[PATCH v2 04/37] dm: core: Allow dropping run-time binding of devices

[Simon Glass]

With OF_PLATDATA_INST devices are bound at build time. we should not allow
binding of devices at runtime. Add an option to control this.

Update the driver model core so that it does not bind devices. Update
device_bind() to return an error if called.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

(no changes since v1)

 drivers/core/device.c | 38 +++++++++++++++++++++-----------------
 dts/Kconfig           | 16 ++++++++++++++++
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/drivers/core/device.c b/drivers/core/device.c
index 8629df8defb..02e28f014b5 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -44,6 +44,9 @@ static int device_bind_common(struct udevice *parent, const struct driver *drv,
 	bool auto_seq = true;
 	void *ptr;
 
+	if (CONFIG_IS_ENABLED(OF_PLATDATA_NO_BIND))
+		return -ENOSYS;
+
 	if (devp)
 		*devp = NULL;
 	if (!name)
@@ -382,26 +385,27 @@ int device_of_to_plat(struct udevice *dev)
 	if (dev_get_flags(dev) & DM_FLAG_PLATDATA_VALID)
 		return 0;
 
-	/* Ensure all parents have ofdata */
-	if (dev->parent) {
-		ret = device_of_to_plat(dev->parent);
+	if (!CONFIG_IS_ENABLED(OF_PLATDATA_NO_BIND)) {
+		/* Ensure all parents have ofdata */
+		if (dev->parent) {
+			ret = device_of_to_plat(dev->parent);
+			if (ret)
+				goto fail;
+
+			/*
+			 * The device might have already been probed during
+			 * the call to device_probe() on its parent device
+			 * (e.g. PCI bridge devices). Test the flags again
+			 * so that we don't mess up the device.
+			 */
+			if (dev_get_flags(dev) & DM_FLAG_PLATDATA_VALID)
+				return 0;
+		}
+
+		ret = device_alloc_priv(dev);
 		if (ret)
 			goto fail;
-
-		/*
-		 * The device might have already been probed during
-		 * the call to device_probe() on its parent device
-		 * (e.g. PCI bridge devices). Test the flags again
-		 * so that we don't mess up the device.
-		 */
-		if (dev_get_flags(dev) & DM_FLAG_PLATDATA_VALID)
-			return 0;
 	}
-
-	ret = device_alloc_priv(dev);
-	if (ret)
-		goto fail;
-
 	drv = dev->driver;
 	assert(drv);
 
diff --git a/dts/Kconfig b/dts/Kconfig
index e861ea48d01..645a2d2b84d 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -371,6 +371,14 @@ config SPL_OF_PLATDATA_INST
 	  Declare devices as udevice instances so that they do not need to be
 	  bound when U-Boot starts. This can save time and code space.
 
+config SPL_OF_PLATDATA_NO_BIND
+	bool "Don't allow run-time binding of devices"
+	depends on SPL_OF_PLATDATA_INST
+	default y
+	help
+	  This removes the ability to bind devices at run time, thus saving
+	  some code space in U-Boot.
+
 endif
 
 config TPL_OF_PLATDATA
@@ -411,6 +419,14 @@ config TPL_OF_PLATDATA_INST
 	  Declare devices as udevice instances so that they do not need to be
 	  bound when U-Boot starts. This can save time and code space.
 
+config TPL_OF_PLATDATA_NO_BIND
+	bool "Don't allow run-time binding of devices"
+	depends on TPL_OF_PLATDATA_INST
+	default y
+	help
+	  This removes the ability to bind devices at run time, thus saving
+	  some code space in U-Boot.
+
 endif
 
 endmenu
-- 
2.30.0.365.g02bc693789-goog