[PATCH v17 02/12] power: reset: reboot-mode: Add firmware node based registration

[Shivendra Pratap]

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.

Remove the dependency on struct device and introduce support for
firmware node (fwnode) 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 at oss.qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 19 ++++++++++++++++---
 include/linux/reboot-mode.h       |  4 +++-
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index ac4223794083f36960b2bd37a601b7e1f1872de5..eff60d6e04df2cb84ba59d38512654336f272f8a 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -8,10 +8,12 @@
 #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-"
 
@@ -67,18 +69,26 @@ static int reboot_mode_notify(struct notifier_block *this,
 /**
  * reboot_mode_register - register a reboot mode driver
  * @reboot: reboot mode driver
+ * @fwnode: Firmware node with reboot-mode configuration
  *
  * 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 fwnode_handle *fwnode)
 {
 	struct mode_info *info;
 	struct mode_info *next;
+	struct device_node *np;
 	struct property *prop;
-	struct device_node *np = reboot->dev->of_node;
 	size_t len = strlen(PREFIX);
 	int ret;
 
+	if (!fwnode)
+		return -EINVAL;
+
+	np = to_of_node(fwnode);
+	if (!np)
+		return -EINVAL;
+
 	INIT_LIST_HEAD(&reboot->head);
 
 	for_each_property_of_node(np, prop) {
@@ -168,11 +178,14 @@ int devm_reboot_mode_register(struct device *dev,
 	struct reboot_mode_driver **dr;
 	int rc;
 
+	if (!reboot->dev || !reboot->dev->of_node)
+		return -EINVAL;
+
 	dr = devres_alloc(devm_reboot_mode_release, sizeof(*dr), GFP_KERNEL);
 	if (!dr)
 		return -ENOMEM;
 
-	rc = reboot_mode_register(reboot);
+	rc = reboot_mode_register(reboot, of_fwnode_handle(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 4a2abb38d1d612ec0fdf05eb18c98b210f631b7f..22f707ade4ba93592823ea8718d467dbfc5ffd7c 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -2,6 +2,8 @@
 #ifndef __REBOOT_MODE_H__
 #define __REBOOT_MODE_H__
 
+#include <linux/fwnode.h>
+
 struct reboot_mode_driver {
 	struct device *dev;
 	struct list_head head;
@@ -9,7 +11,7 @@ struct reboot_mode_driver {
 	struct notifier_block reboot_notifier;
 };
 
-int reboot_mode_register(struct reboot_mode_driver *reboot);
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct fwnode_handle *fwnode);
 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