[PATCH v20 03/10] power: reset: reboot-mode: Add support for predefined reboot modes
From: Shivendra Pratap
Date: Wed Mar 04 2026 - 13:19:55 EST
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.
Introduce a list for predefined modes in the reboot-mode framework and
process the predefined reboot-modes along with the device-tree defined
reboot-modes. Modify existing reboot-mode based drivers to initialize
the predefined list-head as empty.
This patch enables a reboot mode driver to define reboot-modes through a
predefined static list, in addition to the device-tree based reboot-modes.
Signed-off-by: Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
---
drivers/power/reset/nvmem-reboot-mode.c | 1 +
drivers/power/reset/qcom-pon.c | 1 +
drivers/power/reset/reboot-mode.c | 28 ++++++++++++++++++++++------
drivers/power/reset/syscon-reboot-mode.c | 1 +
include/linux/reboot-mode.h | 9 +++++++++
5 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
index bd05d660490c686b43134f82f1eadd7665403d20..83a8d80fd7d1ccb1b736aee5f2d675246a63b8f8 100644
--- a/drivers/power/reset/nvmem-reboot-mode.c
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -53,6 +53,7 @@ static int nvmem_reboot_mode_probe(struct platform_device *pdev)
nvmem_rbm->reboot.dev = &pdev->dev;
nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
+ INIT_LIST_HEAD(&nvmem_rbm->reboot.predefined_modes);
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..9d0e3fc621a6173438c6da4cce38394199451881 100644
--- a/drivers/power/reset/qcom-pon.c
+++ b/drivers/power/reset/qcom-pon.c
@@ -73,6 +73,7 @@ static int qcom_pon_probe(struct platform_device *pdev)
pon->reboot_mode.dev = &pdev->dev;
pon->reason_shift = reason_shift;
pon->reboot_mode.write = qcom_pon_reboot_mode_write;
+ INIT_LIST_HEAD(&pon->reboot_mode.predefined_modes);
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 f5ab6eab210bcd9670441a4d2a301d9efdf2f322..a0cd463cad42cc08c55a9d1cc11174b513995104 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -17,12 +17,6 @@
#define PREFIX "mode-"
-struct mode_info {
- const char *mode;
- u64 magic;
- struct list_head list;
-};
-
static u64 get_reboot_mode_magic(struct reboot_mode_driver *reboot, const char *cmd)
{
const char *normal = "normal";
@@ -73,6 +67,7 @@ static int reboot_mode_notify(struct notifier_block *this,
*/
int reboot_mode_register(struct reboot_mode_driver *reboot)
{
+ struct mode_info *info_predef;
struct mode_info *info;
struct property *prop;
struct device_node *np = reboot->dev->of_node;
@@ -82,6 +77,9 @@ 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) {
if (strncmp(prop->name, PREFIX, len))
continue;
@@ -115,6 +113,24 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
list_add_tail(&info->list, &reboot->head);
}
+predefined_modes:
+ list_for_each_entry(info_predef, &reboot->predefined_modes, list) {
+ info = kzalloc_obj(*info, GFP_KERNEL);
+ if (!info) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ info->mode = kstrdup_const(info_predef->mode, GFP_KERNEL);
+ if (!info->mode) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ info->magic = info_predef->magic;
+ list_add_tail(&info->list, &reboot->head);
+ }
+
reboot->reboot_notifier.notifier_call = reboot_mode_notify;
register_reboot_notifier(&reboot->reboot_notifier);
diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
index 9f4b18c5e46f6a8bf197773ceceb80b250f57541..0218b71541a0cefe1534e306f956ae51ea9ee870 100644
--- a/drivers/power/reset/syscon-reboot-mode.c
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -48,6 +48,7 @@ static int syscon_reboot_mode_probe(struct platform_device *pdev)
syscon_rbm->reboot.dev = &pdev->dev;
syscon_rbm->reboot.write = syscon_reboot_mode_write;
syscon_rbm->mask = 0xffffffff;
+ INIT_LIST_HEAD(&syscon_rbm->reboot.predefined_modes);
syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
if (IS_ERR(syscon_rbm->map))
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 2ce189fdfff4b396d7cc6f175b30016781ae4fe9..f07696f9439063a04fc180e953114ea09475805c 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -4,6 +4,7 @@
#include <linux/bitfield.h>
#include <linux/bits.h>
+#include <linux/reboot.h>
#include <linux/types.h>
/* Construct 64-bit reboot magic: arg2 in upper 32 bits, arg1 in lower 32 */
@@ -15,9 +16,17 @@
/* Get 32 bit arg2 from 64 bit magic */
#define REBOOT_MODE_ARG2(magic) FIELD_GET(GENMASK_ULL(63, 32), magic)
+struct mode_info {
+ const char *mode;
+ u64 magic;
+ struct list_head list;
+};
+
struct reboot_mode_driver {
struct device *dev;
struct list_head head;
+ /* List of predefined reboot-modes, a reboot-mode-driver may populate. */
+ struct list_head predefined_modes;
int (*write)(struct reboot_mode_driver *reboot, u64 magic);
struct notifier_block reboot_notifier;
};
--
2.34.1