[PATCH v9 0/4] add reboot mode driver

[PATCH v9 0/4] add reboot mode driver

[Andy Yan]

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 corresponding  write interfae
to store the boot mode in some place like special register
or ram , 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.


Changes in v9:
- select MFD_SYSCON when syscon-reboot-mode driver enabled
- refactoring error handling in reboot_mode_register

Changes in v8:
- do some cleanup when driver ubind

Changes in v7:
- fix some spelling mistakes
- declare that the mode magic should be none-zero value
- address some suggestions from Krzysztof, make syscon-reboot-mode driver data self-contained.

Changes in v6:
- fix a typo with "property"
- describe property "mask" more clear

Changes in v5:
- delete a unnecessary blank line in syscon-reboot-mode.txt
- rename mode-fastoboot to mode-bootloader in syscon-reboot-mode.txt
- rename macro BOOT_LOADER to BOOT_BL_DOWNLOAD, which gives a more clear mean
- use two blank space under help in Kconfig
- use unsigned int instead of int for member magic in struct mode_info

Changes in v4:
- remove mode-maskrom
- rename mode-fastboot to mode-bootloader to keep compatible with the exiting Android device
- make this driver depends on OF to avoid kbuild test error

Changes in v3:
- descirbe all reboot mode as properity instead of subnode
- scan multi properities
- add mask value for some platform which only use some bits of the register
  to store boot mode magic value
- descirbe all reboot mode as property instead of subnode
- add rk3036 support
- descirbe all reboot mode as property instead of subnode

Changes in v2:
- move to dir drivers/power/reset/
- make syscon-reboot-mode a generic driver
- make this node as a subnode of PMU
- make this node as a subnode of pmugrf

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 (4):
  dt-bindings: power: reset: add document for reboot-mode driver
  power: reset: add reboot mode driver
  ARM: dts: rockchip: add syscon-reboot-mode DT node
  ARM64: dts: rockchip: add syscon-reboot-mode DT node

 .../bindings/power/reset/reboot-mode.txt           |  25 ++++
 .../bindings/power/reset/syscon-reboot-mode.txt    |  35 ++++++
 arch/arm/boot/dts/rk3036.dtsi                      |  11 +-
 arch/arm/boot/dts/rk3288.dtsi                      |  10 ++
 arch/arm/boot/dts/rk3xxx.dtsi                      |  12 +-
 arch/arm64/boot/dts/rockchip/rk3368.dtsi           |  12 +-
 drivers/power/reset/Kconfig                        |  14 +++
 drivers/power/reset/Makefile                       |   2 +
 drivers/power/reset/reboot-mode.c                  | 128 +++++++++++++++++++++
 drivers/power/reset/reboot-mode.h                  |  14 +++
 drivers/power/reset/syscon-reboot-mode.c           | 100 ++++++++++++++++
 include/dt-bindings/soc/rockchip_boot-mode.h       |  15 +++
 12 files changed, 375 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/reset/reboot-mode.txt
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
 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
 create mode 100644 include/dt-bindings/soc/rockchip_boot-mode.h

-- 
2.7.4

[PATCH v9 1/4] dt-bindings: power: reset: add document for reboot-mode driver

[Andy Yan]

Add device tree bindings document for reboot-mode driver.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

---

Changes in v9: None
Changes in v8: None
Changes in v7:
- fix some spelling mistakes
- declare that the mode magic should be none-zero value

Changes in v6:
- fix a typo with "property"
- describe property "mask" more clear

Changes in v5:
- delete a unnecessary blank line in syscon-reboot-mode.txt
- rename mode-fastoboot to mode-bootloader in syscon-reboot-mode.txt
- rename macro BOOT_LOADER to BOOT_BL_DOWNLOAD, which gives a more clear mean

Changes in v4:
- remove mode-maskrom
- rename mode-fastboot to mode-bootloader to keep compatible with the exiting Android device

