From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Yan Subject: Re: [PATCH v8 2/4] power: reset: add reboot mode driver Date: Mon, 25 Apr 2016 19:29:52 +0800 Message-ID: <571DFFB0.4010409@rock-chips.com> References: <1461567051-21734-1-git-send-email-andy.yan@rock-chips.com> <1461567336-21834-1-git-send-email-andy.yan@rock-chips.com> <571DF49F.6000706@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <571DF49F.6000706-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Krzysztof Kozlowski , robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org, sre-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, moritz.fischer-+aYTwkv1SeIAvxtiuMwx3w@public.gmane.org, f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Krzysztof: On 2016=E5=B9=B404=E6=9C=8825=E6=97=A5 18:42, Krzysztof Kozlowski wrote= : > On 04/25/2016 08:55 AM, Andy Yan wrote: >> This driver parses the reboot commands like "reboot bootloader" >> and "reboot recovery" to get a boot mode described in the >> device tree , then call the 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, then the bootloader >> can take different action according to the mode stored. >> >> This is commonly used on Android based devices, in order to >> reboot the device into fastboot or recovery mode. >> >> Reviewed-by: Matthias Brugger >> Reviewed-by: Moritz Fischer >> Tested-by: John Stultz >> Acked-by: John Stultz >> Signed-off-by: Andy Yan >> >> --- >> >> Changes in v8: >> - do some cleanup when driver ubind >> >> Changes in v7: >> - address some suggestions from Krzysztof, make syscon-reboot-mode d= river data self-contained. >> >> Changes in v6: None >> Changes in v5: >> - use two blank space under help in Kconfig >> - use unsigned int instead of int for member magic in struct mode_in= fo >> >> Changes in v4: >> - make this driver depends on OF to avoid kbuild test error >> >> Changes in v3: >> - scan multi properities >> - add mask value for some platform which only use some bits of the r= egister >> to store boot mode magic value >> >> Changes in v2: >> - move to dir drivers/power/reset/ >> - make syscon-reboot-mode a generic driver >> >> Changes in v1: >> - fix the embarrassed compile warning >> - correct the maskrom magic number >> - check for the normal reboot >> >> drivers/power/reset/Kconfig | 13 ++++ >> drivers/power/reset/Makefile | 2 + >> drivers/power/reset/reboot-mode.c | 118 +++++++++++++++++++= ++++++++++++ >> drivers/power/reset/reboot-mode.h | 14 ++++ >> drivers/power/reset/syscon-reboot-mode.c | 99 +++++++++++++++++++= +++++++ >> 5 files changed, 246 insertions(+) >> create mode 100644 drivers/power/reset/reboot-mode.c >> create mode 100644 drivers/power/reset/reboot-mode.h >> create mode 100644 drivers/power/reset/syscon-reboot-mode.c >> >> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconf= ig >> index 1131cf7..cf50630 100644 >> --- a/drivers/power/reset/Kconfig >> +++ b/drivers/power/reset/Kconfig >> @@ -173,5 +173,18 @@ config POWER_RESET_ZX >> help >> Reboot support for ZTE SoCs. >> =20 >> +config REBOOT_MODE >> + tristate >> + >> +config SYSCON_REBOOT_MODE >> + bool "Generic SYSCON regmap reboot mode driver" >> + depends on OF >> + select REBOOT_MODE >> + help >> + Say y here will enable reboot mode driver. This will >> + get reboot mode arguments and store it in SYSCON mapped >> + register, then the bootloader can read it to take different >> + action according to the mode. >> + >> endif >> =20 >> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Make= file >> index 096fa67..a63865b 100644 >> --- a/drivers/power/reset/Makefile >> +++ b/drivers/power/reset/Makefile >> @@ -20,3 +20,5 @@ obj-$(CONFIG_POWER_RESET_SYSCON) +=3D syscon-reboo= t.o >> obj-$(CONFIG_POWER_RESET_SYSCON_POWEROFF) +=3D syscon-poweroff.o >> obj-$(CONFIG_POWER_RESET_RMOBILE) +=3D