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Diffstat (limited to 'drivers/misc/mpu3050/README')
| -rwxr-xr-x | drivers/misc/mpu3050/README | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/misc/mpu3050/README b/drivers/misc/mpu3050/README new file mode 100755 index 0000000..2734dc1 --- /dev/null +++ b/drivers/misc/mpu3050/README @@ -0,0 +1,250 @@ +Kernel driver mpu
+=====================
+
+Supported chips:
+ * InvenSense IMU3050
+ Prefix: 'mpu3050'
+ Datasheet:
+ PS-MPU-3000A-00.2.4b.pdf
+
+ * InvenSense IMU6000
+ Prefix: 'mpu6000'
+ Datasheet:
+ MPU-6000A-00 v1.0.pdf
+
+Author: InvenSense <http://invensense.com>
+
+Description
+-----------
+The mpu is a motion processor unit that controls the mpu3050 gyroscope, a slave
+accelerometer, a compass and a pressure sensor, or the mpu6000 and slave
+compass. This document describes how to install the driver into a Linux kernel
+and a small note about how to set up the file permissions in an android file
+system.
+
+Sysfs entries
+-------------
+/dev/mpu
+/dev/mpuirq
+/dev/accelirq
+/dev/compassirq
+/dev/pressureirq
+
+General Remarks MPU3050
+-----------------------
+* Valid addresses for the MPU3050 is 0x68.
+* Accelerometer must be on the secondary I2C bus for MPU3050, the
+ magnetometer must be on the primary bus and pressure sensor must
+ be on the primary bus.
+
+General Remarks MPU6000
+-----------------------
+* Valid addresses for the MPU6000 is 0x68.
+* Magnetometer must be on the secondary I2C bus for the MPU6000.
+* Accelerometer slave address must be set to 0x68
+* Gyro and Accel orientation matrices should be the same
+
+Programming the chip using /dev/mpu
+----------------------------------
+Programming of MPU3050 or MPU6000 is done by first opening the /dev/mpu file and
+then performing a series of IOCTLS on the handle returned. The IOCTL codes can
+be found in mpu.h. Typically this is done by the mllite library in user
+space.
+
+Adding to a Kernel
+==================
+
+The mpu driver is designed to be inserted in the drivers/misc part of the
+kernel. Extracting the tarball from the root kernel dir will place the
+contents of the tarball here:
+
+ <kernel root dir>/drivers/misc/mpu3050
+ <kernel root dir>/include/linux/mpu.h
+ <kernel root dir>/include/linux/mpu3050.h
+ <kernel root dir>/include/linux/mpu6000.h
+
+After this is done the drivers/misc/Kconfig must be edited to add the line:
+
+ source "drivers/misc/mpu3050/Kconfig"
+
+Similarly drivers/misc/Makefile must be edited to add the line:
+
+ obj-y += mpu3050/
+
+Configuration can then be done as normal.
+
+NOTE: This driver depends on a kernel patch to drivers/char/char.c. This patch
+started to be included in most 2.6.35 based kernels.
+drivers: misc: pass miscdevice pointer via file private data
+https://patchwork.kernel.org/patch/96412/
+
+---
+ drivers/char/misc.c | 1 +
+ 1 files changed, 1 insertions(+), 0 deletions(-)
+
+
+diff --git a/drivers/char/misc.c b/drivers/char/misc.c
+index 92ab03d..cd650ca 100644
+--- a/drivers/char/misc.c
++++ b/drivers/char/misc.c
+@@ -144,6 +144,7 @@ static int misc_open(struct inode * inode, struct file * file)
+ old_fops = file->f_op;
+ file->f_op = new_fops;
+ if (file->f_op->open) {
++ file->private_data = c;
+ err=file->f_op->open(inode,file);
+ if (err) {
+ fops_put(file->f_op);
+---
+
+Board and Platform Data
+-----------------------
+
+In order for the driver to work, board and platform data specific to the device
+needs to be added to the board file. A mpu3050_platform_data structure must
+be created and populated and set in the i2c_board_info_structure. For details
+of each structure member see mpu.h. All values below are simply an example and
+should be modified for your platform.
