[PATCH 03/19] of: platform: Keep track of populated platform devices

[Sascha Hauer]

From: Marco Felsch <m.felsch at pengutronix.de>

Linux does not allow to populate the same of device more than once.
Linux uses the OF_POPULATED flag for that purpose. Align the logic with
the current linux state with the exception that we are returning the
already created device. This is needed for the later added deep-probe
mechanism.

Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
Link: https://lore.pengutronix.de/20201021115813.31645-4-m.felsch@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/of/platform.c | 20 +++++++++++++++++++-
 include/of.h          |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 51781798c6..01de6f98af 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -106,6 +106,13 @@ struct device_d *of_platform_device_create(struct device_node *np,
 	if (!of_device_is_available(np))
 		return NULL;
 
+	/*
+	 * Linux uses the OF_POPULATED flag to skip already populated/created
+	 * devices.
+	 */
+	if (np->dev)
+		return np->dev;
+
 	/* count the io resources */
 	if (of_can_translate_address(np))
 		while (of_address_to_resource(np, num_reg, &temp_res) == 0)
@@ -141,8 +148,10 @@ struct device_d *of_platform_device_create(struct device_node *np,
 		(num_reg) ? &dev->resource[0].start : &resinval);
 
 	ret = platform_device_register(dev);
-	if (!ret)
+	if (!ret) {
+		np->dev = dev;
 		return dev;
+	}
 
 	free(dev);
 	if (num_reg)
@@ -223,6 +232,13 @@ static struct device_d *of_amba_device_create(struct device_node *np)
 	if (!of_device_is_available(np))
 		return NULL;
 
+	/*
+	 * Linux uses the OF_POPULATED flag to skip already populated/created
+	 * devices.
+	 */
+	if (np->dev)
+		return np->dev;
+
 	dev = xzalloc(sizeof(*dev));
 
 	/* setup generic device info */
@@ -246,6 +262,8 @@ static struct device_d *of_amba_device_create(struct device_node *np)
 	if (ret)
 		goto amba_err_free;
 
+	np->dev = &dev->dev;
+
 	return &dev->dev;
 
 amba_err_free:
diff --git a/include/of.h b/include/of.h
index d67a40bd19..84d6e9b682 100644
--- a/include/of.h
+++ b/include/of.h
@@ -35,6 +35,7 @@ struct device_node {
 	struct list_head parent_list;
 	struct list_head list;
 	phandle phandle;
+	struct device_d *dev;
 };
 
 struct of_device_id {
-- 
2.29.2