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

On 18.6.2018 15:56, Jean-Jacques Hiblot wrote:

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

---

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@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;
  

I am getting compilation warnings bout this ret handling.

cmd/bind.c: In function ‘do_bind_unbind’: cmd/bind.c:237:5: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (ret) ^

+}

+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"

+);

I have played with this series with zynq_gpio driver on zcu100. It can be only one instance of this driver but I can call bind multiple times and instance is listed with new index. Log below.

ZynqMP> dm tree Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver serial 0 [ ] arm_dcc |-- dcc simple_bus 0 [ ] generic_si |-- amba_apu@0 simple_bus 1 [ + ] generic_si |-- amba gpio 0 [ ] gpio_zynq | |-- gpio@ff0a0000 mmc 0 [ + ] arasan_sdh | |-- sdhci@ff160000 ... ZynqMP> bind /amba/gpio@ff0a0000 gpio_zynq EFI: Initializing UCLASS_EFI Calling zynq_gpio_bind ZynqMP> dm tree Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver serial 0 [ ] arm_dcc |-- dcc simple_bus 0 [ ] generic_si |-- amba_apu@0 simple_bus 1 [ + ] generic_si |-- amba gpio 0 [ ] gpio_zynq | |-- gpio@ff0a0000 gpio 1 [ ] gpio_zynq | | `-- gpio_zynq mmc 0 [ + ] arasan_sdh | |-- sdhci@ff160000 ... ZynqMP>

I can read dev->seq in probe and fail if dev->seq is not 0 but not sure if this should be checked in probe.

The second thing is that when I call unbind for probed device that it is failing because it hasn't been removed.

ZynqMP> dm tree Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver serial 0 [ ] arm_dcc |-- dcc simple_bus 0 [ ] generic_si |-- amba_apu@0 simple_bus 1 [ + ] generic_si |-- amba gpio 0 [ ] gpio_zynq | |-- gpio@ff0a0000 mmc 0 [ + ] arasan_sdh | |-- sdhci@ff160000 ... ZynqMP> gpio status 0 Calling zynq_gpio_ofdata_to_platdata Calling zynq_gpio_probe 0 ZynqMP> dm tree Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver serial 0 [ ] arm_dcc |-- dcc simple_bus 0 [ ] generic_si |-- amba_apu@0 simple_bus 1 [ + ] generic_si |-- amba gpio 0 [ + ] gpio_zynq | |-- gpio@ff0a0000 mmc 0 [ + ] arasan_sdh | |-- sdhci@ff160000 ... ZynqMP> unbind /amba/gpio@ff0a0000 EFI: Initializing UCLASS_EFI activated Unable to unbind. err:-22

That's why I am curious if this command enable to unbind device then there should be also an option to remove that device too.

More generic note. I have been taking information about structure from dm tree command and I would consider to move test/dm/cmd_dm.c to cmd folder and extend this file by these new functionality.

Thanks, Michal