Add a driver to support InvenSense mpu3050 gyroscope chip.

From: Joseph Lai <[email protected]>

This driver is registered as an input device with sysfs control interface, but it still can output 3 axes data in non-interrupt mode.

This is primarily an input device but can also be used as for other things. It thus exposes the power control (so you can keep power on when you want) and x/y/z co-ordinates directly.

If IIO ever gets upstream the assumption is that the non-input side would move to IIO.

Signed-off-by Joseph Lai <[email protected]>

[Cleaned up PM_RUNTIME defines]

Signed-off-by Alan Cox <[email protected]>

---

 drivers/input/misc/Kconfig   |   10 +
 drivers/input/misc/Makefile  |    1 
 drivers/input/misc/mpu3050.c |  493 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 504 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/misc/mpu3050.c

drivers/input/misc/Kconfig +10 -0

index 3b595b8..db92371 100644
@@ -464,4 +464,14 @@ config INPUT_BMA023
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma023.
 
+config INPUT_MPU3050
+	tristate "MPU3050 Triaxial gyroscope sensor"
+	depends on I2C
+	help
+	  Say Y here if you want to support InvenSense MPU3050
+	  connected via an I2C bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mpu3050.
+
 endif

drivers/input/misc/Makefile +1 -0

index aa2fd2e..216824c 100644
@@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
 obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o
+obj-$(CONFIG_INPUT_MPU3050)		+= mpu3050.o
 obj-$(CONFIG_INPUT_PCAP)		+= pcap_keys.o
 obj-$(CONFIG_INPUT_PCF50633_PMU)	+= pcf50633-input.o
 obj-$(CONFIG_INPUT_PCF8574)		+= pcf8574_keypad.o

drivers/input/misc/mpu3050.c new file +130 -0

new file mode 100644
index 0000000..86fe397
@@ -0,0 +1,493 @@
+/*
+ * mpu3050.c - MPU3050 Tri-axis gyroscope driver
+ *
+ * Copyright (C) 2011 Wistron Co.Ltd
+ * Joseph Lai <[email protected]>
+ *
+ * This program is based on bma023.c.
+ *
+ * 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/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+
+#define MPU3050_CHIP_ID_REG	0x00
+#define MPU3050_CHIP_ID		0x69
+#define MPU3050_XOUT_H		0x1D
+#define MPU3050_PWR_MGM		0x3E
+#define MPU3050_PWR_MGM_POS	6
+#define MPU3050_PWR_MGM_MASK	0x40
+
+#define MPU3050_AUTO_DELAY	1000
+
+#define MPU3050_MIN_VALUE	-32768
+#define MPU3050_MAX_VALUE	32767
+
+struct axis_data {
+	s16 x;
+	s16 y;
+	s16 z;
+};
+
+struct mpu3050_sensor {
+	struct i2c_client *client;
+	struct device *dev;
+	struct input_dev *idev;
+	struct mutex lock;
+};
+
+/**
+ *	mpu3050_xyz_read_reg	-	read the axes values
+ *	@buffer: provide register addr and get register
+ *	@length: length of register
+ *
+ *	Reads the register values in one transaction or returns a negative
+ *	error code on failure/
+ */
+static int mpu3050_xyz_read_reg(struct i2c_client *client,
+			       u8 *buffer, int length)
+{
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = 1,
+			.buf = buffer,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = length,
+			.buf = buffer,
+		},
+	};
+	return i2c_transfer(client->adapter, msg, 2);
+}
+
+/**
+ *	mpu3050_read_xyz	-	get co-ordinates from device
+ *	@client: i2c address of sensor
+ *	@coords: co-ordinates to update
+ *
+ *	Return the converted X Y and Z co-ordinates from the sensor device
+ */
+static void mpu3050_read_xyz(struct i2c_client *client,
+				struct axis_data *coords)
+{
+	u8 buffer[6];
+	buffer[0] = MPU3050_XOUT_H;
+	mpu3050_xyz_read_reg(client, buffer, 6);
+	coords->x = buffer[0];
+	coords->x = coords->x << 8 | buffer[1];
+	coords->y = buffer[2];
+	coords->y = coords->y << 8 | buffer[3];
+	coords->z = buffer[4];
+	coords->z = coords->z << 8 | buffer[5];
+	dev_dbg(&client->dev, "%s: x %d, y %d, z %d\n", __func__,
+					coords->x, coords->y, coords->z);
+}
+
+/**
+ *	mpu3050_set_power_mode	-	set the power mode
+ *	@client: i2c client for the sensor
+ *	@val: value to switch on/off of power, 1: normal power, 0: low power
+ *
+ *	Put device to normal-power mode or low-power mode.
+ */
+static void mpu3050_set_power_mode(struct i2c_client *client, u8 val)
+{
+	u8 value;
+	value = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
+	value = (value & ~MPU3050_PWR_MGM_MASK) |
+		(((val << MPU3050_PWR_MGM_POS) & MPU3050_PWR_MGM_MASK) ^
+		 MPU3050_PWR_MGM_MASK);
+	i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, value);
+}
+
+static int mpu3050_get_power_mode(struct i2c_client *client)
+{

