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>

drivers/hwmon/Kconfig

@@ -106,6 +106,31 @@ config SENSORS_K8TEMP
 	  This driver can also be built as a module.  If so, the module
 	  will be called k8temp.
 
+config SENSORS_AMS
+	tristate "Apple Motion Sensor driver"
+	depends on HWMON && PPC_PMAC && !PPC64 && INPUT && ((ADB_PMU && I2C = y) || (ADB_PMU && !I2C) || I2C) && EXPERIMENTAL
+	help
+	  Support for the motion sensor included in PowerBooks. Includes
+	  implementations for PMU and I2C.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called ams.
+
+config SENSORS_AMS_PMU
+	bool "PMU variant"
+	depends on SENSORS_AMS && ADB_PMU
+	default y
+	help
+	  PMU variant of motion sensor, found in late 2005 PowerBooks.
+
+config SENSORS_AMS_I2C
+	bool "I2C variant"
+	depends on SENSORS_AMS && I2C
+	default y
+	help
+	  I2C variant of motion sensor, found in early 2005 PowerBooks and
+	  iBooks.
+
 config SENSORS_ASB100
 	tristate "Asus ASB100 Bach"
 	depends on HWMON && I2C && EXPERIMENTAL

drivers/hwmon/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_SENSORS_ADM1025)	+= adm1025.o
 obj-$(CONFIG_SENSORS_ADM1026)	+= adm1026.o
 obj-$(CONFIG_SENSORS_ADM1031)	+= adm1031.o
 obj-$(CONFIG_SENSORS_ADM9240)	+= adm9240.o
+obj-$(CONFIG_SENSORS_AMS)	+= ams/
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
 obj-$(CONFIG_SENSORS_F71805F)	+= f71805f.o

drivers/hwmon/ams/Makefile

+#
+# Makefile for Apple Motion Sensor driver
+#
+
+ams-y					:= ams-core.o ams-input.o
+ams-$(CONFIG_SENSORS_AMS_PMU)		+= ams-pmu.o
+ams-$(CONFIG_SENSORS_AMS_I2C)		+= ams-i2c.o
+obj-$(CONFIG_SENSORS_AMS)		+= ams.o