Changes in v3:
- descirbe all reboot mode as properity instead of subnode

Changes in v2: None
Changes in v1: None

 .../bindings/power/reset/reboot-mode.txt           | 25 ++++++++++++++++
 .../bindings/power/reset/syscon-reboot-mode.txt    | 35 ++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/reset/reboot-mode.txt
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt

diff --git a/Documentation/devicetree/bindings/power/reset/reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/reboot-mode.txt
new file mode 100644
index 0000000..de34f27
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/reboot-mode.txt
@@ -0,0 +1,25 @@
+Generic reboot mode core map driver
+
+This driver get reboot mode arguments and call the write
+interface to store the magic value in special register
+or ram. Then the bootloader can read it and take different
+action according to the argument stored.
+
+All mode properties are vendor specific, it is a indication to tell
+the bootloader what to do when the system reboots, and should be named
+as mode-xxx = <magic> (xxx is mode name, magic should be a none-zero value).
+
+For example modes common on Android platform:
+- mode-normal: Normal reboot mode, system reboot with command "reboot".
+- mode-recovery: Android Recovery mode, it is a mode to format the device or update a new image.
+- mode-bootloader: Android fastboot mode, it's a mode to re-flash partitions on the Android based device.
+- mode-loader: A bootloader mode, it's a mode used to download image on Rockchip platform,
+	       usually used in development.
+
+Example:
+	reboot-mode {
+		mode-normal = <BOOT_NORMAL>;
+		mode-recovery = <BOOT_RECOVERY>;
+		mode-bootloader = <BOOT_FASTBOOT>;
+		mode-loader = <BOOT_BL_DOWNLOAD>;
+	}
diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
new file mode 100644
index 0000000..f7ce1d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
@@ -0,0 +1,35 @@
+SYSCON reboot mode driver
+
+This driver gets reboot mode magic value form reboot-mode driver
+and stores it in a SYSCON mapped register. Then the bootloader
+can read it and take different action according to the magic
+value stored.
+
+This DT node should be represented as a sub-node of a "syscon", "simple-mfd"
+node.
+
+Required properties:
+- compatible: should be "syscon-reboot-mode"
+- offset: offset in the register map for the storage register (in bytes)
+
+Optional property:
+- mask: bits mask of the bits in the register to store the reboot mode magic value,
+  default set to 0xffffffff if missing.
+
+The rest of the properties should follow the generic reboot-mode description
+found in reboot-mode.txt
+
+Example:
+	pmu: pmu@20004000 {
+		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
+		reg = <0x20004000 0x100>;
+
+		reboot-mode {
+			compatible = "syscon-reboot-mode";
+			offset = <0x40>;
+			mode-normal = <BOOT_NORMAL>;
+			mode-recovery = <BOOT_RECOVERY>;
+			mode-bootloader = <BOOT_FASTBOOT>;
+			mode-loader = <BOOT_BL_DOWNLOAD>;
+		};
+	};
-- 
2.7.4

[PATCH v9 2/4] power: reset: add reboot mode driver

[Andy Yan]

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@gmail.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v9:
- select MFD_SYSCON when syscon-reboot-mode driver enabled
- refactoring error handling in reboot_mode_register

