[PATCH] counter: microchip-tcb-capture: Fix undefined counter channel state on probe

[William Breathitt Gray]

Hardware initialize of the timer counter channel does not occur on probe
thus leaving the Count in an undefined state until the first
function_write() callback is executed. Fix this by performing the proper
hardware initialization during probe.

Fixes: 106b104137fd ("counter: Add microchip TCB capture counter")
Reported-by: Csókás Bence <csokas.bence@xxxxxxxxx>
Closes: https://lore.kernel.org/all/bfa70e78-3cc3-4295-820b-3925c26135cb@xxxxxxxxx/
Signed-off-by: William Breathitt Gray <wbg@xxxxxxxxxx>
---
This should fix the issue where a user needs to set the count function
before they can use the counter. I don't have this hardware in person,
so please test this patch and let me know whether it works for you.
---
 drivers/counter/microchip-tcb-capture.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c
index 2f096a5b973d18edf5de5a2b33f2f72571deefb7..c391ac38b990939c6764a9120a4bd03289f68469 100644
--- a/drivers/counter/microchip-tcb-capture.c
+++ b/drivers/counter/microchip-tcb-capture.c
@@ -368,6 +368,25 @@ static int mchp_tc_probe(struct platform_device *pdev)
 			channel);
 	}
 
+	/* Disable Quadrature Decoder and position measure */
+	ret = regmap_update_bits(regmap, ATMEL_TC_BMR, ATMEL_TC_QDEN | ATMEL_TC_POSEN, 0);
+	if (ret)
+		return ret;
+
+	/* Setup the period capture mode */
+	ret = regmap_update_bits(regmap, ATMEL_TC_REG(priv->channel[0], CMR),
+				 ATMEL_TC_WAVE | ATMEL_TC_ABETRG | ATMEL_TC_CMR_MASK |
+				 ATMEL_TC_TCCLKS,
+				 ATMEL_TC_CMR_MASK);
+	if (ret)
+		return ret;
+
+	/* Enable clock and trigger counter */
+	ret = regmap_write(regmap, ATMEL_TC_REG(priv->channel[0], CCR),
+			   ATMEL_TC_CLKEN | ATMEL_TC_SWTRG);
+	if (ret)
+		return ret;
+
 	priv->tc_cfg = tcb_config;
 	priv->regmap = regmap;
 	counter->name = dev_name(&pdev->dev);

---
base-commit: 8744dcd4fc7800de2eb9369410470bb2930d4c14
change-id: 20250305-preset-capture-mode-microchip-tcb-capture-fa31550ef594

Best regards,
-- 
William Breathitt Gray <wbg@xxxxxxxxxx>