drivers/input/misc/mpu3050.c new file +287 -0

+	mpu3050_set_power_mode(sensor->client, buf[0] == '1' ? 1 : 0);
+	mutex_unlock(&sensor->lock);
+
+	return count;
+}
+static DEVICE_ATTR(power_mode, S_IRUGO | S_IWUSR,
+		mpu3050_show_power_mode, mpu3050_store_power_mode);
+
+/**
+ *	mpu3050_show_xyz	-	show co-ordinate readings
+ *	@dev: device of sensor
+ *	@attr: device attributes of sysfs node
+ *	@buf: buffer for output
+ *
+ *	Perform a one off read of the sensor data. In non-interrupt mode
+ *	the sensor can be used for one off reads of the axes rather than
+ *	as an input device.
+ */
+static ssize_t mpu3050_show_xyz(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct mpu3050_sensor *sensor = dev_get_drvdata(dev);
+	struct axis_data data;
+
+	pm_runtime_get_sync(dev);
+	pm_runtime_mark_last_busy(dev);
+
+	mutex_lock(&sensor->lock);
+	mpu3050_read_xyz(sensor->client, &data);
+	mutex_unlock(&sensor->lock);
+
+	pm_runtime_put(dev);
+
+	return sprintf(buf, "%d %d %d\n", data.x, data.y, data.z);
+}
+static DEVICE_ATTR(gyro_data, S_IRUGO, mpu3050_show_xyz, NULL);
+
+static struct attribute *mpu3050_attributes[] = {
+	&dev_attr_gyro_data.attr,
+	&dev_attr_power_mode.attr,
+	NULL
+};
+
+static const struct attribute_group mpu3050_group = {
+	.attrs	= mpu3050_attributes,
+};
+
+/**
+ *	mpu3050_input_open	-	called on input event open
+ *	@input: input dev of opened device
+ *
+ *	The input layer calls this function when input event is opened. The
+ *	function will push the device to resume. Then, the device is ready
+ *	to provide data.
+ */
+static int mpu3050_input_open(struct input_dev *input)
+{
+	struct mpu3050_sensor *sensor = input_get_drvdata(input);
+	pm_runtime_get(sensor->dev);
+	return 0;
+}
+
+/**
+ *	mpu3050_input_close	-	called on input event close
+ *	@input: input dev of closed device
+ *
+ *	The input layer calls this function when input event is closed. The
+ *	function will push the device to suspend.
+ */
+static void mpu3050_input_close(struct input_dev *input)
+{
+	struct mpu3050_sensor *sensor = input_get_drvdata(input);
+	pm_runtime_put(sensor->dev);
+}
+
+/**
+ *	mpu3050_interrupt_thread	-	handle an IRQ
+ *	@irq: interrupt numner
+ *	@data: the sensor
+ *
+ *	Called by the kernel single threaded after an interrupt occurs. Read
+ *	the sensor data and generate an input event for it.
+ */
+static irqreturn_t mpu3050_interrupt_thread(int irq, void *data)
+{
+	struct mpu3050_sensor *sensor = data;
+	struct axis_data axis;
+
+	mutex_lock(&sensor->lock);
+	mpu3050_read_xyz(sensor->client, &axis);
+	mutex_unlock(&sensor->lock);
+
+	input_report_abs(sensor->idev, ABS_X, axis.x);
+	input_report_abs(sensor->idev, ABS_Y, axis.y);
+	input_report_abs(sensor->idev, ABS_Z, axis.z);
+	input_sync(sensor->idev);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ *	mpu3050_unregister_input_device	-	remove input dev
+ *	@sensor: sensor to remove from input
+ *
+ *	Free the interrupt and input device for the sensor. We must free
+ *	the interrupt first
+ */
+static void mpu3050_unregister_input_device(struct mpu3050_sensor *sensor)
+{
+	struct i2c_client *client = sensor->client;
+	if (client->irq > 0)
+		free_irq(client->irq, sensor);
+	input_unregister_device(sensor->idev);
+	sensor->idev = NULL;
+}
+
+/**
+ *	mpu3050_register_input_device	-	remove input dev
+ *	@sensor: sensor to remove from input
+ *
+ *	Add an input device to the sensor. This will be used to report
+ *	events from the sensor itself.
+ */
+static int mpu3050_register_input_device(struct mpu3050_sensor *sensor)
+{
+	struct i2c_client *client = sensor->client;
+	struct input_dev *idev;
+	int ret;
+	sensor->idev = input_allocate_device();
+	idev = sensor->idev;
+	if (!idev) {
+		dev_err(&client->dev, "failed to allocate input device\n");
+		ret = -ENOMEM;
+		goto failed_alloc;
+	}
+	idev->name = "MPU3050";
