]> git.karo-electronics.de Git - mv-sheeva.git/blobdiff - drivers/staging/iio/gyro/adis16251_core.c
Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[mv-sheeva.git] / drivers / staging / iio / gyro / adis16251_core.c
diff --git a/drivers/staging/iio/gyro/adis16251_core.c b/drivers/staging/iio/gyro/adis16251_core.c
new file mode 100644 (file)
index 0000000..a0d400f
--- /dev/null
@@ -0,0 +1,777 @@
+/*
+ * ADIS16251 Programmable Digital Gyroscope Sensor Driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "gyro.h"
+#include "../adc/adc.h"
+
+#include "adis16251.h"
+
+#define DRIVER_NAME            "adis16251"
+
+/* At the moment the spi framework doesn't allow global setting of cs_change.
+ * It's in the likely to be added comment at the top of spi.h.
+ * This means that use cannot be made of spi_write etc.
+ */
+
+/**
+ * adis16251_spi_write_reg_8() - write single byte to a register
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @reg_address: the address of the register to be written
+ * @val: the value to write
+ **/
+int adis16251_spi_write_reg_8(struct device *dev,
+               u8 reg_address,
+               u8 val)
+{
+       int ret;
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+
+       mutex_lock(&st->buf_lock);
+       st->tx[0] = ADIS16251_WRITE_REG(reg_address);
+       st->tx[1] = val;
+
+       ret = spi_write(st->us, st->tx, 2);
+       mutex_unlock(&st->buf_lock);
+
+       return ret;
+}
+
+/**
+ * adis16251_spi_write_reg_16() - write 2 bytes to a pair of registers
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @reg_address: the address of the lower of the two registers. Second register
+ *               is assumed to have address one greater.
+ * @val: value to be written
+ **/
+static int adis16251_spi_write_reg_16(struct device *dev,
+               u8 lower_reg_address,
+               u16 value)
+{
+       int ret;
+       struct spi_message msg;
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+       struct spi_transfer xfers[] = {
+               {
+                       .tx_buf = st->tx,
+                       .bits_per_word = 8,
+                       .len = 2,
+                       .cs_change = 1,
+               }, {
+                       .tx_buf = st->tx + 2,
+                       .bits_per_word = 8,
+                       .len = 2,
+                       .cs_change = 1,
+               },
+       };
+
+       mutex_lock(&st->buf_lock);
+       st->tx[0] = ADIS16251_WRITE_REG(lower_reg_address);
+       st->tx[1] = value & 0xFF;
+       st->tx[2] = ADIS16251_WRITE_REG(lower_reg_address + 1);
+       st->tx[3] = (value >> 8) & 0xFF;
+
+       spi_message_init(&msg);
+       spi_message_add_tail(&xfers[0], &msg);
+       spi_message_add_tail(&xfers[1], &msg);
+       ret = spi_sync(st->us, &msg);
+       mutex_unlock(&st->buf_lock);
+
+       return ret;
+}
+
+/**
+ * adis16251_spi_read_reg_16() - read 2 bytes from a 16-bit register
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @reg_address: the address of the lower of the two registers. Second register
+ *               is assumed to have address one greater.