drivers/hwmon/ams/ams-core.c

+/*
+ * Apple Motion Sensor driver
+ *
+ * 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.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <asm/pmac_pfunc.h>
+#include <asm/of_platform.h>
+
+#include "ams.h"
+
+/* There is only one motion sensor per machine */
+struct ams ams_info;
+
+static unsigned int verbose;
+module_param(verbose, bool, 0644);
+MODULE_PARM_DESC(verbose, "Show free falls and shocks in kernel output");
+
+/* Call with ams_info.lock held! */
+void ams_sensors(s8 *x, s8 *y, s8 *z)
+{
+	u32 orient = ams_info.vflag? ams_info.orient1 : ams_info.orient2;
+
+	if (orient & 0x80)
+		/* X and Y swapped */
+		ams_info.get_xyz(y, x, z);
+	else
+		ams_info.get_xyz(x, y, z);
+
+	if (orient & 0x04)
+		*z = ~(*z);
+	if (orient & 0x02)
+		*y = ~(*y);
+	if (orient & 0x01)
+		*x = ~(*x);
+}
+
+static ssize_t ams_show_current(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	s8 x, y, z;
+
+	mutex_lock(&ams_info.lock);
+	ams_sensors(&x, &y, &z);
+	mutex_unlock(&ams_info.lock);
+
+	return snprintf(buf, PAGE_SIZE, "%d %d %d\n", x, y, z);
+}
+
+static DEVICE_ATTR(current, S_IRUGO, ams_show_current, NULL);
+
+static void ams_handle_irq(void *data)
+{
+	enum ams_irq irq = *((enum ams_irq *)data);
+
+	spin_lock(&ams_info.irq_lock);
+
+	ams_info.worker_irqs |= irq;
+	schedule_work(&ams_info.worker);
+
+	spin_unlock(&ams_info.irq_lock);
+}
+
+static enum ams_irq ams_freefall_irq_data = AMS_IRQ_FREEFALL;
+static struct pmf_irq_client ams_freefall_client = {
+	.owner = THIS_MODULE,
+	.handler = ams_handle_irq,
+	.data = &ams_freefall_irq_data,
+};
+
+static enum ams_irq ams_shock_irq_data = AMS_IRQ_SHOCK;
+static struct pmf_irq_client ams_shock_client = {
+	.owner = THIS_MODULE,
+	.handler = ams_handle_irq,
+	.data = &ams_shock_irq_data,
+};
+
+/* Once hard disk parking is implemented in the kernel, this function can
+ * trigger it.
+ */
+static void ams_worker(struct work_struct *work)
+{
+	mutex_lock(&ams_info.lock);
+
+	if (ams_info.has_device) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&ams_info.irq_lock, flags);
+
+		if (ams_info.worker_irqs & AMS_IRQ_FREEFALL) {
+			if (verbose)
+				printk(KERN_INFO "ams: freefall detected!\n");
+
+			ams_info.worker_irqs &= ~AMS_IRQ_FREEFALL;
+
+			/* we must call this with interrupts enabled */
+			spin_unlock_irqrestore(&ams_info.irq_lock, flags);
+			ams_info.clear_irq(AMS_IRQ_FREEFALL);
+			spin_lock_irqsave(&ams_info.irq_lock, flags);
+		}
+
+		if (ams_info.worker_irqs & AMS_IRQ_SHOCK) {
+			if (verbose)
+				printk(KERN_INFO "ams: shock detected!\n");
+
+			ams_info.worker_irqs &= ~AMS_IRQ_SHOCK;
+
+			/* we must call this with interrupts enabled */
+			spin_unlock_irqrestore(&ams_info.irq_lock, flags);
+			ams_info.clear_irq(AMS_IRQ_SHOCK);
+			spin_lock_irqsave(&ams_info.irq_lock, flags);
+		}
+
+		spin_unlock_irqrestore(&ams_info.irq_lock, flags);
+	}
+
+	mutex_unlock(&ams_info.lock);
+}
+
+/* Call with ams_info.lock held! */
