[RFC][PATCH 4/5] drivers: input: powerkey for HISI 65xx SoC

[John Stultz <john.stultz@linaro.org>]

From: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>

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 <xuezhiliang@huawei.com>
then basically rewritten by Jorge, but preserving the original
module author credits.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Guodong Xu <guodong.xu@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
[jstultz: Reworked commit message, folded in other fixes/cleanups
from Jorge, and made a few small fixes and cleanups of my own]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/input/misc/Kconfig         |   8 ++
 drivers/input/misc/Makefile        |   1 +
 drivers/input/misc/hisi_powerkey.c | 228 +++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)
 create mode 100644 drivers/input/misc/hisi_powerkey.c

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 1f2337a..2e57bbd 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -796,4 +796,12 @@ config INPUT_DRV2667_HAPTICS
 	  To compile this driver as a module, choose M here: the
 	  module will be called drv2667-haptics.
 
+config HISI_POWERKEY
+	tristate "Hisilicon PMIC ONKEY support"
+	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
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 0357a08..f264777 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -75,3 +75,4 @@ obj-$(CONFIG_INPUT_WM831X_ON)		+= wm831x-on.o
 obj-$(CONFIG_INPUT_XEN_KBDDEV_FRONTEND)	+= xen-kbdfront.o
 obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
 obj-$(CONFIG_INPUT_IDEAPAD_SLIDEBAR)	+= ideapad_slidebar.o
+obj-$(CONFIG_HISI_POWERKEY)		+= hisi_powerkey.o
diff --git a/drivers/input/misc/hisi_powerkey.c b/drivers/input/misc/hisi_powerkey.c
new file mode 100644
index 0000000..3a35a75
--- /dev/null
+++ b/drivers/input/misc/hisi_powerkey.c
@@ -0,0 +1,228 @@
+/*
+ * hisi_powerkey.c - Hisilicon MIC 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 above held interrupt will trigger after 4 seconds */
+#define MAX_HELD_TIME	(4 * MSEC_PER_SEC)
+
+
+typedef irqreturn_t (*hi65xx_irq_handler) (int irq, void *data);
+enum { id_pressed, id_released, id_held, id_last };
+static irqreturn_t hi65xx_pkey_irq_handler(int irq, void *q);
+
+/*
+ * power key irq information
+ */
+static struct hi65xx_pkey_irq_info {
+	hi65xx_irq_handler handler;
+	const char *const name;
+	int irq;
+} irq_info[id_last] = {
+	[id_pressed] = {
+		.handler = hi65xx_pkey_irq_handler,
+		.name = "down",
+		.irq = -1,
+	},
+	[id_released] = {
+		.handler = hi65xx_pkey_irq_handler,
+		.name = "up",
+		.irq = -1,
+	},
+	[id_held] = {
+		.handler = hi65xx_pkey_irq_handler,
+		.name = "hold 4s",
+		.irq = -1,
+	},
+};
+
+/*
+ * power key events
+ */
+static struct key_report_pairs {
+	int code;
+	int value;
+} pkey_report[id_last] = {
+	[id_released] = {
+		.code = KEY_POWER,
+		.value = 0
+	},
+	[id_pressed] = {
+		.code = KEY_POWER,
+		.value = 1
+	},
+	[id_held] = {
+		.code = KEY_RESTART,
+		.value = 0
+	},
+};
+
+struct hi65xx_priv {
+	struct input_dev *input;
+	struct wakeup_source wlock;
+};
+
+static inline void report_key(struct input_dev *dev, int id_action)
+{
+	/*
+	 * track the state of the key held event since only ON/OFF values are
+	 * allowed on EV_KEY types: KEY_RESTART will always toggle its value to
+	 * guarantee that the event is passed to handlers (dispossition update).
+	 */
+	if (id_action == id_held)
+		pkey_report[id_held].value ^= 1;
+
+	dev_dbg(dev->dev.parent, "received - code %d, value %d\n",
+		pkey_report[id_action].code,
+		pkey_report[id_action].value);
+
+	input_report_key(dev, pkey_report[id_action].code,
+		pkey_report[id_action].value);
+}
+
+static irqreturn_t hi65xx_pkey_irq_handler(int irq, void *q)
+{
+	struct hi65xx_priv *p = q;
+	int i, action = -1;
+
+	for (i = 0; i < id_last; i++)
+		if (irq == irq_info[i].irq)
+			action = i;
+
+	if (action == -1)
+		return IRQ_NONE;
+
+	__pm_wakeup_event(&p->wlock, MAX_HELD_TIME);
+
+	report_key(p->input, action);
+	input_sync(p->input);
+
+	return IRQ_HANDLED;
+}
+
+static int hi65xx_powerkey_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct hi65xx_priv *priv;
+	int irq, i, ret;
+
+	if (pdev == NULL) {
+		dev_err(dev, "parameter error\n");
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(dev, sizeof(struct hi65xx_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->input = input_allocate_device();
+	if (!priv->input) {
+		dev_err(&pdev->dev, "failed to allocate input device\n");
+		return -ENOENT;
+	}
+
+	priv->input->evbit[0] = BIT_MASK(EV_KEY);
+	priv->input->dev.parent = &pdev->dev;
+	priv->input->phys = "hisi_on/input0";
+	priv->input->name = "HISI 65xx PowerOn Key";
+
+	for (i = 0; i < ARRAY_SIZE(pkey_report); i++)
+		input_set_capability(priv->input, EV_KEY, pkey_report[i].code);
+
+	for (i = 0; i < ARRAY_SIZE(irq_info); i++) {
+
+		irq = platform_get_irq_byname(pdev, irq_info[i].name);
+		if (irq < 0) {
+			dev_err(dev, "couldn't get irq %s\n", irq_info[i].name);
+			ret = irq;
+			goto err_irq;
+		}
+
+		ret = devm_request_threaded_irq(dev, irq, NULL,
+					irq_info[i].handler, IRQF_ONESHOT,
+					irq_info[i].name, priv);
+		if (ret < 0) {
+			dev_err(dev, "couldn't get irq %s\n", irq_info[i].name);
+			goto err_irq;
+		}
+
+		irq_info[i].irq = irq;
+	}
+
+	wakeup_source_init(&priv->wlock, "hisi-powerkey");
+
+	ret = input_register_device(priv->input);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register input device: %d\n",
+			ret);
+		ret = -ENOENT;
+		goto err_register;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+err_register:
+	wakeup_source_trash(&priv->wlock);
+err_irq:
+	input_free_device(priv->input);
+
+	return ret;
+}
+
+static int hi65xx_powerkey_remove(struct platform_device *pdev)
+{
+	struct hi65xx_priv *priv = platform_get_drvdata(pdev);
+
+	wakeup_source_trash(&priv->wlock);
+	input_unregister_device(priv->input);
+
+	return 0;
+}
+
+static const struct of_device_id hi65xx_powerkey_of_match[] = {
+	{ .compatible = "hisilicon,hi6552-powerkey", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, hi65xx_powerkey_of_match);
+
+static struct platform_driver hi65xx_powerkey_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "hi65xx-powerkey",
+		.of_match_table = hi65xx_powerkey_of_match,
+	},
+	.probe = hi65xx_powerkey_probe,
+	.remove  = hi65xx_powerkey_remove,
+};
+
+module_platform_driver(hi65xx_powerkey_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Zhiliang Xue <xuezhiliang@huawei.com");
+MODULE_DESCRIPTION("Hisi PMIC Power key driver");
+MODULE_LICENSE("GPL v2");
+
+
-- 
1.9.1