+ * @val: somewhere to pass back the value read
+ **/
+static int adis16251_spi_read_reg_16(struct device *dev,
+               u8 lower_reg_address,
+               u16 *val)
+{
+       struct spi_message msg;
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+       int ret;
+       struct spi_transfer xfers[] = {
+               {
+                       .tx_buf = st->tx,
+                       .bits_per_word = 8,
+                       .len = 2,
+                       .cs_change = 1,
+               }, {
+                       .rx_buf = st->rx,
+                       .bits_per_word = 8,
+                       .len = 2,
+                       .cs_change = 1,
+               },
+       };
+
+       mutex_lock(&st->buf_lock);
+       st->tx[0] = ADIS16251_READ_REG(lower_reg_address);
+       st->tx[1] = 0;
+       st->tx[2] = 0;
+       st->tx[3] = 0;
+
+       spi_message_init(&msg);
+       spi_message_add_tail(&xfers[0], &msg);
+       spi_message_add_tail(&xfers[1], &msg);
+       ret = spi_sync(st->us, &msg);
+       if (ret) {
+               dev_err(&st->us->dev, "problem when reading 16 bit register 0x%02X",
+                               lower_reg_address);
+               goto error_ret;
+       }
+       *val = (st->rx[0] << 8) | st->rx[1];
+
+error_ret:
+       mutex_unlock(&st->buf_lock);
+       return ret;
+}
+
+/**
+ * adis16251_spi_read_burst() - read all data registers
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @rx: somewhere to pass back the value read (min size is 24 bytes)
+ **/
+int adis16251_spi_read_burst(struct device *dev, u8 *rx)
+{
+       struct spi_message msg;
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+       u32 old_speed_hz = st->us->max_speed_hz;
+       int ret;
+
+       struct spi_transfer xfers[] = {
+               {
+                       .tx_buf = st->tx,
+                       .bits_per_word = 8,
+                       .len = 2,
+                       .cs_change = 0,
+               }, {
+                       .rx_buf = rx,
+                       .bits_per_word = 8,
+                       .len = 24,
+                       .cs_change = 1,
+               },
+       };
+
+       mutex_lock(&st->buf_lock);
+       st->tx[0] = ADIS16251_READ_REG(ADIS16251_GLOB_CMD);
+       st->tx[1] = 0;
+
+       spi_message_init(&msg);
+       spi_message_add_tail(&xfers[0], &msg);
+       spi_message_add_tail(&xfers[1], &msg);
+
+       st->us->max_speed_hz = min(ADIS16251_SPI_BURST, old_speed_hz);
+       spi_setup(st->us);
+
+       ret = spi_sync(st->us, &msg);
+       if (ret)
+               dev_err(&st->us->dev, "problem when burst reading");
+
+       st->us->max_speed_hz = old_speed_hz;
+       spi_setup(st->us);
+       mutex_unlock(&st->buf_lock);
+       return ret;
+}
+
+/**
+ * adis16251_spi_read_sequence() - read a sequence of 16-bit registers
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @tx: register addresses in bytes 0,2,4,6... (min size is 2*num bytes)
+ * @rx: somewhere to pass back the value read (min size is 2*num bytes)
+ **/
+int adis16251_spi_read_sequence(struct device *dev,
+               u8 *tx, u8 *rx, int num)
+{
+       struct spi_message msg;
+       struct spi_transfer *xfers;
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+       int ret, i;
+
+       xfers = kzalloc(num + 1, GFP_KERNEL);
+       if (xfers == NULL) {
+               dev_err(&st->us->dev, "memory alloc failed");
+               ret = -ENOMEM;
+               goto error_ret;
+       }
+
+       /* tx: |add1|addr2|addr3|...|addrN |zero|
+        * rx: |zero|res1 |res2 |...|resN-1|resN| */
+       spi_message_init(&msg);
+       for (i = 0; i < num + 1; i++) {
+               if (i > 0)
+                       xfers[i].rx_buf = st->rx + 2*(i - 1);
+               if (i < num)
+                       xfers[i].tx_buf = st->tx + 2*i;
+               xfers[i].bits_per_word = 8;
+               xfers[i].len = 2;
+               xfers[i].cs_change = 1;
+               spi_message_add_tail(&xfers[i], &msg);