+int ams_sensor_attach(void)
+{
+	int result;
+	u32 *prop;
+
+	/* Get orientation */
+	prop = (u32*)get_property(ams_info.of_node, "orientation", NULL);
+	if (!prop)
+		return -ENODEV;
+	ams_info.orient1 = *prop;
+	ams_info.orient2 = *(prop + 1);
+
+	/* Register freefall interrupt handler */
+	result = pmf_register_irq_client(ams_info.of_node,
+			"accel-int-1",
+			&ams_freefall_client);
+	if (result < 0)
+		return -ENODEV;
+
+	/* Reset saved irqs */
+	ams_info.worker_irqs = 0;
+
+	/* Register shock interrupt handler */
+	result = pmf_register_irq_client(ams_info.of_node,
+			"accel-int-2",
+			&ams_shock_client);
+	if (result < 0)
+		goto release_freefall;
+
+	/* Create device */
+	ams_info.of_dev = of_platform_device_create(ams_info.of_node, "ams", NULL);
+	if (!ams_info.of_dev) {
+		result = -ENODEV;
+		goto release_shock;
+	}
+
+	/* Create attributes */
+	result = device_create_file(&ams_info.of_dev->dev, &dev_attr_current);
+	if (result)
+		goto release_of;
+
+	ams_info.vflag = !!(ams_info.get_vendor() & 0x10);
+
+	/* Init input device */
+	result = ams_input_init();
+	if (result)
+		goto release_device_file;
+
+	return result;
+release_device_file:
+	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
+release_of:
+	of_device_unregister(ams_info.of_dev);
+release_shock:
+	pmf_unregister_irq_client(&ams_shock_client);
+release_freefall:
+	pmf_unregister_irq_client(&ams_freefall_client);
+	return result;
+}
+
+int __init ams_init(void)
+{
+	struct device_node *np;
+
+	spin_lock_init(&ams_info.irq_lock);
+	mutex_init(&ams_info.lock);
+	INIT_WORK(&ams_info.worker, ams_worker);
+
+#ifdef CONFIG_SENSORS_AMS_I2C
+	np = of_find_node_by_name(NULL, "accelerometer");
+	if (np && device_is_compatible(np, "AAPL,accelerometer_1"))
+		/* Found I2C motion sensor */
+		return ams_i2c_init(np);
+#endif
+
+#ifdef CONFIG_SENSORS_AMS_PMU
+	np = of_find_node_by_name(NULL, "sms");
+	if (np && device_is_compatible(np, "sms"))
+		/* Found PMU motion sensor */
+		return ams_pmu_init(np);
+#endif
+
+	printk(KERN_ERR "ams: No motion sensor found.\n");
+
+	return -ENODEV;
+}
+
+void ams_exit(void)
+{
+	mutex_lock(&ams_info.lock);
+
+	if (ams_info.has_device) {
+		/* Remove input device */
+		ams_input_exit();
+
+		/* Shut down implementation */
+		ams_info.exit();
+
+		/* Flush interrupt worker
+		 *
+		 * We do this after ams_info.exit(), because an interrupt might
+		 * have arrived before disabling them.
+		 */
+		flush_scheduled_work();
+
+		/* Remove attributes */
+		device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
+
+		/* Remove device */
+		of_device_unregister(ams_info.of_dev);
+
+		/* Remove handler */
+		pmf_unregister_irq_client(&ams_shock_client);
+		pmf_unregister_irq_client(&ams_freefall_client);
+	}
+
+	mutex_unlock(&ams_info.lock);
+}
+
+MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
+MODULE_DESCRIPTION("Apple Motion Sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(ams_init);
+module_exit(ams_exit);

