The reboot-mode driver does not have a strict requirement for
device-based registration. It primarily uses the device's of_node
to read mode-<cmd> properties and the device pointer for logging.
Remove the dependency on struct device and introduce support for
Device Tree (DT) node-based registration. This enables drivers
that are not associated with a struct device to leverage the
reboot-mode framework.
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
drivers/power/reset/reboot-mode.c | 37 ++++++++++++++++++++++++++-----------
include/linux/reboot-mode.h | 2 +-
2 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index 42bb99128ed3846d4bff62416dc31135ddeaeb90..9bb97bcd33cd3d58c75c791e9b568024e810e5b0 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -3,13 +3,17 @@
* Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
*/
+#define pr_fmt(fmt) "reboot-mode: " fmt
+
#include <linux/device.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/reboot.h>
#include <linux/reboot-mode.h>
+#include <linux/slab.h>
#define PREFIX "mode-"
@@ -75,17 +79,21 @@ static int reboot_mode_notify(struct notifier_block *this,
/**
* reboot_mode_register - register a reboot mode driver
* @reboot: reboot mode driver
+ * @np: Pointer to device tree node
*
* Returns: 0 on success or a negative error code on failure.
*/
-int reboot_mode_register(struct reboot_mode_driver *reboot)
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np)
{
struct mode_info *info;
+ struct mode_info *next;
struct property *prop;
- struct device_node *np = reboot->dev->of_node;
size_t len = strlen(PREFIX);
int ret;
+ if (!np)
+ return -EINVAL;
+
INIT_LIST_HEAD(&reboot->head);
mutex_init(&reboot->rb_lock);
@@ -94,28 +102,28 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
if (strncmp(prop->name, PREFIX, len))
continue;
- info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
+ info = kzalloc(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);
+ pr_err("reboot mode %s without magic number\n", info->mode);
+ kfree(info);
continue;
}
info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
if (!info->mode) {
ret = -ENOMEM;
+ kfree(info);
goto error;
} else if (info->mode[0] == '\0') {
kfree_const(info->mode);
+ kfree(info);
ret = -EINVAL;
- dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
- prop->name);
+ pr_err("invalid mode name(%s): too short!\n", prop->name);
goto error;
}
@@ -129,8 +137,11 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
return 0;
error:
- list_for_each_entry(info, &reboot->head, list)
+ list_for_each_entry_safe(info, next, &reboot->head, list) {
+ list_del(&info->list);
kfree_const(info->mode);
+ kfree(info);
+ }
mutex_unlock(&reboot->rb_lock);
return ret;
@@ -144,12 +155,16 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
int reboot_mode_unregister(struct reboot_mode_driver *reboot)
{
struct mode_info *info;
+ struct mode_info *next;
unregister_reboot_notifier(&reboot->reboot_notifier);
mutex_lock(&reboot->rb_lock);
- list_for_each_entry(info, &reboot->head, list)
+ list_for_each_entry_safe(info, next, &reboot->head, list) {
+ list_del(&info->list);
kfree_const(info->mode);
+ kfree(info);
+ }
mutex_unlock(&reboot->rb_lock);
return 0;
@@ -178,7 +193,7 @@ int devm_reboot_mode_register(struct device *dev,
if (!dr)
return -ENOMEM;
- rc = reboot_mode_register(reboot);
+ rc = reboot_mode_register(reboot, reboot->dev->of_node);
if (rc) {
devres_free(dr);
return rc;
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index b73f80708197677db8dc2e43affc519782b7146e..98f68f95c9e8460be23282c51ef7fcbed73887bd 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -13,7 +13,7 @@ struct reboot_mode_driver {
struct mutex rb_lock;
};
-int reboot_mode_register(struct reboot_mode_driver *reboot);
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np);
int reboot_mode_unregister(struct reboot_mode_driver *reboot);
int devm_reboot_mode_register(struct device *dev,
struct reboot_mode_driver *reboot);
--
2.34.1Hi,
On Fri, Aug 15, 2025 at 08:05:07PM +0530, Shivendra Pratap wrote:
> The reboot-mode driver does not have a strict requirement for
> device-based registration. It primarily uses the device's of_node
> to read mode-<cmd> properties and the device pointer for logging.
>
> Remove the dependency on struct device and introduce support for
> Device Tree (DT) node-based registration. This enables drivers
> that are not associated with a struct device to leverage the
> reboot-mode framework.
