Description
-----------
Extend the reboot mode driver to use a NVMEM cell as writing interface.
Testing
-------
The testing is done by configuring DT from a custom board.
The NVMEM cell is configured in an RTC non-volatile memory.
Kernel: 4.14.60 (the patchset was rebased on kernel master)
DT configurations:
`
...
reboot-mode-nvmem@0 {
compatible = "simple-mfd";
reboot-mode {
compatible = "nvmem-reboot-mode";
nvmem-cells = <&reboot_mode>;
nvmem-cell-names = "reboot-mode";
mode-test = <0x21969147>;
};
};
...
reboot_mode: nvmem_reboot_mode@0 {
reg = <0x00 0x4>;
};
...
`
1. Reboot the system using the command `reboot test`
2. Verify that kernel logs show that reboot was done in mode `test`:
PASS
`[ 413.957172] reboot: Restarting system with command 'test' `
3. Stop in U-Boot and verify that mode `test` magic value is present
in RTCs non-volatile memory: PASS
Kernel: 5.1.0-rc3
1. Configure `arch/arm/configs/imx_v6_v7_defconfig` to contain
`CONFIG_NVMEM_REBOOT_MODE=y`
2. Verify that Kernel compiles successful: PASS
`
make ARCH=arm CROSS_COMPILE=arm-linux-gnu- imx_v6_v7_defconfig zImage
...
CC drivers/power/reset/nvmem-reboot-mode.o
...
Kernel: arch/arm/boot/zImage is ready
`
Changes since v1:
-----------------
- split the documentation on a separate patch
- add a missing header
Changes since v2:
----------------
- change the module license to GPL since GPL v2 is deprecated
Changes since v3:
----------------
- documentation updated according to the comments
Nandor Han (2):
power: reset: nvmem-reboot-mode: use NVMEM as reboot mode write
interface
dt-bindings: power: reset: add document for NVMEM based reboot-mode
.../power/reset/nvmem-reboot-mode.txt | 26 +++++++
drivers/power/reset/Kconfig | 9 +++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/nvmem-reboot-mode.c | 76 +++++++++++++++++++
4 files changed, 112 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt
create mode 100644 drivers/power/reset/nvmem-reboot-mode.c
--
2.17.2
Add a new reboot mode write interface that is using an NVMEM cell
to store the reboot mode magic.
Signed-off-by: Nandor Han <[email protected]>
---
drivers/power/reset/Kconfig | 9 +++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/nvmem-reboot-mode.c | 76 +++++++++++++++++++++++++
3 files changed, 86 insertions(+)
create mode 100644 drivers/power/reset/nvmem-reboot-mode.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 6533aa560aa1..bb4a4e854f96 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -245,5 +245,14 @@ config POWER_RESET_SC27XX
PMICs includes the SC2720, SC2721, SC2723, SC2730
and SC2731 chips.
+config NVMEM_REBOOT_MODE
+ tristate "Generic NVMEM reboot mode driver"
+ select REBOOT_MODE
+ help
+ Say y here will enable reboot mode driver. This will
+ get reboot mode arguments and store it in a NVMEM cell,
+ then the bootloader can read it and take different
+ action according to the mode.
+
endif
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 0aebee954ac1..85da3198e4e0 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -29,3 +29,4 @@ obj-$(CONFIG_POWER_RESET_ZX) += zx-reboot.o
obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
+obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
new file mode 100644
index 000000000000..e229308d43e2
--- /dev/null
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) Vaisala Oyj. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/platform_device.h>
+#include <linux/reboot-mode.h>
+
+struct nvmem_reboot_mode {
+ struct reboot_mode_driver reboot;
+ struct nvmem_cell *cell;
+};
+
+static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
+ unsigned int magic)
+{
+ int ret;
+ struct nvmem_reboot_mode *nvmem_rbm;
+
+ nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
+
+ ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
+ if (ret < 0)
+ dev_err(reboot->dev, "update reboot mode bits failed\n");
+
+ return ret;
+}
+
+static int nvmem_reboot_mode_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct nvmem_reboot_mode *nvmem_rbm;
+
+ nvmem_rbm = devm_kzalloc(&pdev->dev, sizeof(*nvmem_rbm), GFP_KERNEL);
+ if (!nvmem_rbm)
+ return -ENOMEM;
+
+ nvmem_rbm->reboot.dev = &pdev->dev;
+ nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
+
+ nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
+ if (IS_ERR(nvmem_rbm->cell)) {
+ dev_err(&pdev->dev, "failed to get the nvmem cell reboot-mode\n");
+ return PTR_ERR(nvmem_rbm->cell);
+ }
+
+ ret = devm_reboot_mode_register(&pdev->dev, &nvmem_rbm->reboot);
+ if (ret)
+ dev_err(&pdev->dev, "can't register reboot mode\n");
+
+ return ret;
+}
+
+static const struct of_device_id nvmem_reboot_mode_of_match[] = {
+ { .compatible = "nvmem-reboot-mode" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, nvmem_reboot_mode_of_match);
+
+static struct platform_driver nvmem_reboot_mode_driver = {
+ .probe = nvmem_reboot_mode_probe,
+ .driver = {
+ .name = "nvmem-reboot-mode",
+ .of_match_table = nvmem_reboot_mode_of_match,
+ },
+};
+module_platform_driver(nvmem_reboot_mode_driver);
+
+MODULE_AUTHOR("Nandor Han <[email protected]>");
+MODULE_DESCRIPTION("NVMEM reboot mode driver");
+MODULE_LICENSE("GPL");
--
2.17.2
Add the device tree bindings document for the NVMEM based reboot-mode
driver.
