InvenSense ITG3200 Digital 3-Axis Gyroscope I2C driver

Signed-off-by: Thorsten Nowak <n...@iis.fhg.de>
---
 drivers/staging/iio/gyro/Kconfig           |   11 +
 drivers/staging/iio/gyro/Makefile          |    4 +
 drivers/staging/iio/gyro/itg3200.h         |  161 ++++++++
 drivers/staging/iio/gyro/itg3200_buffer.c  |  171 ++++++++
 drivers/staging/iio/gyro/itg3200_core.c    |  592 ++++++++++++++++++++++++++++
 drivers/staging/iio/gyro/itg3200_trigger.c |   90 +++++
 6 files changed, 1029 insertions(+)
 create mode 100644 drivers/staging/iio/gyro/itg3200.h
 create mode 100644 drivers/staging/iio/gyro/itg3200_buffer.c
 create mode 100644 drivers/staging/iio/gyro/itg3200_core.c
 create mode 100644 drivers/staging/iio/gyro/itg3200_trigger.c

diff --git a/drivers/staging/iio/gyro/Kconfig b/drivers/staging/iio/gyro/Kconfig
index ea295b2..47b383d 100644
--- a/drivers/staging/iio/gyro/Kconfig
+++ b/drivers/staging/iio/gyro/Kconfig
@@ -46,4 +46,15 @@ config ADXRS450
          This driver can also be built as a module.  If so, the module
          will be called adxrs450.
 
+config ITG3200
+       tristate "InvenSense ITG3200 Digital 3-Axis Gyroscope I2C driver"
+       depends on I2C
+       select IIO_KFIFO_BUF if IIO_BUFFER
+       help
+         Say Y here to add support for the InvenSense ITG3200 digital
+         3-axis gyroscope sensor.
+
+         To compile this driver as a module, choose M here: the module
+         will be called itg3200.
+
 endmenu
diff --git a/drivers/staging/iio/gyro/Makefile 
b/drivers/staging/iio/gyro/Makefile
index 9ba5ec1..7567a50 100644
--- a/drivers/staging/iio/gyro/Makefile
+++ b/drivers/staging/iio/gyro/Makefile
@@ -20,3 +20,7 @@ obj-$(CONFIG_ADIS16251) += adis16251.o
 
 adxrs450-y             := adxrs450_core.o
 obj-$(CONFIG_ADXRS450) += adxrs450.o
+
+itg3200-y               := itg3200_core.o
+itg3200-$(CONFIG_IIO_BUFFER) += itg3200_buffer.o itg3200_trigger.o
+obj-$(CONFIG_ITG3200)   += itg3200.o
diff --git a/drivers/staging/iio/gyro/itg3200.h 
b/drivers/staging/iio/gyro/itg3200.h
new file mode 100644
index 0000000..a98d37d
--- /dev/null
+++ b/drivers/staging/iio/gyro/itg3200.h
@@ -0,0 +1,161 @@
+/*
+ * itg3200.h -- support InvenSense ITG3200
+ *              Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.stro...@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.st...@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.no...@iis.fraunhofer.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef I2C_ITG3200_H_
+#define I2C_ITG3200_H_
+
+#include <linux/iio/iio.h>
+#include "../ring_sw.h"
+
+/* Register with I2C address (34h) */
+#define ITG3200_REG_ADDRESS             0x00
+
+/* Sample rate divider
+ * Range: 0 to 255
+ * Default value: 0x00 */
+#define ITG3200_REG_SAMPLE_RATE_DIV         0x15
+
+/* Digital low pass filter settings */
+#define ITG3200_REG_DLPF                0x16
+/* DLPF full scale range */
+#define ITG3200_DLPF_FS_SEL_2000            0x18
+/* Bandwidth (Hz) and internal sample rate
+ * (kHz) of DLPF */
+#define ITG3200_DLPF_256_8              0x00
+#define ITG3200_DLPF_188_1              0x01
+#define ITG3200_DLPF_98_1               0x02
+#define ITG3200_DLPF_42_1               0x03
+#define ITG3200_DLPF_20_1               0x04
+#define ITG3200_DLPF_10_1               0x05
+#define ITG3200_DLPF_5_1                0x06
+
