[PATCH] power: reset: make reboot-mode user selectable

From: Arnd Bergmann
Date: Mon Aug 05 2019 - 03:58:39 EST


Nandor Han points out that there might be drivers that can use
the reboot-mode interfaces but might also be usable on configurations
without device tree.

Move the 'depends on OF' dependency into CONFIG_REBOOT_MODE since
that is the only thing that truely has a compile-time dependency
on CONFIG_OF, and make it user visible to make it possible to
disable it.

The drivers that used to 'select REBOOT_MODE' of course now have to
use 'depends on REBOOT_MODE instead'. With this, we can soften the
dependency and allow compile-testing the three front-end drivers
on non-OF platforms.

Note: anyone who was using a reboot mode driver in their kernel
configuration now has to enable CONFIG_REBOOT_MODE as well.

Suggested-by: Nandor Han <nandor.han@xxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
Nandor, this is so far untested, could you make sure this
works in all configurations and forward it along with the
bugfix?

Sebastian, I'm not convinced this is a good idea, just sending
it as Nandor requested. Please decide for yourself.
---
arch/arm/configs/davinci_all_defconfig | 1 +
arch/arm64/configs/defconfig | 1 +
drivers/power/reset/Kconfig | 22 +++++++++++++---------
include/linux/reboot-mode.h | 20 ++++++++++++++++++++
4 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/arch/arm/configs/davinci_all_defconfig b/arch/arm/configs/davinci_all_defconfig
index b34970ce6b31..ebf506c01899 100644
--- a/arch/arm/configs/davinci_all_defconfig
+++ b/arch/arm/configs/davinci_all_defconfig
@@ -139,6 +139,7 @@ CONFIG_GPIO_PCA953X_IRQ=y
CONFIG_RESET_CONTROLLER=y
CONFIG_POWER_RESET=y
CONFIG_POWER_RESET_GPIO=y
+CONFIG_REBOOT_MODE=m
CONFIG_SYSCON_REBOOT_MODE=m
CONFIG_BATTERY_LEGO_EV3=m
CONFIG_WATCHDOG=y
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 0e58ef02880c..bb7d7bec1413 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -419,6 +419,7 @@ CONFIG_ROCKCHIP_IODOMAIN=y
CONFIG_POWER_RESET_MSM=y
CONFIG_POWER_RESET_XGENE=y
CONFIG_POWER_RESET_SYSCON=y
+CONFIG_REBOOT_MODE=y
CONFIG_SYSCON_REBOOT_MODE=y
CONFIG_BATTERY_SBS=m
CONFIG_BATTERY_BQ27XXX=y
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index a564237278ff..997323d443f5 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -9,6 +9,13 @@ menuconfig POWER_RESET

if POWER_RESET

+config REBOOT_MODE
+ tristate "Pass reboot-mode to firmware"
+ depends on OF
+ help
+ Some drivers allow setting the reboot mode through a platform
+ interface that the boot firmware can read.
+
config POWER_RESET_AS3722
bool "ams AS3722 power-off driver"
depends on MFD_AS3722
@@ -107,9 +114,9 @@ config POWER_RESET_MSM

config POWER_RESET_QCOM_PON
tristate "Qualcomm power-on driver"
- depends on ARCH_QCOM
+ depends on ARCH_QCOM || COMPILE_TEST
depends on MFD_SPMI_PMIC
- select REBOOT_MODE
+ depends on REBOOT_MODE || !REBOOT_MODE
help
Power On support for Qualcomm boards.
If you have a Qualcomm platform and need support for
@@ -223,14 +230,11 @@ config POWER_RESET_ZX
help
Reboot support for ZTE SoCs.

-config REBOOT_MODE
- tristate
-
config SYSCON_REBOOT_MODE
tristate "Generic SYSCON regmap reboot mode driver"
- depends on OF
+ depends on OF || COMPILE_TEST
depends on MFD_SYSCON
- select REBOOT_MODE
+ depends on REBOOT_MODE || !REBOOT_MODE
help
Say y here will enable reboot mode driver. This will
get reboot mode arguments and store it in SYSCON mapped
@@ -248,8 +252,8 @@ config POWER_RESET_SC27XX

config NVMEM_REBOOT_MODE
tristate "Generic NVMEM reboot mode driver"
- depends on OF
- select REBOOT_MODE
+ depends on OF || COMPILE_TEST
+ depends on REBOOT_MODE || !REBOOT_MODE
help
Say y here will enable reboot mode driver. This will
get reboot mode arguments and store it in a NVMEM cell,
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 4a2abb38d1d6..bd002060e3d0 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -9,11 +9,31 @@ struct reboot_mode_driver {
struct notifier_block reboot_notifier;
};

+#if IS_ENABLED(CONFIG_REBOOT_MODE)
int reboot_mode_register(struct reboot_mode_driver *reboot);
int reboot_mode_unregister(struct reboot_mode_driver *reboot);
int devm_reboot_mode_register(struct device *dev,
struct reboot_mode_driver *reboot);
void devm_reboot_mode_unregister(struct device *dev,
struct reboot_mode_driver *reboot);
+#else
+static inline int reboot_mode_register(struct reboot_mode_driver *reboot)
+{
+ return 0;
+}
+static inline int reboot_mode_unregister(struct reboot_mode_driver *reboot)
+{
+ return 0;
+}
+static inline int devm_reboot_mode_register(struct device *dev,
+ struct reboot_mode_driver *reboot)
+{
+ return 0;
+}
+static inline void devm_reboot_mode_unregister(struct device *dev,
+ struct reboot_mode_driver *reboot)
+{
+}
+#endif

#endif
--
2.20.0