+	idev->open = mpu3050_input_open;
+	idev->close = mpu3050_input_close;
+	idev->id.bustype = BUS_I2C;
+	idev->dev.parent = &client->dev;
+	idev->evbit[0] = BIT_MASK(EV_ABS);
+	input_set_abs_params(idev, ABS_X, MPU3050_MIN_VALUE,
+			MPU3050_MAX_VALUE, 0, 0);
+	input_set_abs_params(idev, ABS_Y, MPU3050_MIN_VALUE,
+			MPU3050_MAX_VALUE, 0, 0);
+	input_set_abs_params(idev, ABS_Z, MPU3050_MIN_VALUE,
+			MPU3050_MAX_VALUE, 0, 0);
+	input_set_drvdata(idev, sensor);
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(&client->dev, "failed to register input device\n");
+		goto failed_reg;
+	}
+	if (client->irq > 0) {
+		ret = request_threaded_irq(client->irq, NULL,
+				mpu3050_interrupt_thread, IRQF_TRIGGER_RISING,
+					"mpu_int", sensor);
+		if (ret) {
+			dev_err(&client->dev, "can't get IRQ %d, ret %d\n",
+					client->irq, ret);
+			goto failed_irq;
+		}
+	}
+	return 0;
+failed_irq:
+	input_unregister_device(idev);
+	return ret;
+failed_reg:
+	if (idev)
+		input_free_device(idev);
+failed_alloc:
+	return ret;
+}
+
+/**
+ *	mpu3050_probe	-	device detection callback
+ *	@client: i2c client of found device
+ *	@id: id match information
+ *
+ *	The I2C layer calls us when it believes a sensor is present at this
+ *	address. Probe to see if this is correct and to validate the device.
+ *
+ *	If present install the relevant sysfs interfaces and input device.
+ */
+static int __devinit mpu3050_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct mpu3050_sensor *sensor;
+	int ret;
+	sensor = kzalloc(sizeof(struct mpu3050_sensor), GFP_KERNEL);
+	if (!sensor) {
+		dev_err(&client->dev, "failed to allocate driver data\n");
+		return -ENOMEM;
+	}
+	sensor->dev = &client->dev;
+	sensor->client = client;
+	i2c_set_clientdata(client, sensor);
+
+	ret = i2c_smbus_read_byte_data(client, MPU3050_CHIP_ID_REG);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to detect device\n");
+		goto failed_free;
+	}
+	if (ret != MPU3050_CHIP_ID) {
+		dev_err(&client->dev, "unsupported chip id\n");
+		goto failed_free;
+	}
+
+	mutex_init(&sensor->lock);
+
+	ret = sysfs_create_group(&client->dev.kobj, &mpu3050_group);
+	if (ret) {
+		dev_err(&client->dev, "failed to create attribute group\n");
+		goto failed_free;
+	}
+
+	pm_runtime_set_active(&client->dev);
+
+	ret = mpu3050_register_input_device(sensor);
+	if (ret)
+		dev_err(&client->dev, "only provide sysfs\n");
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, MPU3050_AUTO_DELAY);
+
+	dev_info(&client->dev, "%s registered\n", id->name);
+	return 0;
+
+failed_free:
+	kfree(sensor);
+	return ret;
+}
+
+/**
+ *	bma023_remove	-	remove a sensor
+ *	@client: i2c client of sensor being removed
+ *
+ *	Our sensor is going away, clean up the resources.
+ */
+static int __devexit mpu3050_remove(struct i2c_client *client)
+{
+	struct mpu3050_sensor *sensor = i2c_get_clientdata(client);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	if (sensor->idev)
+		mpu3050_unregister_input_device(sensor);
+	sysfs_remove_group(&client->dev.kobj, &mpu3050_group);
+	kfree(sensor);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+/**
+ *	mpu3050_suspend		-	called on device suspend
+ *	@client: i2c client of sensor
+ *	@mesg: actual suspend type
+ *
+ *	Put the device into sleep mode before we suspend the machine.
+ */
+static int mpu3050_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	mpu3050_set_power_mode(client, 0);
+	return 0;
+}
+
+/**
+ *	mpu3050_resume		-	called on device resume
+ *	@client: i2c client of sensor
+ *
+ *	Put the device into powered mode on resume.
+ */
+static int mpu3050_resume(struct i2c_client *client)
+{
+	mpu3050_set_power_mode(client, 1);
+	msleep(100);  /* wait for gyro chip resume */
+	return 0;
+}
+#else
+#define mpu3050_suspend NULL
+#define mpu3050_resume NULL
+#endif
+
+#ifdef CONFIG_PM_RUNTIME
+static int mpu3050_runtime_suspend(struct device *dev)
+{

