Commit 86f6710d authored by Jiri Kosina's avatar Jiri Kosina
Browse files

Merge branch 'for-5.20/elan' into for-linus 

- support for Elan eKTH6915 touchscreens (Douglas Anderson)
parents ebf95514 bd3cba00

Documentation/devicetree/bindings/input/elan,ekth6915.yaml

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/input/elan,ekth6915.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#



title: Elan eKTH6915 touchscreen controller



maintainers:

  - Douglas Anderson <dianders@chromium.org>



description:

  Supports the Elan eKTH6915 touchscreen controller.

  This touchscreen controller uses the i2c-hid protocol with a reset GPIO.



properties:

  compatible:

    items:

      - const: elan,ekth6915



  reg:

    const: 0x10



  interrupts:

    maxItems: 1



  reset-gpios:

    description: Reset GPIO; not all touchscreens using eKTH6915 hook this up.



  vcc33-supply:

    description: The 3.3V supply to the touchscreen.



  vccio-supply:

    description:

      The IO supply to the touchscreen. Need not be specified if this is the

      same as the 3.3V supply.



required:

  - compatible

  - reg

  - interrupts

  - vcc33-supply



additionalProperties: false



examples:

  - |

    #include <dt-bindings/gpio/gpio.h>

    #include <dt-bindings/interrupt-controller/irq.h>



    i2c {

      #address-cells = <1>;

      #size-cells = <0>;



      ap_ts: touchscreen@10 {

        compatible = "elan,ekth6915";

        reg = <0x10>;



        interrupt-parent = <&tlmm>;

        interrupts = <9 IRQ_TYPE_LEVEL_LOW>;



        reset-gpios = <&tlmm 8 GPIO_ACTIVE_LOW>;

        vcc33-supply = <&pp3300_ts>;

      };

    };

drivers/hid/i2c-hid/Kconfig

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@@ -32,6 +32,21 @@ config I2C_HID_OF 
	  will be called i2c-hid-of.  It will also build/depend on the

	  module i2c-hid.



config I2C_HID_OF_ELAN

	tristate "Driver for Elan hid-i2c based devices on OF systems"

	default n

	depends on I2C && INPUT && OF

	help

	  Say Y here if you want support for Elan i2c devices that use

	  the i2c-hid protocol on Open Firmware (Device Tree)-based

	  systems.



	  If unsure, say N.



	  This support is also available as a module.  If so, the module

	  will be called i2c-hid-of-elan.  It will also build/depend on

	  the module i2c-hid.



config I2C_HID_OF_GOODIX

	tristate "Driver for Goodix hid-i2c based devices on OF systems"

	default n

drivers/hid/i2c-hid/Makefile

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@@ -10,4 +10,5 @@ i2c-hid-$(CONFIG_DMI) += i2c-hid-dmi-quirks.o 


obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o

obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o

obj-$(CONFIG_I2C_HID_OF_ELAN)			+= i2c-hid-of-elan.o

obj-$(CONFIG_I2C_HID_OF_GOODIX)			+= i2c-hid-of-goodix.o

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

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// SPDX-License-Identifier: GPL-2.0

/*

 * Driver for Elan touchscreens that use the i2c-hid protocol.

 *

 * Copyright 2020 Google LLC

 */



#include <linux/delay.h>

#include <linux/device.h>

#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/pm.h>

#include <linux/regulator/consumer.h>



#include "i2c-hid.h"



struct elan_i2c_hid_chip_data {

	unsigned int post_gpio_reset_delay_ms;

	unsigned int post_power_delay_ms;

	u16 hid_descriptor_address;

};



struct i2c_hid_of_elan {

	struct i2chid_ops ops;



	struct regulator *vcc33;

	struct regulator *vccio;

	struct gpio_desc *reset_gpio;

	const struct elan_i2c_hid_chip_data *chip_data;

};



static int elan_i2c_hid_power_up(struct i2chid_ops *ops)

{

	struct i2c_hid_of_elan *ihid_elan =

		container_of(ops, struct i2c_hid_of_elan, ops);

	int ret;



	ret = regulator_enable(ihid_elan->vcc33);

	if (ret)

		return ret;



	ret = regulator_enable(ihid_elan->vccio);

	if (ret) {

		regulator_disable(ihid_elan->vcc33);

		return ret;

	}



	if (ihid_elan->chip_data->post_power_delay_ms)

		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);



	return 0;

}



static void elan_i2c_hid_power_down(struct i2chid_ops *ops)

{

	struct i2c_hid_of_elan *ihid_elan =

		container_of(ops, struct i2c_hid_of_elan, ops);



	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);

	regulator_disable(ihid_elan->vccio);

	regulator_disable(ihid_elan->vcc33);

}



static int i2c_hid_of_elan_probe(struct i2c_client *client,

				 const struct i2c_device_id *id)

{

	struct i2c_hid_of_elan *ihid_elan;



	ihid_elan = devm_kzalloc(&client->dev, sizeof(*ihid_elan), GFP_KERNEL);

	if (!ihid_elan)

		return -ENOMEM;



	ihid_elan->ops.power_up = elan_i2c_hid_power_up;

	ihid_elan->ops.power_down = elan_i2c_hid_power_down;



	/* Start out with reset asserted */

	ihid_elan->reset_gpio =

		devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);

	if (IS_ERR(ihid_elan->reset_gpio))

		return PTR_ERR(ihid_elan->reset_gpio);



	ihid_elan->vccio = devm_regulator_get(&client->dev, "vccio");

	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);



	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,

	.hid_descriptor_address = 0x0001,

};



static const struct of_device_id elan_i2c_hid_of_match[] = {

	{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },

	{ }

};

MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match);



static struct i2c_driver elan_i2c_hid_ts_driver = {

	.driver = {

		.name	= "i2c_hid_of_elan",

		.pm	= &i2c_hid_core_pm,

		.probe_type = PROBE_PREFER_ASYNCHRONOUS,

		.of_match_table = of_match_ptr(elan_i2c_hid_of_match),

	},

	.probe		= i2c_hid_of_elan_probe,

	.remove		= i2c_hid_core_remove,

	.shutdown	= i2c_hid_core_shutdown,

};

module_i2c_driver(elan_i2c_hid_ts_driver);



MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>");

MODULE_DESCRIPTION("Elan i2c-hid touchscreen driver");

MODULE_LICENSE("GPL");