Input: add powerkey driver for HISI 65xx SoC

This driver provides a input driver for the power button on the
HiSi 65xx SoC for boards like HiKey.

This driver was originally by Zhiliang Xue <[e-mail]>
then basically rewritten by Jorge, but preserving the original
module author credits.

Signed-off-by: Jorge Ramirez-Ortiz <[e-mail]>
[jstultz: Reworked commit message, folded in other fixes/cleanups
from Jorge, implemented some larger cleanups suggested by DmitryT]
Signed-off-by: John Stultz <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called drv2667-haptics.
 
+config INPUT_HISI_POWERKEY
+	tristate "Hisilicon PMIC ONKEY support"
+	depends on ARCH_HISI || COMPILE_TEST
+	help
+	  Say Y to enable support for PMIC ONKEY.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hisi_powerkey.
+
 endif

drivers/input/misc/Makefile

···
 obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o
 obj-$(CONFIG_INPUT_GPIO_BEEPER)		+= gpio-beeper.o
 obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
+obj-$(CONFIG_INPUT_HISI_POWERKEY)	+= hisi_powerkey.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
 obj-$(CONFIG_INPUT_IMS_PCU)		+= ims-pcu.o
 obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o

drivers/input/misc/hisi_powerkey.c

···
+/*
+ * Hisilicon PMIC powerkey driver
+ *
+ * Copyright (C) 2013 Hisilicon Ltd.
+ * Copyright (C) 2015, 2016 Linaro Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+
+/* the held interrupt will trigger after 4 seconds */
+#define MAX_HELD_TIME	(4 * MSEC_PER_SEC)
+
+static irqreturn_t hi65xx_power_press_isr(int irq, void *q)
+{
+	struct input_dev *input = q;
+
+	pm_wakeup_event(input->dev.parent, MAX_HELD_TIME);
+	input_report_key(input, KEY_POWER, 1);
+	input_sync(input);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t hi65xx_power_release_isr(int irq, void *q)
+{
+	struct input_dev *input = q;
+
+	pm_wakeup_event(input->dev.parent, MAX_HELD_TIME);
+	input_report_key(input, KEY_POWER, 0);
+	input_sync(input);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t hi65xx_restart_toggle_isr(int irq, void *q)
+{
+	struct input_dev *input = q;
+	int value = test_bit(KEY_RESTART, input->key);
+
+	pm_wakeup_event(input->dev.parent, MAX_HELD_TIME);
+	input_report_key(input, KEY_RESTART, !value);
+	input_sync(input);
+
+	return IRQ_HANDLED;
+}
+
+static const struct {
+	const char *name;
+	irqreturn_t (*handler)(int irq, void *q);
+} hi65xx_irq_info[] = {
+	{ "down", hi65xx_power_press_isr },
+	{ "up", hi65xx_power_release_isr },
+	{ "hold 4s", hi65xx_restart_toggle_isr },
+};
+
+static int hi65xx_powerkey_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *input;
+	int irq, i, error;
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input) {
+		dev_err(&pdev->dev, "failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	input->phys = "hisi_on/input0";
+	input->name = "HISI 65xx PowerOn Key";
+
+	input_set_capability(input, EV_KEY, KEY_POWER);
+	input_set_capability(input, EV_KEY, KEY_RESTART);
+
+	for (i = 0; i < ARRAY_SIZE(hi65xx_irq_info); i++) {
+
+		irq = platform_get_irq_byname(pdev, hi65xx_irq_info[i].name);
+		if (irq < 0) {
+			error = irq;
+			dev_err(dev, "couldn't get irq %s: %d\n",
+				hi65xx_irq_info[i].name, error);
+			return error;
+		}
+
+		error = devm_request_any_context_irq(dev, irq,
+						     hi65xx_irq_info[i].handler,
+						     IRQF_ONESHOT,
+						     hi65xx_irq_info[i].name,
+						     input);
+		if (error < 0) {
+			dev_err(dev, "couldn't request irq %s: %d\n",
+				hi65xx_irq_info[i].name, error);
+			return error;
+		}
+	}
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register input device: %d\n",
+			error);
+		return error;
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	return 0;
+}
+
+static int hi65xx_powerkey_remove(struct platform_device *pdev)
+{
+	device_init_wakeup(&pdev->dev, 0);
+
+	return 0;
+}
+
+static struct platform_driver hi65xx_powerkey_driver = {
+	.driver = {
+		.name = "hi65xx-powerkey",
+	},
+	.probe = hi65xx_powerkey_probe,
+	.remove  = hi65xx_powerkey_remove,
+};
+module_platform_driver(hi65xx_powerkey_driver);
+
+MODULE_AUTHOR("Zhiliang Xue <[e-mail]");
+MODULE_DESCRIPTION("Hisi PMIC Power key driver");
+MODULE_LICENSE("GPL v2");