Input: add driver for AXP20x Power Enable Key

This change adds support for the Power Enable Key found on MFD AXP202
and AXP209. Besides the basic support for the button, the driver adds
two entries in sysfs to configure the time delay for power on/off.
Signed-off-by: Carlo Caione <carlo@caione.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[wens@csie.org: made axp20x_pek_remove() static; removed driver owner
 field; fixed path for sysfs entries]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/ABI/testing/sysfs-driver-input-axp-pek

+What:		/sys/class/input/input(x)/device/startup
+Date:		March 2014
+Contact:	Carlo Caione <carlo@caione.org>
+Description:	Startup time in us. Board is powered on if the button is pressed
+		for more than <startup_time>
+
+What:		/sys/class/input/input(x)/device/shutdown
+Date:		March 2014
+Contact:	Carlo Caione <carlo@caione.org>
+Description:	Shutdown time in us. Board is powered off if the button is pressed
+		for more than <shutdown_time>

drivers/input/misc/Kconfig

@@ -426,6 +426,17 @@ config INPUT_TPS65218_PWRBUTTON
 	  To compile this driver as a module, choose M here. The module will
 	  be called tps65218-pwrbutton.
 
+config INPUT_AXP20X_PEK
+	tristate "X-Powers AXP20X power button driver"
+	depends on MFD_AXP20X
+	help
+	  Say Y here if you want to enable power key reporting via the
+	  AXP20X PMIC.
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called axp20x-pek.
+
+
 config INPUT_TWL4030_PWRBUTTON
 	tristate "TWL4030 Power button Driver"
 	depends on TWL4030_CORE

drivers/input/misc/Makefile

@@ -55,6 +55,7 @@ obj-$(CONFIG_INPUT_PWM_BEEPER)		+= pwm-beeper.o
 obj-$(CONFIG_INPUT_RB532_BUTTON)	+= rb532_button.o
 obj-$(CONFIG_INPUT_REGULATOR_HAPTIC)	+= regulator-haptic.o
 obj-$(CONFIG_INPUT_RETU_PWRBUTTON)	+= retu-pwrbutton.o
+obj-$(CONFIG_INPUT_AXP20X_PEK)		+= axp20x-pek.o
 obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER)	+= rotary_encoder.o
 obj-$(CONFIG_INPUT_SGI_BTNS)		+= sgi_btns.o
 obj-$(CONFIG_INPUT_SIRFSOC_ONKEY)	+= sirfsoc-onkey.o