+       }
+
+       mutex_lock(&st->buf_lock);
+
+       ret = spi_sync(st->us, &msg);
+       if (ret)
+               dev_err(&st->us->dev, "problem when reading sequence");
+
+       mutex_unlock(&st->buf_lock);
+       kfree(xfers);
+
+error_ret:
+       return ret;
+}
+
+static ssize_t adis16251_spi_read_signed(struct device *dev,
+               struct device_attribute *attr,
+               char *buf,
+               unsigned bits)
+{
+       int ret;
+       s16 val = 0;
+       unsigned shift = 16 - bits;
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+       ret = adis16251_spi_read_reg_16(dev, this_attr->address, (u16 *)&val);
+       if (ret)
+               return ret;
+
+       if (val & ADIS16251_ERROR_ACTIVE)
+               adis16251_check_status(dev);
+       val = ((s16)(val << shift) >> shift);
+       return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t adis16251_read_12bit_unsigned(struct device *dev,
+               struct device_attribute *attr,
+               char *buf)
+{
+       int ret;
+       u16 val = 0;
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+       ret = adis16251_spi_read_reg_16(dev, this_attr->address, &val);
+       if (ret)
+               return ret;
+
+       if (val & ADIS16251_ERROR_ACTIVE)
+               adis16251_check_status(dev);
+
+       return sprintf(buf, "%u\n", val & 0x0FFF);
+}
+
+static ssize_t adis16251_read_14bit_signed(struct device *dev,
+               struct device_attribute *attr,
+               char *buf)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       ssize_t ret;
+
+       /* Take the iio_dev status lock */
+       mutex_lock(&indio_dev->mlock);
+       ret =  adis16251_spi_read_signed(dev, attr, buf, 14);
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret;
+}
+
+static ssize_t adis16251_read_12bit_signed(struct device *dev,
+               struct device_attribute *attr,
+               char *buf)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       ssize_t ret;
+
+       /* Take the iio_dev status lock */
+       mutex_lock(&indio_dev->mlock);
+       ret =  adis16251_spi_read_signed(dev, attr, buf, 12);
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret;
+}
+
+static ssize_t adis16251_write_16bit(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf,
+               size_t len)
+{
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       int ret;
+       long val;
+
+       ret = strict_strtol(buf, 10, &val);
+       if (ret)
+               goto error_ret;
+       ret = adis16251_spi_write_reg_16(dev, this_attr->address, val);
+
+error_ret:
+       return ret ? ret : len;
+}
+
+static ssize_t adis16251_read_frequency(struct device *dev,
+               struct device_attribute *attr,
+               char *buf)
+{
+       int ret, len = 0;
+       u16 t;
+       int sps;
+       ret = adis16251_spi_read_reg_16(dev,
+                       ADIS16251_SMPL_PRD,
+                       &t);
+       if (ret)
+               return ret;
+       sps =  (t & ADIS16251_SMPL_PRD_TIME_BASE) ? 8 : 256;
+       sps /= (t & ADIS16251_SMPL_PRD_DIV_MASK) + 1;
+       len = sprintf(buf, "%d SPS\n", sps);
+       return len;
+}
+
+static ssize_t adis16251_write_frequency(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf,
+               size_t len)
+{
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct adis16251_state *st = iio_dev_get_devdata(indio_dev);
+       long val;
+       int ret;
+       u8 t;
+
+       ret = strict_strtol(buf, 10, &val);
+       if (ret)
+               return ret;
+
+       mutex_lock(&indio_dev->mlock);
+
+       t = (256 / val);
+       if (t > 0)
+               t--;
+       t &= ADIS16251_SMPL_PRD_DIV_MASK;
+       if ((t & ADIS16251_SMPL_PRD_DIV_MASK) >= 0x0A)
+               st->us->max_speed_hz = ADIS16251_SPI_SLOW;
+       else
+               st->us->max_speed_hz = ADIS16251_SPI_FAST;
+
+       ret = adis16251_spi_write_reg_8(dev,
+                       ADIS16251_SMPL_PRD,
