Commit bb7e3611 authored by Heiko Stuebner's avatar Heiko Stuebner Committed by Lee Jones
Browse files

Input: add driver for the input part of qnap-mcu devices 



The MCU controls the power-button and beeper, so expose them as input
device. There is of course no interrupt line, so the status of the
power-button needs to be polled. To generate an event the power-button
also needs to be held for 1-2 seconds, so the polling interval does
not need to be overly fast.

Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Acked-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20241107114712.538976-7-heiko@sntech.de


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 2ec8bb47

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -19108,6 +19108,7 @@ F: drivers/media/tuners/qm1d1c0042* 
QNAP MCU DRIVER

M:	Heiko Stuebner <heiko@sntech.de>

S:	Maintained

F:	drivers/input/misc/qnap-mcu-input.c

F:	drivers/leds/leds-qnap-mcu.c

F:	drivers/mfd/qnap-mcu.c

F:	include/linux/qnap-mcu.h

drivers/input/misc/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -917,6 +917,18 @@ config INPUT_HISI_POWERKEY 
	  To compile this driver as a module, choose M here: the

	  module will be called hisi_powerkey.



config INPUT_QNAP_MCU

	tristate "Input Support for QNAP MCU controllers"

	depends on MFD_QNAP_MCU

	help

	  This option enables support for input elements available on

	  embedded controllers used in QNAP NAS devices.



	  This includes a polled power-button as well as a beeper.



	  To compile this driver as a module, choose M here: the

	  module will be called qnap-mcu-input.



config INPUT_RAVE_SP_PWRBUTTON

	tristate "RAVE SP Power button Driver"

	depends on RAVE_SP_CORE

drivers/input/misc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ obj-$(CONFIG_INPUT_PMIC8XXX_PWRKEY) += pmic8xxx-pwrkey.o 
obj-$(CONFIG_INPUT_POWERMATE)		+= powermate.o

obj-$(CONFIG_INPUT_PWM_BEEPER)		+= pwm-beeper.o

obj-$(CONFIG_INPUT_PWM_VIBRA)		+= pwm-vibra.o

obj-$(CONFIG_INPUT_QNAP_MCU)		+= qnap-mcu-input.o

obj-$(CONFIG_INPUT_RAVE_SP_PWRBUTTON)	+= rave-sp-pwrbutton.o

obj-$(CONFIG_INPUT_RB532_BUTTON)	+= rb532_button.o

obj-$(CONFIG_INPUT_REGULATOR_HAPTIC)	+= regulator-haptic.o

drivers/input/misc/qnap-mcu-input.c

0 → 100644
+153 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



/*

 * Driver for input events on QNAP-MCUs

 *

 * Copyright (C) 2024 Heiko Stuebner <heiko@sntech.de>

 */



#include <linux/input.h>

#include <linux/mfd/qnap-mcu.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <uapi/linux/input-event-codes.h>



/*

 * The power-key needs to be pressed for a while to create an event,

 * so there is no use for overly frequent polling.

 */

#define POLL_INTERVAL		500



struct qnap_mcu_input_dev {

	struct input_dev *input;

	struct qnap_mcu *mcu;

	struct device *dev;



	struct work_struct beep_work;

	int beep_type;

};



static void qnap_mcu_input_poll(struct input_dev *input)

{

	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);

	static const u8 cmd[] = { '@', 'C', 'V' };

	u8 reply[4];

	int state, ret;



	/* poll the power button */

	ret = qnap_mcu_exec(idev->mcu, cmd, sizeof(cmd), reply, sizeof(reply));

	if (ret)

		return;



	/* First bytes must mirror the sent command */

	if (memcmp(cmd, reply, sizeof(cmd))) {

		dev_err(idev->dev, "malformed data received\n");

		return;

	}



	state = reply[3] - 0x30;

	input_event(input, EV_KEY, KEY_POWER, state);

	input_sync(input);

}



static void qnap_mcu_input_beeper_work(struct work_struct *work)

{

	struct qnap_mcu_input_dev *idev =

		container_of(work, struct qnap_mcu_input_dev, beep_work);

	const u8 cmd[] = { '@', 'C', (idev->beep_type == SND_TONE) ? '3' : '2' };



	qnap_mcu_exec_with_ack(idev->mcu, cmd, sizeof(cmd));

}



static int qnap_mcu_input_event(struct input_dev *input, unsigned int type,

				unsigned int code, int value)

{

	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);



	if (type != EV_SND || (code != SND_BELL && code != SND_TONE))

		return -EOPNOTSUPP;



	if (value < 0)

		return -EINVAL;



	/* beep runtime is determined by the MCU */

	if (value == 0)

		return 0;



	/* Schedule work to actually turn the beeper on */

	idev->beep_type = code;

	schedule_work(&idev->beep_work);



	return 0;

}



static void qnap_mcu_input_close(struct input_dev *input)

{

	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);



	cancel_work_sync(&idev->beep_work);

}



static int qnap_mcu_input_probe(struct platform_device *pdev)

{

	struct qnap_mcu *mcu = dev_get_drvdata(pdev->dev.parent);

	struct qnap_mcu_input_dev *idev;

	struct device *dev = &pdev->dev;

	struct input_dev *input;

	int ret;



	idev = devm_kzalloc(dev, sizeof(*idev), GFP_KERNEL);

	if (!idev)

		return -ENOMEM;



	input = devm_input_allocate_device(dev);

	if (!input)

		return dev_err_probe(dev, -ENOMEM, "no memory for input device\n");



	idev->input = input;

	idev->dev = dev;

	idev->mcu = mcu;



	input_set_drvdata(input, idev);



	input->name		= "qnap-mcu";

	input->phys		= "qnap-mcu-input/input0";

	input->id.bustype	= BUS_HOST;

	input->id.vendor	= 0x0001;

	input->id.product	= 0x0001;

	input->id.version	= 0x0100;

	input->event		= qnap_mcu_input_event;

	input->close		= qnap_mcu_input_close;



	input_set_capability(input, EV_KEY, KEY_POWER);

	input_set_capability(input, EV_SND, SND_BELL);

	input_set_capability(input, EV_SND, SND_TONE);



	INIT_WORK(&idev->beep_work, qnap_mcu_input_beeper_work);



	ret = input_setup_polling(input, qnap_mcu_input_poll);

	if (ret)

		return dev_err_probe(dev, ret, "unable to set up polling\n");



	input_set_poll_interval(input, POLL_INTERVAL);



	ret = input_register_device(input);

	if (ret)

		return dev_err_probe(dev, ret, "unable to register input device\n");



	return 0;

}



static struct platform_driver qnap_mcu_input_driver = {

	.probe = qnap_mcu_input_probe,

	.driver = {

		.name = "qnap-mcu-input",

	},

};

module_platform_driver(qnap_mcu_input_driver);



MODULE_ALIAS("platform:qnap-mcu-input");

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");

MODULE_DESCRIPTION("QNAP MCU input driver");

MODULE_LICENSE("GPL");