[U-Boot] [PATCH v2 3/5] cmd: Add bind/unbind commands to bind a device to a driver from the command line

Jean-Jacques Hiblot jjhiblot at ti.com
Mon Jun 18 13:56:50 UTC 2018


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 at 48380000/usb at 48390000 usb_ether
unbind /ocp/omap_dwc3 at 48380000/usb at 48390000

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>

---

Changes in v2:
- Make the bind/unbind command generic, not specific to usb device.
- Update the API to be able to bind/unbind based on DTS node path
- Add a Kconfig option to select the bind/unbind commands

 cmd/Kconfig  |   9 +++
 cmd/Makefile |   1 +
 cmd/bind.c   | 256 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 266 insertions(+)
 create mode 100644 cmd/bind.c

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 1eb55e5..d6bbfba 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -607,6 +607,15 @@ config CMD_ADC
 	  Shows ADC device info and permit printing one-shot analog converted
 	  data from a named Analog to Digital Converter.
 
+config CMD_BIND
+	bool "bind/unbind - Bind or unbind a device to/from a driver"
+	depends on DM
+	help
+	  Bind or unbind a device to/from a driver from the command line.
+	  This is useful in situations where a device may be handled by several
+	  drivers. For example, this can be used to bind a UDC to the usb ether
+	  gadget driver from the command line.
+
 config CMD_CLK
 	bool "clk - Show clock frequencies"
 	help
diff --git a/cmd/Makefile b/cmd/Makefile
index e0088df..b12aca3 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_SOURCE) += source.o
 obj-$(CONFIG_CMD_SOURCE) += source.o
 obj-$(CONFIG_CMD_BDI) += bdinfo.o
 obj-$(CONFIG_CMD_BEDBUG) += bedbug.o
+obj-$(CONFIG_CMD_BIND) += bind.o
 obj-$(CONFIG_CMD_BINOP) += binop.o
 obj-$(CONFIG_CMD_BLOCK_CACHE) += blkcache.o
 obj-$(CONFIG_CMD_BMP) += bmp.o
diff --git a/cmd/bind.c b/cmd/bind.c
new file mode 100644
index 0000000..60d84d6
--- /dev/null
+++ b/cmd/bind.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2018 JJ Hiblot <jjhiblot at ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
+
+static int bind_by_class_index(const char *uclass, int index,
+			       const char *drv_name)
+{
+	static enum uclass_id uclass_id;
+	struct udevice *dev;
+	struct udevice *parent;
+	int ret;
+	struct driver *drv;
+
+	drv = lists_driver_lookup_name(drv_name);
+	if (!drv) {
+		printf("Cannot find driver '%s'\n", drv_name);
+		return -ENOENT;
+	}
+
+	uclass_id = uclass_get_by_name(uclass);
+	if (uclass_id == UCLASS_INVALID) {
+		printf("%s is not a valid uclass\n", uclass);
+		return -EINVAL;
+	}
+
+	ret = uclass_find_device(uclass_id, index, &parent);
+	if (!parent || ret) {
+		printf("Cannot find device %d of class %s\n", index, uclass);
+		return ret;
+	}
+
+	ret = device_bind_with_driver_data(parent, drv, drv->name, 0,
+					   ofnode_null(), &dev);
+	if (!dev || ret) {
+		printf("Unable to bind. err:%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int unbind_by_class_index(const char *uclass, int index)
+{
+	static enum uclass_id uclass_id;
+	struct udevice *dev;
+	int ret;
+
+	uclass_id = uclass_get_by_name(uclass);
+	if (uclass_id == UCLASS_INVALID) {
+		printf("%s is not a valid uclass\n", uclass);
+		return -EINVAL;
+	}
+
+	ret = uclass_find_device(uclass_id, index, &dev);
+	if (!dev || ret) {
+		printf("Cannot find device %d of class %s\n", index, uclass);
+		return ret;
+	}
+
+	ret = device_unbind(dev);
+	if (ret) {
+		printf("Unable to unbind. err:%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int unbind_child_by_class_index(const char *uclass, int index,
+				       const char *drv_name)
+{
+	static enum uclass_id uclass_id;
+	struct udevice *parent;
+	struct udevice *dev, *n;
+	int ret;
+	struct driver *drv;
+