+                       t);
+
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret ? ret : len;
+}
+
+static ssize_t adis16251_write_reset(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf, size_t len)
+{
+       if (len < 1)
+               return -1;
+       switch (buf[0]) {
+       case '1':
+       case 'y':
+       case 'Y':
+               return adis16251_reset(dev);
+       }
+       return -1;
+}
+
+
+
+int adis16251_set_irq(struct device *dev, bool enable)
+{
+       int ret;
+       u16 msc;
+       ret = adis16251_spi_read_reg_16(dev, ADIS16251_MSC_CTRL, &msc);
+       if (ret)
+               goto error_ret;
+
+       msc |= ADIS16251_MSC_CTRL_DATA_RDY_POL_HIGH;
+       if (enable)
+               msc |= ADIS16251_MSC_CTRL_DATA_RDY_EN;
+       else
+               msc &= ~ADIS16251_MSC_CTRL_DATA_RDY_EN;
+
+       ret = adis16251_spi_write_reg_16(dev, ADIS16251_MSC_CTRL, msc);
+       if (ret)
+               goto error_ret;
+
+error_ret:
+       return ret;
+}
+
+int adis16251_reset(struct device *dev)
+{
+       int ret;
+       ret = adis16251_spi_write_reg_8(dev,
+                       ADIS16251_GLOB_CMD,
+                       ADIS16251_GLOB_CMD_SW_RESET);
+       if (ret)
+               dev_err(dev, "problem resetting device");
+
+       return ret;
+}
+
+/* Power down the device */
+int adis16251_stop_device(struct device *dev)
+{
+       int ret;
+       u16 val = ADIS16251_SLP_CNT_POWER_OFF;
+
+       ret = adis16251_spi_write_reg_16(dev, ADIS16251_SLP_CNT, val);
+       if (ret)
+               dev_err(dev, "problem with turning device off: SLP_CNT");
+
+       return ret;
+}
+
+static int adis16251_self_test(struct device *dev)
+{
+       int ret;
+
+       ret = adis16251_spi_write_reg_16(dev,
+                       ADIS16251_MSC_CTRL,
+                       ADIS16251_MSC_CTRL_INT_SELF_TEST);
+       if (ret) {
+               dev_err(dev, "problem starting self test");
+               goto err_ret;
+       }
+
+       adis16251_check_status(dev);
+
+err_ret:
+       return ret;
+}
+
+int adis16251_check_status(struct device *dev)
+{
+       u16 status;
+       int ret;
+
+       ret = adis16251_spi_read_reg_16(dev, ADIS16251_DIAG_STAT, &status);
+
+       if (ret < 0) {
+               dev_err(dev, "Reading status failed\n");
+               goto error_ret;
+       }
+
+       if (!(status & ADIS16251_DIAG_STAT_ERR_MASK)) {
+               ret = 0;
+               goto error_ret;
+       }
+
+       ret = -EFAULT;
+
+       if (status & ADIS16251_DIAG_STAT_ALARM2)
+               dev_err(dev, "Alarm 2 active\n");
+       if (status & ADIS16251_DIAG_STAT_ALARM1)
+               dev_err(dev, "Alarm 1 active\n");
+       if (status & ADIS16251_DIAG_STAT_SELF_TEST)
+               dev_err(dev, "Self test error\n");
+       if (status & ADIS16251_DIAG_STAT_OVERFLOW)
+               dev_err(dev, "Sensor overrange\n");
+       if (status & ADIS16251_DIAG_STAT_SPI_FAIL)
+               dev_err(dev, "SPI failure\n");
+       if (status & ADIS16251_DIAG_STAT_FLASH_UPT)
+               dev_err(dev, "Flash update failed\n");
+       if (status & ADIS16251_DIAG_STAT_POWER_HIGH)
+               dev_err(dev, "Power supply above 5.25V\n");
+       if (status & ADIS16251_DIAG_STAT_POWER_LOW)
+               dev_err(dev, "Power supply below 4.75V\n");
+
+error_ret:
+       return ret;
+}
+
+static int adis16251_initial_setup(struct adis16251_state *st)
+{
+       int ret;
+       u16 smp_prd;
+       struct device *dev = &st->indio_dev->dev;
+
+       /* use low spi speed for init */
+       st->us->max_speed_hz = ADIS16251_SPI_SLOW;
+       st->us->mode = SPI_MODE_3;
+       spi_setup(st->us);
+
+       /* Disable IRQ */
+       ret = adis16251_set_irq(dev, false);
+       if (ret) {
+               dev_err(dev, "disable irq failed");
+               goto err_ret;
+       }
+
+       /* Do self test */
+
+       /* Read status register to check the result */
+       ret = adis16251_check_status(dev);
+       if (ret) {
