From c6cb8bf79466ae66bd0d07338c7c505ce758e9d7 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Thu, 10 Apr 2025 14:46:32 -0400 Subject: [PATCH] Input: cyttsp5 - ensure minimum reset pulse width 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 Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20250410184633.1164837-1-hugo@hugovil.com Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/cyttsp5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) 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 */ -- 2.50.1