+#define ITG3200_DLPF_CFG_MASK               0x07
+
+/* Configuration for interrupt operations */
+#define ITG3200_REG_IRQ_CONFIG              0x17
+/* Logic level */
+#define ITG3200_IRQ_ACTIVE_LOW              0x80
+#define ITG3200_IRQ_ACTIVE_HIGH             0x00
+/* Drive type */
+#define ITG3200_IRQ_OPEN_DRAIN              0x40
+#define ITG3200_IRQ_PUSH_PULL               0x00
+/* Latch mode */
+#define ITG3200_IRQ_LATCH_UNTIL_CLEARED         0x20
+#define ITG3200_IRQ_LATCH_50US_PULSE            0x00
+/* Latch clear method */
+#define ITG3200_IRQ_LATCH_CLEAR_ANY         0x10
+#define ITG3200_IRQ_LATCH_CLEAR_STATUS          0x00
+/* Enable interrupt when device is ready */
+#define ITG3200_IRQ_DEVICE_RDY_ENABLE           0x04
+/* Enable interrupt when data is available */
+#define ITG3200_IRQ_DATA_RDY_ENABLE         0x01
+
+/* Determine the status of ITG-3200 interrupts */
+#define ITG3200_REG_IRQ_STATUS              0x1A
+/* Status of 'device is ready'-interrupt */
+#define ITG3200_IRQ_DEVICE_RDY_STATUS           0x04
+/* Status of 'data is available'-interrupt */
+#define ITG3200_IRQ_DATA_RDY_STATUS         0x01
+
+/* Sensor registers */
+#define ITG3200_REG_TEMP_OUT_H              0x1B
+#define ITG3200_REG_TEMP_OUT_L              0x1C
+#define ITG3200_REG_GYRO_XOUT_H             0x1D
+#define ITG3200_REG_GYRO_XOUT_L             0x1E
+#define ITG3200_REG_GYRO_YOUT_H             0x1F
+#define ITG3200_REG_GYRO_YOUT_L             0x20
+#define ITG3200_REG_GYRO_ZOUT_H             0x21
+#define ITG3200_REG_GYRO_ZOUT_L             0x22
+
+/* Power management */
+#define ITG3200_REG_POWER_MANAGEMENT            0x3E
+/* Reset device and internal registers to the
+ * power-up-default settings */
+#define ITG3200_RESET                   0x80
+/* Enable low power sleep mode */
+#define ITG3200_SLEEP                   0x40
+/* Put according gyroscope in standby mode */
+#define ITG3200_STANDBY_GYRO_X              0x20
+#define ITG3200_STANDBY_GYRO_Y              0x10
+#define ITG3200_STANDBY_GYRO_Z              0x08
+/* Determine the device clock source */
+#define ITG3200_CLK_INTERNAL                0x00
+#define ITG3200_CLK_GYRO_X              0x01
+#define ITG3200_CLK_GYRO_Y              0x02
+#define ITG3200_CLK_GYRO_Z              0x03
+#define ITG3200_CLK_EXT_32K             0x04
+#define ITG3200_CLK_EXT_19M             0x05
+
+#define ITG3200_MAX_TX 1
+#define ITG3200_MAX_RX 16 /* 4 * 16bit + 64bit timestamp */
+
+/**
+ * struct itg3200_state - device instance specific data
+ * @i2c:    actual i2c_client
+ * @trig:   data ready trigger registered with iio
+ **/
+struct itg3200_state {
+       struct i2c_client   *i2c;
+       struct iio_trigger  *trig;
+       bool            trigger_on;
+       u8      tx[ITG3200_MAX_TX] ____cacheline_aligned;
+       __be16      rx[ITG3200_MAX_RX] ____cacheline_aligned;
+};
+
+int itg3200_read_irq_status(struct iio_dev *indio_dev);
+
+int itg3200_set_irq_data_rdy(struct iio_dev *indio_dev, bool enable);
+
+enum ITG3200_CHANNELS {
+       ITG3200_TEMP,
+       ITG3200_GYRO_X,
+       ITG3200_GYRO_Y,
+       ITG3200_GYRO_Z,
+       ITG3200_SCAN_ELEMENTS = 4,
+};
+
+#ifdef CONFIG_IIO_BUFFER
+
+void itg3200_remove_trigger(struct iio_dev *indio_dev);
+int itg3200_probe_trigger(struct iio_dev *indio_dev);
+
+int itg3200_buffer_configure(struct iio_dev *indio_dev);