drivers/hwmon/ams/ams-i2c.c

+/*
+ * Apple Motion Sensor driver (I2C variant)
+ *
+ * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
+ * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * Clean room implementation based on the reverse engineered Mac OS X driver by
+ * Johannes Berg <johannes@sipsolutions.net>, documentation available at
+ * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification
+ *
+ * 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"
+
+/* AMS registers */
+#define AMS_COMMAND	0x00	/* command register */
+#define AMS_STATUS	0x01	/* status register */
+#define AMS_CTRL1	0x02	/* read control 1 (number of values) */
+#define AMS_CTRL2	0x03	/* read control 2 (offset?) */
+#define AMS_CTRL3	0x04	/* read control 3 (size of each value?) */
+#define AMS_DATA1	0x05	/* read data 1 */
+#define AMS_DATA2	0x06	/* read data 2 */
+#define AMS_DATA3	0x07	/* read data 3 */
+#define AMS_DATA4	0x08	/* read data 4 */
+#define AMS_DATAX	0x20	/* data X */
+#define AMS_DATAY	0x21	/* data Y */
+#define AMS_DATAZ	0x22	/* data Z */
+#define AMS_FREEFALL	0x24	/* freefall int control */
+#define AMS_SHOCK	0x25	/* shock int control */
+#define AMS_SENSLOW	0x26	/* sensitivity low limit */
+#define AMS_SENSHIGH	0x27	/* sensitivity high limit */
+#define AMS_CTRLX	0x28	/* control X */
+#define AMS_CTRLY	0x29	/* control Y */
+#define AMS_CTRLZ	0x2A	/* control Z */
+#define AMS_UNKNOWN1	0x2B	/* unknown 1 */
+#define AMS_UNKNOWN2	0x2C	/* unknown 2 */
+#define AMS_UNKNOWN3	0x2D	/* unknown 3 */
+#define AMS_VENDOR	0x2E	/* vendor */
+
+/* AMS commands - use with the AMS_COMMAND register */
+enum ams_i2c_cmd {
+	AMS_CMD_NOOP = 0,
+	AMS_CMD_VERSION,
+	AMS_CMD_READMEM,
+	AMS_CMD_WRITEMEM,
+	AMS_CMD_ERASEMEM,
+	AMS_CMD_READEE,
+	AMS_CMD_WRITEEE,
+	AMS_CMD_RESET,
+	AMS_CMD_START,
+};
+
+static int ams_i2c_attach(struct i2c_adapter *adapter);
+static int ams_i2c_detach(struct i2c_adapter *adapter);
+
+static struct i2c_driver ams_i2c_driver = {
+	.driver = {
+		.name   = "ams",
+		.owner  = THIS_MODULE,
+	},
+	.attach_adapter = ams_i2c_attach,
+	.detach_adapter = ams_i2c_detach,
+};
+
+static s32 ams_i2c_read(u8 reg)
+{
+	return i2c_smbus_read_byte_data(&ams_info.i2c_client, reg);
+}
+
+static int ams_i2c_write(u8 reg, u8 value)
+{
+	return i2c_smbus_write_byte_data(&ams_info.i2c_client, reg, value);
+}
+
+static int ams_i2c_cmd(enum ams_i2c_cmd cmd)
+{
+	s32 result;
+	int remaining = HZ / 20;
+
+	ams_i2c_write(AMS_COMMAND, cmd);
+	mdelay(5);
+
+	while (remaining) {
+		result = ams_i2c_read(AMS_COMMAND);
+		if (result == 0 || result & 0x80)
+			return 0;
+
+		remaining = schedule_timeout(remaining);
+	}
+
+	return -1;
+}
+
+static void ams_i2c_set_irq(enum ams_irq reg, char enable)
+{
+	if (reg & AMS_IRQ_FREEFALL) {
+		u8 val = ams_i2c_read(AMS_CTRLX);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_i2c_write(AMS_CTRLX, val);
+	}
+
+	if (reg & AMS_IRQ_SHOCK) {
+		u8 val = ams_i2c_read(AMS_CTRLY);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_i2c_write(AMS_CTRLY, val);
+	}
+
+	if (reg & AMS_IRQ_GLOBAL) {
+		u8 val = ams_i2c_read(AMS_CTRLZ);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_i2c_write(AMS_CTRLZ, val);
+	}
+}
+
+static void ams_i2c_clear_irq(enum ams_irq reg)
+{
+	if (reg & AMS_IRQ_FREEFALL)
+		ams_i2c_write(AMS_FREEFALL, 0);
+
+	if (reg & AMS_IRQ_SHOCK)
+		ams_i2c_write(AMS_SHOCK, 0);
+}
+
+static u8 ams_i2c_get_vendor(void)
+{
+	return ams_i2c_read(AMS_VENDOR);
+}
+
