Re: [PATCH v2 0/9] Add device tree support for on-chip SRAM

From: Shawn Guo
Date: Sun Sep 02 2012 - 21:53:46 EST


I do not understand the point of introducing those imx patches, 1 ~ 4
and 7, 8. They are all unnecessary churns to me. IMO, 4 patches are
enough.

* genalloc: add a global pool list, allow to find pools by phys address
* misc: Generic on-chip SRAM allocation driver
* ARM i.MX: remove IRAM_ALLOC facility
* ARM: dts: add sram for imx53 and imx6q

Regards,
Shawn

On Fri, Aug 31, 2012 at 11:26:55AM +0200, Philipp Zabel wrote:
> 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 v1:
> - Added a generic SRAM driver in drivers/misc that does nothing but
> request/ioremap its given memory region and serve it via the genalloc
> API.
> - Renamed the i.MX device tree nodes from "iram" to "ocram".
>
> 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 | 8 +++
> drivers/misc/Makefile | 1 +
> drivers/misc/sram.c | 105 +++++++++++++++++++++++++++++++++
> include/linux/genalloc.h | 14 +++++
> lib/genalloc.c | 77 ++++++++++++++++++++++++
> 11 files changed, 215 insertions(+), 119 deletions(-)
>
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