+               adis16251_reset(dev);
+               dev_err(dev, "device not playing ball -> reset");
+               msleep(ADIS16251_STARTUP_DELAY);
+               ret = adis16251_check_status(dev);
+               if (ret) {
+                       dev_err(dev, "giving up");
+                       goto err_ret;
+               }
+       }
+
+       printk(KERN_INFO DRIVER_NAME ": at CS%d (irq %d)\n",
+                       st->us->chip_select, st->us->irq);
+
+       /* use high spi speed if possible */
+       ret = adis16251_spi_read_reg_16(dev, ADIS16251_SMPL_PRD, &smp_prd);
+       if (!ret && (smp_prd & ADIS16251_SMPL_PRD_DIV_MASK) < 0x0A) {
+               st->us->max_speed_hz = ADIS16251_SPI_SLOW;
+               spi_setup(st->us);
+       }
+
+err_ret:
+       return ret;
+}
+
+static IIO_DEV_ATTR_IN_NAMED_RAW(0, supply, adis16251_read_12bit_signed,
+               ADIS16251_SUPPLY_OUT);
+static IIO_CONST_ATTR(in0_supply_scale, "0.0018315");
+
+static IIO_DEV_ATTR_GYRO(adis16251_read_14bit_signed,
+               ADIS16251_GYRO_OUT);
+static IIO_DEV_ATTR_GYRO_SCALE(S_IWUSR | S_IRUGO,
+               adis16251_read_12bit_signed,
+               adis16251_write_16bit,
+               ADIS16251_GYRO_SCALE);
+static IIO_DEV_ATTR_GYRO_OFFSET(S_IWUSR | S_IRUGO,
+               adis16251_read_12bit_signed,
+               adis16251_write_16bit,
+               ADIS16251_GYRO_OFF);
+
+static IIO_DEV_ATTR_TEMP_RAW(adis16251_read_12bit_signed);
+static IIO_CONST_ATTR(temp_offset, "25 K");
+static IIO_CONST_ATTR(temp_scale, "0.1453 K");
+
+static IIO_DEV_ATTR_IN_NAMED_RAW(1, aux, adis16251_read_12bit_unsigned,
+               ADIS16251_AUX_ADC);
+static IIO_CONST_ATTR(in1_aux_scale, "0.0006105");
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+               adis16251_read_frequency,
+               adis16251_write_frequency);
+static IIO_DEV_ATTR_ANGL(adis16251_read_14bit_signed,
+               ADIS16251_ANGL_OUT);
+
+static IIO_DEV_ATTR_RESET(adis16251_write_reset);
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("0.129 ~ 256");
+
+static IIO_CONST_ATTR(name, "adis16251");
+
+static struct attribute *adis16251_event_attributes[] = {
+       NULL
+};
+
+static struct attribute_group adis16251_event_attribute_group = {
+       .attrs = adis16251_event_attributes,
+};
+
+static struct attribute *adis16251_attributes[] = {
+       &iio_dev_attr_in0_supply_raw.dev_attr.attr,
+       &iio_const_attr_in0_supply_scale.dev_attr.attr,
+       &iio_dev_attr_gyro_raw.dev_attr.attr,
+       &iio_dev_attr_gyro_scale.dev_attr.attr,
+       &iio_dev_attr_gyro_offset.dev_attr.attr,
+       &iio_dev_attr_angl_raw.dev_attr.attr,
+       &iio_dev_attr_temp_raw.dev_attr.attr,
+       &iio_const_attr_temp_offset.dev_attr.attr,
+       &iio_const_attr_temp_scale.dev_attr.attr,
+       &iio_dev_attr_in1_aux_raw.dev_attr.attr,
+       &iio_const_attr_in1_aux_scale.dev_attr.attr,
+       &iio_dev_attr_sampling_frequency.dev_attr.attr,
+       &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+       &iio_dev_attr_reset.dev_attr.attr,
+       &iio_const_attr_name.dev_attr.attr,
+       NULL
+};
+
+static const struct attribute_group adis16251_attribute_group = {
+       .attrs = adis16251_attributes,
+};
+
+static int __devinit adis16251_probe(struct spi_device *spi)
+{
+       int ret, regdone = 0;
+       struct adis16251_state *st = kzalloc(sizeof *st, GFP_KERNEL);
+       if (!st) {
+               ret =  -ENOMEM;
+               goto error_ret;
+       }
+       /* this is only used for removal purposes */
+       spi_set_drvdata(spi, st);
+
+       /* Allocate the comms buffers */
+       st->rx = kzalloc(sizeof(*st->rx)*ADIS16251_MAX_RX, GFP_KERNEL);
+       if (st->rx == NULL) {
+               ret = -ENOMEM;
+               goto error_free_st;
+       }
+       st->tx = kzalloc(sizeof(*st->tx)*ADIS16251_MAX_TX, GFP_KERNEL);
+       if (st->tx == NULL) {
+               ret = -ENOMEM;
+               goto error_free_rx;
+       }
+       st->us = spi;