+void itg3200_buffer_unconfigure(struct iio_dev *indio_dev);
+
+#define itg3200_free_buf iio_sw_rb_free
+#define itg3200_alloc_buf iio_sw_rb_allocate
+#define itg3200_access_funcs ring_sw_access_funcs
+
+#else /* CONFIG_IIO_BUFFER */
+
+static inline void itg3200_remove_trigger(struct iio_dev *indio_dev)
+{
+}
+
+static inline int itg3200_probe_trigger(struct iio_dev *indio_dev)
+{
+       return 0;
+}
+
+static inline int itg3200_buffer_configure(struct iio_dev *indio_dev)
+{
+       return 0;
+}
+
+static inline void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
+{
+}
+
+#endif  /* CONFIG_IIO_RING_BUFFER */
+
+#endif /* ITG3200_H_ */
diff --git a/drivers/staging/iio/gyro/itg3200_buffer.c 
b/drivers/staging/iio/gyro/itg3200_buffer.c
new file mode 100644
index 0000000..07596d3
--- /dev/null
+++ b/drivers/staging/iio/gyro/itg3200_buffer.c
@@ -0,0 +1,171 @@
+/*
+ * itg3200_ring.c -- support InvenSense ITG3200
+ *                   Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.stro...@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.st...@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.no...@iis.fraunhofer.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "itg3200.h"
+
+static irqreturn_t itg3200_trigger_handler(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct itg3200_state *st = iio_priv(indio_dev);
+       struct iio_buffer *buffer = indio_dev->buffer;
+       int len = 0;
+
+       /* Clear IRQ */
+       itg3200_read_irq_status(indio_dev);
+
+       if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) {
+               int ret;
+               unsigned i, j = 0;
+               st->tx[0] = 0x80 | ITG3200_REG_TEMP_OUT_H;
+               ret = i2c_master_send(st->i2c, st->tx, 1);
+               if (ret != 1)
+                       goto error_ret;
+
+               /* Receive all scan elements */
+               ret = i2c_master_recv(st->i2c, (u8 *)st->rx,
+                               ITG3200_SCAN_ELEMENTS * 2);
+               if (ret < 0)
+                       goto error_ret;
+
+               /* Select only active scan elements */
+               for (i = 0; i < ITG3200_SCAN_ELEMENTS; i++)
+                       if (iio_scan_mask_query(indio_dev, buffer, i))
+                               st->rx[j++] = st->rx[i];
+
+               len = j * sizeof(u16);
+       }
+       /* Guaranteed to be aligned with 8 byte boundary */
+       if (buffer->scan_timestamp)
+               *(s64 *)(((phys_addr_t)st->rx + len
+                                       + sizeof(s64) - 1) & ~(sizeof(s64) - 1))
+               = pf->timestamp;
+       buffer->access->store_to(buffer, (u8 *)st->rx, pf->timestamp);
+
+       iio_trigger_notify_done(indio_dev->trig);
+error_ret:
+       return IRQ_HANDLED;
+}
+
+/*
+static int itg3200_ring_postenable(struct iio_dev *indio_dev)
+{
+       u8 t;
+       int ret;
+
+       ret = itg3200_spi_read_reg_8(indio_dev,
+                                    ITG3200_REG_POWER_MANAGEMENT,
+                                    &t);
+       if (ret)
+               goto error_ret;
+
+       if (iio_scan_mask_query(indio_dev->ring, 1))
+               t &= ~ITG3200_STANDBY_GYRO_X;
+       else
+               t |= ~ITG3200_STANDBY_GYRO_X;
+
+       if (iio_scan_mask_query(indio_dev->ring, 2))
+               t &= ~ITG3200_STANDBY_GYRO_Y;
+       else
