Input: cyttsp5 - ensure minimum reset pulse width

JIRA: https://issues.redhat.com/browse/RHEL-101770
Upstream Status: since v6.15
Tested: with the hid-tools test suite and some hardware

commit c6cb8bf
Author: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Date:   Thu Apr 10 14:46:32 2025 -0400

    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: 5b0c03e ("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: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Author: bentiss

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 */