[PATCH v8 0/4] add reboot mode driver

[PATCH v8 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 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                        |  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 +++++++++++++++++
 include/dt-bindings/soc/rockchip_boot-mode.h       |  15 +++
 12 files changed, 363 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

-- 
1.9.1

[PATCH v8 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 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>;
+		};
+	};
-- 
1.9.1

[PATCH v8 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 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);
+			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");
+
+	return ret;
+
+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..93ab703
--- /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, 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..5489dd9
--- /dev/null
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -0,0 +1,99 @@
+/*
+ * 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,
+				    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");
-- 
1.9.1

[PATCH v8 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 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 b9567c1..4011c2e 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"
 
 / {
@@ -261,8 +262,16 @@
 	};
 
 	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 8ac49f3..9aa7d73 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"
 
 / {
@@ -713,6 +714,15 @@
 				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 99eeea7..f8f661f 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"
 
 / {
@@ -243,8 +244,17 @@
 	};
 
 	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
-- 
1.9.1

[PATCH v8 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 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 122777b..df062ea 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>
 
 / {
@@ -554,8 +555,17 @@
 	};
 
 	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 {
-- 
1.9.1

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

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@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 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

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Krzysztof:

On 2016年04月25日 18:42, Krzysztof Kozlowski wrote:
> On 04/25/2016 08:55 AM, Andy Yan wrote:
>> This driver parses the reboot commands like "reboot bootloader"
>> and "reboot recovery" to get a boot mode described in the
>> device tree , then call the write interfae to store the boot
>> mode in some place like special register or sram, which can
>> be read by the bootloader after system reboot, then the bootloader
>> can take different action according to the mode stored.
>>
>> This is commonly used on Android based devices, in order to
>> reboot the device into fastboot or recovery mode.
>>
>> Reviewed-by: Matthias Brugger <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 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().

    Each mode has a mode_info,  if one of them gets an error whith 
devm_kzalloc, they other mode_info add to the list before should be freed.
>
>> +			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?

     If this is an error, I think only the duplicated string should be 
clean up,because other resources allocated by devm. If there is 
something else, please let me know.

  thanks.


> Best regards,
> Krzysztof
>
>
>

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Krzysztof Kozlowski]

On 04/25/2016 01:29 PM, Andy Yan wrote:
> Hi Krzysztof:
> 
> On 2016年04月25日 18:42, Krzysztof Kozlowski wrote:
>> On 04/25/2016 08:55 AM, Andy Yan wrote:
>>> This driver parses the reboot commands like "reboot bootloader"
>>> and "reboot recovery" to get a boot mode described in the
>>> device tree , then call the write interfae to store the boot
>>> mode in some place like special register or sram, which can
>>> be read by the bootloader after system reboot, then the bootloader
>>> can take different action according to the mode stored.
>>>
>>> This is commonly used on Android based devices, in order to
>>> reboot the device into fastboot or recovery mode.
>>>
>>> Reviewed-by: Matthias Brugger <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 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().
> 
>    Each mode has a mode_info,  if one of them gets an error whith
> devm_kzalloc, they other mode_info add to the list before should be freed.

Please, write it again. I don't understand.

You are allocating 'info'. Then you are const-allocating 'info->mode'.
In this error path you are freeing 'info'. Where is the kfree_const()
for 'info->mode'?

>>
>>> +            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?
> 
>     If this is an error, I think only the duplicated string should be
> clean up,because other resources allocated by devm. If there is
> something else, please let me know.

Just goto error...

Best regards,
Krzysztof

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Krzysztof:

On 2016年04月25日 20:48, Krzysztof Kozlowski wrote:
> On 04/25/2016 01:29 PM, Andy Yan wrote:
>> Hi Krzysztof:
>>
>> On 2016年04月25日 18:42, Krzysztof Kozlowski wrote:
>>> On 04/25/2016 08:55 AM, Andy Yan wrote:
>>>> This driver parses the reboot commands like "reboot bootloader"
>>>> and "reboot recovery" to get a boot mode described in the
>>>> device tree , then call the write interfae to store the boot
>>>> mode in some place like special register or sram, which can
>>>> be read by the bootloader after system reboot, then the bootloader
>>>> can take different action according to the mode stored.
>>>>
>>>> This is commonly used on Android based devices, in order to
>>>> reboot the device into fastboot or recovery mode.
>>>>
>>>> Reviewed-by: Matthias Brugger <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 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().
>>     Each mode has a mode_info,  if one of them gets an error whith
>> devm_kzalloc, they other mode_info add to the list before should be freed.
> Please, write it again. I don't understand.
>
> You are allocating 'info'. Then you are const-allocating 'info->mode'.
> In this error path you are freeing 'info'. Where is the kfree_const()
> for 'info->mode'?
>

     Sorry, I got it, it's my fault.Thanks for your review.

