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, 265 insertions, 0 deletions

diff --git a/drivers/hwmon/ams/ams-core.c b/drivers/hwmon/ams/ams-core.c
new file mode 100644
index 00000000000..f1f0f5d0442
--- /dev/null
+++ b/drivers/hwmon/ams/ams-core.c
@@ -0,0 +1,265 @@
+/*
+ * 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);