input: tps6594-pwrbutton: Add power button functionality

TPS6594 defines two interrupts for the power button one for push and
one for release.

This driver is very simple in that it maps the push interrupt to a key
input and the release interrupt to a key release.

Signed-off-by: Job Sava <jsava@criticallink.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20250826134631.1499936-2-mwalle@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/input/misc/Kconfig

@@ -506,6 +506,16 @@ config INPUT_TPS65219_PWRBUTTON
 	  To compile this driver as a module, choose M here. The module will
 	  be called tps65219-pwrbutton.
 
+config INPUT_TPS6594_PWRBUTTON
+	tristate "TPS6594 Power button driver"
+	depends on MFD_TPS6594
+	help
+	  Say Y here if you want to enable power button reporting for
+	  TPS6594 Power Management IC devices.
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called tps6594-pwrbutton.
+
 config INPUT_AXP20X_PEK
 	tristate "X-Powers AXP20X power button driver"
 	depends on MFD_AXP20X

drivers/input/misc/Makefile

@@ -83,6 +83,7 @@ obj-$(CONFIG_INPUT_SPARCSPKR)		+= sparcspkr.o
 obj-$(CONFIG_INPUT_STPMIC1_ONKEY)  	+= stpmic1_onkey.o
 obj-$(CONFIG_INPUT_TPS65218_PWRBUTTON)	+= tps65218-pwrbutton.o
 obj-$(CONFIG_INPUT_TPS65219_PWRBUTTON)	+= tps65219-pwrbutton.o
+obj-$(CONFIG_INPUT_TPS6594_PWRBUTTON)	+= tps6594-pwrbutton.o
 obj-$(CONFIG_INPUT_TWL4030_PWRBUTTON)	+= twl4030-pwrbutton.o
 obj-$(CONFIG_INPUT_TWL4030_VIBRA)	+= twl4030-vibra.o
 obj-$(CONFIG_INPUT_TWL6040_VIBRA)	+= twl6040-vibra.o

drivers/input/misc/tps6594-pwrbutton.c

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * power button driver for TI TPS6594 PMICs
+ *
+ * Copyright (C) 2025 Critical Link LLC - https://www.criticallink.com/
+ */
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/tps6594.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+struct tps6594_pwrbutton {
+	struct device *dev;
+	struct input_dev *idev;
+	char phys[32];
+};
+
+static irqreturn_t tps6594_pb_push_irq(int irq, void *_pwr)
+{
+	struct tps6594_pwrbutton *pwr = _pwr;
+
+	input_report_key(pwr->idev, KEY_POWER, 1);
+	pm_wakeup_event(pwr->dev, 0);
+	input_sync(pwr->idev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t tps6594_pb_release_irq(int irq, void *_pwr)
+{
+	struct tps6594_pwrbutton *pwr = _pwr;
+
+	input_report_key(pwr->idev, KEY_POWER, 0);
+	input_sync(pwr->idev);
+
+	return IRQ_HANDLED;
+}
+
+static int tps6594_pb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tps6594_pwrbutton *pwr;
+	struct input_dev *idev;
+	int error;
+	int push_irq;
+	int release_irq;
+
+	pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL);
+	if (!pwr)
+		return -ENOMEM;
+
+	idev = devm_input_allocate_device(dev);
+	if (!idev)
+		return -ENOMEM;
+
+	idev->name = pdev->name;
+	snprintf(pwr->phys, sizeof(pwr->phys), "%s/input0",
+		 pdev->name);
+	idev->phys = pwr->phys;
+	idev->id.bustype = BUS_I2C;
+
+	input_set_capability(idev, EV_KEY, KEY_POWER);
+
+	pwr->dev = dev;
+	pwr->idev = idev;
+	device_init_wakeup(dev, true);
+
+	push_irq = platform_get_irq(pdev, 0);
+	if (push_irq < 0)
+		return -EINVAL;
+
+	release_irq = platform_get_irq(pdev, 1);
+	if (release_irq < 0)
+		return -EINVAL;
+
+	error = devm_request_threaded_irq(dev, push_irq, NULL,
+					  tps6594_pb_push_irq,
+					  IRQF_ONESHOT,
+					  pdev->resource[0].name, pwr);
+	if (error) {
+		dev_err(dev, "failed to request push IRQ #%d: %d\n", push_irq,
+			error);
+		return error;
+	}
+
+	error = devm_request_threaded_irq(dev, release_irq, NULL,
+					  tps6594_pb_release_irq,
+					  IRQF_ONESHOT,
+					  pdev->resource[1].name, pwr);
+	if (error) {
+		dev_err(dev, "failed to request release IRQ #%d: %d\n",
+			release_irq, error);
+		return error;
+	}
+
+	error = input_register_device(idev);
+	if (error) {
+		dev_err(dev, "Can't register power button: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id tps6594_pwrbtn_id_table[] = {
+	{ "tps6594-pwrbutton", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, tps6594_pwrbtn_id_table);
+
+static struct platform_driver tps6594_pb_driver = {
+	.probe = tps6594_pb_probe,
+	.driver = {
+		.name = "tps6594_pwrbutton",
+	},
+	.id_table = tps6594_pwrbtn_id_table,
+};
+module_platform_driver(tps6594_pb_driver);
+
+MODULE_DESCRIPTION("TPS6594 Power Button");
+MODULE_LICENSE("GPL");