| Message ID | 1452598319-8324-1-git-send-email-andy.yan@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 12, 2016 at 3:31 AM, Andy Yan <andy.yan@rock-chips.com> 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 write interfae to store the boot > mode in some persistent storage like special register or ram, > 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, which in order > to reboot the device into fastboot or recovery mode. > > Signed-off-by: Andy Yan <andy.yan@rock-chips.com> Hey Andy! Thanks for keeping this work going! I've just successfully reworked my Nexus7 tree to use your implementation (using the syscon version, setting up a syscon for IMEM as Bjorn had requested earlier). All is working well so far! The one thing I was working on supporting with my own version that seems to be missing here are for devices that use string based codes, rather then magic numbers. This was mostly a theoretical issue. I think the Galaxy Nexus used it, and when I was looking at some of the HTC devices, they support a text based reason along with the magic code, but at least in some implementations the text mode isn't used, so I suspect there its just for extra debugging. So this may not be critical to solve until someone tries to add support for such a device. Anyway, I'm going to look at porting this to the HiKey board next (which just uses reserved ram, not syscon), so I'll try to do a an SRAM driver implementaiton to see how that goes. thanks! -john
Hi John: On 2016?01?16? 04:27, John Stultz wrote: > On Tue, Jan 12, 2016 at 3:31 AM, Andy Yan <andy.yan@rock-chips.com> 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 write interfae to store the boot >> mode in some persistent storage like special register or ram, >> 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, which in order >> to reboot the device into fastboot or recovery mode. >> >> Signed-off-by: Andy Yan <andy.yan@rock-chips.com> > > Hey Andy! > Thanks for keeping this work going! I've just successfully reworked > my Nexus7 tree to use your implementation (using the syscon version, > setting up a syscon for IMEM as Bjorn had requested earlier). > > All is working well so far! > > The one thing I was working on supporting with my own version that > seems to be missing here are for devices that use string based codes, > rather then magic numbers. > > This was mostly a theoretical issue. I think the Galaxy Nexus used it, > and when I was looking at some of the HTC devices, they support a text > based reason along with the magic code, but at least in some > implementations the text mode isn't used, so I suspect there its just > for extra debugging. So this may not be critical to solve until > someone tries to add support for such a device. > > Anyway, I'm going to look at porting this to the HiKey board next > (which just uses reserved ram, not syscon), so I'll try to do a an > SRAM driver implementaiton to see how that goes. > > thanks! > -john > > > > Very glad to hear news from you. And welcome your SRAM based driver implementation.
On 12/01/16 12:31, 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 write interfae to store the boot > mode in some persistent storage like special register or ram, > 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, which in order > to reboot the device into fastboot or recovery mode. > > Signed-off-by: Andy Yan <andy.yan@rock-chips.com> > > --- Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> > > 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 | 16 +++++ > drivers/power/reset/Makefile | 2 + > drivers/power/reset/reboot-mode.c | 100 +++++++++++++++++++++++++++++++ > drivers/power/reset/reboot-mode.h | 6 ++ > drivers/power/reset/syscon-reboot-mode.c | 62 +++++++++++++++++++ > 5 files changed, 186 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..2e6d873 100644 > --- a/drivers/power/reset/Kconfig > +++ b/drivers/power/reset/Kconfig > @@ -173,5 +173,21 @@ config POWER_RESET_ZX > help > Reboot support for ZTE SoCs. > > +config REBOOT_MODE > + tristate > + depends on OF > + help > + This driver will help to pass the system reboot mode > + to bootloader > + > +config SYSCON_REBOOT_MODE > + bool "Generic SYSCON regmap reboot mode