[PATCH v2] Input: qt1050 - wait for calibration to complete

[Miles Krause via B4 Relay <devnull+mileskrause5200.gmail.com@kernel.org>]

From: Miles Krause <mileskrause5200@gmail.com>

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.

Name the calibration status bit and invert the polling condition so the
subsequent soft reset does not potentially interrupt calibration.

Fixes: cbebf5addec1 ("Input: qt1050 - add Microchip AT42QT1050 support")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/r/20260711011903.0605C1F000E9@smtp.kernel.org
Signed-off-by: Miles Krause <mileskrause5200@gmail.com>
---
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 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@gmail.com

To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Rob Herring <robh@kernel.org>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/input/keyboard/qt1050.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/input/keyboard/qt1050.c b/drivers/input/keyboard/qt1050.c
index f9f480c91032..457acae0986a 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
@@ -498,7 +499,8 @@ 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);
 		return err;

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

Best regards,
--  
Miles Krause <mileskrause5200@gmail.com>