[PATCH] intel_mid_powerbtn: add power button driver for Medfield platform (#3)

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

From: Hong Liu <hong.liu@intel.com>

The power button is connected to MSIC on Medfield, we will get two
interrupts from IOAPIC when pressing or releasing the power button.

Signed-off-by: Hong Liu <hong.liu@intel.com>
[Minor fixes as noted by Dmitry]
Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/platform/x86/Kconfig              |    8 ++
 drivers/platform/x86/Makefile             |    2 
 drivers/platform/x86/intel_mid_powerbtn.c |  144 +++++++++++++++++++++++++++++
 3 files changed, 154 insertions(+), 0 deletions(-)
 create mode 100644 drivers/platform/x86/intel_mid_powerbtn.c


diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index d163bc2..95817b0 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -654,4 +654,12 @@ config XO1_RFKILL
 	  Support for enabling/disabling the WLAN interface on the OLPC XO-1
 	  laptop.
 
+config INTEL_MID_POWER_BUTTON
+	tristate "power button driver for Intel MID platforms"
+	depends on INTEL_SCU_IPC
+	help
+	  This driver handles the power button on the Intel MID platforms.
+
+	  If unsure, say N.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 4ec4ff8..a24cd62 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -34,3 +34,5 @@ obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
 obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
+obj-$(CONFIG_INTEL_MID_POWER_BUTTON)	+= intel_mid_powerbtn.o
+
diff --git a/drivers/platform/x86/intel_mid_powerbtn.c b/drivers/platform/x86/intel_mid_powerbtn.c
new file mode 100644
index 0000000..d503d29
--- /dev/null
+++ b/drivers/platform/x86/intel_mid_powerbtn.c
@@ -0,0 +1,144 @@
+/*
+ * Power button driver for Medfield.
+ *
+ * Copyright (C) 2010 Intel Corp
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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/interrupt.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <asm/intel_scu_ipc.h>
+
+#define DRIVER_NAME "msic_power_btn"
+
+#define MSIC_IRQ_STAT	0x02
+  #define MSIC_IRQ_PB	(1 << 0)
+#define MSIC_PB_CONFIG	0x3e
+#define MSIC_PB_STATUS	0x3f
+  #define MSIC_PB_LEVEL (1 << 3) /* 1 - release, 0 - press */
+
+struct mfld_pb_priv {
+	struct input_dev *input;
+	int irq;
+};
+
+static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
+{
+	struct mfld_pb_priv *priv = dev_id;
+	int ret;
+	u8 pbstat;
+
+	ret = intel_scu_ipc_ioread8(MSIC_PB_STATUS, &pbstat);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	input_event(priv->input, EV_KEY, KEY_POWER, !(pbstat & MSIC_PB_LEVEL));
+	input_sync(priv->input);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit mfld_pb_probe(struct platform_device *pdev)
+{
+	struct mfld_pb_priv *priv;
+	struct input_dev *input;
+	int ret;
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EINVAL;
+
+	priv = kzalloc(sizeof(struct mfld_pb_priv), GFP_KERNEL);
+	input = input_allocate_device();
+	if (!priv || !input) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	priv->input = input;
+	priv->irq = irq;
+	platform_set_drvdata(pdev, priv);
+
+	input->name = pdev->name;
+	input->phys = "power-button/input0";
+	input->dev.parent = &pdev->dev;
+
+	input_set_capability(input, EV_KEY, KEY_POWER);
+
+	ret = request_threaded_irq(priv->irq, NULL, mfld_pb_isr,
+				   0, DRIVER_NAME, priv);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"unable to request irq %d for mfld power button\n",
+									irq);
+		goto fail;
+	}
+
+	ret = input_register_device(input);
+	if (ret == 0)
+		goto ok;
+
+	dev_err(&pdev->dev, "unable to register input dev, error %d\n", ret);
+	free_irq(priv->irq, priv);
+
+fail:
+	platform_set_drvdata(pdev, NULL);
+	input_free_device(input);
+	kfree(priv);
+ok:
+	return ret;
+}
+
+static int __devexit mfld_pb_remove(struct platform_device *pdev)
+{
+	struct mfld_pb_priv *priv = platform_get_drvdata(pdev);
+
+	free_irq(priv->irq, priv);
+	input_unregister_device(priv->input);
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver mfld_pb_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+	.probe	= mfld_pb_probe,
+	.remove	= __devexit_p(mfld_pb_remove),
+};
+
+static int __init mfld_pb_init(void)
+{
+	return platform_driver_register(&mfld_pb_driver);
+}
+
+static void __exit mfld_pb_exit(void)
+{
+	platform_driver_unregister(&mfld_pb_driver);
+}
+
+module_init(mfld_pb_init);
+module_exit(mfld_pb_exit);
+
+MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
+MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
+MODULE_LICENSE("GPL v2");