+static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z)
+{
+	*x = ams_i2c_read(AMS_DATAX);
+	*y = ams_i2c_read(AMS_DATAY);
+	*z = ams_i2c_read(AMS_DATAZ);
+}
+
+static int ams_i2c_attach(struct i2c_adapter *adapter)
+{
+	unsigned long bus;
+	int vmaj, vmin;
+	int result;
+
+	/* There can be only one */
+	if (unlikely(ams_info.has_device))
+		return -ENODEV;
+
+	if (strncmp(adapter->name, "uni-n", 5))
+		return -ENODEV;
+
+	bus = simple_strtoul(adapter->name + 6, NULL, 10);
+	if (bus != ams_info.i2c_bus)
+		return -ENODEV;
+
+	ams_info.i2c_client.addr = ams_info.i2c_address;
+	ams_info.i2c_client.adapter = adapter;
+	ams_info.i2c_client.driver = &ams_i2c_driver;
+	strcpy(ams_info.i2c_client.name, "Apple Motion Sensor");
+
+	if (ams_i2c_cmd(AMS_CMD_RESET)) {
+		printk(KERN_INFO "ams: Failed to reset the device\n");
+		return -ENODEV;
+	}
+
+	if (ams_i2c_cmd(AMS_CMD_START)) {
+		printk(KERN_INFO "ams: Failed to start the device\n");
+		return -ENODEV;
+	}
+
+	/* get version/vendor information */
+	ams_i2c_write(AMS_CTRL1, 0x02);
+	ams_i2c_write(AMS_CTRL2, 0x85);
+	ams_i2c_write(AMS_CTRL3, 0x01);
+
+	ams_i2c_cmd(AMS_CMD_READMEM);
+
+	vmaj = ams_i2c_read(AMS_DATA1);
+	vmin = ams_i2c_read(AMS_DATA2);
+	if (vmaj != 1 || vmin != 52) {
+		printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n",
+			vmaj, vmin);
+		return -ENODEV;
+	}
+
+	ams_i2c_cmd(AMS_CMD_VERSION);
+
+	vmaj = ams_i2c_read(AMS_DATA1);
+	vmin = ams_i2c_read(AMS_DATA2);
+	if (vmaj != 0 || vmin != 1) {
+		printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n",
+			vmaj, vmin);
+		return -ENODEV;
+	}
+
+	/* Disable interrupts */
+	ams_i2c_set_irq(AMS_IRQ_ALL, 0);
+
+	result = ams_sensor_attach();
+	if (result < 0)
+		return result;
+
+	/* Set default values */
+	ams_i2c_write(AMS_SENSLOW, 0x15);
+	ams_i2c_write(AMS_SENSHIGH, 0x60);
+	ams_i2c_write(AMS_CTRLX, 0x08);
+	ams_i2c_write(AMS_CTRLY, 0x0F);
+	ams_i2c_write(AMS_CTRLZ, 0x4F);
+	ams_i2c_write(AMS_UNKNOWN1, 0x14);
+
+	/* Clear interrupts */
+	ams_i2c_clear_irq(AMS_IRQ_ALL);
+
+	ams_info.has_device = 1;
+
+	/* Enable interrupts */
+	ams_i2c_set_irq(AMS_IRQ_ALL, 1);
+
+	printk(KERN_INFO "ams: Found I2C based motion sensor\n");
+
+	return 0;
+}
+
+static int ams_i2c_detach(struct i2c_adapter *adapter)
+{
+	if (ams_info.has_device) {
+		/* Disable interrupts */
+		ams_i2c_set_irq(AMS_IRQ_ALL, 0);
+
+		/* Clear interrupts */
+		ams_i2c_clear_irq(AMS_IRQ_ALL);
+
+		printk(KERN_INFO "ams: Unloading\n");
+
+		ams_info.has_device = 0;
+	}
+
+	return 0;
+}
+
+static void ams_i2c_exit(void)
+{
+	i2c_del_driver(&ams_i2c_driver);
+}
+
+int __init ams_i2c_init(struct device_node *np)
+{
+	char *tmp_bus;
+	int result;
+	u32 *prop;
+
+	mutex_lock(&ams_info.lock);
+
+	/* Set implementation stuff */
+	ams_info.of_node = np;
+	ams_info.exit = ams_i2c_exit;
+	ams_info.get_vendor = ams_i2c_get_vendor;
+	ams_info.get_xyz = ams_i2c_get_xyz;
+	ams_info.clear_irq = ams_i2c_clear_irq;
+	ams_info.bustype = BUS_I2C;
+
+	/* look for bus either using "reg" or by path */
+	prop = (u32*)get_property(ams_info.of_node, "reg", NULL);
+	if (!prop) {
+		result = -ENODEV;
+
+		goto exit;
+	}
+
+	tmp_bus = strstr(ams_info.of_node->full_name, "/i2c-bus@");
+	if (tmp_bus)
+		ams_info.i2c_bus = *(tmp_bus + 9) - '0';
+	else
+		ams_info.i2c_bus = ((*prop) >> 8) & 0x0f;
+	ams_info.i2c_address = ((*prop) & 0xff) >> 1;
+
+	result = i2c_add_driver(&ams_i2c_driver);
+
+exit:
+	mutex_unlock(&ams_info.lock);
+
+	return result;
+}