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              |  14 ++++
 drivers/power/reset/Makefile             |   2 +
 drivers/power/reset/reboot-mode.c        | 128 +++++++++++++++++++++++++++++++
 drivers/power/reset/reboot-mode.h        |  14 ++++
 drivers/power/reset/syscon-reboot-mode.c | 100 ++++++++++++++++++++++++
 5 files changed, 258 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 9bb2622..4ceaf74 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -183,5 +183,19 @@ 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
+	select MFD_SYSCON
+	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 ab7aa86..d6b2560 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -21,3 +21,5 @@ 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..5c9881e
--- /dev/null
+++ b/drivers/power/reset/reboot-mode.c
@@ -0,0 +1,128 @@
+/*
+ * 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;
+	u32 magic;
+	struct list_head list;
+};
+
+static unsigned 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;
+	unsigned 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 (strncmp(prop->name, PREFIX, len))
+			continue;
+
+		info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
+		if (!info) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		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);
+			continue;
+		}
+
+		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
+		if (!info->mode) {
+			ret =  -ENOMEM;
+			goto error;
+		} else if (info->mode[0] == '\0') {
+			kfree_const(info->mode);
+			ret = -EINVAL;
+			dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
+				prop->name);
+			goto error;
+		}
+
+		list_add_tail(&info->list, &reboot->head);
+	}
+
+	reboot->reboot_notifier.notifier_call = reboot_mode_notify;
+	register_reboot_notifier(&reboot->reboot_notifier);
+
+	return 0;
+
+error:
+	list_for_each_entry(info, &reboot->head, list)
+		kfree_const(info->mode);
+
+	return ret;
+}
+
+int reboot_mode_unregister(struct reboot_mode_driver *reboot)
+{
+	struct mode_info *info;
+
+	unregister_reboot_notifier(&reboot->reboot_notifier);
+
+	list_for_each_entry(info, &reboot->head, list)
+		kfree_const(info->mode);
+
+	return 0;
+}
+
+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..2491bb7
--- /dev/null
+++ b/drivers/power/reset/reboot-mode.h
@@ -0,0 +1,14 @@
+#ifndef __REBOOT_MODE_H__
+#define __REBOOT_MODE_H__
+
+struct reboot_mode_driver {
+	struct device *dev;
+	struct list_head head;
+	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
+	struct notifier_block reboot_notifier;
+};
+
+int reboot_mode_register(struct reboot_mode_driver *reboot);
+int reboot_mode_unregister(struct reboot_mode_driver *reboot);
+
+#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..22e0685
--- /dev/null
+++ b/drivers/power/reset/syscon-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/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include "reboot-mode.h"
+
+struct syscon_reboot_mode {
+	struct regmap *map;
+	struct reboot_mode_driver reboot;
+	u32 offset;
+	u32 mask;
+};
+
+static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
+				    unsigned int magic)
+{
+	struct syscon_reboot_mode *syscon_rbm;
+	int ret;
+
+	syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
+
+	ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
+				 syscon_rbm->mask, magic);
+	if (ret < 0)
+		dev_err(reboot->dev, "update reboot mode bits failed\n");
+
+	return ret;
+}
+
+static int syscon_reboot_mode_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct syscon_reboot_mode *syscon_rbm;
+
+	syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL);
+	if (!syscon_rbm)
+		return -ENOMEM;
+
+	syscon_rbm->reboot.dev = &pdev->dev;
+	syscon_rbm->reboot.write = syscon_reboot_mode_write;
+	syscon_rbm->mask = 0xffffffff;
+
+	dev_set_drvdata(&pdev->dev, syscon_rbm);
+
+	syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
+	if (IS_ERR(syscon_rbm->map))
+		return PTR_ERR(syscon_rbm->map);
+
+	if (of_property_read_u32(pdev->dev.of_node, "offset",
+	    &syscon_rbm->offset))
+		return -EINVAL;
+
+	of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask);
+
+
+	ret = reboot_mode_register(&syscon_rbm->reboot);
+	if (ret)
+		dev_err(&pdev->dev, "can't register reboot mode\n");
+
+	return ret;
+}
+
+static int syscon_reboot_mode_remove(struct platform_device *pdev)
+{
+	struct syscon_reboot_mode *syscon_rbm = dev_get_drvdata(&pdev->dev);
+
+	return reboot_mode_unregister(&syscon_rbm->reboot);
+}
+
+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,
+	.remove = syscon_reboot_mode_remove,
+	.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");
-- 
2.7.4

[PATCH v9 3/4] ARM: dts: rockchip: add syscon-reboot-mode DT node

[Andy Yan]

Rockchip platform use a SYSCON mapped register store
the reboot mode magic value for bootloader to use when
system reboot. So add syscon-reboot-mode driver DT node
for rk3xxx/rk3036/rk3288 based platform

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v9: None
Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
- descirbe all reboot mode as property instead of subnode
- add rk3036 support

Changes in v2:
- make this node as a subnode of PMU

Changes in v1:
- correct the maskrom magic number
- use macro defined in rockchip_boot-mode.h for reboot-mode DT node

 arch/arm/boot/dts/rk3036.dtsi                | 11 ++++++++++-
 arch/arm/boot/dts/rk3288.dtsi                | 10 ++++++++++
 arch/arm/boot/dts/rk3xxx.dtsi                | 12 +++++++++++-
 include/dt-bindings/soc/rockchip_boot-mode.h | 15 +++++++++++++++
 4 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 include/dt-bindings/soc/rockchip_boot-mode.h

diff --git a/arch/arm/boot/dts/rk3036.dtsi b/arch/arm/boot/dts/rk3036.dtsi
index 843d2be..f22b7df 100644
--- a/arch/arm/boot/dts/rk3036.dtsi
+++ b/arch/arm/boot/dts/rk3036.dtsi
@@ -43,6 +43,7 @@
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/pinctrl/rockchip.h>
 #include <dt-bindings/clock/rk3036-cru.h>
+#include <dt-bindings/soc/rockchip_boot-mode.h>
 #include "skeleton.dtsi"
 
