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Jiri Kosina
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Merge branch 'for-5.20/elan' into for-linus
- support for Elan eKTH6915 touchscreens (Douglas Anderson)
2 parents ebf9551 + bd3cba0 commit 86f6710

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

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/input/elan,ekth6915.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: Elan eKTH6915 touchscreen controller
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maintainers:
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- Douglas Anderson <[email protected]>
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description:
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Supports the Elan eKTH6915 touchscreen controller.
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This touchscreen controller uses the i2c-hid protocol with a reset GPIO.
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properties:
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compatible:
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items:
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- const: elan,ekth6915
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reg:
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const: 0x10
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interrupts:
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maxItems: 1
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reset-gpios:
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description: Reset GPIO; not all touchscreens using eKTH6915 hook this up.
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vcc33-supply:
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description: The 3.3V supply to the touchscreen.
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vccio-supply:
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description:
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The IO supply to the touchscreen. Need not be specified if this is the
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same as the 3.3V supply.
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required:
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- compatible
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- reg
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- interrupts
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- vcc33-supply
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additionalProperties: false
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examples:
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- |
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#include <dt-bindings/gpio/gpio.h>
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#include <dt-bindings/interrupt-controller/irq.h>
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i2c {
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#address-cells = <1>;
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#size-cells = <0>;
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ap_ts: touchscreen@10 {
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compatible = "elan,ekth6915";
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reg = <0x10>;
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interrupt-parent = <&tlmm>;
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interrupts = <9 IRQ_TYPE_LEVEL_LOW>;
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reset-gpios = <&tlmm 8 GPIO_ACTIVE_LOW>;
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vcc33-supply = <&pp3300_ts>;
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};
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};

‎drivers/hid/i2c-hid/Kconfig

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will be called i2c-hid-of. It will also build/depend on the
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module i2c-hid.
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config I2C_HID_OF_ELAN
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tristate "Driver for Elan hid-i2c based devices on OF systems"
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default n
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depends on I2C && INPUT && OF
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help
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Say Y here if you want support for Elan i2c devices that use
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the i2c-hid protocol on Open Firmware (Device Tree)-based
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systems.
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If unsure, say N.
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This support is also available as a module. If so, the module
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will be called i2c-hid-of-elan. It will also build/depend on
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the module i2c-hid.
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config I2C_HID_OF_GOODIX
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tristate "Driver for Goodix hid-i2c based devices on OF systems"
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default n

‎drivers/hid/i2c-hid/Makefile

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obj-$(CONFIG_I2C_HID_ACPI) += i2c-hid-acpi.o
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obj-$(CONFIG_I2C_HID_OF) += i2c-hid-of.o
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obj-$(CONFIG_I2C_HID_OF_ELAN) += i2c-hid-of-elan.o
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obj-$(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
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/*
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* Driver for Elan touchscreens that use the i2c-hid protocol.
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*
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* Copyright 2020 Google LLC
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*/
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/gpio/consumer.h>
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#include <linux/i2c.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/pm.h>
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#include <linux/regulator/consumer.h>
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#include "i2c-hid.h"
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struct elan_i2c_hid_chip_data {
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unsigned int post_gpio_reset_delay_ms;
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unsigned int post_power_delay_ms;
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u16 hid_descriptor_address;
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};
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struct i2c_hid_of_elan {
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struct i2chid_ops ops;
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struct regulator *vcc33;
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struct regulator *vccio;
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struct gpio_desc *reset_gpio;
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const struct elan_i2c_hid_chip_data *chip_data;
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};
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static int elan_i2c_hid_power_up(struct i2chid_ops *ops)
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{
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struct i2c_hid_of_elan *ihid_elan =
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container_of(ops, struct i2c_hid_of_elan, ops);
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int ret;
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ret = regulator_enable(ihid_elan->vcc33);
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if (ret)
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return ret;
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ret = regulator_enable(ihid_elan->vccio);
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if (ret) {
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regulator_disable(ihid_elan->vcc33);
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return ret;
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}
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if (ihid_elan->chip_data->post_power_delay_ms)
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msleep(ihid_elan->chip_data->post_power_delay_ms);
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gpiod_set_value_cansleep(ihid_elan->reset_gpio, 0);
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if (ihid_elan->chip_data->post_gpio_reset_delay_ms)
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msleep(ihid_elan->chip_data->post_gpio_reset_delay_ms);
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return 0;
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}
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static void elan_i2c_hid_power_down(struct i2chid_ops *ops)
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{
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struct i2c_hid_of_elan *ihid_elan =
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container_of(ops, struct i2c_hid_of_elan, ops);
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gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
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regulator_disable(ihid_elan->vccio);
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regulator_disable(ihid_elan->vcc33);
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}
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static int i2c_hid_of_elan_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct i2c_hid_of_elan *ihid_elan;
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ihid_elan = devm_kzalloc(&client->dev, sizeof(*ihid_elan), GFP_KERNEL);
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if (!ihid_elan)
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return -ENOMEM;
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ihid_elan->ops.power_up = elan_i2c_hid_power_up;
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ihid_elan->ops.power_down = elan_i2c_hid_power_down;
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/* Start out with reset asserted */
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ihid_elan->reset_gpio =
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devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
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if (IS_ERR(ihid_elan->reset_gpio))
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return PTR_ERR(ihid_elan->reset_gpio);
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ihid_elan->vccio = devm_regulator_get(&client->dev, "vccio");
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if (IS_ERR(ihid_elan->vccio))
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return PTR_ERR(ihid_elan->vccio);
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ihid_elan->vcc33 = devm_regulator_get(&client->dev, "vcc33");
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if (IS_ERR(ihid_elan->vcc33))
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return PTR_ERR(ihid_elan->vcc33);
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ihid_elan->chip_data = device_get_match_data(&client->dev);
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return i2c_hid_core_probe(client, &ihid_elan->ops,
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ihid_elan->chip_data->hid_descriptor_address, 0);
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}
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static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
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.post_power_delay_ms = 1,
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.post_gpio_reset_delay_ms = 300,
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.hid_descriptor_address = 0x0001,
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};
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static const struct of_device_id elan_i2c_hid_of_match[] = {
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{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },
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{ }
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};
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MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match);
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static struct i2c_driver elan_i2c_hid_ts_driver = {
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.driver = {
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.name = "i2c_hid_of_elan",
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.pm = &i2c_hid_core_pm,
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.probe_type = PROBE_PREFER_ASYNCHRONOUS,
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.of_match_table = of_match_ptr(elan_i2c_hid_of_match),
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},
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.probe = i2c_hid_of_elan_probe,
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.remove = i2c_hid_core_remove,
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.shutdown = i2c_hid_core_shutdown,
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};
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module_i2c_driver(elan_i2c_hid_ts_driver);
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MODULE_AUTHOR("Douglas Anderson <[email protected]>");
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MODULE_DESCRIPTION("Elan i2c-hid touchscreen driver");
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MODULE_LICENSE("GPL");

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