drivers/hwmon/ams/ams-input.c

+/*
+ * 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);
+}

drivers/hwmon/ams/ams-pmu.c

+/*
+ * Apple Motion Sensor driver (PMU variant)
+ *
+ * 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/adb.h>
+#include <linux/pmu.h>
+
+#include "ams.h"
+
+/* Attitude */
+#define AMS_X			0x00
+#define AMS_Y			0x01
+#define AMS_Z			0x02
+
+/* Not exactly known, maybe chip vendor */
+#define AMS_VENDOR		0x03
+
+/* Freefall registers */
+#define AMS_FF_CLEAR		0x04
+#define AMS_FF_ENABLE		0x05
+#define AMS_FF_LOW_LIMIT	0x06
+#define AMS_FF_DEBOUNCE		0x07
+
+/* Shock registers */
+#define AMS_SHOCK_CLEAR		0x08
+#define AMS_SHOCK_ENABLE	0x09
+#define AMS_SHOCK_HIGH_LIMIT	0x0a
+#define AMS_SHOCK_DEBOUNCE	0x0b
+
+/* Global interrupt and power control register */
+#define AMS_CONTROL		0x0c
+
+static u8 ams_pmu_cmd;
+
+static void ams_pmu_req_complete(struct adb_request *req)
+{
+	complete((struct completion *)req->arg);
+}
+
+/* Only call this function from task context */
+static void ams_pmu_set_register(u8 reg, u8 value)
+{
+	static struct adb_request req;
+	DECLARE_COMPLETION(req_complete);
+
+	req.arg = &req_complete;
+	if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
+		return;
+
+	wait_for_completion(&req_complete);
+}
+
+/* Only call this function from task context */
+static u8 ams_pmu_get_register(u8 reg)
+{
+	static struct adb_request req;
+	DECLARE_COMPLETION(req_complete);
+
+	req.arg = &req_complete;
+	if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
+		return 0;
+
+	wait_for_completion(&req_complete);
+
+	if (req.reply_len > 0)
+		return req.reply[0];
+	else
+		return 0;
+}
+
+/* Enables or disables the specified interrupts */
+static void ams_pmu_set_irq(enum ams_irq reg, char enable)
+{
+	if (reg & AMS_IRQ_FREEFALL) {
+		u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_FF_ENABLE, val);
+	}
+
+	if (reg & AMS_IRQ_SHOCK) {
+		u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
+	}
+
+	if (reg & AMS_IRQ_GLOBAL) {
+		u8 val = ams_pmu_get_register(AMS_CONTROL);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_CONTROL, val);
+	}
+}
+
+static void ams_pmu_clear_irq(enum ams_irq reg)
+{
+	if (reg & AMS_IRQ_FREEFALL)
+		ams_pmu_set_register(AMS_FF_CLEAR, 0x00);
+
+	if (reg & AMS_IRQ_SHOCK)
+		ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
+}
+
+static u8 ams_pmu_get_vendor(void)
+{
+	return ams_pmu_get_register(AMS_VENDOR);
+}
+
+static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
+{
+	*x = ams_pmu_get_register(AMS_X);
+	*y = ams_pmu_get_register(AMS_Y);
+	*z = ams_pmu_get_register(AMS_Z);
+}
+
+static void ams_pmu_exit(void)
+{
+	/* Disable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	ams_info.has_device = 0;
+
+	printk(KERN_INFO "ams: Unloading\n");
+}
+
+int __init ams_pmu_init(struct device_node *np)
+{
+	u32 *prop;
+	int result;
+
+	mutex_lock(&ams_info.lock);
+
+	/* Set implementation stuff */
+	ams_info.of_node = np;
+	ams_info.exit = ams_pmu_exit;
+	ams_info.get_vendor = ams_pmu_get_vendor;
+	ams_info.get_xyz = ams_pmu_get_xyz;
+	ams_info.clear_irq = ams_pmu_clear_irq;
+	ams_info.bustype = BUS_HOST;
+
+	/* Get PMU command, should be 0x4e, but we can never know */
+	prop = (u32*)get_property(ams_info.of_node, "reg", NULL);
+	if (!prop) {
+		result = -ENODEV;
+		goto exit;
+	}
+	ams_pmu_cmd = ((*prop) >> 8) & 0xff;
+
+	/* Disable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	result = ams_sensor_attach();
+	if (result < 0)
+		goto exit;
+
+	/* Set default values */
+	ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
+	ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
+	ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);
+
+	ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
+	ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
+	ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);
+
+	ams_pmu_set_register(AMS_CONTROL, 0x4f);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	ams_info.has_device = 1;
+
+	/* Enable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 1);
+
+	printk(KERN_INFO "ams: Found PMU based motion sensor\n");
+
+	result = 0;
+
+exit:
+	mutex_unlock(&ams_info.lock);
+
+	return result;
+}

drivers/hwmon/ams/ams.h

+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <asm/of_device.h>
+
+enum ams_irq {
+	AMS_IRQ_FREEFALL = 0x01,
+	AMS_IRQ_SHOCK = 0x02,
+	AMS_IRQ_GLOBAL = 0x04,
+	AMS_IRQ_ALL =
+		AMS_IRQ_FREEFALL |
+		AMS_IRQ_SHOCK |
+		AMS_IRQ_GLOBAL,
+};
+
+struct ams {
+	/* Locks */
+	spinlock_t irq_lock;
+	struct mutex lock;
+
+	/* General properties */
+	struct device_node *of_node;
+	struct of_device *of_dev;
+	char has_device;
+	char vflag;
+	u32 orient1;
+	u32 orient2;
+
+	/* Interrupt worker */
+	struct work_struct worker;
+	u8 worker_irqs;
+
+	/* Implementation
+	 *
+	 * Only call these functions with the main lock held.
+	 */
+	void (*exit)(void);
+
+	void (*get_xyz)(s8 *x, s8 *y, s8 *z);
+	u8 (*get_vendor)(void);
+
+	void (*clear_irq)(enum ams_irq reg);
+
+#ifdef CONFIG_SENSORS_AMS_I2C
+	/* I2C properties */
+	int i2c_bus;
+	int i2c_address;
+	struct i2c_client i2c_client;
+#endif
+
+	/* Joystick emulation */
+	struct task_struct *kthread;
+	struct input_dev *idev;
+	__u16 bustype;
+
+	/* calibrated null values */
+	int xcalib, ycalib, zcalib;
+};
+
+extern struct ams ams_info;
+
+extern void ams_sensors(s8 *x, s8 *y, s8 *z);
+extern int ams_sensor_attach(void);
+
+extern int ams_pmu_init(struct device_node *np);
+extern int ams_i2c_init(struct device_node *np);
+
+extern int ams_input_init(void);
+extern void ams_input_exit(void);