>
> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
> ---
Please use fwnode instead of device_node, so that the same thing
can be used with non DT setups, if that becomes necessary. Otherwise
LGTM.
Greetings,
-- Sebastian
> drivers/power/reset/reboot-mode.c | 37 ++++++++++++++++++++++++++-----------
> include/linux/reboot-mode.h | 2 +-
> 2 files changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
> index 42bb99128ed3846d4bff62416dc31135ddeaeb90..9bb97bcd33cd3d58c75c791e9b568024e810e5b0 100644
> --- a/drivers/power/reset/reboot-mode.c
> +++ b/drivers/power/reset/reboot-mode.c
> @@ -3,13 +3,17 @@
> * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
> */
>
> +#define pr_fmt(fmt) "reboot-mode: " fmt
> +
> #include <linux/device.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> +#include <linux/list.h>
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/reboot.h>
> #include <linux/reboot-mode.h>
> +#include <linux/slab.h>
>
> #define PREFIX "mode-"
>
> @@ -75,17 +79,21 @@ static int reboot_mode_notify(struct notifier_block *this,
> /**
> * reboot_mode_register - register a reboot mode driver
> * @reboot: reboot mode driver
> + * @np: Pointer to device tree node
> *
> * Returns: 0 on success or a negative error code on failure.
> */
> -int reboot_mode_register(struct reboot_mode_driver *reboot)
> +int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np)
> {
> struct mode_info *info;
> + struct mode_info *next;
> struct property *prop;
> - struct device_node *np = reboot->dev->of_node;
> size_t len = strlen(PREFIX);
> int ret;
>
> + if (!np)
> + return -EINVAL;
> +
> INIT_LIST_HEAD(&reboot->head);
> mutex_init(&reboot->rb_lock);
>
> @@ -94,28 +102,28 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
> if (strncmp(prop->name, PREFIX, len))
> continue;
>
> - info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
> + info = kzalloc(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);
> + pr_err("reboot mode %s without magic number\n", info->mode);
> + kfree(info);
> continue;
> }
>
> info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
> if (!info->mode) {
> ret = -ENOMEM;
> + kfree(info);
> goto error;
> } else if (info->mode[0] == '\0') {
> kfree_const(info->mode);
> + kfree(info);
> ret = -EINVAL;
> - dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
> - prop->name);
> + pr_err("invalid mode name(%s): too short!\n", prop->name);
> goto error;
> }
>
> @@ -129,8 +137,11 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
> return 0;
>
> error:
> - list_for_each_entry(info, &reboot->head, list)
> + list_for_each_entry_safe(info, next, &reboot->head, list) {
> + list_del(&info->list);
> kfree_const(info->mode);
> + kfree(info);
> + }
>
> mutex_unlock(&reboot->rb_lock);
> return ret;
> @@ -144,12 +155,16 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
> int reboot_mode_unregister(struct reboot_mode_driver *reboot)
> {
> struct mode_info *info;
> + struct mode_info *next;
>
> unregister_reboot_notifier(&reboot->reboot_notifier);
>
> mutex_lock(&reboot->rb_lock);
> - list_for_each_entry(info, &reboot->head, list)
> + list_for_each_entry_safe(info, next, &reboot->head, list) {
> + list_del(&info->list);
> kfree_const(info->mode);
> + kfree(info);
> + }
> mutex_unlock(&reboot->rb_lock);
>
> return 0;
> @@ -178,7 +193,7 @@ int devm_reboot_mode_register(struct device *dev,
> if (!dr)
> return -ENOMEM;
>
> - rc = reboot_mode_register(reboot);
> + rc = reboot_mode_register(reboot, reboot->dev->of_node);
> if (rc) {
> devres_free(dr);
> return rc;
> diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
> index b73f80708197677db8dc2e43affc519782b7146e..98f68f95c9e8460be23282c51ef7fcbed73887bd 100644
> --- a/include/linux/reboot-mode.h
> +++ b/include/linux/reboot-mode.h
> @@ -13,7 +13,7 @@ struct reboot_mode_driver {
> struct mutex rb_lock;
> };
>
> -int reboot_mode_register(struct reboot_mode_driver *reboot);
> +int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np);
> int reboot_mode_unregister(struct reboot_mode_driver *reboot);
> int devm_reboot_mode_register(struct device *dev,
> struct reboot_mode_driver *reboot);
>
> --
> 2.34.1
>