drivers/input/misc/mpu3050.c new file +44 -1

+	return 0;
+}
+
+static const struct dev_pm_ops mpu3050_pm = {
+	.runtime_suspend = mpu3050_runtime_suspend,
+	.runtime_resume  = mpu3050_runtime_resume,
+};
+#endif
+
+static const struct i2c_device_id mpu3050_ids[] = {
+	{ "mpu3050", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mpu3050_ids);
+
+static struct i2c_driver mpu3050_i2c_driver = {
+	.driver	= {
+		.name	= "mpu3050",
+#ifdef CONFIG_PM_RUNTIME
+		.pm		= &mpu3050_pm,
+#endif
+	},
+	.probe		= mpu3050_probe,
+	.remove		= __devexit_p(mpu3050_remove),
+	.suspend	= mpu3050_suspend,
+	.resume		= mpu3050_resume,
+	.id_table	= mpu3050_ids,
+};
+
+static int __init mpu3050_init(void)
+{
+	return i2c_add_driver(&mpu3050_i2c_driver);
+}
+module_init(mpu3050_init);
+
+static void __exit mpu3050_exit(void)
+{
+	i2c_del_driver(&mpu3050_i2c_driver);
+}
+module_exit(mpu3050_exit);
+
+MODULE_AUTHOR("Wistron Corp.");
+MODULE_DESCRIPTION("MPU3050 Tri-axis gyroscope driver");
+MODULE_LICENSE("GPL");
 
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It is a slim sysfs interface so for once I'm not going to moan (much...) I'd prefer something with actual units rather than adc
counts but can live with having this interface alongside something more generalizable.

drivers/input/misc/mpu3050.c line 140

Quoted 6 lines

drivers/input/misc/mpu3050.c new file +6 -0

+/* Methods for the sysfs attributes */
+static ssize_t mpu3050_show_power_mode(struct device *dev,
+		struct device_attribute *att, char *buf)
+{
+	struct mpu3050_sensor *sensor = dev_get_drvdata(dev);
+	int is_suspended = mpu3050_get_power_mode(sensor->client);

!is_suspended is cleaner.

Quoted 6 lines

drivers/input/misc/mpu3050.c new file +6 -0

+	return sprintf(buf, "%d\n", is_suspended ? 0 : 1);
+}
+
+static ssize_t mpu3050_store_power_mode(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{

drivers/input/misc/mpu3050.c line 152

Quoted 6 lines

drivers/input/misc/mpu3050.c new file +6 -0

+	struct mpu3050_sensor *sensor = dev_get_drvdata(dev);
+
+	if (!count || !(buf[0] == '1' || buf[0] == '0'))
+		return count;
+
+	mutex_lock(&sensor->lock);

Could use the sysfs_streq function to deal with leading white space and other fun. Also do we need the trinary operator?

drivers/input/misc/mpu3050.c line 449

Quoted 5 lines

drivers/input/misc/mpu3050.c new file +5 -0

+static int mpu3050_runtime_resume(struct device *dev)
+{
+	struct mpu3050_sensor *sensor = dev_get_drvdata(dev);
+	mpu3050_set_power_mode(sensor->client, 1);
+	msleep(100);  /* wait for gyro chip resume */

Could perhaps make the obvious connection between this and the non runtime versions more explicit? Just a thought...