Signed-off-by: Nandor Han <[email protected]>
---
.../power/reset/nvmem-reboot-mode.txt | 26 +++++++++++++++++++
1 file changed, 26 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt
diff --git a/Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt
new file mode 100644
index 000000000000..752d6126d5da
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt
@@ -0,0 +1,26 @@
+NVMEM reboot mode driver
+
+This driver gets reboot mode magic value from reboot-mode driver
+and stores it in a NVMEM cell named "reboot-mode". Then the bootloader
+can read it and take different action according to the magic
+value stored.
+
+Required properties:
+- compatible: should be "nvmem-reboot-mode".
+- nvmem-cells: A phandle to the reboot mode provided by a nvmem device.
+- nvmem-cell-names: Should be "reboot-mode".
+
+The rest of the properties should follow the generic reboot-mode description
+found in reboot-mode.txt
+
+Example:
+ reboot-mode {
+ compatible = "nvmem-reboot-mode";
+ nvmem-cells = <&reboot_mode>;
+ nvmem-cell-names = "reboot-mode";
+
+ mode-normal = <0xAAAA5501>;
+ mode-bootloader = <0xBBBB5500>;
+ mode-recovery = <0xCCCC5502>;
+ mode-test = <0xDDDD5503>;
+ };
--
2.17.2
On Wed, 15 May 2019 10:47:15 +0000, Han Nandor wrote:
> Add the device tree bindings document for the NVMEM based reboot-mode
> driver.
>
> Signed-off-by: Nandor Han <[email protected]>
> ---
> .../power/reset/nvmem-reboot-mode.txt | 26 +++++++++++++++++++
> 1 file changed, 26 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/reset/nvmem-reboot-mode.txt
>
Reviewed-by: Rob Herring <[email protected]>
Hi,
On Wed, May 15, 2019 at 10:47:14AM +0000, Han Nandor wrote:
> Description
> -----------
> Extend the reboot mode driver to use a NVMEM cell as writing interface.
>
> Testing
> -------
> The testing is done by configuring DT from a custom board.
> The NVMEM cell is configured in an RTC non-volatile memory.
> Kernel: 4.14.60 (the patchset was rebased on kernel master)
>
> DT configurations:
> `
> ...
> reboot-mode-nvmem@0 {
> compatible = "simple-mfd";
> reboot-mode {
> compatible = "nvmem-reboot-mode";
> nvmem-cells = <&reboot_mode>;
> nvmem-cell-names = "reboot-mode";
>
> mode-test = <0x21969147>;
> };
> };
> ...
> reboot_mode: nvmem_reboot_mode@0 {
> reg = <0x00 0x4>;
> };
> ...
> `
>
> 1. Reboot the system using the command `reboot test`
>
> 2. Verify that kernel logs show that reboot was done in mode `test`:
> PASS
> `[ 413.957172] reboot: Restarting system with command 'test' `
>
> 3. Stop in U-Boot and verify that mode `test` magic value is present
> in RTCs non-volatile memory: PASS
>
> Kernel: 5.1.0-rc3
>
> 1. Configure `arch/arm/configs/imx_v6_v7_defconfig` to contain
> `CONFIG_NVMEM_REBOOT_MODE=y`
> 2. Verify that Kernel compiles successful: PASS
> `
> make ARCH=arm CROSS_COMPILE=arm-linux-gnu- imx_v6_v7_defconfig zImage
> ...
> CC drivers/power/reset/nvmem-reboot-mode.o
> ...
> Kernel: arch/arm/boot/zImage is ready
> `
> Changes since v1:
> -----------------
> - split the documentation on a separate patch
> - add a missing header
>
> Changes since v2:
> ----------------
> - change the module license to GPL since GPL v2 is deprecated
>
> Changes since v3:
> ----------------
> - documentation updated according to the comments
Thanks, queued. Please fix your git/mail setup, I had to fix the
line endings (\r\n -> \n) to apply this.
-- Sebastian
Hi,
>> Changes since v3:
>> ----------------
>> - documentation updated according to the comments
>
> Thanks, queued. Please fix your git/mail setup, I had to fix the
> line endings (\r\n -> \n) to apply this.
>
> -- Sebastian
>
Ok. Thanks Sebastian.
--
Nandor