driver" > + 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..92b7b4d > --- /dev/null > +++ b/drivers/power/reset/reboot-mode.c > @@ -0,0 +1,100 @@ > +/* > + * 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" > + > +struct mode_info { > + const char *mode; > + int magic; > + struct list_head list; > +}; > + > +struct reboot_mode_driver { > + struct list_head head; > + int (*write)(int magic); > + struct notifier_block reboot_notifier; > +}; > + > +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(magic); > + > + return NOTIFY_DONE; > +} > + > +int reboot_mode_register(struct device *dev, int (*write)(int)) > +{ > + struct reboot_mode_driver *reboot; > + struct mode_info *info; > + struct device_node *child; > + int ret; > + > + reboot = devm_kzalloc(dev, sizeof(*reboot), GFP_KERNEL); > + if (!reboot) > + return -ENOMEM; > + > + reboot->write = write; > + INIT_LIST_HEAD(&reboot->head); > + for_each_child_of_node(dev->of_node, child) { > + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); > + if (!info) > + return -ENOMEM; > + info->mode = of_get_property(child, "linux,mode", NULL); > + if (of_property_read_u32(child, "loader,magic", &info->magic)) { > + dev_err(dev, "reboot mode %s without magic number\n", > + info->mode); > + devm_kfree(dev, info); > + 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(dev, "can't register reboot notifier\n"); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(reboot_mode_register); > + > +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); > +MODULE_DESCRIPTION("System reboot mode driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/power/reset/reboot-mode.h b/drivers/power/reset/reboot-mode.h > new file mode 100644 > index 0000000..76646e7 > --- /dev/null > +++ b/drivers/power/reset/reboot-mode.h > @@ -0,0 +1,6 @@ > +#ifndef __REBOOT_MODE_H__ > +#define __REBOOT_MODE_H__ > + > +extern int reboot_mode_register(struct device *dev, int (*write)(int)); > + > +#endif > diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c > new file mode 100644 > index 0000000..b9370f3 > --- /dev/null > +++ b/drivers/power/reset/syscon-reboot-mode.c > @@ -0,0 +1,62 @@ > +/* > + * 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/init.h> > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/reboot.h> > +#include <linux/regmap.h> > +#include <linux/mfd/syscon.h> > +#include "reboot-mode.h" > + > +static struct regmap *map; > +static u32 offset; > + > +static int syscon_reboot_mode_write(int magic) > +{ > + regmap_write(map, offset, magic); > + > + return 0; > +} > + > +static int syscon_reboot_mode_probe(struct platform_device *pdev) > +{ > + int ret; > + > + map = syscon_node_to_regmap(pdev->dev.parent->of_node); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) > + return -EINVAL; > + ret = reboot_mode_register(&pdev->dev, syscon_reboot_mode_write); > + if (ret) > + dev_err(&pdev->dev, "can't register reboot mode\n"); > + > + return ret; > +} > + > +static const struct of_device_id syscon_reboot_mode_of_match[] = { > + { .compatible = "syscon-reboot-mode" }, > + {} > +}; > + > +static struct platform_driver syscon_reboot_mode_driver = { > + .probe = syscon_reboot_mode_probe, > + .driver = { > + .name = "syscon-reboot-mode", > + .of_match_table = syscon_reboot_mode_of_match, > + }, > +}; > +module_platform_driver(syscon_reboot_mode_driver); > + > +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); > +MODULE_DESCRIPTION("SYSCON reboot mode driver"); > +MODULE_LICENSE("GPL v2"); >
Hi Andy, On Tue, Jan 12, 2016 at 12:31 PM, Andy Yan <andy.yan@rock-chips.com> 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 write interfae to store the boot > mode in some persistent storage like special register or ram, > 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, which in order > to reboot the device into fastboot or recovery mode. > > Signed-off-by: Andy Yan <andy.yan@rock-chips.com> > > --- > > 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 | 16 +++++ > drivers/power/reset/Makefile | 2 + > drivers/power/reset/reboot-mode.c | 100 +++++++++++++++++++++++++++++++ > drivers/power/reset/reboot-mode.h | 6 ++ > drivers/power/reset/syscon-reboot-mode.c | 62 +++++++++++++++++++ > 5 files changed, 186 