Input: add twl4030-pwrbutton driver

This is part of the twl4030 multifunction device driver that supports
reporting KEY_POWER events via the input layer.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/misc/twl4030-pwrbutton.c b/drivers/input/misc/twl4030-pwrbutton.c
new file mode 100644
index 0000000..f5fc997
--- /dev/null
+++ b/drivers/input/misc/twl4030-pwrbutton.c
@@ -0,0 +1,145 @@
+/**
+ * twl4030-pwrbutton.c - TWL4030 Power Button Input Driver
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
+ * Several fixes by Felipe Balbi <felipe.balbi@nokia.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/i2c/twl4030.h>
+
+#define PWR_PWRON_IRQ (1 << 0)
+
+#define STS_HW_CONDITIONS 0xf
+
+static irqreturn_t powerbutton_irq(int irq, void *_pwr)
+{
+	struct input_dev *pwr = _pwr;
+	int err;
+	u8 value;
+
+#ifdef CONFIG_LOCKDEP
+	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+	 * we don't want and can't tolerate since this is a threaded
+	 * IRQ and can sleep due to the i2c reads it has to issue.
+	 * Although it might be friendlier not to borrow this thread
+	 * context...
+	 */
+	local_irq_enable();
+#endif
+
+	err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
+				  STS_HW_CONDITIONS);
+	if (!err)  {
+		input_report_key(pwr, KEY_POWER, value & PWR_PWRON_IRQ);
+		input_sync(pwr);
+	} else {
+		dev_err(pwr->dev.parent, "twl4030: i2c error %d while reading"
+			" TWL4030 PM_MASTER STS_HW_CONDITIONS register\n", err);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit twl4030_pwrbutton_probe(struct platform_device *pdev)
+{
+	struct input_dev *pwr;
+	int irq = platform_get_irq(pdev, 0);
+	int err;
+
+	pwr = input_allocate_device();
+	if (!pwr) {
+		dev_dbg(&pdev->dev, "Can't allocate power button\n");
+		return -ENOMEM;
+	}
+
+	pwr->evbit[0] = BIT_MASK(EV_KEY);
+	pwr->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
+	pwr->name = "twl4030_pwrbutton";
+	pwr->phys = "twl4030_pwrbutton/input0";
+	pwr->dev.parent = &pdev->dev;
+
+	err = request_irq(irq, powerbutton_irq,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"twl4030_pwrbutton", pwr);
+	if (err < 0) {
+		dev_dbg(&pdev->dev, "Can't get IRQ for pwrbutton: %d\n", err);
+		goto free_input_dev;
+	}
+
+	err = input_register_device(pwr);
+	if (err) {
+		dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
+		goto free_irq;
+	}
+
+	platform_set_drvdata(pdev, pwr);
+
+	return 0;
+
+free_irq:
+	free_irq(irq, NULL);
+free_input_dev:
+	input_free_device(pwr);
+	return err;
+}
+
+static int __devexit twl4030_pwrbutton_remove(struct platform_device *pdev)
+{
+	struct input_dev *pwr = platform_get_drvdata(pdev);
+	int irq = platform_get_irq(pdev, 0);
+
+	free_irq(irq, pwr);
+	input_unregister_device(pwr);
+
+	return 0;
+}
+
+struct platform_driver twl4030_pwrbutton_driver = {
+	.probe		= twl4030_pwrbutton_probe,
+	.remove		= __devexit_p(twl4030_pwrbutton_remove),
+	.driver		= {
+		.name	= "twl4030_pwrbutton",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init twl4030_pwrbutton_init(void)
+{
+	return platform_driver_register(&twl4030_pwrbutton_driver);
+}
+module_init(twl4030_pwrbutton_init);
+
+static void __exit twl4030_pwrbutton_exit(void)
+{
+	platform_driver_unregister(&twl4030_pwrbutton_driver);
+}
+module_exit(twl4030_pwrbutton_exit);
+
+MODULE_ALIAS("platform:twl4030_pwrbutton");
+MODULE_DESCRIPTION("Triton2 Power Button");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Peter De Schrijver <peter.de-schrijver@nokia.com>");
+MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
+