Input: exc3000 - support power supply regulators

Add power supply regulator support to the exc3000 devices.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Link: https://lore.kernel.org/r/20230707131042.10795-2-mike.looijmans@topic.nl
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: MikeLooijmans

drivers/input/touchscreen/exc3000.c

@@ -18,6 +18,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sizes.h>
 #include <linux/timer.h>
 #include <asm/unaligned.h>
@@ -360,6 +361,12 @@ static int exc3000_probe(struct i2c_client *client)
 	if (IS_ERR(data->reset))
 		return PTR_ERR(data->reset);
 
+	/* For proper reset sequence, enable power while reset asserted */
+	error = devm_regulator_get_enable(&client->dev, "vdd");
+	if (error && error != -ENODEV)
+		return dev_err_probe(&client->dev, error,
+				     "failed to request vdd regulator\n");
+
 	if (data->reset) {
 		msleep(EXC3000_RESET_MS);
 		gpiod_set_value_cansleep(data->reset, 0);