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..2e6d873 100644 > --- a/drivers/power/reset/Kconfig > +++ b/drivers/power/reset/Kconfig > @@ -173,5 +173,21 @@ config POWER_RESET_ZX > help > Reboot support for ZTE SoCs. > > +config REBOOT_MODE > + tristate > + depends on OF > + help > + This driver will help to pass the system reboot mode > + to bootloader > + > +config SYSCON_REBOOT_MODE > + bool "Generic SYSCON regmap reboot mode driver" > + 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..92b7b4d > --- /dev/null > +++ b/drivers/power/reset/reboot-mode.c > @@ -0,0 +1,100 @@ > +/* > + * 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" > + > +struct mode_info { > + const char *mode; > + int magic; > + struct list_head list; > +}; > + > +struct reboot_mode_driver { > + struct list_head head; > + int (*write)(int magic); > + struct notifier_block reboot_notifier; > +}; > + > +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(magic); > + > + return NOTIFY_DONE; > +} > + > +int reboot_mode_register(struct device *dev, int (*write)(int)) > +{ > + struct reboot_mode_driver *reboot; > + struct mode_info *info; > + struct device_node *child; > + int ret; > + > + reboot = devm_kzalloc(dev, sizeof(*reboot), GFP_KERNEL); > + if (!reboot) > + return -ENOMEM; > + > + reboot->write = write; > + INIT_LIST_HEAD(&reboot->head); > + for_each_child_of_node(dev->of_node, child) { > + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); > + if (!info) > + return -ENOMEM; > + info->mode = of_get_property(child, "linux,mode", NULL); > + if (of_property_read_u32(child, "loader,magic", &info->magic)) { > + dev_err(dev, "reboot mode %s without magic number\n", > + info->mode); > + devm_kfree(dev, info); > + 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(dev, "can't register reboot notifier\n"); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(reboot_mode_register); > + > +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); > +MODULE_DESCRIPTION("System reboot mode driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/power/reset/reboot-mode.h b/drivers/power/reset/reboot-mode.h > new file mode 100644 > index 0000000..76646e7 > --- /dev/null > +++ b/drivers/power/reset/reboot-mode.h > @@ -0,0 +1,6 @@ > +#ifndef __REBOOT_MODE_H__ > +#define __REBOOT_MODE_H__ > + > +extern int reboot_mode_register(struct device *dev, int (*write)(int)); > + > +#endif > diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c > new file mode 100644 > index 0000000..b9370f3 > --- /dev/null > +++ b/drivers/power/reset/syscon-reboot-mode.c > @@ -0,0 +1,62 @@ > +/* > + * 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/init.h> > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/reboot.h> > +#include <linux/regmap.h> > +#include <linux/mfd/syscon.h> > +#include "reboot-mode.h" > + > +static struct regmap *map; > +static u32 offset; > + > +static int syscon_reboot_mode_write(int magic) > +{ > + regmap_write(map, offset, magic); See suggestion below. I think using regmap_update_bits() would be even more useful for cases where you have other stuff in that register, too. > + > + return 0; > +} > + > +static int syscon_reboot_mode_probe(struct platform_device *pdev) > +{ > + int ret; > + > + map = syscon_node_to_regmap(pdev->dev.parent->of_node); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) > + return -EINVAL; I think it would be worthwhile to have a mask value here, that you can use with regmap_update_bits() + if (of_property_read_u32(pdev->dev.of_node, "mask", &mask)) + return -EINVAL; Cheers, Moritz
Hi Moritz: On 2016?01?27? 18:53, Moritz Fischer wrote: > Hi Andy, > > On Tue, Jan 12, 2016 at 12:31 PM, Andy Yan <andy.yan@rock-chips.com> 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 write interfae to store the boot >> mode in some persistent storage like special register or ram, >> 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, which in order >> to reboot the device into fastboot or recovery mode. >> >> Signed-off-by: Andy Yan <andy.yan@rock-chips.com> >> >> --- >> >> 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 | 16 +++++ >> drivers/power/reset/Makefile | 2 + >> drivers/power/reset/reboot-mode.c | 100 +++++++++++++++++++++++++++++++ >> drivers/power/reset/reboot-mode.h | 6 ++ >> drivers/power/reset/syscon-reboot-mode.c | 62 +++++++++++++++++++ >> 5 files changed, 186 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..2e6d873 100644 >> --- a/drivers/power/reset/Kconfig >> +++ b/drivers/power/reset/Kconfig >> @@ -173,5 +173,21 @@ config POWER_RESET_ZX >> help >> Reboot support for ZTE SoCs. >> >> +config REBOOT_MODE >> + tristate >> + depends on OF >> + help >> + This driver will help to pass the system reboot mode >> + to bootloader >> + >> +config SYSCON_REBOOT_MODE >> + bool "Generic SYSCON regmap reboot mode driver" >> + 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..92b7b4d >> --- /dev/null >> +++ b/drivers/power/reset/reboot-mode.c >> @@ -0,0 +1,100 @@ >> +/* >> + * 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" >> + >> +struct mode_info { >> + const char *mode; >> + int magic; >> + struct list_head list; >> +}; >> + >> +struct reboot_mode_driver { >> + struct list_head head; >> + int (*write)(int magic); >> + struct notifier_block reboot_notifier; >> +}; >> + >> +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(magic); >> + >> + return NOTIFY_DONE; >> +} >> + >> +int reboot_mode_register(struct device *dev, int (*write)(int)) >> +{ >> + struct reboot_mode_driver *reboot; >> + struct mode_info *info; >> + struct device_node *child; >> + int ret; >> + >> + reboot = devm_kzalloc(dev, sizeof(*reboot), GFP_KERNEL); >> + if (!reboot) >> + return -ENOMEM; >> + >> + reboot->write = write; >> + INIT_LIST_HEAD(&reboot->head); >> + for_each_child_of_node(dev->of_node, child) { >> + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); >> + if (!info) >> + return -ENOMEM; >> + info->mode = of_get_property(child, "linux,mode", NULL); >> + if (of_property_read_u32(child, "loader,magic", &info->magic)) { >> + dev_err(dev, "reboot mode %s without magic number\n", >> + info->mode); >> + devm_kfree(dev, info); >> + 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(dev, "can't register reboot notifier\n"); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(reboot_mode_register); >> + >> +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); >> +MODULE_DESCRIPTION("System reboot mode driver"); >> +MODULE_LICENSE("GPL v2"); >> diff --git a/drivers/power/reset/reboot-mode.h b/drivers/power/reset/reboot-mode.h >> new file mode 100644 >> index 0000000..76646e7 >> --- /dev/null >> +++ b/drivers/power/reset/reboot-mode.h >> @@ -0,0 +1,6 @@ >> +#ifndef __REBOOT_MODE_H__ >> +#define __REBOOT_MODE_H__ >> + >> +extern int reboot_mode_register(struct device *dev, int (*write)(int)); >> + >> +#endif >> diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c >> new file mode 100644 >> index 0000000..b9370f3 >> --- /dev/null >> +++ b/drivers/power/reset/syscon-reboot-mode.c >> @@ -0,0 +1,62 @@ >> +/* >> + * 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/init.h> >> +#include <linux/module.h> >> +#include <linux/kernel.h> >> +#include <linux/of.h> >> +#include <linux/of_address.h> >> +#include <linux/platform_device.h> >> +#include <linux/reboot.h> >> +#include <linux/regmap.h> >> +#include <linux/mfd/syscon.h> >> +#include "reboot-mode.h" >> + >> +static struct regmap *map; >> +static u32 offset; >> + >> +static int syscon_reboot_mode_write(int magic) >> +{ >> + regmap_write(map, offset, magic); > See suggestion below. I think using regmap_update_bits() would be even > more useful for cases where you have other stuff in that register, too. > >> + >> + return 0; >> +} >> + >> +static int syscon_reboot_mode_probe(struct platform_device *pdev) >> +{ >> + int ret; >> + >> + map = syscon_node_to_regmap(pdev->dev.parent->of_node); >> + if (IS_ERR(map)) >> + return PTR_ERR(map); >> + if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) >> + return -EINVAL; > I think it would be worthwhile to have a mask value here, that you can use > with regmap_update_bits() That sounds reasonable, I already fond some drivers like tegra[0] only use some bits to store the mode value. So I will add it in V3. [0] drivers/soc/tegra/pmc.c > > + if (of_property_read_u32(pdev->dev.of_node, "mask", &mask)) > + return -EINVAL; > > > Cheers, > > Moritz > > >
