[PATCH 1/2] input: himax_hx83112b: Add hx83102d support

[Henri Ommer <henri.ommer@gmx.net>]

The core functionality of the hx83102d is software-compatible with the hx83112b. As with the hx83112b, firmware flashing is unimplemented.
This commit also adds support for touchscreen chips which do not have a reset GPIO, like the hx83102d in the Samsung Galaxy A20e.

Tested on: Samsung Galaxy A20e (SM-A202F)

Signed-off-by: Henri Ommer <henri.ommer@gmx.net>
---
 drivers/input/touchscreen/himax_hx83112b.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/himax_hx83112b.c b/drivers/input/touchscreen/himax_hx83112b.c
index 345ece27fe74..04c9c6aba396 100644
--- a/drivers/input/touchscreen/himax_hx83112b.c
+++ b/drivers/input/touchscreen/himax_hx83112b.c
@@ -7,6 +7,9 @@
  * HX83100A support
  * Copyright (C) 2024 Felix Kaechele <felix@kaechele.ca>
  *
+ * HX83102D support
+ * Copyright (C) 2026 Henri Ommer <henri.ommer@gmx.net>
+ *
  * This code is based on "Himax Android Driver Sample Code for QCT platform":
  *
  * Copyright (C) 2017 Himax Corporation.
@@ -132,6 +135,14 @@ static int himax_bus_read(struct himax_ts_data *ts, u32 address, void *dst,
 
 static void himax_reset(struct himax_ts_data *ts)
 {
+	/*
+	 * Some versions of himax touchscreen chips do not contain a reset
+	 * GPIO. The downstream driver only resets these chips for firmware
+	 * updates (which aren't implemented in this driver)
+	 */
+	if (!ts->gpiod_rst)
+		return;
+
 	gpiod_set_value_cansleep(ts->gpiod_rst, 1);
 
 	/* Delay copied from downstream driver */
@@ -349,7 +360,7 @@ static int himax_probe(struct i2c_client *client)
 		return error;
 	}
 
-	ts->gpiod_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	ts->gpiod_rst = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	error = PTR_ERR_OR_ZERO(ts->gpiod_rst);
 	if (error) {
 		dev_err(dev, "Failed to get reset GPIO: %d\n", error);
@@ -399,6 +410,12 @@ static const struct himax_chip hx83100a_chip = {
 	.read_events = hx83100a_read_events,
 };
 
+static const struct himax_chip hx83102d_chip = {
+	.id = 0x83102d,
+	.check_id = himax_check_product_id,
+	.read_events = himax_read_events,
+};
+
 static const struct himax_chip hx83112b_chip = {
 	.id = 0x83112b,
 	.check_id = himax_check_product_id,
@@ -407,6 +424,7 @@ static const struct himax_chip hx83112b_chip = {
 
 static const struct i2c_device_id himax_ts_id[] = {
 	{ .name = "hx83100a", .driver_data = (kernel_ulong_t)&hx83100a_chip },
+	{ .name = "hx83102d", .driver_data = (kernel_ulong_t)&hx83102d_chip },
 	{ .name = "hx83112b", .driver_data = (kernel_ulong_t)&hx83112b_chip },
 	{ /* sentinel */ }
 };
@@ -415,6 +433,7 @@ MODULE_DEVICE_TABLE(i2c, himax_ts_id);
 #ifdef CONFIG_OF
 static const struct of_device_id himax_of_match[] = {
 	{ .compatible = "himax,hx83100a", .data = &hx83100a_chip },
+	{ .compatible = "himax,hx83102d", .data = &hx83102d_chip },
 	{ .compatible = "himax,hx83112b", .data = &hx83112b_chip },
 	{ /* sentinel */ }
 };
-- 
2.56.0