txt [new file with mode: 0644]
drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/sram.c [new file with mode: 0644]