Quoted 4 lines

It is a slim sysfs interface so for once I'm not going to moan (much...) I'd prefer something with actual units rather than adc
counts but can live with having this interface alongside something more generalizable.

It's not even ADC counts - the mpu3050 has its own processing.

Quoted 1 line

It's not even ADC counts - the mpu3050 has its own processing.

Oh goody..

Just had a look at the datasheet. 'Interesting'

I'm particularly looking forward to seeing use of the on gyro master i2c bus for talking to an external accelerometer :)

There are quoted conversion parameters for going from the raw readings to degree's per sec. You 'could' apply them in kernel I guess, or maybe provide details of what they are to userspace....

From: Joseph Lai <[email protected]>

This driver is registered as an input device with sysfs control interface, but it still can output 3 axes data in non-interrupt mode.

This is primarily an input device but can also be used as for other things. It thus exposes the power control (so you can keep power on when you want) and x/y/z co-ordinates directly.

Hi Alan,

Quoted 8 lines · Alan Cox

From: Joseph Lai <[email protected]>

This driver is registered as an input device with sysfs control interface, but it still can output 3 axes data in non-interrupt mode.

This is primarily an input device but can also be used as for other things. It thus exposes the power control (so you can keep power on when you want) and x/y/z co-ordinates directly.

I'd be more happy if it was just an input device. If non-wired interrupt is a common case then we should probably add polled input device mode, but we certainly should not register completely non-functional input device as the driver does now.

We also have a way of retrieving current (or rather most recent) coordinates via EVIOCGABS so I am not sure why we want the sysfs way of retrieving coordinates as well.

Regarding power mode - I really believe that this should be done on the driver core level instead of implementing "manual off" in every single driver out there.

I'd be more happy if it was just an input device. If non-wired interrupt is a common case then we should probably add polled input device mode,

but we certainly should not register completely non-functional input device as the driver does now.

We also have a way of retrieving current (or rather most recent) coordinates via EVIOCGABS so I am not sure why we want the sysfs way of retrieving coordinates as well.

Regarding power mode - I really believe that this should be done on the driver core level instead of implementing "manual off" in every single driver out there.

Quoted 2 lines

I'd be more happy if it was just an input device. If non-wired interrupt is a common case then we should probably add polled input device mode,

I can't really answer how common it is or would be - its a generic chip that is used on all sorts of equipment

Quoted 2 lines

but we certainly should not register completely non-functional input device as the driver does now.

Agreed

Quoted 3 lines

We also have a way of retrieving current (or rather most recent) coordinates via EVIOCGABS so I am not sure why we want the sysfs way of retrieving coordinates as well.

The sysfs way comes about because the devices are very very power oriented, waking up and polling regularly burns power, hence also the power control side. Opening an input device would power it up for the duration it was open and the polling would cause a lot of wakeups burning power.

Doing open/EVIOCGABS/close to avoid that aspect of the input layer won't ensure you get current data that I can see - because an IRQ may not have occurred between the open and the EVIOCGABS so any data may be very stale or non-existent.

The polled case looks trivial to sort but for an IRQ driver driver it looks like you would need a new "get co-ordinates right now" optional method tht EVIOCGABS would use if available ?

Quoted 3 lines

Regarding power mode - I really believe that this should be done on the driver core level instead of implementing "manual off" in every single driver out there.

Definitely - not sure what plans Rafael has there ?

Quoted 21 lines · Alan Cox

Quoted 2 lines

I'd be more happy if it was just an input device. If non-wired interrupt is a common case then we should probably add polled input device mode,

I can't really answer how common it is or would be - its a generic chip that is used on all sorts of equipment

Quoted 2 lines

but we certainly should not register completely non-functional input device as the driver does now.

Agreed

Quoted 3 lines

We also have a way of retrieving current (or rather most recent) coordinates via EVIOCGABS so I am not sure why we want the sysfs way of retrieving coordinates as well.

The sysfs way comes about because the devices are very very power oriented, waking up and polling regularly burns power, hence also the power control side. Opening an input device would power it up for the duration it was open and the polling would cause a lot of wakeups burning power.

