hwmon: New AMS hardware monitoring driver

This driver adds support for the Apple Motion Sensor (AMS) as found in 2005
revisions of Apple PowerBooks and iBooks.  It implements both the PMU and
I2C variants.  The I2C driver and mouse emulation is based on code by
Stelian Pop, while the PMU driver has been developped by Michael Hanselmann.
HD parking support will be added later.

Various people contributed fixes to this driver, including
Aristeu Sergio Rozanski Filho and Jean Delvare.

Signed-off-by: Stelian Pop <stelian@popies.net>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Robert Love <rml@novell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 160 insertions, 0 deletions

diff --git a/drivers/hwmon/ams/ams-input.c b/drivers/hwmon/ams/ams-input.c
new file mode 100644
index 00000000000..f126aa48513
--- /dev/null
+++ b/drivers/hwmon/ams/ams-input.c
@@ -0,0 +1,160 @@
+/*
+ * Apple Motion Sensor driver (joystick emulation)
+ *
+ * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
+ * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+
+#include "ams.h"
+
+static unsigned int joystick;
+module_param(joystick, bool, 0644);
+MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
+
+static unsigned int invert;
+module_param(invert, bool, 0644);
+MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
+
+static int ams_input_kthread(void *data)
+{
+	s8 x, y, z;
+
+	while (!kthread_should_stop()) {
+		mutex_lock(&ams_info.lock);
+
+		ams_sensors(&x, &y, &z);
+
+		x -= ams_info.xcalib;
+		y -= ams_info.ycalib;
+		z -= ams_info.zcalib;
+
+		input_report_abs(ams_info.idev, ABS_X, invert ? -x : x);
+		input_report_abs(ams_info.idev, ABS_Y, invert ? -y : y);
+		input_report_abs(ams_info.idev, ABS_Z, z);
+
+		input_sync(ams_info.idev);
+
+		mutex_unlock(&ams_info.lock);
+
+		msleep(25);
+	}
+
+	return 0;
+}
+
+static int ams_input_open(struct input_dev *dev)
+{
+	ams_info.kthread = kthread_run(ams_input_kthread, NULL, "kams");
+	return IS_ERR(ams_info.kthread) ? PTR_ERR(ams_info.kthread) : 0;
+}
+
+static void ams_input_close(struct input_dev *dev)
+{
+	kthread_stop(ams_info.kthread);
+}
+
+/* Call with ams_info.lock held! */
+static void ams_input_enable(void)
+{
+	s8 x, y, z;
+
+	if (ams_info.idev)
+		return;
+
+	ams_sensors(&x, &y, &z);
+	ams_info.xcalib = x;
+	ams_info.ycalib = y;
+	ams_info.zcalib = z;
+
+	ams_info.idev = input_allocate_device();
+	if (!ams_info.idev)
+		return;
+
+	ams_info.idev->name = "Apple Motion Sensor";
+	ams_info.idev->id.bustype = ams_info.bustype;
+	ams_info.idev->id.vendor = 0;
+	ams_info.idev->open = ams_input_open;
+	ams_info.idev->close = ams_input_close;
+	ams_info.idev->cdev.dev = &ams_info.of_dev->dev;
+
+	input_set_abs_params(ams_info.idev, ABS_X, -50, 50, 3, 0);
+	input_set_abs_params(ams_info.idev, ABS_Y, -50, 50, 3, 0);
+	input_set_abs_params(ams_info.idev, ABS_Z, -50, 50, 3, 0);
+
+	set_bit(EV_ABS, ams_info.idev->evbit);
+	set_bit(EV_KEY, ams_info.idev->evbit);
+	set_bit(BTN_TOUCH, ams_info.idev->keybit);
+
+	if (input_register_device(ams_info.idev)) {
+		input_free_device(ams_info.idev);
+		ams_info.idev = NULL;
+		return;
+	}
+}
+
+/* Call with ams_info.lock held! */
+static void ams_input_disable(void)
+{
+	if (ams_info.idev) {
+		input_unregister_device(ams_info.idev);
+		ams_info.idev = NULL;
+	}
+}
+
+static ssize_t ams_input_show_joystick(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", joystick);
+}
+
+static ssize_t ams_input_store_joystick(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	if (sscanf(buf, "%d\n", &joystick) != 1)
+		return -EINVAL;
+
+	mutex_lock(&ams_info.lock);
+
+	if (joystick)
+		ams_input_enable();
+	else
+		ams_input_disable();
+
+	mutex_unlock(&ams_info.lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
+	ams_input_show_joystick, ams_input_store_joystick);
+
+/* Call with ams_info.lock held! */
+int ams_input_init(void)
+{
+	int result;
+
+	result = device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
+
+	if (!result && joystick)
+		ams_input_enable();
+	return result;
+}
+
+/* Call with ams_info.lock held! */
+void ams_input_exit()
+{
+	ams_input_disable();
+	device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
+}