From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kuninori Morimoto Date: Thu, 05 Jun 2014 00:17:53 +0000 Subject: Re: [PATCH v2 5/7] ARM: shmobile: r8a7791 dtsi: Add SYS-DMAC0 and SYS-DMAC1 nodes Message-Id: <871tv4jjkh.wl%kuninori.morimoto.gx@gmail.com> List-Id: References: <1401716531-29794-1-git-send-email-geert+renesas@glider.be> <1401716531-29794-6-git-send-email-geert+renesas@glider.be> <2440127.sDc7m91LPu@avalon> In-Reply-To: <2440127.sDc7m91LPu@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi Laurent > > Add nodes for the SYS-DMA controllers, SYS-DMAC0 and SYS-DMAC1. These > > both share the same device sources, so are wrapped in the shdma-mux > > node to allow both to be used. > > > > Cfr. the r8a7790 version by Ben Dooks. > > > > Signed-off-by: Geert Uytterhoeven > > --- (snip) > > + sysdma0: dma-controller@e6700020 { > > + compatible = "renesas,shdma-r8a7791"; > > + reg = <0 0xe6700020 0 0xffc0>; > > Even though the registered defined in the datasheet start at 0xe6700020, the > documentation clearly states that "The base address of registers for the > lower-numbered channels (0 to 14) is H'E670 0000". I'm also wondering where > the size comes from, if you want to span the 0xe6700000 to 0xe670ffff range, > the size should be 0xffe0, not 0xffc0. Unfortunately, this mapping (form 0x20) is required from driver for historical reasons. So, driver setting needs to care about it. Please check DMA_CHANNEL macro for each setup-xxx.c # but, it works without care about it (?) # becase there are mirror register there (?), I'm not sure detail Best regards --- Kuninori Morimoto