+               t |= ITG3200_STANDBY_GYRO_Y;
+
+       if (iio_scan_mask_query(indio_dev->ring, 3))
+               t &= ITG3200_STANDBY_GYRO_Z;
+       else
+               t |= ITG3200_STANDBY_GYRO_Z;
+
+       ret = itg3200_spi_write_reg_8(indio_dev,
+                                     ITG3200_REG_POWER_MANAGEMENT,
+                                     t);
+       if (ret)
+               goto error_ret;
+
+       return iio_triggered_ring_postenable(indio_dev);
+error_ret:
+       return ret;
+}
+
+static int itg3200_ring_predisable(struct iio_dev *indio_dev)
+{
+       u8 t;
+       int ret;
+
+       ret = iio_triggered_ring_predisable(indio_dev);
+       if (ret)
+               goto error_ret;
+
+       ret = itg3200_spi_read_reg_8(indio_dev,
+                                    ITG3200_REG_POWER_MANAGEMENT,
+                                    &t);
+       if (ret)
+               goto error_ret;
+       t &= ~(ITG3200_STANDBY_GYRO_X |
+               ITG3200_STANDBY_GYRO_Y |
+               ITG3200_STANDBY_GYRO_Z);
+
+       ret = itg3200_spi_write_reg_8(indio_dev,
+               ITG3200_REG_POWER_MANAGEMENT, t);
+
+error_ret:
+       return ret;
+}
+*/
+static const struct iio_buffer_setup_ops itg3200_buffer_setup_ops = {
+       .preenable = &iio_sw_buffer_preenable,
+       .postenable = &iio_triggered_buffer_postenable,
+       .predisable = &iio_triggered_buffer_predisable,
+};
+
+int itg3200_buffer_configure(struct iio_dev *indio_dev)
+{
+       int ret = 0;
+       struct iio_buffer *buffer;
+
+       buffer = iio_kfifo_allocate(indio_dev);
+       if (!buffer)
+               return -ENOMEM;
+
+       /* buffer->access = &kfifo_access_funcs; */
+       indio_dev->buffer = buffer;
+       indio_dev->setup_ops = &itg3200_buffer_setup_ops;
+       indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
+                       &itg3200_trigger_handler, IRQF_ONESHOT,
+                       indio_dev, "itg3200_consumer%d", indio_dev->id);
+       if (!indio_dev->pollfunc) {
+               ret = -ENOMEM;
+               goto error_free_buffer;
+       }
+
+       indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
+       return 0;
+
+error_free_buffer:
+       iio_kfifo_free(indio_dev->buffer);
+       return ret;
+}
+
+void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
+{
+       iio_dealloc_pollfunc(indio_dev->pollfunc);
+       iio_kfifo_free(indio_dev->buffer);
+}
diff --git a/drivers/staging/iio/gyro/itg3200_core.c 
b/drivers/staging/iio/gyro/itg3200_core.c
new file mode 100644
index 0000000..0096b38
--- /dev/null
+++ b/drivers/staging/iio/gyro/itg3200_core.c
@@ -0,0 +1,592 @@
+/*
+ * itg3200_core.c -- support InvenSense ITG3200
+ *                   Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.stro...@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.st...@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.no...@iis.fraunhofer.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define DEBUG
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/buffer.h>
+
+#include "itg3200.h"
+
+/* Copied from: linux-source-3.2/arch/arm/plat-omap/include/plat/gpio.h */
+/* Wrappers for "new style" GPIO calls, using the new infrastructure
+ * which lets us plug in FPGA, I2C, and other implementations.
+ * *
+ * The original OMAP-specific calls should eventually be removed.
