From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: [PATCH v6 0/4] Add generic driver for on-chip SRAM Date: Fri, 16 Nov 2012 11:30:13 +0100 Message-ID: <1353061817-3207-1-git-send-email-p.zabel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Fabio Estevam , Matt Porter , Dong Aisheng , Greg Kroah-Hartman , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Rob Herring , Paul Gortmaker , Richard Zhao , Javier Martin , kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, Huang Shijie List-Id: devicetree@vger.kernel.org These patches add support to configure on-chip SRAM via device-tree node or platform data and to obtain the resulting genalloc pool from the physical address or a phandle pointing at the device tree node. This allows drivers to allocate SRAM with the genalloc API without hard-coding the genalloc pool pointer. The on-chip SRAM on i.MX53 and i.MX6q can be 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 1: vpu@63ff4000 { /* ... */ iram = <&ocram>; }; Changes since v5: - Addressed Paul Gortmaker's comments, merging the clock patch into the SRAM driver patch. - Hard coded the allocation granularity to 512 bytes and dropped Matt Porter's patch for now. Whether or not this should be configured in the device tree could use further discussion. - Added a coda driver patch to use the genalloc API and, again, the i.MX53/i.MX6 device tree patch to show the whole picture. regards Philipp --- Documentation/devicetree/bindings/misc/sram.txt | 17 ++++ arch/arm/boot/dts/imx53.dtsi | 5 + arch/arm/boot/dts/imx6q.dtsi | 6 ++ drivers/media/platform/Kconfig | 3 +- drivers/media/platform/coda.c | 47 ++++++--- drivers/misc/Kconfig | 9 ++ drivers/misc/Makefile | 1 + drivers/misc/sram.c | 121 +++++++++++++++++++++++ include/linux/genalloc.h | 14 +++ lib/genalloc.c | 67 +++++++++++++ 10 files changed, 274 insertions(+), 16 deletions(-)