[PATCH v22 03/13] power: reset: reboot-mode: Add support for predefined reboot modes
Shivendra Pratap
shivendra.pratap at oss.qualcomm.com
Thu May 14 07:25:44 PDT 2026
reboot-mode based drivers can define a reboot-mode by adding it under
the reboot-mode node in device tree. This limits such drivers, to define
any predefined reboot-modes statically within the driver and creates a
dependency on device-tree.
Extend the reboot-mode framework to handle predefined modes alongside
those defined in device tree. Drivers can now define their own
reboot-modes and register them via the framework. A centralized init
call has been added to the reboot-mode framework and adopted by
existing drivers. This ensures driver state is initialized together
with predefined modes.
Signed-off-by: Shivendra Pratap <shivendra.pratap at oss.qualcomm.com>
---
drivers/power/reset/nvmem-reboot-mode.c | 4 +-
drivers/power/reset/qcom-pon.c | 4 +-
drivers/power/reset/reboot-mode.c | 142 ++++++++++++++++++++++++-------
drivers/power/reset/syscon-reboot-mode.c | 4 +-
include/linux/reboot-mode.h | 13 +++
5 files changed, 130 insertions(+), 37 deletions(-)
diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
index bd05d660490c686b43134f82f1eadd7665403d20..50e5e1ff4cd3b14f634dc50cdadd97472cf0b1d0 100644
--- a/drivers/power/reset/nvmem-reboot-mode.c
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -51,8 +51,8 @@ static int nvmem_reboot_mode_probe(struct platform_device *pdev)
if (!nvmem_rbm)
return -ENOMEM;
- nvmem_rbm->reboot.dev = &pdev->dev;
- nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
+ reboot_mode_driver_init(&nvmem_rbm->reboot, &pdev->dev,
+ nvmem_reboot_mode_write);
nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
if (IS_ERR(nvmem_rbm->cell)) {
diff --git a/drivers/power/reset/qcom-pon.c b/drivers/power/reset/qcom-pon.c
index 57b36e6186f80aff947fd7f5aae5ce280c65dc6b..95d6f5dd134d54783f5ab6c600d455862e3d39f1 100644
--- a/drivers/power/reset/qcom-pon.c
+++ b/drivers/power/reset/qcom-pon.c
@@ -70,9 +70,9 @@ static int qcom_pon_probe(struct platform_device *pdev)
reason_shift = (long)of_device_get_match_data(&pdev->dev);
if (reason_shift != NO_REASON_SHIFT) {
- pon->reboot_mode.dev = &pdev->dev;
+ reboot_mode_driver_init(&pon->reboot_mode, &pdev->dev,
+ qcom_pon_reboot_mode_write);
pon->reason_shift = reason_shift;
- pon->reboot_mode.write = qcom_pon_reboot_mode_write;
error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
if (error) {
dev_err(&pdev->dev, "can't register reboot mode\n");
diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index f1372dc700e48043320812c3d3619ab1539e1854..d76aee524749a6ec3dff9729c2b678b7244e4f09 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -31,12 +31,12 @@ struct reboot_mode_sysfs_data {
struct list_head head;
};
-static inline void reboot_mode_release_list(struct reboot_mode_sysfs_data *priv)
+static inline void reboot_mode_release_list(struct list_head *head)
{
struct mode_info *info;
struct mode_info *next;
- list_for_each_entry_safe(info, next, &priv->head, list) {
+ list_for_each_entry_safe(info, next, head, list) {
list_del(&info->list);
kfree_const(info->mode);
kfree(info);
@@ -116,6 +116,51 @@ static int reboot_mode_notify(struct notifier_block *this,
return NOTIFY_DONE;
}
+/**
+ * reboot_mode_driver_init - Initialize reboot-mode state
+ * @reboot: reboot mode driver object to initialize
+ * @dev: backing device
+ * @write: write callback for programming magic
+ *
+ * This function must be called with a valid @dev and @write before calling
+ * reboot_mode_register(), reboot_mode_add_predefined_modes(), or any other
+ * reboot-mode framework API.
