From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kishon Vijay Abraham I Subject: Re: [RFC PATCH 2/3] mmc: host: omap_hsmmc: Enable ADMA2 Date: Thu, 19 May 2016 11:36:18 +0530 Message-ID: <573D57DA.20900@ti.com> References: <1463561115-31798-1-git-send-email-kishon@ti.com> <1463561115-31798-3-git-send-email-kishon@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Peter Ujfalusi , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mmc@vger.kernel.org, afenkart@gmail.com, ulf.hansson@linaro.org, linux@armlinux.org.uk, tony@atomide.com Cc: rogerq@ti.com, bcousson@baylibre.com, galak@codeaurora.org, ijc+devicetree@hellion.org.uk, mark.rutland@arm.com, pawel.moll@arm.com, robh+dt@kernel.org, nsekhar@ti.com List-Id: linux-mmc@vger.kernel.org Hi Peter, On Wednesday 18 May 2016 03:54 PM, Peter Ujfalusi wrote: > On 05/18/16 11:45, Kishon Vijay Abraham I wrote: >> omap hsmmc host controller has ADMA2 feature. Enable it here >> for better read and write throughput. Add a new dt binding >> "ti,use_adma" to enable ADMA2. >> >> Signed-off-by: Kishon Vijay Abraham I >> --- >> .../devicetree/bindings/mmc/ti-omap-hsmmc.txt | 1 + >> drivers/mmc/host/omap_hsmmc.c | 320 ++++++++++++++++---- >> include/linux/platform_data/hsmmc-omap.h | 1 + >> 3 files changed, 256 insertions(+), 66 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> index 74166a0..eb5ceec2 100644 >> --- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> +++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> @@ -28,6 +28,7 @@ specifier is required. >> dma-names: List of DMA request names. These strings correspond >> 1:1 with the DMA specifiers listed in dmas. The string naming is >> to be "rx" and "tx" for RX and TX DMA requests, respectively. >> +ti,use_adma: enable adma2 feature > > Do we have use case when you want to fall back to generic DMA instead of aDMA2? > IMHO if the driver supports aDMA2, it is going to use it instead of the > generic s/eDMA. > What I mean is: > the driver implements the aDMA2 support. > if the IP has support for aDMA2, then it is going to use it, otherwise it will > use the generic DMA. hmm.. how will the driver know if the IP has support for aDMA2. Using dt binding is one way. Using MMCHS_HL_HWINFO is another way but then the register offsets in omap_hsmmc driver has to be modified for omap4+. Thanks Kishon