 / {
@@ -313,8 +314,16 @@
 	};
 
 	grf: syscon@20008000 {
-		compatible = "rockchip,rk3036-grf", "syscon";
+		compatible = "rockchip,rk3036-grf", "syscon", "simple-mfd";
 		reg = <0x20008000 0x1000>;
+		reboot-mode {
+			compatible = "syscon-reboot-mode";
+			offset = <0x1d8>;
+			mode-normal = <BOOT_NORMAL>;
+			mode-recovery = <BOOT_RECOVERY>;
+			mode-bootloader = <BOOT_FASTBOOT>;
+			mode-loader = <BOOT_BL_DOWNLOAD>;
+		};
 	};
 
 	acodec: acodec-ana@20030000 {
diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 3b44ef3..8c3defd 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -45,6 +45,7 @@
 #include <dt-bindings/clock/rk3288-cru.h>
 #include <dt-bindings/thermal/thermal.h>
 #include <dt-bindings/power/rk3288-power.h>
+#include <dt-bindings/soc/rockchip_boot-mode.h>
 #include "skeleton.dtsi"
 
 / {
@@ -790,6 +791,15 @@
 				clocks = <&cru ACLK_GPU>;
 			};
 		};
+
+		reboot-mode {
+			compatible = "syscon-reboot-mode";
+			offset = <0x94>;
+			mode-normal = <BOOT_NORMAL>;
+			mode-recovery = <BOOT_RECOVERY>;
+			mode-bootloader = <BOOT_FASTBOOT>;
+			mode-loader = <BOOT_BL_DOWNLOAD>;
+		};
 	};
 
 	sgrf: syscon@ff740000 {
diff --git a/arch/arm/boot/dts/rk3xxx.dtsi b/arch/arm/boot/dts/rk3xxx.dtsi
index 99bbcc2..cc4bc7f 100644
--- a/arch/arm/boot/dts/rk3xxx.dtsi
+++ b/arch/arm/boot/dts/rk3xxx.dtsi
@@ -43,6 +43,7 @@
 
 #include <dt-bindings/interrupt-controller/irq.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/soc/rockchip_boot-mode.h>
 #include "skeleton.dtsi"
 
 / {
@@ -246,8 +247,17 @@
 	};
 
 	pmu: pmu@20004000 {
-		compatible = "rockchip,rk3066-pmu", "syscon";
+		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
 		reg = <0x20004000 0x100>;
+
+		reboot-mode {
+			compatible = "syscon-reboot-mode";
+			offset = <0x40>;
+			mode-normal = <BOOT_NORMAL>;
+			mode-recovery = <BOOT_RECOVERY>;
+			mode-bootloader = <BOOT_FASTBOOT>;
+			mode-loader = <BOOT_BL_DOWNLOAD>;
+		};
 	};
 
 	grf: grf@20008000 {
diff --git a/include/dt-bindings/soc/rockchip_boot-mode.h b/include/dt-bindings/soc/rockchip_boot-mode.h
new file mode 100644
index 0000000..ae7c867
--- /dev/null
+++ b/include/dt-bindings/soc/rockchip_boot-mode.h
@@ -0,0 +1,15 @@
+#ifndef __ROCKCHIP_BOOT_MODE_H
+#define __ROCKCHIP_BOOT_MODE_H
+
+/*high 24 bits is tag, low 8 bits is type*/
+#define REBOOT_FLAG		0x5242C300
+/* normal boot */
+#define BOOT_NORMAL		(REBOOT_FLAG + 0)
+/* enter bootloader rockusb mode */
+#define BOOT_BL_DOWNLOAD	(REBOOT_FLAG + 1)
+/* enter recovery */
+#define BOOT_RECOVERY		(REBOOT_FLAG + 3)
+ /* enter fastboot mode */
+#define BOOT_FASTBOOT		(REBOOT_FLAG + 9)
+
+#endif
-- 
2.7.4

[PATCH v9 4/4] ARM64: dts: rockchip: add syscon-reboot-mode DT node

[Andy Yan]

