[PATCH v3 1/4] cmd: bind: Add unbind command with driver filter

[Marek Vasut <marex@denx.de>]

Extend the driver core to perform lookup by both OF node and driver
bound to the node. Use this to look up specific device instances to
unbind from nodes in the unbind command. One example where this is
needed is USB peripheral controller, which may have multiple gadget
drivers bound to it. The unbind command has to select that specific
gadget driver instance to unbind from the controller, not unbind the
controller driver itself from the controller.

USB ethernet gadget usage looks as follows with this change. Notice
the extra 'usb_ether' addition in the 'unbind' command at the end.
"
bind /soc/usb-otg@49000000 usb_ether
setenv ethact usb_ether
setenv loadaddr 0xc2000000
setenv ipaddr 10.0.0.2
setenv serverip 10.0.0.1
setenv netmask 255.255.255.0
tftpboot 0xc2000000 10.0.0.1:test.file
unbind /soc/usb-otg@49000000 usb_ether
"

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Simon Glass <sjg@chromium.org>
---
V2: No change
V3: No change
---
 cmd/bind.c            | 10 +++++-----
 drivers/core/device.c | 20 +++++++++++++++-----
 include/dm/device.h   | 17 +++++++++++++++++
 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/cmd/bind.c b/cmd/bind.c
index 4d1b7885e60..3137cdf6cb5 100644
--- a/cmd/bind.c
+++ b/cmd/bind.c
@@ -162,7 +162,7 @@ static int bind_by_node_path(const char *path, const char *drv_name)
 	return 0;
 }
 
-static int unbind_by_node_path(const char *path)
+static int unbind_by_node_path(const char *path, const char *drv_name)
 {
 	struct udevice *dev;
 	int ret;
@@ -174,7 +174,7 @@ static int unbind_by_node_path(const char *path)
 		return -EINVAL;
 	}
 
-	ret = device_find_global_by_ofnode(ofnode, &dev);
+	ret = device_find_global_by_ofnode_driver(ofnode, drv_name, &dev);
 
 	if (!dev || ret) {
 		printf("Cannot find a device with path %s\n", path);
@@ -214,9 +214,9 @@ static int do_bind_unbind(struct cmd_tbl *cmdtp, int flag, int argc,
 			return CMD_RET_USAGE;
 		ret = bind_by_node_path(argv[1], argv[2]);
 	} else if (by_node && !bind) {
-		if (argc != 2)
+		if (argc != 2 && argc != 3)
 			return CMD_RET_USAGE;
-		ret = unbind_by_node_path(argv[1]);
+		ret = unbind_by_node_path(argv[1], argv[2]);
 	} else if (!by_node && bind) {
 		int index = (argc > 2) ? dectoul(argv[2], NULL) : 0;
 
@@ -251,7 +251,7 @@ U_BOOT_CMD(
 U_BOOT_CMD(
 	unbind,	4,	0,	do_bind_unbind,
 	"Unbind a device from a driver",
-	"<node path>\n"
+	"<node path> [<driver>]\n"
 	"unbind <class> <index>\n"
 	"unbind <class> <index> <driver>\n"
 );
diff --git a/drivers/core/device.c b/drivers/core/device.c
index 6e26b64fb81..52fceb69341 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -877,15 +877,17 @@ int device_get_child_by_of_offset(const struct udevice *parent, int node,
 }
 
 static struct udevice *_device_find_global_by_ofnode(struct udevice *parent,
-						     ofnode ofnode)
+						     ofnode ofnode,
+						     const char *drv)
 {
 	struct udevice *dev, *found;
 
-	if (ofnode_equal(dev_ofnode(parent), ofnode))
+	if (ofnode_equal(dev_ofnode(parent), ofnode) &&
+	    (!drv || (drv && !strcmp(parent->driver->name, drv))))
 		return parent;
 
 	device_foreach_child(dev, parent) {
-		found = _device_find_global_by_ofnode(dev, ofnode);
+		found = _device_find_global_by_ofnode(dev, ofnode, drv);
 		if (found)
 			return found;
 	}
@@ -895,7 +897,15 @@ static struct udevice *_device_find_global_by_ofnode(struct udevice *parent,
 
 int device_find_global_by_ofnode(ofnode ofnode, struct udevice **devp)
 {
-	*devp = _device_find_global_by_ofnode(gd->dm_root, ofnode);
+	*devp = _device_find_global_by_ofnode(gd->dm_root, ofnode, NULL);
+
+	return *devp ? 0 : -ENOENT;
+}
+
+int device_find_global_by_ofnode_driver(ofnode ofnode, const char *drv,
+					struct udevice **devp)
+{
+	*devp = _device_find_global_by_ofnode(gd->dm_root, ofnode, drv);
 
 	return *devp ? 0 : -ENOENT;
 }
@@ -904,7 +914,7 @@ int device_get_global_by_ofnode(ofnode ofnode, struct udevice **devp)
 {
 	struct udevice *dev;
 
-	dev = _device_find_global_by_ofnode(gd->dm_root, ofnode);
+	dev = _device_find_global_by_ofnode(gd->dm_root, ofnode, NULL);
 	return device_get_device_tail(dev, dev ? 0 : -ENOENT, devp);
 }
 
diff --git a/include/dm/device.h b/include/dm/device.h
index b86bf90609b..5f05ae0924f 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -748,6 +748,23 @@ int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
 
 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
 
+/**
+ * device_find_global_by_ofnode_driver() - Get a device based on ofnode and driver
+ *
+ * Locates a device by its device tree ofnode and driver currently bound to
+ * it, searching globally throughout the all driver model devices.
+ *
+ * The device is NOT probed
+ *
+ * @node: Device tree ofnode to find
+ * @drv: Driver name bound to device
+ * @devp: Returns pointer to device if found, otherwise this is set to NULL
+ * Return: 0 if OK, -ve on error
+ */
+
+int device_find_global_by_ofnode_driver(ofnode node, const char *drv,
+					struct udevice **devp);
+
 /**
  * device_get_global_by_ofnode() - Get a device based on ofnode
  *
-- 
2.40.1