cmd: Add bind/unbind commands to bind a device to a driver from the command line

In some cases it can be useful to be able to bind a device to a driver from
the command line.
The obvious example is for versatile devices such as USB gadget.
Another use case is when the devices are not yet ready at startup and
require some setup before the drivers are bound (ex: FPGA which bitsream is
fetched from a mass storage or ethernet)

usage example:

bind usb_dev_generic 0 usb_ether
unbind usb_dev_generic 0 usb_ether
or
unbind eth 1

bind /ocp/omap_dwc3@48380000/usb@48390000 usb_ether
unbind /ocp/omap_dwc3@48380000/usb@48390000

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
diff --git a/test/py/tests/test_bind.py b/test/py/tests/test_bind.py
new file mode 100644
index 0000000..f21b705
--- /dev/null
+++ b/test/py/tests/test_bind.py
@@ -0,0 +1,178 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+
+import os.path
+import pytest
+import re
+
+def in_tree(response, name, uclass, drv, depth, last_child):
+	lines = [x.strip() for x in response.splitlines()]
+	leaf = ' ' * 4 * depth;
+	if not last_child:
+		leaf = leaf + '\|'
+	else:
+		leaf = leaf + '`'
+	leaf = leaf + '-- ' + name
+	line = ' *{:10.10}  [0-9]*  \[ [ +] \]   {:10.10}  {}$'.format(uclass, drv,leaf)
+	prog = re.compile(line)
+	for l in lines:
+		if prog.match(l):
+			return True
+	return False
+
+
+@pytest.mark.buildconfigspec('cmd_bind')
+def test_bind_unbind_with_node(u_boot_console):
+
+	#bind /bind-test. Device should come up as well as its children
+	response = u_boot_console.run_command("bind  /bind-test generic_simple_bus")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert in_tree(tree, "bind-test-child1", "phy", "phy_sandbox", 1, False)
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+
+	#Unbind child #1. No error expected and all devices should be there except for bind-test-child1
+	response = u_boot_console.run_command("unbind  /bind-test/bind-test-child1")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert "bind-test-child1" not in tree
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+
+	#bind child #1. No error expected and all devices should be there
+	response = u_boot_console.run_command("bind  /bind-test/bind-test-child1 phy_sandbox")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert in_tree(tree, "bind-test-child1", "phy", "phy_sandbox", 1, True)
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, False)
+
+	#Unbind child #2. No error expected and all devices should be there except for bind-test-child2
+	response = u_boot_console.run_command("unbind  /bind-test/bind-test-child2")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert in_tree(tree, "bind-test-child1", "phy", "phy_sandbox", 1, True)
+	assert "bind-test-child2" not in tree
+
+
+	#Bind child #2. No error expected and all devices should be there
+	response = u_boot_console.run_command("bind /bind-test/bind-test-child2 generic_simple_bus")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert in_tree(tree, "bind-test-child1", "phy", "phy_sandbox", 1, False)
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+
+	#Unbind parent. No error expected. All devices should be removed and unbound
+	response = u_boot_console.run_command("unbind  /bind-test")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert "bind-test" not in tree
+	assert "bind-test-child1" not in tree
+	assert "bind-test-child2" not in tree
+
+	#try binding invalid node with valid driver
+	response = u_boot_console.run_command("bind  /not-a-valid-node generic_simple_bus")
+	assert response != ''
+	tree = u_boot_console.run_command("dm tree")
+	assert "not-a-valid-node" not in tree
+
+	#try binding valid node with invalid driver
+	response = u_boot_console.run_command("bind  /bind-test not_a_driver")
+	assert response != ''
+	tree = u_boot_console.run_command("dm tree")
+	assert "bind-test" not in tree