+
+#include <linux/mpu.h>
+
+#if defined(CONFIG_SENSORS_MPU3050) || defined(CONFIG_SENSORS_MPU3050_MODULE)
+
+#define SENSOR_MPU_NAME "mpu3050"
+
+static struct mpu3050_platform_data mpu_data = {
+ .int_config = 0x10,
+ .orientation = { -1, 0, 0,
+ 0, 1, 0,
+ 0, 0, -1 },
+ /* accel */
+ .accel = {
+#ifdef CONFIG_SENSORS_MPU3050_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_accel_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_SECONDARY,
+ .address = 0x0F,
+ .orientation = { -1, 0, 0,
+ 0, 1, 0,
+ 0, 0, -1 },
+ },
+ /* compass */
+ .compass = {
+#ifdef CONFIG_SENSORS_MPU3050_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_compass_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_PRIMARY,
+ .address = 0x0E,
+ .orientation = { 1, 0, 0,
+ 0, 1, 0,
+ 0, 0, 1 },
+ },
+ /* pressure */
+ .pressure = {
+#ifdef CONFIG_SENSORS_MPU3050_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_pressure_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_PRIMARY,
+ .address = 0x77,
+ .orientation = { 1, 0, 0,
+ 0, 1, 0,
+ 0, 0, 1 },
+ },
+};
+#endif
+
+#if defined(CONFIG_SENSORS_MPU6000) || defined(CONFIG_SENSORS_MPU6000_MODULE)
+
+#define SENSOR_MPU_NAME "mpu6000"
+
+static struct mpu3050_platform_data mpu_data = {
+ .int_config = 0x10,
+ .orientation = { -1, 0, 0,
+ 0, 1, 0,
+ 0, 0, -1 },
+ /* accel */
+ .accel = {
+#ifdef CONFIG_SENSORS_MPU6000_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_accel_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_PRIMARY,
+ .address = 0x68,
+ .orientation = { -1, 0, 0,
+ 0, 1, 0,
+ 0, 0, -1 },
+ },
+ /* compass */
+ .compass = {
+#ifdef CONFIG_SENSORS_MPU6000_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_compass_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_SECONDARY,
+ .address = 0x0E,
+ .orientation = { 1, 0, 0,
+ 0, 1, 0,
+ 0, 0, 1 },
+ },
+ /* pressure */
+ .pressure = {
+#ifdef CONFIG_SENSORS_MPU6000_MODULE
+ .get_slave_descr = NULL,
+#else
+ .get_slave_descr = get_pressure_slave_descr,
+#endif
+ .adapt_num = 2,
+ .bus = EXT_SLAVE_BUS_PRIMARY,
+ .address = 0x77,
+ .orientation = { 1, 0, 0,
+ 0, 1, 0,
+ 0, 0, 1 },
+ },
+
+};
+#endif
+
+static struct i2c_board_info __initdata beagle_i2c_2_boardinfo[] = {
+ {
+ I2C_BOARD_INFO(SENSOR_MPU_NAME, 0x68),
+ .irq = (IH_GPIO_BASE + MPU_GPIO_IRQ),
+ .platform_data = &mpu_data,
+ },
+};
+
+Typically the IRQ is a GPIO input pin and needs to be configured properly. If
+in the above example GPIO 168 corresponds to IRQ 299, the following should be
+done as well:
+
+#define MPU_GPIO_IRQ 168
+
+ gpio_request(MPU_GPIO_IRQ,"MPUIRQ");
+ gpio_direction_input(MPU_GPIO_IRQ)
+
+
+Android File Permissions
+========================
+
+To set up the file permissions on an android system, the /dev/mpu and
+/dev/mpuirq files needs to be added to the system/core/init/devices.c file
+inside the perms_ structure.
+
+static struct perms_ devperms[] = {
+ { "/dev/mpu" ,0640, AID_SYSTEM, AID_SYSTEM, 1 },
+};
+
+Sufficient file permissions need to be give to read and write it by the system.
+
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