[PATCH v3 06/31] dm: core: Allow finding a uclass device by partial name

[Heinrich Schuchardt]

On 1/19/22 02:42, Simon Glass wrote:
> In some cases two devices are related and the only way to tell is to
> check that the names partially patch. Add a way to check this without
> needing to create a new string for the comparison.
>
> Fix the comment for device_find_child_by_namelen() while we are here.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> Changes in v3:
> - Add new patch to support finding a uclass device by partial name
>
>   drivers/core/uclass.c        | 13 ++++++++++---
>   include/dm/device.h          |  2 +-
>   include/dm/uclass-internal.h | 16 ++++++++++++++++
>   3 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
> index 563ff9b2856..a0d3840802b 100644
> --- a/drivers/core/uclass.c
> +++ b/drivers/core/uclass.c
> @@ -274,8 +274,8 @@ int uclass_find_next_device(struct udevice **devp)
>   	return 0;
>   }
>
> -int uclass_find_device_by_name(enum uclass_id id, const char *name,
> -			       struct udevice **devp)
> +int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
> +				  struct udevice **devp)
>   {
>   	struct uclass *uc;
>   	struct udevice *dev;
> @@ -289,7 +289,8 @@ int uclass_find_device_by_name(enum uclass_id id, const char *name,
>   		return ret;
>
>   	uclass_foreach_dev(dev, uc) {
> -		if (!strcmp(dev->name, name)) {
> +		if (!strncmp(dev->name, name, len) &&
> +		    strlen(dev->name) == len) {
>   			*devp = dev;
>   			return 0;
>   		}
> @@ -298,6 +299,12 @@ int uclass_find_device_by_name(enum uclass_id id, const char *name,
>   	return -ENODEV;
>   }
>
> +int uclass_find_device_by_name(enum uclass_id id, const char *name,
> +			       struct udevice **devp)
> +{
> +	return uclass_find_device_by_namelen(id, name, strlen(name), devp);
> +}
> +
>   int uclass_find_next_free_seq(struct uclass *uc)
>   {
>   	struct udevice *dev;
> diff --git a/include/dm/device.h b/include/dm/device.h
> index 435a1114f1c..30703af96e4 100644
> --- a/include/dm/device.h
> +++ b/include/dm/device.h
> @@ -791,7 +791,7 @@ int device_find_first_child_by_uclass(const struct udevice *parent,
>   				      struct udevice **devp);
>
>   /**
> - * device_find_child_by_name() - Find a child by device name
> + * device_find_child_by_namelen() - Find a child by device name
>    *
>    * @parent:	Parent device to search
>    * @name:	Name to look for
> diff --git a/include/dm/uclass-internal.h b/include/dm/uclass-internal.h
> index fb0edcc2969..1118f64bdfd 100644
> --- a/include/dm/uclass-internal.h
> +++ b/include/dm/uclass-internal.h
> @@ -154,6 +154,22 @@ int uclass_find_first_device(enum uclass_id id, struct udevice **devp);
>    */
>   int uclass_find_next_device(struct udevice **devp);
>
> +/**
> + * uclass_find_device_by_namelen() - Find uclass device based on ID and name
> + *
> + * This searches for a device with the exactly given name.
> + *
> + * The device is NOT probed, it is merely returned.
> + *
> + * @id: ID to look up
> + * @name: name of a device to find
> + * @len: Length of @name (the uclass driver name must have the same length)
> + * @devp: Returns pointer to device (the first one with the name)
> + * @return 0 if OK, -ve on error

Return:
https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation

Best regards

Heinrich

> + */
> +int uclass_find_device_by_namelen(enum uclass_id id, const char *name, int len,
> +				  struct udevice **devp);
> +
>   /**
>    * uclass_find_device_by_name() - Find uclass device based on ID and name
>    *