+
+	#bind /bind-test. Device should come up as well as its children
+	response = u_boot_console.run_command("bind  /bind-test generic_simple_bus")
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test", "simple_bus", "generic_simple", 0, True)
+	assert in_tree(tree, "bind-test-child1", "phy", "phy_sandbox", 1, False)
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+
+	response = u_boot_console.run_command("unbind  /bind-test")
+	assert response == ''
+
+def get_next_line(tree, name):
+	treelines = [x.strip() for x in tree.splitlines() if x.strip()]
+	child_line = ""
+	for idx, line in enumerate(treelines):
+		if ("-- " + name) in line:
+			try:
+				child_line = treelines[idx+1]
+			except:
+				pass
+			break
+	return child_line
+
+@pytest.mark.buildconfigspec('cmd_bind')
+def test_bind_unbind_with_uclass(u_boot_console):
+	#bind /bind-test
+	response = u_boot_console.run_command("bind  /bind-test generic_simple_bus")
+	assert response == ''
+
+	#make sure bind-test-child2 is there and get its uclass/index pair
+	tree = u_boot_console.run_command("dm tree")
+	child2_line = [x.strip() for x in tree.splitlines() if "-- bind-test-child2" in x]
+	assert len(child2_line) == 1
+
+	child2_uclass = child2_line[0].split()[0]
+	child2_index = int(child2_line[0].split()[1])
+
+	#bind generic_simple_bus as a child of bind-test-child2
+	response = u_boot_console.run_command("bind  {} {} generic_simple_bus".format(child2_uclass, child2_index, "generic_simple_bus"))
+
+	#check that the child is there and its uclass/index pair is right
+	tree = u_boot_console.run_command("dm tree")
+
+	child_of_child2_line = get_next_line(tree, "bind-test-child2")
+	assert child_of_child2_line
+	child_of_child2_index = int(child_of_child2_line.split()[1])
+	assert in_tree(tree, "generic_simple_bus", "simple_bus", "generic_simple_bus", 2, True)
+	assert child_of_child2_index == child2_index + 1
+
+	#unbind the child and check it has been removed
+	response = u_boot_console.run_command("unbind  simple_bus {}".format(child_of_child2_index))
+	assert response == ''
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+	assert not in_tree(tree, "generic_simple_bus", "simple_bus", "generic_simple_bus", 2, True)
+	child_of_child2_line = get_next_line(tree, "bind-test-child2")
+	assert child_of_child2_line == ""
+
+	#bind generic_simple_bus as a child of bind-test-child2
+	response = u_boot_console.run_command("bind  {} {} generic_simple_bus".format(child2_uclass, child2_index, "generic_simple_bus"))
+
+	#check that the child is there and its uclass/index pair is right
+	tree = u_boot_console.run_command("dm tree")
+	treelines = [x.strip() for x in tree.splitlines() if x.strip()]
+
+	child_of_child2_line = get_next_line(tree, "bind-test-child2")
+	assert child_of_child2_line
+	child_of_child2_index = int(child_of_child2_line.split()[1])
+	assert in_tree(tree, "generic_simple_bus", "simple_bus", "generic_simple_bus", 2, True)
+	assert child_of_child2_index == child2_index + 1
+
+	#unbind the child and check it has been removed
+	response = u_boot_console.run_command("unbind  {} {} generic_simple_bus".format(child2_uclass, child2_index, "generic_simple_bus"))
+	assert response == ''
+
+	tree = u_boot_console.run_command("dm tree")
+	assert in_tree(tree, "bind-test-child2", "simple_bus", "generic_simple", 1, True)
+
+	child_of_child2_line = get_next_line(tree, "bind-test-child2")
+	assert child_of_child2_line == ""
+
+	#unbind the child again and check it doesn't change the tree
+	tree_old = u_boot_console.run_command("dm tree")
+	response = u_boot_console.run_command("unbind  {} {} generic_simple_bus".format(child2_uclass, child2_index, "generic_simple_bus"))
+	tree_new = u_boot_console.run_command("dm tree")
+
+	assert response == ''
+	assert tree_old == tree_new
+
+	response = u_boot_console.run_command("unbind  /bind-test")
+	assert response == ''