ASoC: Add a new SoundWire enumeration helper

Charles Keepax <ckeepax@opensource.cirrus.com> says:

Add a new SoundWire enumeration helper function, many drivers have
almost identical code in runtime resume so it makes sense to move this
to the core.

It is worth noting this is really step one of a larger process, there
are a few drivers that do more custom things and are not covered by this
series. But this series picks up the low hanging fruit and moves things
in a good direction.

The next step is to look at drivers that also wait at probe time, where
the unattached_request flag is not going to be valid.

Link: https://patch.msgid.link/20260512103022.1154645-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index fe5316d93fef..ea3a24f805c0 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -1372,6 +1372,37 @@ int sdw_slave_get_current_bank(struct sdw_slave *slave)
 }
 EXPORT_SYMBOL_GPL(sdw_slave_get_current_bank);
 
+/**
+ * sdw_slave_wait_for_init - Wait for device initialisation
+ * @slave: Pointer to the SoundWire peripheral.
+ * @timeout_ms: Timeout in milliseconds.
+ *
+ * Wait for a peripheral device to enumerate and be initialised by the
+ * SoundWire core.
+ *
+ * Return: Zero on success, and a negative error code on failure.
+ */
+int sdw_slave_wait_for_init(struct sdw_slave *slave, int timeout_ms)
+{
+	unsigned long time;
+
+	if (!slave->unattach_request)
+		return 0;
+
+	time = wait_for_completion_timeout(&slave->initialization_complete,
+					   msecs_to_jiffies(timeout_ms));
+	if (!time) {
+		dev_err(&slave->dev, "Initialization not complete\n");
+		sdw_show_ping_status(slave->bus, true);
+		return -ETIMEDOUT;
+	}
+
+	slave->unattach_request = 0;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sdw_slave_wait_for_init);
+
 static int sdw_slave_set_frequency(struct sdw_slave *slave)
 {
 	int scale_index;