Input: cyttsp - reduce reset pulse timings

The data sheet for CY8CTMA340 specifies that the reset pulse shall be at
least 1 ms. Specify 1-2 ms with usleep_range() to cut some slack for the
scheduler.

Curiously the datasheet does not specify how long we have to wait after a
hard reset until the chip is up, but I have found a vendor tree (Samsung
GT-S7710) that has code for this touch screen and there this is set to 5
ms so I use this with the same 1 ms fuzz.
Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210408131153.3446138-6-linus.walleij@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/cyttsp_core.c

@@ -229,10 +229,16 @@ static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
 static void cyttsp_hard_reset(struct cyttsp *ts)
 {
 	if (ts->reset_gpio) {
+		/*
+		 * According to the CY8CTMA340 datasheet page 21, the external
+		 * reset pulse width should be >= 1 ms. The datasheet does not
+		 * specify how long we have to wait after reset but a vendor
+		 * tree specifies 5 ms here.
+		 */
 		gpiod_set_value_cansleep(ts->reset_gpio, 1);
-		msleep(CY_DELAY_DFLT);
+		usleep_range(1000, 2000);
 		gpiod_set_value_cansleep(ts->reset_gpio, 0);
-		msleep(CY_DELAY_DFLT);
+		usleep_range(5000, 6000);
 	}
 }