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authorHugo Villeneuve <hvilleneuve@dimonoff.com>2025-04-10 14:46:32 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-05-18 08:24:50 +0200
commitee25256789c31ab4f379af89fcf7ddb2cc72f0fd (patch)
treeac52a31995ddd1a7fdafed8bb7e985b07b72a16d
parentde02eb727f1a296c9459512586d069397db3f34c (diff)
Input: cyttsp5 - ensure minimum reset pulse width
commit c6cb8bf79466ae66bd0d07338c7c505ce758e9d7 upstream. 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 Acked-by: Alistair Francis <alistair@alistair23.me> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20250410184633.1164837-1-hugo@hugovil.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/input/touchscreen/cyttsp5.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c
index eafe5a9b8964..14c43f0a6c21 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(10); /* Ensure long-enough reset pulse (minimum 10us). */
+
gpiod_set_value_cansleep(ts->reset_gpio, 0);
/* Need a delay to have device up */