Quoted 4 lines

Doing open/EVIOCGABS/close to avoid that aspect of the input layer won't ensure you get current data that I can see - because an IRQ may not have occurred between the open and the EVIOCGABS so any data may be very stale or non-existent.

I would be perfectly fine with a driver that does refresh it's state in dev->open() if we expect that data might be stale. We normally do not do that because old data is normally not interesting for touchpads, mice or keyboards and we not always have option of querying current hardware state.

Quoted 9 lines

The polled case looks trivial to sort but for an IRQ driver driver it looks like you would need a new "get co-ordinates right now" optional method tht EVIOCGABS would use if available ?

Quoted 3 lines

Regarding power mode - I really believe that this should be done on the driver core level instead of implementing "manual off" in every single driver out there.

Quoted 2 lines

Definitely - not sure what plans Rafael has there ?

Last time we discussed this we were talking about sysfs entry at the driver core level allowing userspace to "expire" idle timer and force runtime PM action. Rafael, did I remember that right?

drivers/input/misc/mpu3050.c new file +91 -0

@@ -0,0 +1,493 @@
+/*
+ * mpu3050.c - MPU3050 Tri-axis gyroscope driver
+ *
+ * Copyright (C) 2011 Wistron Co.Ltd
+ * Joseph Lai<[email protected]>
+ *
+ * This program is based on bma023.c.
+ *
+ * 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/platform_device.h>
+#include<linux/mutex.h>
+#include<linux/err.h>
+#include<linux/i2c.h>
+#include<linux/input.h>
+#include<linux/delay.h>
+#include<linux/slab.h>
+#include<linux/pm_runtime.h>
+
+#define MPU3050_CHIP_ID_REG	0x00
+#define MPU3050_CHIP_ID		0x69
+#define MPU3050_XOUT_H		0x1D
+#define MPU3050_PWR_MGM		0x3E
+#define MPU3050_PWR_MGM_POS	6
+#define MPU3050_PWR_MGM_MASK	0x40
+
+#define MPU3050_AUTO_DELAY	1000
+
+#define MPU3050_MIN_VALUE	-32768
+#define MPU3050_MAX_VALUE	32767
+
+struct axis_data {
+	s16 x;
+	s16 y;
+	s16 z;
+};
+
+struct mpu3050_sensor {
+	struct i2c_client *client;
+	struct device *dev;
+	struct input_dev *idev;
+	struct mutex lock;
+};
+
+/**
+ *	mpu3050_xyz_read_reg	-	read the axes values
+ *	@buffer: provide register addr and get register
+ *	@length: length of register
+ *
+ *	Reads the register values in one transaction or returns a negative
+ *	error code on failure/
+ */
+static int mpu3050_xyz_read_reg(struct i2c_client *client,
+			       u8 *buffer, int length)
+{
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = 1,
+			.buf = buffer,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = length,
+			.buf = buffer,
+		},
+	};
+	return i2c_transfer(client->adapter, msg, 2);
+}
+
+/**
+ *	mpu3050_read_xyz	-	get co-ordinates from device
+ *	@client: i2c address of sensor

drivers/input/misc/mpu3050.c new file +25 -0

+	coords->x = buffer[0];
+	coords->x = coords->x<<  8 | buffer[1];
+	coords->y = buffer[2];
+	coords->y = coords->y<<  8 | buffer[3];
+	coords->z = buffer[4];
+	coords->z = coords->z<<  8 | buffer[5];
+	dev_dbg(&client->dev, "%s: x %d, y %d, z %d\n", __func__,
+					coords->x, coords->y, coords->z);
+}
+
+/**
+ *	mpu3050_set_power_mode	-	set the power mode
+ *	@client: i2c client for the sensor
+ *	@val: value to switch on/off of power, 1: normal power, 0: low power
+ *
+ *	Put device to normal-power mode or low-power mode.
+ */
+static void mpu3050_set_power_mode(struct i2c_client *client, u8 val)
+{
+	u8 value;
+	value = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
+	value = (value&  ~MPU3050_PWR_MGM_MASK) |
+		(((val<<  MPU3050_PWR_MGM_POS)&  MPU3050_PWR_MGM_MASK) ^
+		 MPU3050_PWR_MGM_MASK);
+	i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, value);