+ */
+
+#include <linux/errno.h>
+#include <asm-generic/gpio.h>
+
+static inline int irq_to_gpio(unsigned irq)
+{
+       int tmp;
+
+       /* omap1 SOC mpuio */
+       if (cpu_class_is_omap1() && (irq < (IH_MPUIO_BASE + 16)))
+               return (irq - IH_MPUIO_BASE) + OMAP_MAX_GPIO_LINES;
+
+       /* SOC gpio */
+       tmp = irq - IH_GPIO_BASE;
+       if (tmp < OMAP_MAX_GPIO_LINES)
+               return tmp;
+
+       /* we don't supply reverse mappings for non-SOC gpios */
+       return -EIO;
+}
+
+
+static int itg3200_write_reg_8(struct iio_dev *indio_dev,
+               u8 reg_address, u8 val)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       int ret;
+
+       u8 buf[2];
+
+       buf[0] = 0x80 | reg_address;
+       buf[1] = val;
+
+       ret = i2c_master_send(st->i2c, buf, sizeof(buf));
+
+       return (ret == sizeof(buf)) ? 0 : ret;
+}
+
+static int itg3200_read_reg_8(struct iio_dev *indio_dev,
+               u8 reg_address, u8 *val)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       struct i2c_client *client = st->i2c;
+       int ret;
+
+       struct i2c_msg msg[2];
+
+       msg[0].addr = client->addr;
+       msg[0].flags = client->flags & I2C_M_TEN;
+       msg[0].len = 1;
+       msg[0].buf = (char *)&reg_address;
+
+       msg[1].addr = client->addr;
+       msg[1].flags = client->flags & I2C_M_TEN;
+       msg[1].flags |= I2C_M_RD;
+       msg[1].len = 1;
+       msg[1].buf = (char *)val;
+
+       reg_address |= 0x80;
+       ret = i2c_transfer(client->adapter, msg, 2);
+       return (ret == 2) ? 0 : ret;
+}
+
+static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 
lower_reg_address,
+               int *val)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       struct i2c_client *client = st->i2c;
+       int ret;
+       s16 out;
+
+       struct i2c_msg msg[2];
+
+       msg[0].addr = client->addr;
+       msg[0].flags = client->flags & I2C_M_TEN;
+       msg[0].len = 1;
+       msg[0].buf = (char *)&lower_reg_address;
+
+       msg[1].addr = client->addr;
+       msg[1].flags = client->flags & I2C_M_TEN;
+       msg[1].flags |= I2C_M_RD;
+       msg[1].len = 2;
+       msg[1].buf = (char *)&out;
+
+       lower_reg_address |= 0x80;
+       ret = i2c_transfer(client->adapter, msg, 2);
+       be16_to_cpus(&out);
+       *val = out;
+
+       return (ret == 2) ? 0 : ret;
+}
+
+static int itg3200_read_raw(struct iio_dev *indio_dev,
+               struct iio_chan_spec const *chan,
+               int *val, int *val2, long mask)
+{
+       ssize_t ret = 0;
+       u8 reg;
+
+       switch (mask) {
+       case 0:
+               reg = (u8)chan->address;
+               /* Take the iio_dev status lock */
+               mutex_lock(&indio_dev->mlock);
+               ret = itg3200_read_reg_s16(indio_dev, reg, val);
+               mutex_unlock(&indio_dev->mlock);
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               *val = 0;
+               if (chan->scan_index == ITG3200_TEMP)
+                       *val2 = 1000000000/280;
+               else
+                       *val2 = 1214142;
+               return IIO_VAL_INT_PLUS_NANO;
+       case IIO_CHAN_INFO_OFFSET:
+               if (chan->scan_index == ITG3200_TEMP)
+                       *val = 13200;
+               return IIO_VAL_INT;
+       }
+
+       return ret;
+}
+
+static ssize_t itg3200_read_frequency(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       int ret, len = 0;
+       u8 val;
+       int sps;
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
+       if (ret)
+               return ret;
+
+       sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val);
+       if (ret)
+               return ret;
+
+       sps /= val + 1;
+
+       len = sprintf(buf, "%d\n", sps);
+       return len;
+}
+
+static ssize_t itg3200_write_frequency(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf,
+               size_t len)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       long val;
+       int ret;
+       u8 t;
+
+       ret = kstrtol(buf, 10, &val);
+       if (ret)
+               return ret;
+
+       mutex_lock(&indio_dev->mlock);
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
+       if (ret)
+               goto err_ret;
+
+       t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000) / val - 1;
+
+       ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t);
+
+err_ret:
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret ? ret : len;
