On 11/17/20 10:00 AM, Vabhav Sharma wrote:
From: Vabhav Sharma vabhav.sharma@nxp.com
Support a common method to probe all devices associated with uclass.
This includes data structures and code for finding the first device and looping for remaining devices associated with uclasses (groups of devices with the same purpose, e.g. all SERIAL ports will be in the same uclass).
An example is SBSA compliant PL011 UART IP, where firmware does the serial port initialization and prepare uart device to let the kernel use it for sending and reveiving the characters.SERIAL uclass will use this function to initialize PL011 UART ports.
The feature is enabled with CONFIG_DM.
Signed-off-by: Vabhav Sharma vabhav.sharma@nxp.com Reviewed-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org -- v4: Incorporated review comments of Simon Removed if (dev).. conditional check
v3: Incorporated review comments of Stephan,Simon Related discussion https://patchwork.ozlabs.org/project/uboot/patch/1601400 385-11854-1-git-send-email-vabhav.sharma@oss.nxp.com/
drivers/core/uclass.c | 16 ++++++++++++++++ include/dm/uclass.h | 12 ++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c index c3f1b73..a1dc8bb 100644 --- a/drivers/core/uclass.c +++ b/drivers/core/uclass.c @@ -792,6 +792,22 @@ int uclass_pre_remove_device(struct udevice *dev) } #endif
+int uclass_probe_all(enum uclass_id id) +{
- struct udevice *dev;
- int ret;
- ret = uclass_first_device(id, &dev);
- if (ret || !dev)
return ret;- /* Scanning uclass to probe all devices */
- for (; dev; uclass_next_device(&dev))
You must check the return value of this function.
Also, I would suggest using a while loop instead of an empty for loop.
;- return 0;
+}
UCLASS_DRIVER(nop) = { .id = UCLASS_NOP, .name = "nop", diff --git a/include/dm/uclass.h b/include/dm/uclass.h index 7188304..7ac0aaa 100644 --- a/include/dm/uclass.h +++ b/include/dm/uclass.h @@ -381,6 +381,18 @@ int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data, int uclass_resolve_seq(struct udevice *dev);
/**
- uclass_probe_all() - Probe all devices based on an uclass ID
- Every uclass is identified by an ID, a number from 0 to n-1 where n is
- the number of uclasses. This function probe all devices asocciated with
nit: probes associated
- a uclass by looking its ID.
nit: for its
AFAICT uclass_find_next_device walks the linked-list of devices in a uclass, and does not care about the ID. So this documentation is incorrect.
- @id: uclass ID to look up
- @return 0 if OK, other -ve on error
- */
+int uclass_probe_all(enum uclass_id id);
+/**
- uclass_id_foreach_dev() - Helper function to iteration through devices
- This creates a for() loop which works through the available devices in