+       mutex_init(&st->buf_lock);
+       /* setup the industrialio driver allocated elements */
+       st->indio_dev = iio_allocate_device();
+       if (st->indio_dev == NULL) {
+               ret = -ENOMEM;
+               goto error_free_tx;
+       }
+
+       st->indio_dev->dev.parent = &spi->dev;
+       st->indio_dev->num_interrupt_lines = 1;
+       st->indio_dev->event_attrs = &adis16251_event_attribute_group;
+       st->indio_dev->attrs = &adis16251_attribute_group;
+       st->indio_dev->dev_data = (void *)(st);
+       st->indio_dev->driver_module = THIS_MODULE;
+       st->indio_dev->modes = INDIO_DIRECT_MODE;
+
+       ret = adis16251_configure_ring(st->indio_dev);
+       if (ret)
+               goto error_free_dev;
+
+       ret = iio_device_register(st->indio_dev);
+       if (ret)
+               goto error_unreg_ring_funcs;
+       regdone = 1;
+
+       ret = adis16251_initialize_ring(st->indio_dev->ring);
+       if (ret) {
+               printk(KERN_ERR "failed to initialize the ring\n");
+               goto error_unreg_ring_funcs;
+       }
+
+       if (spi->irq && gpio_is_valid(irq_to_gpio(spi->irq)) > 0) {
+               ret = iio_register_interrupt_line(spi->irq,
+                               st->indio_dev,
+                               0,
+                               IRQF_TRIGGER_RISING,
+                               "adis16251");
+               if (ret)
+                       goto error_uninitialize_ring;
+
+               ret = adis16251_probe_trigger(st->indio_dev);
+               if (ret)
+                       goto error_unregister_line;
+       }
+
+       /* Get the device into a sane initial state */
+       ret = adis16251_initial_setup(st);
+       if (ret)
+               goto error_remove_trigger;
+       return 0;
+
+error_remove_trigger:
+       if (st->indio_dev->modes & INDIO_RING_TRIGGERED)
+               adis16251_remove_trigger(st->indio_dev);
+error_unregister_line:
+       if (st->indio_dev->modes & INDIO_RING_TRIGGERED)
+               iio_unregister_interrupt_line(st->indio_dev, 0);
+error_uninitialize_ring:
+       adis16251_uninitialize_ring(st->indio_dev->ring);
+error_unreg_ring_funcs:
+       adis16251_unconfigure_ring(st->indio_dev);
+error_free_dev:
+       if (regdone)
+               iio_device_unregister(st->indio_dev);
+       else
+               iio_free_device(st->indio_dev);
+error_free_tx:
+       kfree(st->tx);
+error_free_rx:
+       kfree(st->rx);
+error_free_st:
+       kfree(st);
+error_ret:
+       return ret;
+}
+
+/* fixme, confirm ordering in this function */
+static int adis16251_remove(struct spi_device *spi)
+{
+       int ret;
+       struct adis16251_state *st = spi_get_drvdata(spi);
+       struct iio_dev *indio_dev = st->indio_dev;
+
+       ret = adis16251_stop_device(&(indio_dev->dev));
+       if (ret)
+               goto err_ret;
+
+       flush_scheduled_work();
+
+       adis16251_remove_trigger(indio_dev);
+       if (spi->irq && gpio_is_valid(irq_to_gpio(spi->irq)) > 0)
+               iio_unregister_interrupt_line(indio_dev, 0);
+
+       adis16251_uninitialize_ring(indio_dev->ring);
+       adis16251_unconfigure_ring(indio_dev);
+       iio_device_unregister(indio_dev);
+       kfree(st->tx);
+       kfree(st->rx);
+       kfree(st);
+
+       return 0;
+
+err_ret:
+       return ret;
+}
+
+static struct spi_driver adis16251_driver = {
+       .driver = {
+               .name = "adis16251",
+               .owner = THIS_MODULE,
+       },
+       .probe = adis16251_probe,
+       .remove = __devexit_p(adis16251_remove),
+};
+
+static __init int adis16251_init(void)
+{
+       return spi_register_driver(&adis16251_driver);
+}
+module_init(adis16251_init);
+
+static __exit void adis16251_exit(void)
+{
+       spi_unregister_driver(&adis16251_driver);
+}
+module_exit(adis16251_exit);
+
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_DESCRIPTION("Analog Devices ADIS16251 Digital Gyroscope Sensor SPI driver");
+MODULE_LICENSE("GPL v2");