drivers/input/misc/mpu3050.c new file +51 -0

+/**
+ *	mpu3050_probe	-	device detection callback
+ *	@client: i2c client of found device
+ *	@id: id match information
+ *
+ *	The I2C layer calls us when it believes a sensor is present at this
+ *	address. Probe to see if this is correct and to validate the device.
+ *
+ *	If present install the relevant sysfs interfaces and input device.
+ */
+static int __devinit mpu3050_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct mpu3050_sensor *sensor;
+	int ret;
+	sensor = kzalloc(sizeof(struct mpu3050_sensor), GFP_KERNEL);
+	if (!sensor) {
+		dev_err(&client->dev, "failed to allocate driver data\n");
+		return -ENOMEM;
+	}
+	sensor->dev =&client->dev;
+	sensor->client = client;
+	i2c_set_clientdata(client, sensor);
+
+	ret = i2c_smbus_read_byte_data(client, MPU3050_CHIP_ID_REG);
+	if (ret<  0) {
+		dev_err(&client->dev, "failed to detect device\n");
+		goto failed_free;
+	}
+	if (ret != MPU3050_CHIP_ID) {
+		dev_err(&client->dev, "unsupported chip id\n");
+		goto failed_free;
+	}
+
+	mutex_init(&sensor->lock);
+
+	ret = sysfs_create_group(&client->dev.kobj,&mpu3050_group);
+	if (ret) {
+		dev_err(&client->dev, "failed to create attribute group\n");
+		goto failed_free;
+	}
+
+	pm_runtime_set_active(&client->dev);
+
+	ret = mpu3050_register_input_device(sensor);
+	if (ret)
+		dev_err(&client->dev, "only provide sysfs\n");
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, MPU3050_AUTO_DELAY);
+

+ * @client: i2c client of sensor being removed
+ *
+ * Our sensor is going away, clean up the resources.
+ */

drivers/input/misc/mpu3050.c new file +47 -0

+static int __devexit mpu3050_remove(struct i2c_client *client)
+{
+	struct mpu3050_sensor *sensor = i2c_get_clientdata(client);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	if (sensor->idev)
+		mpu3050_unregister_input_device(sensor);
+	sysfs_remove_group(&client->dev.kobj,&mpu3050_group);
+	kfree(sensor);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+/**
+ *	mpu3050_suspend		-	called on device suspend
+ *	@client: i2c client of sensor
+ *	@mesg: actual suspend type
+ *
+ *	Put the device into sleep mode before we suspend the machine.
+ */
+static int mpu3050_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	mpu3050_set_power_mode(client, 0);
+	return 0;
+}
+
+/**
+ *	mpu3050_resume		-	called on device resume
+ *	@client: i2c client of sensor
+ *
+ *	Put the device into powered mode on resume.
+ */
+static int mpu3050_resume(struct i2c_client *client)
+{
+	mpu3050_set_power_mode(client, 1);
+	msleep(100);  /* wait for gyro chip resume */
+	return 0;
+}
+#else
+#define mpu3050_suspend NULL
+#define mpu3050_resume NULL
+#endif
+
+#ifdef CONFIG_PM_RUNTIME
+static int mpu3050_runtime_suspend(struct device *dev)

drivers/input/misc/mpu3050.c new file +17 -0

+	msleep(100);  /* wait for gyro chip resume */
+	return 0;
+}
+
+static const struct dev_pm_ops mpu3050_pm = {
+	.runtime_suspend = mpu3050_runtime_suspend,
+	.runtime_resume  = mpu3050_runtime_resume,
+};
+#endif
+
+static const struct i2c_device_id mpu3050_ids[] = {
+	{ "mpu3050", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mpu3050_ids);
+
+static struct i2c_driver mpu3050_i2c_driver = {

drivers/input/misc/mpu3050.c new file +18 -1

+	.id_table	= mpu3050_ids,
+};
+
+static int __init mpu3050_init(void)
+{
+	return i2c_add_driver(&mpu3050_i2c_driver);
+}
+module_init(mpu3050_init);
+
+static void __exit mpu3050_exit(void)
+{
+	i2c_del_driver(&mpu3050_i2c_driver);
+}
+module_exit(mpu3050_exit);
+
+MODULE_AUTHOR("Wistron Corp.");
+MODULE_DESCRIPTION("MPU3050 Tri-axis gyroscope driver");
+MODULE_LICENSE("GPL");
 
--

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