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 <matthias.bgg@xxxxxxxxx> > Reviewed-by: Moritz Fischer <moritz.fischer@xxxxxxxxx> > Tested-by: John Stultz <john.stultz@xxxxxxxxxx> > Acked-by: John Stultz <john.stultz@xxxxxxxxxx> > Signed-off-by: Andy Yan <andy.yan@xxxxxxxxxxxxxx> > > --- > > Changes in v8: > - do some cleanup when driver ubind > > Changes in v7: > - address some suggestions from Krzysztof, make syscon-reboot-mode driver 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_info > > 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 register > 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/Kconfig > 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. > > +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 > > diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile > index 096fa67..a63865b 100644 > --- a/drivers/power/reset/Makefile > +++ b/drivers/power/reset/Makefile > @@ -20,3 +20,5 @@ obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o > obj-$(CONFIG_POWER_RESET_SYSCON_POWEROFF) += syscon-poweroff.o > obj-$(CONFIG_POWER_RESET_RMOBILE) += rmobile-reset.o > obj-$(CONFIG_POWER_RESET_ZX) += zx-reboot.o > +obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o > +obj-$(CONFIG_SYSCON_REBOOT_MODE) += 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 modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <linux/device.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/reboot.h> > +#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 = "normal"; > + int magic = 0; > + struct mode_info *info; > + > + if (!cmd) > + cmd = normal; > + > + list_for_each_entry(info, &reboot->head, list) { > + if (!strcmp(info->mode, cmd)) { > + magic = 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 = container_of(this, struct reboot_mode_driver, reboot_notifier); > + magic = 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 = reboot->dev->of_node; > + size_t len = 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 = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL); > + if (!info) { > + ret = -ENOMEM; > + goto error; > + } > + > + info->mode = 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(). > + continue; > + } > + list_add_tail(&info->list, &reboot->head); > + } > + > + reboot->reboot_notifier.notifier_call = reboot_mode_notify; > + ret = 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. This means the probe will fail. So you need to clean up - go to error? Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html