Add syscon-reboot-mode driver DT node for rk3368 platform

Tested-by: Caesar Wang <caesar.upstream@gmail.com>
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v9: None
Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
- descirbe all reboot mode as property instead of subnode

Changes in v2:
- make this node as a subnode of pmugrf

Changes in v1: None

 arch/arm64/boot/dts/rockchip/rk3368.dtsi | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3368.dtsi b/arch/arm64/boot/dts/rockchip/rk3368.dtsi
index 8b4a7c9..8041067 100644
--- a/arch/arm64/boot/dts/rockchip/rk3368.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3368.dtsi
@@ -45,6 +45,7 @@
 #include <dt-bindings/interrupt-controller/irq.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/pinctrl/rockchip.h>
+#include <dt-bindings/soc/rockchip_boot-mode.h>
 #include <dt-bindings/thermal/thermal.h>
 
 / {
@@ -632,8 +633,17 @@
 	};
 
 	pmugrf: syscon@ff738000 {
-		compatible = "rockchip,rk3368-pmugrf", "syscon";
+		compatible = "rockchip,rk3368-pmugrf", "syscon", "simple-mfd";
 		reg = <0x0 0xff738000 0x0 0x1000>;
+
+		reboot-mode {
+			compatible = "syscon-reboot-mode";
+			offset = <0x200>;
+			mode-normal = <BOOT_NORMAL>;
+			mode-recovery = <BOOT_RECOVERY>;
+			mode-bootloader = <BOOT_FASTBOOT>;
+			mode-loader = <BOOT_BL_DOWNLOAD>;
+		};
 	};
 
 	cru: clock-controller@ff760000 {
-- 
2.7.4

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

On 06/20/2016 08:38 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@gmail.com>
> Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
> Tested-by: John Stultz <john.stultz@linaro.org>
> Acked-by: John Stultz <john.stultz@linaro.org>
> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
> 
> ---
> 
> Changes in v9:
> - select MFD_SYSCON when syscon-reboot-mode driver enabled
> - refactoring error handling in reboot_mode_register
> 
> 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              |  14 ++++
>  drivers/power/reset/Makefile             |   2 +
>  drivers/power/reset/reboot-mode.c        | 128 +++++++++++++++++++++++++++++++
>  drivers/power/reset/reboot-mode.h        |  14 ++++
>  drivers/power/reset/syscon-reboot-mode.c | 100 ++++++++++++++++++++++++
>  5 files changed, 258 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 9bb2622..4ceaf74 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -183,5 +183,19 @@ 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"

Why not tristate?

Beside that the patch looks good.

Best regards,
Krzysztof

> +	depends on OF
> +	select REBOOT_MODE
> +	select MFD_SYSCON
> +	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.
> +

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Krzysztof:

On 2016年06月20日 16:09, Krzysztof Kozlowski wrote:
> On 06/20/2016 08:38 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@gmail.com>
>> Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
>> Tested-by: John Stultz <john.stultz@linaro.org>
>> Acked-by: John Stultz <john.stultz@linaro.org>
>> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
>>
>> ---
>>
>> Changes in v9:
>> - select MFD_SYSCON when syscon-reboot-mode driver enabled
>> - refactoring error handling in reboot_mode_register
>>
>> 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              |  14 ++++
>>   drivers/power/reset/Makefile             |   2 +
>>   drivers/power/reset/reboot-mode.c        | 128 +++++++++++++++++++++++++++++++
>>   drivers/power/reset/reboot-mode.h        |  14 ++++
>>   drivers/power/reset/syscon-reboot-mode.c | 100 ++++++++++++++++++++++++
>>   5 files changed, 258 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 9bb2622..4ceaf74 100644
>> --- a/drivers/power/reset/Kconfig
>> +++ b/drivers/power/reset/Kconfig
>> @@ -183,5 +183,19 @@ 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"
> Why not tristate?