+}
+
+int itg3200_read_irq_status(struct iio_dev *indio_dev)
+{
+       u8 val;
+       int ret;
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_STATUS, &val);
+       if (ret < 0)
+               return ret;
+
+       return val;
+}
+
+int itg3200_set_irq_data_rdy(struct iio_dev *indio_dev, bool enable)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       int ret;
+       u8 msc;
+
+       dev_dbg(&st->i2c->dev, "set data ready %s", enable ? "on" : "off");
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
+       if (ret)
+               goto error_ret;
+
+       if (enable)
+               msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
+       else
+               msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;
+
+       ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
+       if (ret)
+               goto error_ret;
+
+error_ret:
+       return ret;
+}
+
+/* Power down the device */
+static int itg3200_stop_device(struct iio_dev *indio_dev)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       int ret;
+
+       dev_dbg(&st->i2c->dev, "suspend device");
+
+       /* Set device in low power mode */
+       ret = itg3200_write_reg_8(indio_dev,
+                       ITG3200_REG_POWER_MANAGEMENT,
+                       ITG3200_SLEEP);
+
+       if (ret)
+               dev_err(&st->i2c->dev, "problem with turning device off: 
SLEEP");
+
+       return 0;
+}
+
+/* Reset device and internal registers to the power-up-default settings
+ * Use the gyro clock as reference, as suggested by the datasheet */
+static int itg3200_reset(struct iio_dev *indio_dev)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       int ret;
+
+       dev_dbg(&st->i2c->dev, "reset device");
+
+       ret = itg3200_write_reg_8(indio_dev,
+                       ITG3200_REG_POWER_MANAGEMENT,
+                       ITG3200_RESET);
+       if (ret) {
+               dev_err(&st->i2c->dev, "error resetting device");
+               goto error_ret;
+       }
+
+       /* Wait for PLL (1ms according to datasheet) */
+       udelay(1500);
+
+       ret = itg3200_write_reg_8(indio_dev,
+                       ITG3200_REG_IRQ_CONFIG,
+                       ITG3200_IRQ_LATCH_50US_PULSE |
+                       ITG3200_IRQ_LATCH_CLEAR_ANY |
+                       ITG3200_IRQ_DEVICE_RDY_ENABLE |
+                       ITG3200_IRQ_DATA_RDY_ENABLE);
+
+       if (ret)
+               dev_err(&st->i2c->dev, "error init device");
+
+error_ret:
+       return ret;
+}
+
+static ssize_t itg3200_write_reset(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf, size_t len)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       int ret = -EINVAL;
+       if (len < 1)
+               goto error_ret;
+
+       switch (buf[0]) {
+       case '1':
+       case 'y':
+       case 'Y':
+               ret = itg3200_reset(indio_dev);
+               if (ret < 0)
+                       goto error_ret;
+               return len;
+       }
+error_ret:
+       return ret;
+}
+
+static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
+{
+       u8 val;
+       int ret;
+
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
+       if (ret)
+               goto err_ret;
+
+       val |= ITG3200_DLPF_FS_SEL_2000;
+       return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
+
+err_ret:
+       return ret;
+}
+
+static int itg3200_initial_setup(struct iio_dev *indio_dev)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+       int ret;
+
+       u8 val;
+       ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
+       if (ret)
+               goto err_ret;
+
+       if (((val >> 1) & 0x3f) != 0x34) {
+               dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
+               /*
+               ret = -EINVAL;
+               goto err_ret;
+               */
+       }
+
+       ret = itg3200_reset(indio_dev);
+       if (ret)
+               goto err_ret;
+
+       ret = itg3200_enable_full_scale(indio_dev);
+
+err_ret:
+       return ret;
+}
+
+#define ITG3200_TEMP_INFO_MASK (IIO_CHAN_INFO_OFFSET_SHARED_BIT | \
+                                IIO_CHAN_INFO_SCALE_SHARED_BIT)
+#define ITG3200_INFO_MASK      IIO_CHAN_INFO_SCALE_SHARED_BIT
+
+#define ITG3200_ST                                             \
+       { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
+
+static const struct iio_chan_spec itg3200_channels[] = {
+       {
