From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH v2 2/6] [media] rockchip/rga: v4l2 m2m support Date: Sat, 15 Jul 2017 12:42:23 +0300 Message-ID: <2363665.x6z9MR1vqI@avalon> References: <1500101920-24039-1-git-send-email-jacob-chen@iotwrt.com> <1500101920-24039-3-git-send-email-jacob-chen@iotwrt.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1500101920-24039-3-git-send-email-jacob-chen@iotwrt.com> Sender: linux-kernel-owner@vger.kernel.org To: Jacob Chen Cc: linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, heiko@sntech.de, robh+dt@kernel.org, mchehab@kernel.org, linux-media@vger.kernel.org, laurent.pinchart+renesas@ideasonboard.com, hans.verkuil@cisco.com, s.nawrocki@samsung.com, tfiga@chromium.org, nicolas@ndufresne.ca List-Id: devicetree@vger.kernel.org Hi Jacob, Thank you for the patch. On Saturday 15 Jul 2017 14:58:36 Jacob Chen wrote: > Rockchip RGA is a separate 2D raster graphic acceleration unit. It > accelerates 2D graphics operations, such as point/line drawing, image > scaling, rotation, BitBLT, alpha blending and image blur/sharpness. > > The drvier is mostly based on s5p-g2d v4l2 m2m driver. > And supports various operations from the rendering pipeline. > - copy > - fast solid color fill > - rotation > - flip > - alpha blending I notice that you don't support the drawing operations. How do you plan to support them later through the V4L2 M2M API ? I hate stating the obvious, but wouldn't the DRM API be better fit for a graphic accelerator ? Additionally, V4L2 M2M has one source and one destination. How do you implement alpha blending in that case, which by definition requires at least two sources ? > The code in rga-hw.c is used to configure regs accroding to operations. > > The code in rga-buf.c is used to create private mmu table for RGA. > The tables is stored in a list, and be removed when buffer is cleanup. Looking at the implementation it seems to be a scatter-gather list, not an MMU. Is that right ? Does the hardware documentation refer to it as an MMU ? > Signed-off-by: Jacob Chen > --- > drivers/media/platform/Kconfig | 11 + > drivers/media/platform/Makefile | 2 + > drivers/media/platform/rockchip-rga/Makefile | 3 + > drivers/media/platform/rockchip-rga/rga-buf.c | 122 ++++ > drivers/media/platform/rockchip-rga/rga-hw.c | 652 ++++++++++++++++++ > drivers/media/platform/rockchip-rga/rga-hw.h | 437 ++++++++++++ > drivers/media/platform/rockchip-rga/rga.c | 958 +++++++++++++++++++++++ > drivers/media/platform/rockchip-rga/rga.h | 111 +++ > 8 files changed, 2296 insertions(+) > create mode 100644 drivers/media/platform/rockchip-rga/Makefile > create mode 100644 drivers/media/platform/rockchip-rga/rga-buf.c > create mode 100644 drivers/media/platform/rockchip-rga/rga-hw.c > create mode 100644 drivers/media/platform/rockchip-rga/rga-hw.h > create mode 100644 drivers/media/platform/rockchip-rga/rga.c > create mode 100644 drivers/media/platform/rockchip-rga/rga.h -- Regards, Laurent Pinchart