On 9/17/2025 12:18 AM, Sebastian Reichel wrote: > Hi, > > On Fri, Aug 15, 2025 at 08:05:07PM +0530, Shivendra Pratap wrote: >> The reboot-mode driver does not have a strict requirement for >> device-based registration. It primarily uses the device's of_node >> to read mode-<cmd> properties and the device pointer for logging. >> >> Remove the dependency on struct device and introduce support for >> Device Tree (DT) node-based registration. This enables drivers >> that are not associated with a struct device to leverage the >> reboot-mode framework. >> >> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com> >> --- > > Please use fwnode instead of device_node, so that the same thing > can be used with non DT setups, if that becomes necessary. Otherwise > LGTM. To be more clear on this, have one question: the current unmodified design of reboot-mode is dt based: struct device_node *np = reboot->dev->of_node; and then parses the node using for_each_property_of_node(np, prop). We want to refactor reboot-mode to support non-DT setups by adding support for fwnode-based approach (struct fwnode_handle *fwnode)? Can you please explain a bit? Some more details would be helpful to make the change. thanks, Shivendra
Hi, On Wed, Sep 17, 2025 at 09:59:44PM +0530, Shivendra Pratap wrote: > On 9/17/2025 12:18 AM, Sebastian Reichel wrote: > > On Fri, Aug 15, 2025 at 08:05:07PM +0530, Shivendra Pratap wrote: > >> The reboot-mode driver does not have a strict requirement for > >> device-based registration. It primarily uses the device's of_node > >> to read mode-<cmd> properties and the device pointer for logging. > >> > >> Remove the dependency on struct device and introduce support for > >> Device Tree (DT) node-based registration. This enables drivers > >> that are not associated with a struct device to leverage the > >> reboot-mode framework. > >> > >> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com> > >> --- > > > > Please use fwnode instead of device_node, so that the same thing > > can be used with non DT setups, if that becomes necessary. Otherwise > > LGTM. > > To be more clear on this, have one question: the current unmodified > design of reboot-mode is dt based: > > struct device_node *np = reboot->dev->of_node; > and then parses the node using for_each_property_of_node(np, prop). > > We want to refactor reboot-mode to support non-DT setups by adding > support for fwnode-based approach (struct fwnode_handle *fwnode)? > > Can you please explain a bit? Some more details would be helpful to > make the change. It's fine to keep using of_node internally. But the external API (include/linux/reboot-mode.h) should use fwnode. Just like the current external API is not DT specific as it just gets a struct device. This keeps the external API somewhat ready for non-DT users and avoids having to change all API users again in the future. Greetings, -- Sebastian
On 9/18/2025 4:02 AM, Sebastian Reichel wrote: > Hi, > > On Wed, Sep 17, 2025 at 09:59:44PM +0530, Shivendra Pratap wrote: >> On 9/17/2025 12:18 AM, Sebastian Reichel wrote: >>> On Fri, Aug 15, 2025 at 08:05:07PM +0530, Shivendra Pratap wrote: >>>> The reboot-mode driver does not have a strict requirement for >>>> device-based registration. It primarily uses the device's of_node >>>> to read mode-<cmd> properties and the device pointer for logging. >>>> >>>> Remove the dependency on struct device and introduce support for >>>> Device Tree (DT) node-based registration. This enables drivers >>>> that are not associated with a struct device to leverage the >>>> reboot-mode framework. >>>> >>>> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com> >>>> --- >>> >>> Please use fwnode instead of device_node, so that the same thing >>> can be used with non DT setups, if that becomes necessary. Otherwise >>> LGTM. >> >> To be more clear on this, have one question: the current unmodified >> design of reboot-mode is dt based: >> >> struct device_node *np = reboot->dev->of_node; >> and then parses the node using for_each_property_of_node(np, prop). >> >> We want to refactor reboot-mode to support non-DT setups by adding >> support for fwnode-based approach (struct fwnode_handle *fwnode)? >> >> Can you please explain a bit? Some more details would be helpful to >> make the change. > > It's fine to keep using of_node internally. But the external API > (include/linux/reboot-mode.h) should use fwnode. Just like the > current external API is not DT specific as it just gets a struct > device. This keeps the external API somewhat ready for non-DT users > and avoids having to change all API users again in the future. > sure. Will check and try to make this change. thanks, Shivendra
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