+ */
+void reboot_mode_driver_init(struct reboot_mode_driver *reboot,
+ struct device *dev,
+ int (*write)(struct reboot_mode_driver *reboot, u64 magic))
+{
+ memset(reboot, 0, sizeof(*reboot));
+ reboot->dev = dev;
+ reboot->write = write;
+ INIT_LIST_HEAD(&reboot->head);
+ INIT_LIST_HEAD(&reboot->predefined_modes);
+}
+EXPORT_SYMBOL_GPL(reboot_mode_driver_init);
+
+static struct mode_info *reboot_mode_create_info(const char *mode, u64 magic)
+{
+ struct mode_info *info;
+
+ if (!mode || mode[0] == '\0') {
+ pr_err("invalid mode name(%s): too short!\n", mode);
+ return ERR_PTR(-EINVAL);
+ }
+
+ info = kzalloc_obj(*info, GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->mode = kstrdup_const(mode, GFP_KERNEL);
+ if (!info->mode) {
+ kfree(info);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ info->magic = magic;
+ return info;
+}
+
static int reboot_mode_create_device(struct reboot_mode_driver *reboot)
{
struct reboot_mode_sysfs_data *priv;
@@ -157,7 +202,7 @@ static int reboot_mode_create_device(struct reboot_mode_driver *reboot)
return 0;
error:
- reboot_mode_release_list(priv);
+ reboot_mode_release_list(&priv->head);
kfree(priv);
return ret;
}
@@ -170,7 +215,7 @@ static int reboot_mode_create_device(struct reboot_mode_driver *reboot)
*/
int reboot_mode_register(struct reboot_mode_driver *reboot)
{
- struct mode_info *info = NULL;
+ struct mode_info *info;
struct property *prop;
struct device_node *np = reboot->dev->of_node;
size_t len = strlen(PREFIX);
@@ -180,9 +225,11 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
INIT_LIST_HEAD(&reboot->head);
+ if (!np)
+ goto predefined_modes;
+
for_each_property_of_node(np, prop) {
memset(magic, 0, sizeof(magic));
-
if (strncmp(prop->name, PREFIX, len))
continue;
@@ -194,28 +241,18 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
continue;
}
- info = kzalloc(sizeof(*info), GFP_KERNEL);
- if (!info) {
- ret = -ENOMEM;
- goto error;
- }
-
- info->magic = REBOOT_MODE_MAGIC(magic[0], magic[1]);
- info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
- if (!info->mode) {
- ret = -ENOMEM;
- goto error;
- } else if (info->mode[0] == '\0') {
- kfree_const(info->mode);
- ret = -EINVAL;
- pr_err("invalid mode name(%s): too short!\n", prop->name);
+ info = reboot_mode_create_info(prop->name + len,
+ REBOOT_MODE_MAGIC(magic[0], magic[1]));
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
goto error;
}
list_add_tail(&info->list, &reboot->head);
- info = NULL;
}
+predefined_modes:
+ list_splice_tail_init(&reboot->predefined_modes, &reboot->head);
reboot->reboot_notifier.notifier_call = reboot_mode_notify;
register_reboot_notifier(&reboot->reboot_notifier);
@@ -226,7 +263,6 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
return 0;
error:
- kfree(info);
reboot_mode_unregister(reboot);
return ret;
}
@@ -259,7 +295,7 @@ static inline void reboot_mode_unregister_device(struct reboot_mode_driver *rebo
if (!priv)
return;
- reboot_mode_release_list(priv);
+ reboot_mode_release_list(&priv->head);
kfree(priv);
}
@@ -269,17 +305,12 @@ static inline void reboot_mode_unregister_device(struct reboot_mode_driver *rebo
*/
int reboot_mode_unregister(struct reboot_mode_driver *reboot)
{
- struct mode_info *info;
- struct mode_info *next;
-
unregister_reboot_notifier(&reboot->reboot_notifier);
+ reboot->reboot_notifier.notifier_call = NULL;
reboot_mode_unregister_device(reboot);
- list_for_each_entry_safe(info, next, &reboot->head, list) {
- list_del(&info->list);
- kfree_const(info->mode);
- kfree(info);
- }
+ reboot_mode_release_list(&reboot->head);
+ reboot_mode_release_list(&reboot->predefined_modes);
return 0;
}
@@ -344,6 +375,55 @@ void devm_reboot_mode_unregister(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_reboot_mode_unregister);
+/**
+ * reboot_mode_add_predefined_modes - Add predefined reboot modes
+ * @reboot: reboot mode driver
+ * @modes: array of predefined reboot mode entries
+ * @count: number of entries in @modes
+ *
+ * Add predefined reboot modes in a single call before registration.
+ *
+ * @reboot must be initialized with reboot_mode_driver_init() before calling
+ * this function.
+ *
+ * Returns: 0 on success, -EINVAL if @modes is NULL, @count is 0, or an entry
+ * has an invalid name, -EBUSY if called after reboot_mode_register()
+ * or if predefined modes are already present, or -ENOMEM on allocation
+ * failures.
+ */
+int reboot_mode_add_predefined_modes(struct reboot_mode_driver *reboot,
+ const struct reboot_mode_entry *modes,
+ size_t count)
+{
+ struct mode_info *info;
+ int ret;
+ size_t i;
+
+ if (reboot->reboot_notifier.notifier_call == reboot_mode_notify ||
+ !list_empty(&reboot->predefined_modes))
+ return -EBUSY;
+
+ if (!modes || !count)
+ return -EINVAL;
+
+ for (i = 0; i < count; i++) {
+ info = reboot_mode_create_info(modes[i].name, modes[i].magic);
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
+ goto error;
+ }
+
+ list_add_tail(&info->list, &reboot->predefined_modes);
+ }
+
+ return 0;
+
+error:
+ reboot_mode_release_list(&reboot->predefined_modes);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(reboot_mode_add_predefined_modes);
+
static int __init reboot_mode_init(void)
{
return class_register(&reboot_mode_class);
diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
index 9f4b18c5e46f6a8bf197773ceceb80b250f57541..55f2fd33e0d2abc599848c936619cb6cdbaed47d 100644
--- a/drivers/power/reset/syscon-reboot-mode.c
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -45,8 +45,8 @@ static int syscon_reboot_mode_probe(struct platform_device *pdev)
if (!syscon_rbm)
return -ENOMEM;
- syscon_rbm->reboot.dev = &pdev->dev;
- syscon_rbm->reboot.write = syscon_reboot_mode_write;
+ reboot_mode_driver_init(&syscon_rbm->reboot, &pdev->dev,
+ syscon_reboot_mode_write);
syscon_rbm->mask = 0xffffffff;
syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 2ce189fdfff4b396d7cc6f175b30016781ae4fe9..4503ee388cd00d5e004600d51056d623ea23e345 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -15,18 +15,31 @@
/* Get 32 bit arg2 from 64 bit magic */
#define REBOOT_MODE_ARG2(magic) FIELD_GET(GENMASK_ULL(63, 32), magic)
+struct reboot_mode_entry {
+ const char *name;
+ u64 magic;
+};
+
struct reboot_mode_driver {
struct device *dev;
struct list_head head;
+ /* List of predefined reboot-modes, populated via reboot_mode_add_predefined_modes(). */
+ struct list_head predefined_modes;
int (*write)(struct reboot_mode_driver *reboot, u64 magic);
struct notifier_block reboot_notifier;
};
+void reboot_mode_driver_init(struct reboot_mode_driver *reboot,
+ struct device *dev,
+ int (*write)(struct reboot_mode_driver *reboot, u64 magic));
int reboot_mode_register(struct reboot_mode_driver *reboot);
int reboot_mode_unregister(struct reboot_mode_driver *reboot);
int devm_reboot_mode_register(struct device *dev,
struct reboot_mode_driver *reboot);
void devm_reboot_mode_unregister(struct device *dev,
struct reboot_mode_driver *reboot);
+int reboot_mode_add_predefined_modes(struct reboot_mode_driver *reboot,
+ const struct reboot_mode_entry *modes,
+ size_t count);
#endif
--
2.34.1
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