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index 1131cf7..2e6d873 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -173,5 +173,21 @@ config POWER_RESET_ZX help Reboot support for ZTE SoCs. +config REBOOT_MODE + tristate + depends on OF + help + This driver will help to pass the system reboot mode + to bootloader + +config SYSCON_REBOOT_MODE + bool "Generic SYSCON regmap reboot mode driver" + 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..92b7b4d --- /dev/null +++ b/drivers/power/reset/reboot-mode.c @@ -0,0 +1,100 @@ +/* + * 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" + +struct mode_info { + const char *mode; + int magic; + struct list_head list; +}; + +struct reboot_mode_driver { + struct list_head head; + int (*write)(int magic); + struct notifier_block reboot_notifier; +}; + +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(magic); + + return NOTIFY_DONE; +} + +int reboot_mode_register(struct device *dev, int (*write)(int)) +{ + struct reboot_mode_driver *reboot; + struct mode_info *info; + struct device_node *child; + int ret; + + reboot = devm_kzalloc(dev, sizeof(*reboot), GFP_KERNEL); + if (!reboot) + return -ENOMEM; + + reboot->write = write; + INIT_LIST_HEAD(&reboot->head); + for_each_child_of_node(dev->of_node, child) { + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + info->mode = of_get_property(child, "linux,mode", NULL); + if (of_property_read_u32(child, "loader,magic", &info->magic)) { + dev_err(dev, "reboot mode %s without magic number\n", + info->mode); + devm_kfree(dev, info); + 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(dev, "can't register reboot notifier\n"); + + return ret; +} +EXPORT_SYMBOL_GPL(reboot_mode_register); + +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); +MODULE_DESCRIPTION("System reboot mode driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/power/reset/reboot-mode.h b/drivers/power/reset/reboot-mode.h new file mode 100644 index 0000000..76646e7 --- /dev/null +++ b/drivers/power/reset/reboot-mode.h @@ -0,0 +1,6 @@ +#ifndef __REBOOT_MODE_H__ +#define __REBOOT_MODE_H__ + +extern int reboot_mode_register(struct device *dev, int (*write)(int)); + +#endif diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c new file mode 100644 index 0000000..b9370f3 --- /dev/null +++ b/drivers/power/reset/syscon-reboot-mode.c @@ -0,0 +1,62 @@ +/* + * 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/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> +#include "reboot-mode.h" + +static struct regmap *map; +static u32 offset; + +static int syscon_reboot_mode_write(int magic) +{ + regmap_write(map, offset, magic); + + return 0; +} + +static int syscon_reboot_mode_probe(struct platform_device *pdev) +{ + int ret; + + map = syscon_node_to_regmap(pdev->dev.parent->of_node); + if (IS_ERR(map)) + return PTR_ERR(map); + if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) + return -EINVAL; + ret = reboot_mode_register(&pdev->dev, syscon_reboot_mode_write); + if (ret) + dev_err(&pdev->dev, "can't register reboot mode\n"); + + return ret; +} + +static const struct of_device_id syscon_reboot_mode_of_match[] = { + { .compatible = "syscon-reboot-mode" }, + {} +}; + +static struct platform_driver syscon_reboot_mode_driver = { + .probe = syscon_reboot_mode_probe, + .driver = { + .name = "syscon-reboot-mode", + .of_match_table = syscon_reboot_mode_of_match, + }, +}; +module_platform_driver(syscon_reboot_mode_driver); + +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); +MODULE_DESCRIPTION("SYSCON reboot mode driver"); +MODULE_LICENSE("GPL v2");
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 write interfae to store the boot mode in some persistent storage like special register or ram, 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, which in order to reboot the device into fastboot or recovery mode. Signed-off-by: Andy Yan <andy.yan@rock-chips.com> --- 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 | 16 +++++ drivers/power/reset/Makefile | 2 + drivers/power/reset/reboot-mode.c | 100 +++++++++++++++++++++++++++++++ drivers/power/reset/reboot-mode.h | 6 ++ drivers/power/reset/syscon-reboot-mode.c | 62 +++++++++++++++++++ 5 files changed, 186 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