    I see many reset drivers in this directories  use bool, so I follow 
them.
>
> Beside that the patch looks good.
>
> Best regards,
> Krzysztof
>
>> +	depends on OF
>> +	select REBOOT_MODE
>> +	select MFD_SYSCON
>> +	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.
>> +
>
>
>

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

On 06/20/2016 10:28 AM, Andy Yan wrote:
> Hi Krzysztof:
> 
> On 2016年06月20日 16:09, Krzysztof Kozlowski wrote:
>> On 06/20/2016 08:38 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@gmail.com>
>>> Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
>>> Tested-by: John Stultz <john.stultz@linaro.org>
>>> Acked-by: John Stultz <john.stultz@linaro.org>
>>> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
>>>
>>> ---
>>>
>>> Changes in v9:
>>> - select MFD_SYSCON when syscon-reboot-mode driver enabled
>>> - refactoring error handling in reboot_mode_register
>>>
>>> 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              |  14 ++++
>>>   drivers/power/reset/Makefile             |   2 +
>>>   drivers/power/reset/reboot-mode.c        | 128
>>> +++++++++++++++++++++++++++++++
>>>   drivers/power/reset/reboot-mode.h        |  14 ++++
>>>   drivers/power/reset/syscon-reboot-mode.c | 100
>>> ++++++++++++++++++++++++
>>>   5 files changed, 258 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 9bb2622..4ceaf74 100644
>>> --- a/drivers/power/reset/Kconfig
>>> +++ b/drivers/power/reset/Kconfig
>>> @@ -183,5 +183,19 @@ 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"
>> Why not tristate?
> 
>    I see many reset drivers in this directories  use bool, so I follow
> them.

+Cc Paul,

I don't mind that although I don't see any particular objections for
making it module-capable. In the same time I just reminded myself about
Paul Gortmaker's long effort (like [1] [2]) about removing module
capability from non-modular drivers.

Following his rationale, I think either this should be a tristate or the
module stuff should be removed.

Best regards,
Krzysztof

[1] https://lkml.org/lkml/2016/2/21/180
[2] https://lkml.org/lkml/2016/6/13/682

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Paul Gortmaker]

[Re: [PATCH v9 2/4] power: reset: add reboot mode driver] On 20/06/2016 (Mon 14:31) Krzysztof Kozlowski wrote:

> On 06/20/2016 10:28 AM, Andy Yan wrote:
> > Hi Krzysztof:
> > 
> > On 2016年06月20日 16:09, Krzysztof Kozlowski wrote:
> >> On 06/20/2016 08:38 AM, Andy Yan wrote:

[...]

> >>> +
> >>> +config SYSCON_REBOOT_MODE
> >>> +    bool "Generic SYSCON regmap reboot mode driver"
> >> Why not tristate?
> > 
> >    I see many reset drivers in this directories  use bool, so I follow
> > them.

Andy - understood, but mistakes done in the past do not justify
repeating them again in the present.  OK, this is not strictly a mistake
in that it causes an error, but it isn't an ideal approach.

> 
> +Cc Paul,
> 
> I don't mind that although I don't see any particular objections for
> making it module-capable. In the same time I just reminded myself about
> Paul Gortmaker's long effort (like [1] [2]) about removing module
> capability from non-modular drivers.

Thanks -- it is nice to see that people are starting to add this to
their review checklist ; early on they were getting added faster than I
could remove them.  :-(   But I think we are making ground now.

For this case, I don't have any bias for it being built-in vs. being
modular, so long as the code is actually consistent with the Kconfig. 

For existing bool settings I just remove the modular references, since I
can't be extending the functionality to include a modular usage when I
can't test it or even be sure if a module has a sensible use case.

Paul.
--

> 
> Following his rationale, I think either this should be a tristate or the
> module stuff should be removed.
> 
> Best regards,
> Krzysztof
> 
> [1] https://lkml.org/lkml/2016/2/21/180
> [2] https://lkml.org/lkml/2016/6/13/682
> 
> 

Re: [PATCH v9 3/4] ARM: dts: rockchip: add syscon-reboot-mode DT node

[Bjorn Andersson]

On Sun 19 Jun 23:39 PDT 2016, Andy Yan wrote:

