Merge branch 'for-6.6/elan' into for-linus

Make use of panel follower for the Ilitek ili9882t
driver by Cong Yang

Author: Benjamin Tissoires

Documentation/devicetree/bindings/input/ilitek,ili9882t.yaml

@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/ilitek,ili9882t.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ili9882t touchscreen controller
+
+maintainers:
+  - Cong Yang <[email protected]>
+
+description:
+  Supports the Ilitek ili9882t touchscreen controller.
+  This touchscreen controller uses the i2c-hid protocol with a reset GPIO.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    const: ilitek,ili9882t
+
+  reg:
+    const: 0x41
+
+  interrupts:
+    maxItems: 1
+
+  panel: true
+
+  reset-gpios:
+    maxItems: 1
+    description: Reset GPIO.
+
+  vccio-supply:
+    description: The 1.8V supply to the touchscreen.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - panel
+  - vccio-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      touchscreen: touchscreen@41 {
+        compatible = "ilitek,ili9882t";
+        reg = <0x41>;
+
+        interrupt-parent = <&pio>;
+        interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
+
+        panel = <&panel>;
+        reset-gpios = <&pio 60 GPIO_ACTIVE_LOW>;
+        vccio-supply = <&mt6366_vio18_reg>;
+      };
+    };

drivers/hid/i2c-hid/i2c-hid-of-elan.c

@@ -18,9 +18,11 @@
 #include "i2c-hid.h"
 
 struct elan_i2c_hid_chip_data {
-	unsigned int post_gpio_reset_delay_ms;
+	unsigned int post_gpio_reset_on_delay_ms;
+	unsigned int post_gpio_reset_off_delay_ms;
 	unsigned int post_power_delay_ms;
 	u16 hid_descriptor_address;
+	const char *main_supply_name;
 };
 
 struct i2c_hid_of_elan {
@@ -38,9 +40,11 @@ static int elan_i2c_hid_power_up(struct i2chid_ops *ops)
 		container_of(ops, struct i2c_hid_of_elan, ops);
 	int ret;
 
-	ret = regulator_enable(ihid_elan->vcc33);
-	if (ret)
-		return ret;
+	if (ihid_elan->vcc33) {
+		ret = regulator_enable(ihid_elan->vcc33);
+		if (ret)
+			return ret;
+	}
 
 	ret = regulator_enable(ihid_elan->vccio);
 	if (ret) {
@@ -52,8 +56,8 @@ static int elan_i2c_hid_power_up(struct i2chid_ops *ops)
 		msleep(ihid_elan->chip_data->post_power_delay_ms);
 
 	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 0);
-	if (ihid_elan->chip_data->post_gpio_reset_delay_ms)
-		msleep(ihid_elan->chip_data->post_gpio_reset_delay_ms);
+	if (ihid_elan->chip_data->post_gpio_reset_on_delay_ms)
+		msleep(ihid_elan->chip_data->post_gpio_reset_on_delay_ms);
 
 	return 0;
 }
@@ -64,8 +68,12 @@ static void elan_i2c_hid_power_down(struct i2chid_ops *ops)
 		container_of(ops, struct i2c_hid_of_elan, ops);
 
 	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
+	if (ihid_elan->chip_data->post_gpio_reset_off_delay_ms)
+		msleep(ihid_elan->chip_data->post_gpio_reset_off_delay_ms);
+
 	regulator_disable(ihid_elan->vccio);
-	regulator_disable(ihid_elan->vcc33);
+	if (ihid_elan->vcc33)
+		regulator_disable(ihid_elan->vcc33);
 }
 
 static int i2c_hid_of_elan_probe(struct i2c_client *client)
@@ -89,24 +97,42 @@ static int i2c_hid_of_elan_probe(struct i2c_client *client)
 	if (IS_ERR(ihid_elan->vccio))
 		return PTR_ERR(ihid_elan->vccio);
 
-	ihid_elan->vcc33 = devm_regulator_get(&client->dev, "vcc33");
-	if (IS_ERR(ihid_elan->vcc33))
-		return PTR_ERR(ihid_elan->vcc33);
-
 	ihid_elan->chip_data = device_get_match_data(&client->dev);
 
+	if (ihid_elan->chip_data->main_supply_name) {
+		ihid_elan->vcc33 = devm_regulator_get(&client->dev,
+						      ihid_elan->chip_data->main_supply_name);
+		if (IS_ERR(ihid_elan->vcc33))
+			return PTR_ERR(ihid_elan->vcc33);
+	}
+
 	return i2c_hid_core_probe(client, &ihid_elan->ops,
 				  ihid_elan->chip_data->hid_descriptor_address, 0);
 }
 
 static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
 	.post_power_delay_ms = 1,
-	.post_gpio_reset_delay_ms = 300,
+	.post_gpio_reset_on_delay_ms = 300,
+	.hid_descriptor_address = 0x0001,
+	.main_supply_name = "vcc33",
+};
+
+static const struct elan_i2c_hid_chip_data ilitek_ili9882t_chip_data = {
+	.post_power_delay_ms = 1,
+	.post_gpio_reset_on_delay_ms = 200,
+	.post_gpio_reset_off_delay_ms = 65,
 	.hid_descriptor_address = 0x0001,
+	/*
+	 * this touchscreen is tightly integrated with the panel and assumes
+	 * that the relevant power rails (other than the IO rail) have already
+	 * been turned on by the panel driver because we're a panel follower.
+	 */
+	.main_supply_name = NULL,
 };
 
 static const struct of_device_id elan_i2c_hid_of_match[] = {
 	{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },
+	{ .compatible = "ilitek,ili9882t", .data = &ilitek_ili9882t_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match);