[PATCH 1/2] mfd: ucb1x00: register software node for GPIO controller

[Dmitry Torokhov]

Define a static software node for the UCB1x00 GPIO controller and attach
it to the core MFD device in ucb1x00_probe(). This node will also be
used by the created GPIO chip.

This allows machine subdrivers (such as Assabet evaluation board
support) to reference the UCB1x00 GPIO controller in property entries
when converting legacy platform data to software nodes, resolving pin
bindings directly via the attached firmware node without relying on
name matching.

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/mfd/ucb1x00-core.c  | 12 ++++++++++++
 include/linux/mfd/ucb1x00.h |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index 16f64e2b2f77..8d1c34c53955 100644
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -25,8 +25,13 @@
 #include <linux/mutex.h>
 #include <linux/mfd/ucb1x00.h>
 #include <linux/pm.h>
+#include <linux/property.h>
 #include <linux/gpio/driver.h>
 
+const struct software_node ucb1x00_gpiochip_node = {
+	.name = "ucb1x00-gpio",
+};
+
 static DEFINE_MUTEX(ucb1x00_mutex);
 static LIST_HEAD(ucb1x00_drivers);
 static LIST_HEAD(ucb1x00_devices);
@@ -530,6 +535,10 @@ static int ucb1x00_probe(struct mcp *mcp)
 	ucb->id  = id;
 	ucb->mcp = mcp;
 
+	ret = device_add_software_node(&ucb->dev, &ucb1x00_gpiochip_node);
+	if (ret)
+		goto err_swnode_add;
+
 	ret = device_add(&ucb->dev);
 	if (ret)
 		goto err_dev_add;
@@ -604,6 +613,8 @@ static int ucb1x00_probe(struct mcp *mcp)
  err_no_irq:
 	device_del(&ucb->dev);
  err_dev_add:
+	device_remove_software_node(&ucb->dev);
+ err_swnode_add:
 	put_device(&ucb->dev);
  out:
 	if (pdata && pdata->reset)
@@ -630,6 +641,7 @@ static void ucb1x00_remove(struct mcp *mcp)
 
 	irq_set_chained_handler(ucb->irq, NULL);
 	irq_free_descs(ucb->irq_base, 16);
+	device_remove_software_node(&ucb->dev);
 	device_unregister(&ucb->dev);
 
 	if (pdata && pdata->reset)
diff --git a/include/linux/mfd/ucb1x00.h b/include/linux/mfd/ucb1x00.h
index ede237384723..214c71a12e84 100644
--- a/include/linux/mfd/ucb1x00.h
+++ b/include/linux/mfd/ucb1x00.h
@@ -103,6 +103,9 @@
 #define UCB_MODE_DYN_VFLAG_ENA	(1 << 12)
 #define UCB_MODE_AUD_OFF_CAN	(1 << 13)
 
+struct software_node;
+extern const struct software_node ucb1x00_gpiochip_node;
+
 enum ucb1x00_reset {
 	UCB_RST_PROBE,
 	UCB_RST_RESUME,

-- 
2.55.0.rc2.803.g1fd1e6609c-goog