+               .type = IIO_TEMP,
+               .output = 0,
+               .modified = 0,
+               .indexed = 0,
+               .extend_name = NULL,
+               .channel = 0,
+               .channel2 = IIO_NO_MOD,
+               .info_mask = ITG3200_TEMP_INFO_MASK,
+               .address = ITG3200_REG_TEMP_OUT_H,
+               .scan_index = ITG3200_TEMP,
+               .scan_type = ITG3200_ST,
+               .event_mask = 0
+       },
+       {
+               .type = IIO_ANGL_VEL,
+               .output = 0,
+               .modified = 1,
+               .indexed = 0,
+               .extend_name = NULL,
+               .channel = 0,
+               .channel2 = IIO_MOD_X,
+               .info_mask = ITG3200_INFO_MASK,
+               .address = ITG3200_REG_GYRO_XOUT_H,
+               .scan_index = ITG3200_GYRO_X,
+               .scan_type = ITG3200_ST,
+               .event_mask = 0
+       },
+       {
+               .type = IIO_ANGL_VEL,
+               .output = 0,
+               .modified = 1,
+               .indexed = 0,
+               .extend_name = NULL,
+               .channel = 0,
+               .channel2 = IIO_MOD_Y,
+               .info_mask = ITG3200_INFO_MASK,
+               .address = ITG3200_REG_GYRO_YOUT_H,
+               .scan_index = ITG3200_GYRO_Y,
+               .scan_type = ITG3200_ST,
+               .event_mask = 0
+       },
+       {
+               .type = IIO_ANGL_VEL,
+               .output = 0,
+               .modified = 1,
+               .indexed = 0,
+               .extend_name = NULL,
+               .channel = 0,
+               .channel2 = IIO_MOD_Z,
+               .info_mask = ITG3200_INFO_MASK,
+               .address = ITG3200_REG_GYRO_ZOUT_H,
+               .scan_index = ITG3200_GYRO_Z,
+               .scan_type = ITG3200_ST,
+               .event_mask = 0
+       },
+       IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+/* IIO device attributes */
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency,
+               itg3200_write_frequency);
+
+static IIO_DEVICE_ATTR(reset, S_IWUSR, NULL, itg3200_write_reset, 0);
+
+static struct attribute *itg3200_attributes[] = {
+       &iio_dev_attr_sampling_frequency.dev_attr.attr,
+       &iio_dev_attr_reset.dev_attr.attr,
+       NULL
+};
+
+static const struct attribute_group itg3200_attribute_group = {
+       .attrs = itg3200_attributes,
+};
+
+static const struct iio_info itg3200_info = {
+       .read_raw = &itg3200_read_raw,
+       /*
+       .write_raw = &itg3200_write_raw,
+       .read_event_value = &itg3200_read_thresh,
+       .write_event_value = &itg3200_write_thresh,
+       .write_event_config = &itg3200_write_event_config,
+       .read_event_config = &itg3200_read_event_config,
+       */
+       .driver_module = THIS_MODULE,
+       .attrs = &itg3200_attribute_group,
+};
+
+static int __devinit itg3200_probe(struct i2c_client *client,
+               const struct i2c_device_id *id)
+{
+       int ret = 0;
+       struct itg3200_state *st;
+       struct iio_dev *indio_dev;
+
+       dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
+
+       indio_dev = iio_device_alloc(sizeof(*st));
+       if (indio_dev == NULL) {
+               ret =  -ENOMEM;
+               goto error_ret;
+       }
+
+       st = iio_priv(indio_dev);
+
+       i2c_set_clientdata(client, indio_dev);
+       st->i2c = client;
+
+       indio_dev->dev.parent = &client->dev;
+       indio_dev->name = client->dev.driver->name;
+       indio_dev->channels = itg3200_channels;
+       indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
+       indio_dev->info = &itg3200_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+
+       ret = itg3200_buffer_configure(indio_dev);
+       if (ret)
+               goto error_free_dev;
+
+       ret = iio_buffer_register(indio_dev,
+                       indio_dev->channels,
+                       ARRAY_SIZE(itg3200_channels));
+       if (ret)
+               goto error_unconfigure_buffer;
+
+       if (client->irq && gpio_is_valid(irq_to_gpio(client->irq)) > 0) {
+               ret = itg3200_probe_trigger(indio_dev);
+               if (ret)
+                       goto error_unregister_buffer;
+       }
+
+       ret = itg3200_initial_setup(indio_dev);
+       if (ret)
+               goto error_remove_trigger;
+
+       ret = iio_device_register(indio_dev);
+       if (ret)
+               goto error_remove_trigger;