rmobile-reset.o >> obj-$(CONFIG_POWER_RESET_ZX) +=3D zx-reboot.o >> +obj-$(CONFIG_REBOOT_MODE) +=3D reboot-mode.o >> +obj-$(CONFIG_SYSCON_REBOOT_MODE) +=3D syscon-reboot-mode.o >> diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset= /reboot-mode.c >> new file mode 100644 >> index 0000000..cdc4d72 >> --- /dev/null >> +++ b/drivers/power/reset/reboot-mode.c >> @@ -0,0 +1,118 @@ >> +/* >> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd >> + * >> + * This program is free software; you can redistribute it and/or mo= dify >> + * it under the terms of the GNU General Public License as publishe= d by >> + * the Free Software Foundation; either version 2 of the License, o= r >> + * (at your option) any later version. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include "reboot-mode.h" >> + >> +#define PREFIX "mode-" >> + >> +struct mode_info { >> + const char *mode; >> + unsigned int magic; >> + struct list_head list; >> +}; >> + >> +static int get_reboot_mode_magic(struct reboot_mode_driver *reboot, >> + const char *cmd) >> +{ >> + const char *normal =3D "normal"; >> + int magic =3D 0; >> + struct mode_info *info; >> + >> + if (!cmd) >> + cmd =3D normal; >> + >> + list_for_each_entry(info, &reboot->head, list) { >> + if (!strcmp(info->mode, cmd)) { >> + magic =3D info->magic; >> + break; >> + } >> + } >> + >> + return magic; >> +} >> + >> +static int reboot_mode_notify(struct notifier_block *this, >> + unsigned long mode, void *cmd) >> +{ >> + struct reboot_mode_driver *reboot; >> + int magic; >> + >> + reboot =3D container_of(this, struct reboot_mode_driver, reboot_no= tifier); >> + magic =3D get_reboot_mode_magic(reboot, cmd); >> + if (magic) >> + reboot->write(reboot, magic); >> + >> + return NOTIFY_DONE; >> +} >> + >> +int reboot_mode_register(struct reboot_mode_driver *reboot) >> +{ >> + struct mode_info *info; >> + struct property *prop; >> + struct device_node *np =3D reboot->dev->of_node; >> + size_t len =3D strlen(PREFIX); >> + int ret; >> + >> + INIT_LIST_HEAD(&reboot->head); >> + >> + for_each_property_of_node(np, prop) { >> + if (len > strlen(prop->name) || strncmp(prop->name, PREFIX, len)) >> + continue; >> + >> + info =3D devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL); >> + if (!info) { >> + ret =3D -ENOMEM; >> + goto error; >> + } >> + >> + info->mode =3D kstrdup_const(prop->name + len, GFP_KERNEL); >> + if (of_property_read_u32(np, prop->name, &info->magic)) { >> + dev_err(reboot->dev, "reboot mode %s without magic number\n", >> + info->mode); >> + devm_kfree(reboot->dev, info); > kfree_const(). The duplicated string won't be added to the list so it > won't be freed in error path or in unregister(). Each mode has a mode_info, if one of them gets an error whith=20 devm_kzalloc, they other mode_info add to the list before should be fre= ed. > >> + continue; >> + } >> + list_add_tail(&info->list, &reboot->head); >> + } >> + >> + reboot->reboot_notifier.notifier_call =3D reboot_mode_notify; >> + ret =3D register_reboot_notifier(&reboot->reboot_notifier); >> + if (ret) >> + dev_err(reboot->dev, "can't register reboot notifier\n"); > I don't understand your error paths. In previous patches they were > buggy... they still look buggy, I think. It's 8th iteration and such > basic things are still present. > > If this is an error then shouldn't everything be cleaned up? You are > returning error code thus the reboot_mode_register() caller will fail= =2E > This means the probe will fail. So you need to clean up - go to error= ? If this is an error, I think only the duplicated string should be=20 clean up,because other resources allocated by devm. If there is=20 something else, please let me know. thanks. > Best regards, > Krzysztof > > > -- 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