[PATCH v9 6/9] Input: add driver for the input part of qnap-mcu devices

Heiko Stuebner
2024-11-07T12:06:51Z

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.

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
MAINTAINERS | 1 +
drivers/input/misc/Kconfig | 12 +++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/qnap-mcu-input.c | 153 ++++++++++++++++++++++++++++
4 files changed, 167 insertions(+)
create mode 100644 drivers/input/misc/qnap-mcu-input.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9abea0772d2b..9e66441c50da 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18881,6 +18881,7 @@ 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
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6a852c76331b..13d135257e06 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -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
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 4f7f736831ba..6d91804d0a6f 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -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
diff --git a/drivers/input/misc/qnap-mcu-input.c b/drivers/input/misc/qnap-mcu-input.c
new file mode 100644
index 000000000000..76e62f0816c1
--- /dev/null
+++ b/drivers/input/misc/qnap-mcu-input.c
@@ -0,0 +1,153 @@
+// 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");
--
2.45.2