>>>> +            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?
>>      If this is an error, I think only the duplicated string should be
>> clean up,because other resources allocated by devm. If there is
>> something else, please let me know.
> Just goto error...
>
> Best regards,
> Krzysztof
>
>
>

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Krzysztof:

On 2016年04月25日 20:48, Krzysztof Kozlowski wrote:
> On 04/25/2016 01:29 PM, Andy Yan wrote:
>> Hi Krzysztof:
>>
>> On 2016年04月25日 18:42, Krzysztof Kozlowski wrote:
>>> On 04/25/2016 08:55 AM, Andy Yan wrote:
>>>> This driver parses the reboot commands like "reboot bootloader"
>>>> and "reboot recovery" to get a boot mode described in the
>>>> device tree , then call the write interfae to store the boot
>>>> mode in some place like special register or sram, which can
>>>> be read by the bootloader after system reboot, then the bootloader
>>>> can take different action according to the mode stored.
>>>>
>>>> This is commonly used on Android based devices, in order to
>>>> reboot the device into fastboot or recovery mode.
>>>>
>>>> Reviewed-by: Matthias Brugger <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 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().
>>     Each mode has a mode_info,  if one of them gets an error whith
>> devm_kzalloc, they other mode_info add to the list before should be freed.
> Please, write it again. I don't understand.
>
> You are allocating 'info'. Then you are const-allocating 'info->mode'.
> In this error path you are freeing 'info'. Where is the kfree_const()
> for 'info->mode'?
>
>>>> +            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?
>>      If this is an error, I think only the duplicated string should be
>> clean up,because other resources allocated by devm. If there is
>> something else, please let me know.
> Just goto error...

     I check the code of register_reboot_notifier, this function only  
return 0. So
Maybe I don't need to check the return value here.
>
> Best regards,
> Krzysztof
>
>
>

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Bjorn Andersson]

On Sun, Apr 24, 2016 at 11:55 PM, Andy Yan <andy.yan@rock-chips.com> wrote:
[..]
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig

[..]

> +config SYSCON_REBOOT_MODE
> +       bool "Generic SYSCON regmap reboot mode driver"
> +       depends on OF

As this isn't really useful without syscon (but still compiles), I
would suggest adding:

depends on SYSCON || COMPILE_TEST

> +       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/reboot-mode.c b/drivers/power/reset/reboot-mode.c

[..]

> +
> +#define PREFIX "mode-"
> +
> +struct mode_info {
> +       const char *mode;
> +       unsigned int magic;

If you're using of_property_read_u32() to populate this directly you
should have this as u32.

> +       struct list_head list;
> +};
> +
> +static int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
> +                                const char *cmd)

Magic comes from an unsigned property and is passed as unsigned to the
regmap api. Please make it unsigned int throughout the implementation.

> +{
> +       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;
> +               }
> +       }
> +

[..]

> +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))

There's no reason to iterate over the string twice here, strncmp will
exit with -1 if you hit a '\0' before strlen(PREFIX). So you can drop
the first check without any difference in functionality.

What passes this checkout though is if the property equals PREFIX, but
this is probably better to handle as an error, rather than skip over.
So do that below

> +                       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);

You need something like this here:

if (!info->mode) {
    ret = -ENOMEM;
    goto error;
} else if (info->mode[0] == '\0')
    dev_err("mode too short");
    ret = -EINVAL;
    goto error;
}


If you do the kernel a favor and submit a patch to
drivers/base/devres.c adding devm_kstrdup_const() you don't have to do
the goto dance at all.

> +               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;
> +               }
> +               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");

You're returning an error but haven't freed your info->modes.

> +
> +       return ret;
> +
> +error:
> +       list_for_each_entry(info, &reboot->head, list)
> +               kfree_const(info->mode);
> +
> +       return ret;
> +}

Regards,
Bjorn

Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Sebastian Reichel]

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Hi,

On Mon, Apr 25, 2016 at 02:55:36PM +0800, 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>

What's the status of this patchset? It still has a few open
comments/issues, but I did not see a newer version.

-- Sebastian

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Re: [PATCH v8 2/4] power: reset: add reboot mode driver

[Andy Yan]

Hi Sebastian:

On 2016年06月16日 22:36, Sebastian Reichel wrote:
> Hi,
>
> On Mon, Apr 25, 2016 at 02:55:36PM +0800, 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>
> What's the status of this patchset? It still has a few open
> comments/issues, but I did not see a newer version.
>
> -- Sebastian

   Sorry for the delay, I will send a new version next week.