From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Yan Subject: Re: [PATCH v1 0/6] misc: add reboot mode driver Date: Wed, 23 Dec 2015 17:31:45 +0800 Message-ID: <567A6A01.8080305@rock-chips.com> References: <1450774949-23901-1-git-send-email-andy.yan@rock-chips.com> <20151222164742.GA8623@piout.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20151222164742.GA8623-m++hUPXGwpdeoWH0uzbU5w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alexandre Belloni Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, sjg-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, wxt-TNX95d0MmH7DzftRWevZcw@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org, geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, sre-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, jun.nie-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org, khilman-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, moritz.fischer-+aYTwkv1SeIAvxtiuMwx3w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Alexandre: On 2015=E5=B9=B412=E6=9C=8823=E6=97=A5 00:47, Alexandre Belloni wrote: > Hi, > > On 22/12/2015 at 17:02:29 +0800, Andy Yan wrote : >> This driver parse the reboot commands like "reboot loader" >> and "reboot recovery" to get a boot mode described in the >> device tree , then call the vendor specific write interfae >> to store the boot mode in some place like special register >> or sram , which can be read by the bootloader after system >> reboot. >> >> This is commonly done on Android based devices, in order to >> reboot the device into fastboot or recovery mode. >> >> Before this patch , I have try some hack on[0], and then found >> John Stultz also doing the same work[1]. >> >> As John is busy these days, I go on with this work. >> >> [0]https://patchwork.kernel.org/patch/7647751/ >> [1]https://patchwork.kernel.org/patch/7802391/ >> >> Changes in v1: >> - fix the embarrassed compile warning >> - correct the maskrom magic number >> - check for the normal reboot >> - correct the maskrom magic number >> - use macro defined in rockchip_boot-mode.h for reboot-mode DT node >> >> Andy Yan (6): >> dt-bindings: misc: add document for reboot-mode driver >> dt-bindings: soc: add document for rockchip reboot-mode driver >> misc: add reboot mode driver >> soc: rockchip: add reboot mode driver >> ARM: dts: rockchip: add reboot-mode node >> ARM64: dts: rockchip: add reboot-mode node >> > This seems nice and useful, some further ideas: > >> .../devicetree/bindings/misc/reboot-mode.txt | 41 +++++++++ >> .../bindings/soc/rockchip/rockchip,reboot-mode.txt | 39 +++++++++ >> arch/arm/boot/dts/rk3288.dtsi | 26 ++++++ >> arch/arm/boot/dts/rk3xxx.dtsi | 26 ++++++ >> arch/arm64/boot/dts/rockchip/rk3368.dtsi | 26 ++++++ >> drivers/misc/Kconfig | 7 ++ >> drivers/misc/Makefile | 1 + >> drivers/misc/reboot_mode.c | 96 ++++++++++= ++++++++++++ > I think this actually belongs to drivers/power/reset/ instead of misc I also have the idea to put is in drivers/power/reset, But conside= ring this driver have not bind anything about power, so I put it in=20 driver/misc at last. So I hope if some people can give more suggestions here. > >> drivers/soc/rockchip/Kconfig | 9 ++ >> drivers/soc/rockchip/Makefile | 1 + >> drivers/soc/rockchip/reboot.c | 68 ++++++++++= +++++ > And maybe that part could be made generic instead of rockchip specifi= c. > It simply uses a regmap to do the accesses, I guess a lot of other > platforms will do that. We have syscon-reboot and syscon-poweroff for= example. > > I think then we can extend the "framework" by having generic drivers = to > store the value in eeprom or nvram for example. > I also hope the write interface can be generic. But I found some=20 platform use different hardware to store the value. For example, John's patc= h=20 use SRAM on qcom apq8064 to store value for nexus7. It seems there also= have some platform use dram or nvram to store it. And these different=20 hardware use different write method. I don't have a generic way to handle this. I have a idea to handle it like this: +static const struct of_device_id reboot_mode_dt_match[] =3D { + { .compatible =3D "linux,reboot-mode-sfr", /*for magic valu= e=20 stored in special function register, which can be accessed by regmap*/ + .data =3D (void *)&reboot-mode-sfr }, + { .compatible =3D "linux,reboot-mode-sram", /*for magic value= =20 stored in + .data =3D (void *)&reboot-mode-sram }, + { .compatible =3D "linux,reboot-mode-sdram", + .data =3D (void *)&reboot-mode-sdram }, /*for magic va= lue=20 stored + { .compatible =3D "rockchip,reboot-mode-nvram", + .data =3D (void *)&reboot-mode-nvram }, + {}, +}; the data point to different hardware access method. Hope to see more suggestions from you. -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html