> Rockchip platform use a SYSCON mapped register store
> the reboot mode magic value for bootloader to use when
> system reboot. So add syscon-reboot-mode driver DT node
> for rk3xxx/rk3036/rk3288 based platform
> 
> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
> 
[..]
> diff --git a/include/dt-bindings/soc/rockchip_boot-mode.h b/include/dt-bindings/soc/rockchip_boot-mode.h
> new file mode 100644
> index 0000000..ae7c867
> --- /dev/null
> +++ b/include/dt-bindings/soc/rockchip_boot-mode.h
> @@ -0,0 +1,15 @@
> +#ifndef __ROCKCHIP_BOOT_MODE_H
> +#define __ROCKCHIP_BOOT_MODE_H
> +
> +/*high 24 bits is tag, low 8 bits is type*/
> +#define REBOOT_FLAG		0x5242C300
> +/* normal boot */
> +#define BOOT_NORMAL		(REBOOT_FLAG + 0)
> +/* enter bootloader rockusb mode */
> +#define BOOT_BL_DOWNLOAD	(REBOOT_FLAG + 1)
> +/* enter recovery */
> +#define BOOT_RECOVERY		(REBOOT_FLAG + 3)
> + /* enter fastboot mode */
> +#define BOOT_FASTBOOT		(REBOOT_FLAG + 9)

The names of these defines are too generic for being in a header file.
You should likely make them include "ROCKCHIP" and "BOOT_MODE".

Regards,
Bjorn

Re: [PATCH v9 3/4] ARM: dts: rockchip: add syscon-reboot-mode DT node

[Andy Yan]

Hi Bjorn:
On 2016年06月21日 05:55, Bjorn Andersson wrote:
> On Sun 19 Jun 23:39 PDT 2016, Andy Yan wrote:
>
>> Rockchip platform use a SYSCON mapped register store
>> the reboot mode magic value for bootloader to use when
>> system reboot. So add syscon-reboot-mode driver DT node
>> for rk3xxx/rk3036/rk3288 based platform
>>
>> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
>> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
>>
> [..]
>> diff --git a/include/dt-bindings/soc/rockchip_boot-mode.h b/include/dt-bindings/soc/rockchip_boot-mode.h
>> new file mode 100644
>> index 0000000..ae7c867
>> --- /dev/null
>> +++ b/include/dt-bindings/soc/rockchip_boot-mode.h
>> @@ -0,0 +1,15 @@
>> +#ifndef __ROCKCHIP_BOOT_MODE_H
>> +#define __ROCKCHIP_BOOT_MODE_H
>> +
>> +/*high 24 bits is tag, low 8 bits is type*/
>> +#define REBOOT_FLAG		0x5242C300
>> +/* normal boot */
>> +#define BOOT_NORMAL		(REBOOT_FLAG + 0)
>> +/* enter bootloader rockusb mode */
>> +#define BOOT_BL_DOWNLOAD	(REBOOT_FLAG + 1)
>> +/* enter recovery */
>> +#define BOOT_RECOVERY		(REBOOT_FLAG + 3)
>> + /* enter fastboot mode */
>> +#define BOOT_FASTBOOT		(REBOOT_FLAG + 9)
> The names of these defines are too generic for being in a header file.
> You should likely make them include "ROCKCHIP" and "BOOT_MODE".
>
> Regards,
> Bjorn
>
>
>
I have already named this file as rockchip_boot-mode.h, I thinks this is
enough to declare it. And I also check some header files like 
qcom,gsbi.h, thermal/theraml_exynos.h, they also don't have include some 
flag like QCOM or EXYNOS.

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Paul:

On 2016年06月20日 22:40, Paul Gortmaker wrote:
> [Re: [PATCH v9 2/4] power: reset: add reboot mode driver] On 20/06/2016 (Mon 14:31) Krzysztof Kozlowski wrote:
>
>> On 06/20/2016 10:28 AM, Andy Yan wrote:
>>> Hi Krzysztof:
>>>
>>> On 2016年06月20日 16:09, Krzysztof Kozlowski wrote:
>>>> On 06/20/2016 08:38 AM, Andy Yan wrote:
> [...]
>
>>>>> +
>>>>> +config SYSCON_REBOOT_MODE
>>>>> +    bool "Generic SYSCON regmap reboot mode driver"
>>>> Why not tristate?
>>>     I see many reset drivers in this directories  use bool, so I follow
>>> them.
> Andy - understood, but mistakes done in the past do not justify
> repeating them again in the present.  OK, this is not strictly a mistake
> in that it causes an error, but it isn't an ideal approach.
>
>> +Cc Paul,
>>
>> I don't mind that although I don't see any particular objections for
>> making it module-capable. In the same time I just reminded myself about
>> Paul Gortmaker's long effort (like [1] [2]) about removing module
>> capability from non-modular drivers.
> Thanks -- it is nice to see that people are starting to add this to
> their review checklist ; early on they were getting added faster than I
> could remove them.  :-(   But I think we are making ground now.
>
> For this case, I don't have any bias for it being built-in vs. being
> modular, so long as the code is actually consistent with the Kconfig.
>
> For existing bool settings I just remove the modular references, since I
> can't be extending the functionality to include a modular usage when I
> can't test it or even be sure if a module has a sensible use case.
>
> Paul.
> --

