From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH 4/6] [RFC] Documentation: dt: Add Renesas RSPI/QSPI bindings Date: Mon, 30 Dec 2013 18:20:50 +0100 Message-ID: References: <1387886210-3634-1-git-send-email-geert+renesas@linux-m68k.org> <2582506.8vb3LhHISh@avalon> <3193607.9r7LL0m5xX@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <3193607.9r7LL0m5xX@avalon> Sender: linux-sh-owner@vger.kernel.org To: Laurent Pinchart Cc: Geert Uytterhoeven , Linux-sh list , "linux-arm-kernel@lists.infradead.org" , linux-spi@vger.kernel.org, "devicetree@vger.kernel.org" List-Id: devicetree@vger.kernel.org On Mon, Dec 30, 2013 at 4:18 PM, Laurent Pinchart wrote: >> There are subtle register differences between RSPI on SH7757 and RZ/A1H, >> cfr. what rspi_parse_platform_data() does when no platform_data is >> passed[*]. RSPI on RZ/A1H seems to be an evolutionary step from RSPI on SH >> towards QSPI on RCar Gen2 (but without Dual/Quad). >> >> [*] setup-sh7757.c doesn't pass platform data, although the rspi driver and >> its platform data has support for DMA on SH7757, which is not used by >> setup-sh7757.c nor any other in-tree platform. > > The only important difference I can see (beside the hardcoded 16-bit width > which could be selected as the default) is that the SSH7757 RSPI has no SPL > bits in SPDCR. I don't have access tot he SH7757 datasheet, could you please > confirm that ? SH7757 has RSPI Control Register 2 and the TX only mode flag, while RSPI-RZ (and QSPI) haven't. The number of interrupts also differ, but that's easily handled via the interrupts property. BTW, I also don't have the SH7757 datasheet (will check), so my knowledge there is purely based on the behavior of the code. >> > in my opinion is whether we want to use >> > >> > compatible = "renesas,rspi-r7s72100", "renesas,rspi"; >> > >> > or >> > >> > compatible = "renesas,rspi-r7s72100", "renesas,rspi-rz", "renesas,rspi"; >> >> So we end up with: >> >> compatible = "renesas,sh7757", "renesas,rspi-sh" (SH legacy) >> compatible = "renesas,rspi-r7s72100", "renesas,rspi-rz" (Genmai) >> compatible = "renesas,rspi-r8a7790", "renesas,qspi" (Lager) >> compatible = "renesas,rspi-r8a7791", "renesas,qspi" (Koelsch) > > Don't you mean "renesas,qspi-r8a7790" and "renesas,qspi-r8a7791" ? Oops, yes, sorry about that. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds