[PATCH v24 02/12] power: reset: reboot-mode: Add support for predefined reboot modes
Shivendra Pratap
shivendra.pratap at oss.qualcomm.com
Mon Aug 3 02:43:33 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 support driver-defined predefined
reboot modes. Add a centralized initcall to initialize driver state
along with predefined modes.
Signed-off-by: Shivendra Pratap <shivendra.pratap at oss.qualcomm.com>
---
drivers/power/reset/nvmem-reboot-mode.c | 7 +-
drivers/power/reset/qcom-pon.c | 7 +-
drivers/power/reset/reboot-mode.c | 192 ++++++++++++++++++++++---------
drivers/power/reset/syscon-reboot-mode.c | 7 +-
include/linux/reboot-mode.h | 26 ++++-
5 files changed, 175 insertions(+), 64 deletions(-)
diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
index d260715fccf6..700732ed0f5b 100644
--- a/drivers/power/reset/nvmem-reboot-mode.c
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -51,8 +51,11 @@ 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;
+ ret = reboot_mode_driver_init(&nvmem_rbm->reboot, &pdev->dev,
+ nvmem_reboot_mode_write, NULL,
+ NULL, 0);
+ if (ret)
+ return ret;
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 7e108982a582..f63996994a25 100644
--- a/drivers/power/reset/qcom-pon.c
+++ b/drivers/power/reset/qcom-pon.c
@@ -70,9 +70,12 @@ 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;
+ error = reboot_mode_driver_init(&pon->reboot_mode, &pdev->dev,
+ qcom_pon_reboot_mode_write, NULL,
+ NULL, 0);
+ if (error)
+ return error;
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 c7e9285c64e9..cf8978c0ce22 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -30,12 +30,12 @@ struct reboot_mode_sysfs_data {
struct list_head head;
};
-static inline void reboot_mode_release_list(struct reboot_mode_sysfs_data *priv)
+static 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);
@@ -119,6 +119,80 @@ 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 to program a single magic value
+ * @write_array: write callback to program multiple magic values
+ * @predefined_modes: optional predefined reboot-mode table
+ * @predefined_mode_count: number of entries in @predefined_modes
+ *
+ * Exactly one write callback must be provided by the driver.
+ *
+ * This function must be called with a valid @dev before calling
+ * reboot_mode_register().
+ *
+ * Returns: 0 on success or -EINVAL if callback/predefined mode configuration
+ * is invalid.
+ */
+int reboot_mode_driver_init(struct reboot_mode_driver *reboot,
+ struct device *dev,
+ int (*write)(struct reboot_mode_driver *reboot, unsigned int magic),
+ int (*write_array)(struct reboot_mode_driver *reboot,
+ const u32 *magic, u32 count),
+ const struct reboot_mode_entry *predefined_modes,
+ size_t predefined_mode_count)
+{
+ if (!reboot || !dev)
+ return -EINVAL;
+
+ if (!write == !write_array)
+ return -EINVAL;
+
+ memset(reboot, 0, sizeof(*reboot));
+ reboot->dev = dev;
+ reboot->write = write;
+ reboot->write_array = write_array;
+ reboot->predefined_modes = predefined_modes;
+ reboot->predefined_mode_count = predefined_mode_count;
+ INIT_LIST_HEAD(&reboot->head);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reboot_mode_driver_init);
+
+static struct mode_info *reboot_mode_create_info(struct device *dev, const char *mode,
+ const u32 *magic, int count)
+{
+ struct mode_info *info;
+
+ if (!mode || mode[0] == '\0') {
+ dev_err(dev, "invalid mode name\n");
+ 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);
+ }
+
+ if (!memchr_inv(magic, 0, count * sizeof(u32))) {
+ dev_dbg(dev, "reboot mode %s with zero magic values\n", mode);
+ info->count = 0;
+ } else {
+ memcpy(info->magic, magic, count * sizeof(u32));
+ info->count = count;
+ }
+
+ return info;
+}
+
static int reboot_mode_create_device(struct reboot_mode_driver *reboot)
{
struct reboot_mode_sysfs_data *priv;
@@ -160,11 +234,38 @@ 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;
}
+static int reboot_mode_add_predefined_modes(struct reboot_mode_driver *reboot)
+{
+ const struct reboot_mode_entry *modes = reboot->predefined_modes;
+ struct mode_info *info;
+ size_t i;
+
+ if (!modes)
+ return 0;
+
+ for (i = 0; i < reboot->predefined_mode_count; i++) {
+ if (modes[i].name && strpbrk(modes[i].name, "\n ,/"))
+ return -EINVAL;
+
+ if (!modes[i].count || modes[i].count > ARRAY_SIZE(modes[i].magic))
+ return -EINVAL;
+
+ info = reboot_mode_create_info(reboot->dev, modes[i].name,
+ modes[i].magic, modes[i].count);
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ list_add_tail(&info->list, &reboot->head);
+ }
+
+ return 0;
+}
+
/**
* reboot_mode_register - register a reboot mode driver
* @reboot: reboot mode driver
@@ -173,7 +274,7 @@ 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);
@@ -183,52 +284,36 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
INIT_LIST_HEAD(&reboot->head);
- for_each_property_of_node(np, prop) {
- memset(magic, 0, sizeof(magic));
-
- if (strncmp(prop->name, PREFIX, len))
- continue;
-
- count = device_property_count_u32(reboot->dev, prop->name);
-
- if (count <= 0 || count > ARRAY_SIZE(magic) ||
- device_property_read_u32_array(reboot->dev, prop->name, magic, count)) {
- dev_dbg(reboot->dev, "reboot mode %s without magic number\n",
- prop->name);
- continue;
- }
-
- info = kzalloc_obj(*info, GFP_KERNEL);
- if (!info) {
- ret = -ENOMEM;
- goto error;
- }
-
- if (!memchr_inv(magic, 0, count * sizeof(u32))) {
- dev_dbg(reboot->dev, "reboot mode %s with zero magic values\n",
- prop->name);
- info->count = 0;
- } else {
- memcpy(info->magic, magic, count * sizeof(u32));
- info->count = count;
- }
-
- info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
- if (!info->mode) {
- ret = -ENOMEM;
- goto error;
- } else if (info->mode[0] == '\0') {
- kfree_const(info->mode);
- ret = -EINVAL;
- dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
- prop->name);
- goto error;
+ if (np) {
+ for_each_property_of_node(np, prop) {
+ memset(magic, 0, sizeof(magic));
+ if (strncmp(prop->name, PREFIX, len))
+ continue;
+
+ count = device_property_count_u32(reboot->dev, prop->name);
+
+ if (count <= 0 || count > ARRAY_SIZE(magic) ||
+ device_property_read_u32_array(reboot->dev, prop->name, magic, count)) {
+ dev_dbg(reboot->dev, "reboot mode %s without magic number\n",
+ prop->name);
+ continue;
+ }
+
+ info = reboot_mode_create_info(reboot->dev, prop->name + len,
+ magic, count);
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
+ goto error;
+ }
+
+ list_add_tail(&info->list, &reboot->head);
}
-
- list_add_tail(&info->list, &reboot->head);
- info = NULL;
}
+ ret = reboot_mode_add_predefined_modes(reboot);
+ if (ret)
+ goto error;
+
reboot->reboot_notifier.notifier_call = reboot_mode_notify;
register_reboot_notifier(&reboot->reboot_notifier);
@@ -239,7 +324,6 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
return 0;
error:
- kfree(info);
reboot_mode_unregister(reboot);
return ret;
}
@@ -272,7 +356,7 @@ 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);
}
@@ -282,17 +366,11 @@ 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);
return 0;
}
diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
index e0772c9f70f7..7d3a95e8dfd7 100644
--- a/drivers/power/reset/syscon-reboot-mode.c
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -45,8 +45,11 @@ 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;
+ ret = reboot_mode_driver_init(&syscon_rbm->reboot, &pdev->dev,
+ syscon_reboot_mode_write, NULL,
+ NULL, 0);
+ if (ret)
+ return ret;
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 29ae39935d69..560d8b4d67ac 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -4,14 +4,38 @@
#include <linux/types.h>
+struct reboot_mode_entry {
+ const char *name;
+ u32 magic[3];
+ u32 count;
+};
+
struct reboot_mode_driver {
struct device *dev;
struct list_head head;
+ /*
+ * Optional predefined reboot-mode table.
+ *
+ * Must be initialized before reboot_mode_register() and remain valid
+ * until reboot_mode_unregister().
+ *
+ * If a predefined mode name duplicates a DT-defined mode name,
+ * the DT-defined mode takes precedence.
+ */
+ const struct reboot_mode_entry *predefined_modes;
+ size_t predefined_mode_count;
+ int (*write_array)(struct reboot_mode_driver *reboot, const u32 *magic, u32 count);
int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
- int (*write_array)(struct reboot_mode_driver *reboot, const u32 *magic, int count);
struct notifier_block reboot_notifier;
};
+int reboot_mode_driver_init(struct reboot_mode_driver *reboot,
+ struct device *dev,
+ int (*write)(struct reboot_mode_driver *reboot, unsigned int magic),
+ int (*write_array)(struct reboot_mode_driver *reboot,
+ const u32 *magic, u32 count),
+ const struct reboot_mode_entry *predefined_modes,
+ size_t predefined_mode_count);
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,
--
2.34.1
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