[PATCH v3 0/4] Add device tree support for on-chip SRAM

From: Philipp Zabel
Date: Mon Sep 03 2012 - 12:02:31 EST


These patches add support to configure on-chip SRAM via device-tree
node and to obtain the resulting genalloc pool from a phandle pointing
at the node.
This allows drivers to allocate SRAM with the genalloc API without
hard-coding the genalloc pool address.

The on-chip SRAM on i.MX53 and i.MX6q is registered via device tree and
changed to use the simple generic SRAM driver:

ocram: ocram@00900000 {
compatible = "fsl,imx-ocram", "sram";
reg = <0x00900000 0x3f000>;
};

A driver that needs to allocate SRAM buffers, like the video processing
unit on i.MX53, can retrieve the genalloc pool from a phandle in the
device tree using of_get_named_gen_pool(node, "iram", 0) from patch 5:

vpu@63ff4000 {
/* ... */
iram = <&ocram>;
};

Changes since v2, as per Shawn's suggestions:
- Moved struct device_node declaration out of #ifdef CONFIG_OF.
- Simplified of_get_named_gen_pool using of_parse_phandle and
of_address_to_resource.
- Return -EADDRNOTAVAIL if devm_request_and_ioremap fails.
- Squashed i.MX changes together.

regards
Philipp

---
arch/arm/boot/dts/imx53.dtsi | 5 ++
arch/arm/boot/dts/imx6q.dtsi | 5 ++
arch/arm/plat-mxc/Kconfig | 4 --
arch/arm/plat-mxc/Makefile | 1 -
arch/arm/plat-mxc/include/mach/iram.h | 41 -------------
arch/arm/plat-mxc/iram_alloc.c | 73 -----------------------
drivers/misc/Kconfig | 9 +++
drivers/misc/Makefile | 1 +
drivers/misc/sram.c | 105 +++++++++++++++++++++++++++++++++
include/linux/genalloc.h | 14 +++++
lib/genalloc.c | 67 +++++++++++++++++++++
11 files changed, 206 insertions(+), 119 deletions(-)

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