+	drv = lists_driver_lookup_name(drv_name);
+	if (!drv) {
+		printf("Cannot find driver '%s'\n", drv_name);
+		return -ENOENT;
+	}
+
+	uclass_id = uclass_get_by_name(uclass);
+	if (uclass_id == UCLASS_INVALID) {
+		printf("%s is not a valid uclass\n", uclass);
+		return -EINVAL;
+	}
+
+	ret = uclass_find_device(uclass_id, index, &parent);
+	if (!parent || ret) {
+		printf("Cannot find device %d of class %s\n", index, uclass);
+		return ret;
+	}
+
+	list_for_each_entry_safe(dev, n, &parent->child_head, sibling_node) {
+		int rc;
+
+		if (dev->driver != drv)
+			continue;
+
+		rc = device_unbind(dev);
+		if (rc && !ret) {
+			printf("failed to unbind %s/%s\n", dev->name,
+			       drv->name);
+			ret = rc;
+		}
+	}
+
+	return ret;
+}
+
+static int bind_by_node_path(const char *path, const char *drv_name)
+{
+	struct udevice *dev;
+	struct udevice *parent = NULL;
+	int ret;
+	int id;
+	ofnode ofnode;
+	struct driver *drv;
+
+	drv = lists_driver_lookup_name(drv_name);
+	if (!drv) {
+		printf("%s is not a valid driver name\n", drv_name);
+		return -ENOENT;
+	}
+
+	ofnode = ofnode_path(path);
+	if (!ofnode_valid(ofnode)) {
+		printf("%s is not a valid node path\n", path);
+		return -EINVAL;
+	}
+
+	while (ofnode_valid(ofnode)) {
+		for (id = 0; id < UCLASS_COUNT; id++) {
+			if (!uclass_find_device_by_ofnode(id, ofnode, &parent))
+				break;
+		}
+		if (parent)
+			break;
+		ofnode = ofnode_get_parent(ofnode);
+	}
+
+	if (!parent) {
+		printf("Cannot find a parent device for node path %s\n", path);
+		return -ENODEV;
+	}
+
+	ret = device_bind_with_driver_data(parent, drv, drv->name, 0,
+					   ofnode_path(path), &dev);
+	if (!dev || ret) {
+		printf("Unable to bind. err:%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int unbind_by_node_path(const char *path)
+{
+	struct udevice *dev;
+	int ret;
+	int id;
+	ofnode ofnode;
+
+	ofnode = ofnode_path(path);
+	if (!ofnode_valid(ofnode)) {
+		printf("%s is not a valid node path\n", path);
+		return -EINVAL;
+	}
+
+	for (id = 0; id < UCLASS_COUNT; id++) {
+		if (uclass_find_device_by_ofnode(id, ofnode, &dev) == 0)
+			break;
+	}
+
+	if (!dev) {
+		printf("Cannot find a device with path %s\n", path);
+		return -ENODEV;
+	}
+
+	ret = device_unbind(dev);
+	if (ret) {
+		printf("Unable to unbind. err:%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int do_bind_unbind(cmd_tbl_t *cmdtp, int flag, int argc,
+			  char * const argv[])
+{
+	int ret;
+	bool bind;
+	bool by_node;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	bind = (argv[0][0] == 'b');
+	by_node = (argv[1][0] == '/');
+
+	if (by_node && bind) {
+		if (argc != 3)
+			return CMD_RET_USAGE;
+		ret = bind_by_node_path(argv[1], argv[2]);
+	} else if (by_node && !bind) {
+		if (argc != 2)
+			return CMD_RET_USAGE;
+		ret = unbind_by_node_path(argv[1]);
+	} else if (!by_node && bind) {
+		int index = (argc > 2) ? simple_strtoul(argv[2], NULL, 10) : 0;
+
+		if (argc != 4)
+			return CMD_RET_USAGE;
+		ret = bind_by_class_index(argv[1], index, argv[3]);
+	} else if (!by_node && !bind) {
+		int index = (argc > 2) ? simple_strtoul(argv[2], NULL, 10) : 0;
+
+		if (argc == 3)
+			ret = unbind_by_class_index(argv[1], index);
+		else if (argc == 4)
+			ret = unbind_child_by_class_index(argv[1], index,
+							  argv[3]);
+		else
+			return CMD_RET_USAGE;
+	}
+
+	if (ret)
+		return CMD_RET_FAILURE;
+	else
+		return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(
+	bind,	4,	0,	do_bind_unbind,
+	"Bind a device to a driver",
+	"<node path> <driver>\n"
+	"bind <class> <index> <driver>\n"
+);
+
+U_BOOT_CMD(
+	unbind,	4,	0,	do_bind_unbind,
+	"Unbind a device from a driver",
+	"<node path>\n"
+	"unbind <class> <index>\n"
+	"unbind <class> <index> <driver>\n"
+);
-- 
2.7.4



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