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Input: cyttsp5 - ensure minimum reset pulse width

Message ID 20250204190100.2210863-1-hugo@hugovil.com
State New
Headers show
Series Input: cyttsp5 - ensure minimum reset pulse width | expand

Commit Message

Hugo Villeneuve Feb. 4, 2025, 7:01 p.m. UTC 
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

The current reset pulse width is measured to be 5us on a
Renesas RZ/G2L SOM. The manufacturer's minimum reset pulse width is
specified as 10us.

Extend reset pulse width to make sure it is long enough on all platforms.

Also reword confusing comments about reset pin assertion.

Fixes: 5b0c03e24a06 ("Input: Add driver for Cypress Generation 5 touchscreen")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/input/touchscreen/cyttsp5.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)


base-commit: 0de63bb7d91975e73338300a57c54b93d3cc151c
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c
index eafe5a9b8964..bb09e84d0e92 100644
--- a/drivers/input/touchscreen/cyttsp5.c
+++ b/drivers/input/touchscreen/cyttsp5.c
@@ -870,13 +870,16 @@  static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
 	ts->input->phys = ts->phys;
 	input_set_drvdata(ts->input, ts);
 
-	/* Reset the gpio to be in a reset state */
+	/* Assert gpio to be in a reset state */
 	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(ts->reset_gpio)) {
 		error = PTR_ERR(ts->reset_gpio);
 		dev_err(dev, "Failed to request reset gpio, error %d\n", error);
 		return error;
 	}
+
+	fsleep(1000); /* Ensure long-enough reset pulse (minimum 10us). */
+
 	gpiod_set_value_cansleep(ts->reset_gpio, 0);
 
 	/* Need a delay to have device up */