   I will remove the module related stuff in the next version.
>> Following his rationale, I think either this should be a tristate or the
>> module stuff should be removed.
>>
>> Best regards,
>> Krzysztof
>>
>> [1] https://lkml.org/lkml/2016/2/21/180
>> [2] https://lkml.org/lkml/2016/6/13/682
>>
>>
>
>

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

On 06/21/2016 08:16 AM, Andy Yan wrote:
>   I will remove the module related stuff in the next version.
>>> Following his rationale, I think either this should be a tristate or the
>>> module stuff should be removed.

How about making it tristate? I think there isn't any obstacles for this
driver being a module. Some distros like modules.

Best regards.
Krzysztof

Re: [PATCH v9 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

On 06/20/2016 08:38 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@gmail.com>
> Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
> Tested-by: John Stultz <john.stultz@linaro.org>
> Acked-by: John Stultz <john.stultz@linaro.org>
> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
> 
> ---
> 
> Changes in v9:
> - select MFD_SYSCON when syscon-reboot-mode driver enabled
> - refactoring error handling in reboot_mode_register
> 
> 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              |  14 ++++
>  drivers/power/reset/Makefile             |   2 +
>  drivers/power/reset/reboot-mode.c        | 128 +++++++++++++++++++++++++++++++
>  drivers/power/reset/reboot-mode.h        |  14 ++++
>  drivers/power/reset/syscon-reboot-mode.c | 100 ++++++++++++++++++++++++
>  5 files changed, 258 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

One minor whitespace issue at the end but beside that:

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

(...)

> diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
> new file mode 100644
> index 0000000..22e0685
> --- /dev/null
> +++ b/drivers/power/reset/syscon-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/init.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include "reboot-mode.h"
> +
> +struct syscon_reboot_mode {
> +	struct regmap *map;
> +	struct reboot_mode_driver reboot;
> +	u32 offset;
> +	u32 mask;
> +};
> +
> +static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
> +				    unsigned int magic)
> +{
> +	struct syscon_reboot_mode *syscon_rbm;
> +	int ret;
> +
> +	syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
> +
> +	ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
> +				 syscon_rbm->mask, magic);
> +	if (ret < 0)
> +		dev_err(reboot->dev, "update reboot mode bits failed\n");
> +
> +	return ret;
> +}
> +
> +static int syscon_reboot_mode_probe(struct platform_device *pdev)
> +{
> +	int ret;
> +	struct syscon_reboot_mode *syscon_rbm;
> +
> +	syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL);
> +	if (!syscon_rbm)
> +		return -ENOMEM;
> +
> +	syscon_rbm->reboot.dev = &pdev->dev;
> +	syscon_rbm->reboot.write = syscon_reboot_mode_write;
> +	syscon_rbm->mask = 0xffffffff;
> +
> +	dev_set_drvdata(&pdev->dev, syscon_rbm);
> +
> +	syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
> +	if (IS_ERR(syscon_rbm->map))
> +		return PTR_ERR(syscon_rbm->map);
> +
> +	if (of_property_read_u32(pdev->dev.of_node, "offset",
> +	    &syscon_rbm->offset))
> +		return -EINVAL;
> +
> +	of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask);
> +
> +

Just one new line.

Best regards,
Krzysztof

> +	ret = reboot_mode_register(&syscon_rbm->reboot);
> +	if (ret)
> +		dev_err(&pdev->dev, "can't register reboot mode\n");
> +
> +	return ret;
> +}
> +
> +static int syscon_reboot_mode_remove(struct platform_device *pdev)
> +{
> +	struct syscon_reboot_mode *syscon_rbm = dev_get_drvdata(&pdev->dev);
> +
> +	return reboot_mode_unregister(&syscon_rbm->reboot);
> +}
> +
> +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,
> +	.remove = syscon_reboot_mode_remove,
> +	.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");
>