+
+       return 0;
+
+error_remove_trigger:
+       if (client->irq && gpio_is_valid(irq_to_gpio(client->irq)) > 0)
+               itg3200_remove_trigger(indio_dev);
+error_unregister_buffer:
+       iio_buffer_unregister(indio_dev);
+error_unconfigure_buffer:
+       itg3200_buffer_unconfigure(indio_dev);
+error_free_dev:
+       iio_device_free(indio_dev);
+error_ret:
+       return ret;
+}
+
+static int itg3200_remove(struct i2c_client *client)
+{
+       /* int ret; */
+       struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+       iio_device_unregister(indio_dev);
+
+       /*
+       ret = itg3200_stop_device(indio_dev);
+       if (ret)
+               goto err_ret;
+       */
+
+       if (client->irq && gpio_is_valid(irq_to_gpio(client->irq)) > 0)
+               itg3200_remove_trigger(indio_dev);
+
+       iio_buffer_unregister(indio_dev);
+       itg3200_buffer_unconfigure(indio_dev);
+
+       iio_device_free(indio_dev);
+
+       return 0;
+
+       /*
+       err_ret:
+           return ret;
+       */
+}
+
+static const struct i2c_device_id itg3200_id[] = {
+       { "itg3200", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, itg3200_id);
+
+static struct i2c_driver itg3200_driver = {
+       .driver = {
+               .owner  = THIS_MODULE,
+               .name   = "itg3200",
+       },
+       .id_table       = itg3200_id,
+       .probe          = itg3200_probe,
+       .remove         = itg3200_remove,
+};
+
+static int __init itg3200_init(void)
+{
+       return i2c_add_driver(&itg3200_driver);
+}
+module_init(itg3200_init);
+
+static void __exit itg3200_exit(void)
+{
+       i2c_del_driver(&itg3200_driver);
+}
+module_exit(itg3200_exit);
+
+MODULE_AUTHOR("Christian Strobel <christian.stro...@iis.fraunhofer.de>");
+MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/iio/gyro/itg3200_trigger.c 
b/drivers/staging/iio/gyro/itg3200_trigger.c
new file mode 100644
index 0000000..18f10a2
--- /dev/null
+++ b/drivers/staging/iio/gyro/itg3200_trigger.c
@@ -0,0 +1,90 @@
+/*
+ * itg3200_trigger.c -- support InvenSense ITG3200
+ *                      Digital 3-Axis Gyroscope driver
+ *
+ * Copyright (c) 2011 Christian Strobel <christian.stro...@iis.fraunhofer.de>
+ * Copyright (c) 2011 Manuel Stahl <manuel.st...@iis.fraunhofer.de>
+ * Copyright (c) 2012 Thorsten Nowak <thorsten.no...@iis.fraunhofer.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+
+#include "itg3200.h"
+
+static irqreturn_t itg3200_data_rdy_trig_poll(int irq, void *private)
+{
+       struct iio_dev *indio_dev = private;
+       struct itg3200_state *st = iio_priv(indio_dev);
+
+       iio_trigger_poll(st->trig, iio_get_time_ns());
+       return IRQ_HANDLED;
+}
+
+/**
+ * itg3200_data_rdy_trigger_set_state() set datardy interrupt state
+ */
+static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
+       bool state)
+{
+       struct iio_dev *indio_dev = trig->private_data;
+       return itg3200_set_irq_data_rdy(indio_dev, state);
+}
+
+static const struct iio_trigger_ops itg3200_trigger_ops = {
+       .owner = THIS_MODULE,
+       .set_trigger_state = &itg3200_data_rdy_trigger_set_state,
+};
+
+int itg3200_probe_trigger(struct iio_dev *indio_dev)
+{
+       int ret;
+       struct itg3200_state *st = iio_priv(indio_dev);
+
+       ret = request_irq(st->i2c->irq, &itg3200_data_rdy_trig_poll,
+                       IRQF_TRIGGER_HIGH, "itg3200_data_rdy", indio_dev);
+       if (ret)
+               goto error_ret;
+
+       st->trig = iio_trigger_alloc("itg3200-dev%d", indio_dev->id);
+       if (!st->trig) {
+               ret = -ENOMEM;
+               goto error_free_irq;
+       }
+
+       st->trig->dev.parent = &st->i2c->dev;
+       st->trig->ops = &itg3200_trigger_ops;
+       st->trig->private_data = indio_dev;
+       ret = iio_trigger_register(st->trig);
+       if (ret)
+               goto error_free_trig;
+
+       /* select default trigger */
+       indio_dev->trig = st->trig;
+
+       return 0;
+
+error_free_trig:
+       iio_trigger_free(st->trig);
+error_free_irq:
+       free_irq(st->i2c->irq, indio_dev);
+error_ret:
+       return ret;
+}
+
+void itg3200_remove_trigger(struct iio_dev *indio_dev)
+{
+       struct itg3200_state *st = iio_priv(indio_dev);
+
+       iio_trigger_unregister(st->trig);
+       iio_trigger_free(st->trig);
+       free_irq(st->i2c->irq, indio_dev);
+}
-- 
1.7.10.4

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