[PATCH v3] Input: qt1050 - wait for calibration to complete

[Miles Krause via B4 Relay]

From: Miles Krause <mileskrause5200@xxxxxxxxx>

The CALIBRATE flag is set when calibration begins and clears when it
finishes. regmap_read_poll_timeout() stops when its condition becomes
true, so the existing condition returns when calibration starts instead
of waiting for it to finish.

First wait for the flag to become set, then wait for it to clear before
continuing with the soft reset. Use a 500 ms completion timeout to leave
margin beyond the usual calibration time.

Fixes: cbebf5addec1 ("Input: qt1050 - add Microchip AT42QT1050 support")
Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/20260711024428.ED7FF1F000E9@xxxxxxxxxxxxxxx
Signed-off-by: Miles Krause <mileskrause5200@xxxxxxxxx>
---
Compile-tested on x86_64 with:

  make O=out allmodconfig
  make O=out W=1 drivers/input/keyboard/qt1050.o

Sparse-tested with:

  make O=out-sparse allmodconfig
  make O=out-sparse C=1 CHECK=sparse drivers/input/keyboard/qt1050.o
---
Changes in v3:
- Wait for calibration to start before waiting for completion.
- Increase the calibration completion timeout to 500 ms.
- Link to v2: https://patch.msgid.link/20260710-qt1050-calibration-status-bit-v2-1-a58da64bdf7e@xxxxxxxxx

Changes in v2:
- Invert the polling condition to wait for calibration to finish.
- Reframe the change as a bug fix based on Sashiko's review.
- Link to v1: https://patch.msgid.link/20260710-qt1050-calibration-status-bit-v1-1-e4f7d1d797b6@xxxxxxxxx

To: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/input/keyboard/qt1050.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/input/keyboard/qt1050.c b/drivers/input/keyboard/qt1050.c
index f9f480c91032..8cd061587302 100644
--- a/drivers/input/keyboard/qt1050.c
+++ b/drivers/input/keyboard/qt1050.c
@@ -27,7 +27,8 @@
 #define QT1050_FW_VERSION	0x01
 
 /* Detection status */
-#define QT1050_DET_STATUS	0x02
+#define QT1050_DET_STATUS		0x02
+#define QT1050_DET_STATUS_CALIBRATE	BIT(7)
 
 /* Key status */
 #define QT1050_KEY_STATUS	0x03
@@ -498,9 +499,18 @@ static int qt1050_probe(struct i2c_client *client)
 		return err;
 	}
 	err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
-				 status >> 7 == 1, 10000, 200000);
+				 status & QT1050_DET_STATUS_CALIBRATE,
+				 10000, 200000);
 	if (err) {
-		dev_err(dev, "Calibration failed: %d\n", err);
+		dev_err(dev, "Calibration did not start: %d\n", err);
+		return err;
+	}
+
+	err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
+				       !(status & QT1050_DET_STATUS_CALIBRATE),
+				 10000, 500000);
+	if (err) {
+		dev_err(dev, "Calibration did not complete: %d\n", err);
 		return err;
 	}
 

---
base-commit: c8f174900926d3b58cd048ac33b4cbb3de419bfe
change-id: 20260710-qt1050-calibration-status-bit-0b2e479ffd4b

Best regards,
--  
Miles Krause <mileskrause5200@xxxxxxxxx>