dm: core: Add a few more specific child-finding functions

Add two functions which can find a child device by uclass or by name.
The first is useful with Multi-Function-Devices (MFDs) to find one of a
particular type. The second is useful when only the name is known.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2018-11-18 08:14:31 -07:00
parent d0b4f68d19
commit 3abe111535
3 changed files with 86 additions and 0 deletions

View file

@ -699,6 +699,40 @@ int device_find_first_inactive_child(struct udevice *parent,
return -ENODEV; return -ENODEV;
} }
int device_find_first_child_by_uclass(struct udevice *parent,
enum uclass_id uclass_id,
struct udevice **devp)
{
struct udevice *dev;
*devp = NULL;
list_for_each_entry(dev, &parent->child_head, sibling_node) {
if (device_get_uclass_id(dev) == uclass_id) {
*devp = dev;
return 0;
}
}
return -ENODEV;
}
int device_find_child_by_name(struct udevice *parent, const char *name,
struct udevice **devp)
{
struct udevice *dev;
*devp = NULL;
list_for_each_entry(dev, &parent->child_head, sibling_node) {
if (!strcmp(dev->name, name)) {
*devp = dev;
return 0;
}
}
return -ENODEV;
}
struct udevice *dev_get_parent(const struct udevice *child) struct udevice *dev_get_parent(const struct udevice *child)
{ {
return child->parent; return child->parent;

View file

@ -525,6 +525,8 @@ int device_find_next_child(struct udevice **devp);
* This is used to locate an existing child of a device which is of a given * This is used to locate an existing child of a device which is of a given
* uclass. * uclass.
* *
* The device is NOT probed
*
* @parent: Parent device to search * @parent: Parent device to search
* @uclass_id: Uclass to look for * @uclass_id: Uclass to look for
* @devp: Returns device found, if any * @devp: Returns device found, if any
@ -534,6 +536,29 @@ int device_find_first_inactive_child(struct udevice *parent,
enum uclass_id uclass_id, enum uclass_id uclass_id,
struct udevice **devp); struct udevice **devp);
/**
* device_find_first_child_by_uclass() - Find the first child of a device in uc
*
* @parent: Parent device to search
* @uclass_id: Uclass to look for
* @devp: Returns first child device in that uclass, if any
* @return 0 if found, else -ENODEV
*/
int device_find_first_child_by_uclass(struct udevice *parent,
enum uclass_id uclass_id,
struct udevice **devp);
/**
* device_find_child_by_name() - Find a child by device name
*
* @parent: Parent device to search
* @name: Name to look for
* @devp: Returns device found, if any
* @return 0 if found, else -ENODEV
*/
int device_find_child_by_name(struct udevice *parent, const char *name,
struct udevice **devp);
/** /**
* device_has_children() - check if a device has any children * device_has_children() - check if a device has any children
* *

View file

@ -631,3 +631,30 @@ static int dm_test_fdt_phandle(struct unit_test_state *uts)
return 0; return 0;
} }
DM_TEST(dm_test_fdt_phandle, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT); DM_TEST(dm_test_fdt_phandle, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
/* Test device_find_first_child_by_uclass() */
static int dm_test_first_child(struct unit_test_state *uts)
{
struct udevice *i2c, *dev, *dev2;
ut_assertok(uclass_first_device_err(UCLASS_I2C, &i2c));
ut_assertok(device_find_first_child_by_uclass(i2c, UCLASS_RTC, &dev));
ut_asserteq_str("rtc@43", dev->name);
ut_assertok(device_find_child_by_name(i2c, "rtc@43", &dev2));
ut_asserteq_ptr(dev, dev2);
ut_assertok(device_find_child_by_name(i2c, "rtc@61", &dev2));
ut_asserteq_str("rtc@61", dev2->name);
ut_assertok(device_find_first_child_by_uclass(i2c, UCLASS_I2C_EEPROM,
&dev));
ut_asserteq_str("eeprom@2c", dev->name);
ut_assertok(device_find_child_by_name(i2c, "eeprom@2c", &dev2));
ut_asserteq_ptr(dev, dev2);
ut_asserteq(-ENODEV, device_find_first_child_by_uclass(i2c,
UCLASS_VIDEO, &dev));
ut_asserteq(-ENODEV, device_find_child_by_name(i2c, "missing", &dev));
return 0;
}
DM_TEST(dm_test_first_child, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);