drivers/input/misc/axp20x-pek.c

+/*
+ * axp20x power button driver.
+ *
+ * Copyright (C) 2013 Carlo Caione <carlo@caione.org>
+ *
+ * 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/errno.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define AXP20X_PEK_STARTUP_MASK		(0xc0)
+#define AXP20X_PEK_SHUTDOWN_MASK	(0x03)
+
+struct axp20x_pek {
+	struct axp20x_dev *axp20x;
+	struct input_dev *input;
+	int irq_dbr;
+	int irq_dbf;
+};
+
+struct axp20x_time {
+	unsigned int time;
+	unsigned int idx;
+};
+
+static const struct axp20x_time startup_time[] = {
+	{ .time = 128,  .idx = 0 },
+	{ .time = 1000, .idx = 2 },
+	{ .time = 3000, .idx = 1 },
+	{ .time = 2000, .idx = 3 },
+};
+
+static const struct axp20x_time shutdown_time[] = {
+	{ .time = 4000,  .idx = 0 },
+	{ .time = 6000,  .idx = 1 },
+	{ .time = 8000,  .idx = 2 },
+	{ .time = 10000, .idx = 3 },
+};
+
+struct axp20x_pek_ext_attr {
+	const struct axp20x_time *p_time;
+	unsigned int mask;
+};
+
+static struct axp20x_pek_ext_attr axp20x_pek_startup_ext_attr = {
+	.p_time	= startup_time,
+	.mask	= AXP20X_PEK_STARTUP_MASK,
+};
+
+static struct axp20x_pek_ext_attr axp20x_pek_shutdown_ext_attr = {
+	.p_time	= shutdown_time,
+	.mask	= AXP20X_PEK_SHUTDOWN_MASK,
+};
+
+static struct axp20x_pek_ext_attr *get_axp_ext_attr(struct device_attribute *attr)
+{
+	return container_of(attr, struct dev_ext_attribute, attr)->var;
+}
+
+static ssize_t axp20x_show_ext_attr(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
+	struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
+	unsigned int val;
+	int ret, i;
+
+	ret = regmap_read(axp20x_pek->axp20x->regmap, AXP20X_PEK_KEY, &val);
+	if (ret != 0)
+		return ret;
+
+	val &= axp20x_ea->mask;
+	val >>= ffs(axp20x_ea->mask) - 1;
+
+	for (i = 0; i < 4; i++)
+		if (val == axp20x_ea->p_time[i].idx)
+			val = axp20x_ea->p_time[i].time;
+
+	return sprintf(buf, "%u\n", val);
+}
+
+static ssize_t axp20x_store_ext_attr(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
+	struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
+	char val_str[20];
+	size_t len;
+	int ret, i;
+	unsigned int val, idx = 0;
+	unsigned int best_err = UINT_MAX;
+
+	val_str[sizeof(val_str) - 1] = '\0';
+	strncpy(val_str, buf, sizeof(val_str) - 1);
+	len = strlen(val_str);
+
+	if (len && val_str[len - 1] == '\n')
+		val_str[len - 1] = '\0';
+
+	ret = kstrtouint(val_str, 10, &val);
+	if (ret)
+		return ret;
+
+	for (i = 3; i >= 0; i--) {
+		unsigned int err;
+
+		err = abs(axp20x_ea->p_time[i].time - val);
+		if (err < best_err) {
+			best_err = err;
+			idx = axp20x_ea->p_time[i].idx;
+		}
+
+		if (!err)
+			break;
+	}
+
+	idx <<= ffs(axp20x_ea->mask) - 1;
+	ret = regmap_update_bits(axp20x_pek->axp20x->regmap,
+				 AXP20X_PEK_KEY,
+				 axp20x_ea->mask, idx);
+	if (ret != 0)
+		return -EINVAL;
+	return count;
+}
+
+static struct dev_ext_attribute axp20x_dev_attr_startup = {
+	.attr	= __ATTR(startup, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
+	.var	= &axp20x_pek_startup_ext_attr
+};
+
+static struct dev_ext_attribute axp20x_dev_attr_shutdown = {
+	.attr	= __ATTR(shutdown, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
+	.var	= &axp20x_pek_shutdown_ext_attr
+};
+
+static irqreturn_t axp20x_pek_irq(int irq, void *pwr)
+{
+	struct input_dev *idev = pwr;
+	struct axp20x_pek *axp20x_pek = input_get_drvdata(idev);
+
+	if (irq == axp20x_pek->irq_dbr)
+		input_report_key(idev, KEY_POWER, true);
+	else if (irq == axp20x_pek->irq_dbf)
+		input_report_key(idev, KEY_POWER, false);
+
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static int axp20x_pek_probe(struct platform_device *pdev)
+{
+	struct axp20x_pek *axp20x_pek;
+	struct axp20x_dev *axp20x;
+	struct input_dev *idev;
+	int error;
+
+	axp20x_pek = devm_kzalloc(&pdev->dev, sizeof(struct axp20x_pek),
+				  GFP_KERNEL);
+	if (!axp20x_pek)
+		return -ENOMEM;
+
+	axp20x_pek->axp20x = dev_get_drvdata(pdev->dev.parent);
+	axp20x = axp20x_pek->axp20x;
+
+	axp20x_pek->irq_dbr = platform_get_irq_byname(pdev, "PEK_DBR");
+	if (axp20x_pek->irq_dbr < 0) {
+		dev_err(&pdev->dev, "No IRQ for PEK_DBR, error=%d\n",
+				axp20x_pek->irq_dbr);
+		return axp20x_pek->irq_dbr;
+	}
+	axp20x_pek->irq_dbr = regmap_irq_get_virq(axp20x->regmap_irqc,
+						  axp20x_pek->irq_dbr);
+
+	axp20x_pek->irq_dbf = platform_get_irq_byname(pdev, "PEK_DBF");
+	if (axp20x_pek->irq_dbf < 0) {
+		dev_err(&pdev->dev, "No IRQ for PEK_DBF, error=%d\n",
+				axp20x_pek->irq_dbf);
+		return axp20x_pek->irq_dbf;
+	}
+	axp20x_pek->irq_dbf = regmap_irq_get_virq(axp20x->regmap_irqc,
+						  axp20x_pek->irq_dbf);
+
+	axp20x_pek->input = devm_input_allocate_device(&pdev->dev);
+	if (!axp20x_pek->input)
+		return -ENOMEM;
+
+	idev = axp20x_pek->input;
+
+	idev->name = "axp20x-pek";
+	idev->phys = "m1kbd/input2";
+	idev->dev.parent = &pdev->dev;
+
+	input_set_capability(idev, EV_KEY, KEY_POWER);
+
+	input_set_drvdata(idev, axp20x_pek);
+
+	error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbr,
+					  axp20x_pek_irq, 0,
+					  "axp20x-pek-dbr", idev);
+	if (error < 0) {
+		dev_err(axp20x->dev, "Failed to request dbr IRQ#%d: %d\n",
+			axp20x_pek->irq_dbr, error);
+
+		return error;
+	}
+
+	error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbf,
+					  axp20x_pek_irq, 0,
+					  "axp20x-pek-dbf", idev);
+	if (error < 0) {
+		dev_err(axp20x->dev, "Failed to request dbf IRQ#%d: %d\n",
+			axp20x_pek->irq_dbf, error);
+		return error;
+	}
+
+	error = device_create_file(&pdev->dev, &axp20x_dev_attr_startup.attr);
+	if (error)
+		return error;
+
+	error = device_create_file(&pdev->dev, &axp20x_dev_attr_shutdown.attr);
+	if (error)
+		goto clear_startup_attr;
+
+	error = input_register_device(idev);
+	if (error) {
+		dev_err(axp20x->dev, "Can't register input device: %d\n",
+			error);
+		goto clear_attr;
+	}
+
+	platform_set_drvdata(pdev, axp20x_pek);
+
+	return 0;
+
+clear_attr:
+	device_remove_file(&pdev->dev, &axp20x_dev_attr_shutdown.attr);
+
+clear_startup_attr:
+	device_remove_file(&pdev->dev, &axp20x_dev_attr_startup.attr);
+
+	return error;
+}
+
+static int axp20x_pek_remove(struct platform_device *pdev)
+{
+	device_remove_file(&pdev->dev, &axp20x_dev_attr_shutdown.attr);
+	device_remove_file(&pdev->dev, &axp20x_dev_attr_startup.attr);
+
+	return 0;
+}
+
+static struct platform_driver axp20x_pek_driver = {
+	.probe		= axp20x_pek_probe,
+	.remove		= axp20x_pek_remove,
+	.driver		= {
+		.name		= "axp20x-pek",
+	},
+};
+module_platform_driver(axp20x_pek_driver);
+
+MODULE_DESCRIPTION("axp20x Power Button");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_LICENSE("GPL");