[RFC PATCH 4/5] input: add onkey driver for Marvell 88PM88X PMICs

[Karel Balej]

From: Karel Balej <balejk@xxxxxxxxx>

The Marvell 88PM88X PMICs provide onkey among other things. Add client
driver to handle it. The driver currently only provides a basic support
omitting additional functions found in the vendor version, such as long
onkey and GPIO integration.

Signed-off-by: Karel Balej <balejk@xxxxxxxxx>
---
 drivers/input/misc/88pm88x-onkey.c | 103 +++++++++++++++++++++++++++++
 drivers/input/misc/Kconfig         |  10 +++
 drivers/input/misc/Makefile        |   1 +
 3 files changed, 114 insertions(+)
 create mode 100644 drivers/input/misc/88pm88x-onkey.c

diff --git a/drivers/input/misc/88pm88x-onkey.c b/drivers/input/misc/88pm88x-onkey.c
new file mode 100644
index 000000000000..0d6056a3cab2
--- /dev/null
+++ b/drivers/input/misc/88pm88x-onkey.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/input.h>
+#include <linux/regmap.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#include <linux/mfd/88pm88x.h>
+
+struct pm88x_onkey {
+	struct input_dev *idev;
+	struct pm88x_chip *chip;
+	int irq;
+};
+
+static irqreturn_t pm88x_onkey_irq_handler(int irq, void *data)
+{
+	struct pm88x_onkey *onkey = data;
+	unsigned int val;
+	int ret = 0;
+
+	ret = regmap_read(onkey->chip->regmaps[PM88X_REGMAP_BASE], PM88X_REG_STATUS1, &val);
+	if (ret) {
+		dev_err(onkey->idev->dev.parent, "Failed to read status: %d\n", ret);
+		return IRQ_NONE;
+	}
+	val &= PM88X_ONKEY_STS1;
+
+	input_report_key(onkey->idev, KEY_POWER, val);
+	input_sync(onkey->idev);
+
+	return IRQ_HANDLED;
+}
+
+static int pm88x_onkey_probe(struct platform_device *pdev)
+{
+	struct pm88x_chip *chip = dev_get_drvdata(pdev->dev.parent);
+	struct pm88x_onkey *onkey;
+	int err;
+
+	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
+	if (!onkey)
+		return -ENOMEM;
+
+	onkey->chip = chip;
+
+	onkey->irq = platform_get_irq(pdev, 0);
+	if (onkey->irq < 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ\n");
+		return -EINVAL;
+	}
+
+	onkey->idev = devm_input_allocate_device(&pdev->dev);
+	if (!onkey->idev) {
+		dev_err(&pdev->dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	onkey->idev->name = "88pm88x-onkey";
+	onkey->idev->phys = "88pm88x-onkey/input0";
+	onkey->idev->id.bustype = BUS_I2C;
+	onkey->idev->dev.parent = &pdev->dev;
+	onkey->idev->evbit[0] = BIT_MASK(EV_KEY);
+	onkey->idev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
+
+	err = devm_request_threaded_irq(&pdev->dev, onkey->irq, NULL, pm88x_onkey_irq_handler,
+			IRQF_ONESHOT | IRQF_NO_SUSPEND, "onkey", onkey);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to request IRQ: %d\n", err);
+		return err;
+	}
+
+	err = input_register_device(onkey->idev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register input device: %d\n", err);
+		return err;
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	return 0;
+}
+
+static const struct of_device_id pm88x_onkey_of_match[] = {
+	{ .compatible = "marvell,88pm88x-onkey", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pm88x_onkey_of_match);
+
+static struct platform_driver pm88x_onkey_driver = {
+	.driver = {
+		.name = "88pm88x-onkey",
+		.of_match_table = of_match_ptr(pm88x_onkey_of_match),
+	},
+	.probe = pm88x_onkey_probe,
+};
+module_platform_driver(pm88x_onkey_driver);
+
+MODULE_DESCRIPTION("Marvell 88PM88X onkey driver");
+MODULE_AUTHOR("Karel Balej <balejk@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6ba984d7f0b1..fdfa3e23c3cf 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -33,6 +33,16 @@ config INPUT_88PM80X_ONKEY
 	  To compile this driver as a module, choose M here: the module
 	  will be called 88pm80x_onkey.
 
+config INPUT_88PM88X_ONKEY
+	tristate "Marvell 88PM88X onkey support"
+	depends on MFD_88PM88X
+	help
+	  Support the onkey of Marvell 88PM88X PMICs as an input device
+	  reporting power button status.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called 88pm88x-onkey.
+
 config INPUT_AB8500_PONKEY
 	tristate "AB8500 Pon (PowerOn) Key"
 	depends on AB8500_CORE
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 04296a4abe8e..eab7a364188c 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -7,6 +7,7 @@
 
 obj-$(CONFIG_INPUT_88PM860X_ONKEY)	+= 88pm860x_onkey.o
 obj-$(CONFIG_INPUT_88PM80X_ONKEY)	+= 88pm80x_onkey.o
+obj-$(CONFIG_INPUT_88PM88X_ONKEY)	+= 88pm88x-onkey.o
 obj-$(CONFIG_INPUT_AB8500_PONKEY)	+= ab8500-ponkey.o
 obj-$(CONFIG_INPUT_AD714X)		+= ad714x.o
 obj-$(CONFIG_INPUT_AD714X_I2C)		+= ad714x-i2c.o
-- 
2.43.0