From mboxrd@z Thu Jan 1 00:00:00 1970 From: fkan@apm.com (Feng Kan) Date: Mon, 2 Feb 2015 14:15:44 -0800 Subject: [PATCH 4/6] i2c: busses: add SLIMpro I2C device driver on APM X-Gene platform In-Reply-To: <20150130061118.GA995@katana> References: <1412726809-7525-1-git-send-email-fkan@apm.com> <1412726809-7525-5-git-send-email-fkan@apm.com> <1894616.4yY7dajl4R@wuerfel> <20150130061118.GA995@katana> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jan 29, 2015 at 10:11 PM, Wolfram Sang wrote: > >> > ctx->dev is probably the wrong device here. The i2c controller is not >> > DMA capable itself, you need to have a pointer to the device that actually >> > performs the DMA here. >> >> Arnd, I do agree this may not be the best identification. There is no >> representation for this on the Linux side. I could put it as NULL. However, >> there are other i2c bus drivers that seem to do the same thing. Please >> let me know what you think. > > For completeness: Those drivers need fixing! I have some doubts. I could hack up a dts node for the helper processor that is doing the dma. However, the dma master could be anything for that matter. I am not sure how I can write this in a generic manner.