[PATCH V2] ptp: clockmatrix: Add Defer probe if firmware load fails

[Sarath Babu Naidu Gaddam]

Clock matrix driver can be probed before the rootfs containing
firmware/initialization .bin is available. The current driver
throws a warning and proceeds to execute probe even when firmware
is not ready. Instead, defer probe and wait for the .bin file to
be available.

Signed-off-by: Sarath Babu Naidu Gaddam <sarath.babu.naidu.gaddam@xxxxxxx>
---
Changes in V2:
1) Added mutex_unlock(idtcm->lock); before returning EPROBE_DEFER.
2) Moved failure log after defer probe.
---
 drivers/ptp/ptp_clockmatrix.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index c9d451bf89e2..b3cb136257e3 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -2424,8 +2424,13 @@ static int idtcm_probe(struct platform_device *pdev)
 
 	err = idtcm_load_firmware(idtcm, &pdev->dev);
 
-	if (err)
+	if (err) {
+		if (err == -ENOENT) {
+			mutex_unlock(idtcm->lock);
+			return -EPROBE_DEFER;
+		}
 		dev_warn(idtcm->dev, "loading firmware failed with %d", err);
+	}
 
 	wait_for_chip_ready(idtcm);
 
-- 
2.25.1