iio:imu: Add support for the ADIS16480 and similar IMUs

This patch adds support for the ADIS16375, ADIS16480, ADIS16485, ADIS16488 6
degree to 10 degree of freedom IMUs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 925 insertions, 0 deletions

diff --git a/drivers/iio/imu/adis16480.c b/drivers/iio/imu/adis16480.c
new file mode 100644
index 000000000000..a080b3515015
--- /dev/null
+++ b/drivers/iio/imu/adis16480.c
@@ -0,0 +1,925 @@
+/*
+ * ADIS16480 and similar IMUs driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * 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/interrupt.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/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/imu/adis.h>
+
+#include <linux/iio/iio.h>
+#include <linux/debugfs.h>
+
+#define ADIS16480_PAGE_SIZE 0x80
+
+#define ADIS16480_REG(page, reg) ((page) * ADIS16480_PAGE_SIZE + (reg))
+
+#define ADIS16480_REG_PAGE_ID 0x00 /* Same address on each page */
+#define ADIS16480_REG_SEQ_CNT			ADIS16480_REG(0x00, 0x06)
+#define ADIS16480_REG_SYS_E_FLA			ADIS16480_REG(0x00, 0x08)
+#define ADIS16480_REG_DIAG_STS			ADIS16480_REG(0x00, 0x0A)
+#define ADIS16480_REG_ALM_STS			ADIS16480_REG(0x00, 0x0C)
+#define ADIS16480_REG_TEMP_OUT			ADIS16480_REG(0x00, 0x0E)
+#define ADIS16480_REG_X_GYRO_OUT		ADIS16480_REG(0x00, 0x10)
+#define ADIS16480_REG_Y_GYRO_OUT		ADIS16480_REG(0x00, 0x14)
+#define ADIS16480_REG_Z_GYRO_OUT		ADIS16480_REG(0x00, 0x18)
+#define ADIS16480_REG_X_ACCEL_OUT		ADIS16480_REG(0x00, 0x1C)
+#define ADIS16480_REG_Y_ACCEL_OUT		ADIS16480_REG(0x00, 0x20)
+#define ADIS16480_REG_Z_ACCEL_OUT		ADIS16480_REG(0x00, 0x24)
+#define ADIS16480_REG_X_MAGN_OUT		ADIS16480_REG(0x00, 0x28)
+#define ADIS16480_REG_Y_MAGN_OUT		ADIS16480_REG(0x00, 0x2A)
+#define ADIS16480_REG_Z_MAGN_OUT		ADIS16480_REG(0x00, 0x2C)
+#define ADIS16480_REG_BAROM_OUT			ADIS16480_REG(0x00, 0x2E)
+#define ADIS16480_REG_X_DELTAANG_OUT		ADIS16480_REG(0x00, 0x40)
+#define ADIS16480_REG_Y_DELTAANG_OUT		ADIS16480_REG(0x00, 0x44)
+#define ADIS16480_REG_Z_DELTAANG_OUT		ADIS16480_REG(0x00, 0x48)
+#define ADIS16480_REG_X_DELTAVEL_OUT		ADIS16480_REG(0x00, 0x4C)
+#define ADIS16480_REG_Y_DELTAVEL_OUT		ADIS16480_REG(0x00, 0x50)
+#define ADIS16480_REG_Z_DELTAVEL_OUT		ADIS16480_REG(0x00, 0x54)
+#define ADIS16480_REG_PROD_ID			ADIS16480_REG(0x00, 0x7E)
+
+#define ADIS16480_REG_X_GYRO_SCALE		ADIS16480_REG(0x02, 0x04)
+#define ADIS16480_REG_Y_GYRO_SCALE		ADIS16480_REG(0x02, 0x06)
+#define ADIS16480_REG_Z_GYRO_SCALE		ADIS16480_REG(0x02, 0x08)
+#define ADIS16480_REG_X_ACCEL_SCALE		ADIS16480_REG(0x02, 0x0A)
+#define ADIS16480_REG_Y_ACCEL_SCALE		ADIS16480_REG(0x02, 0x0C)
+#define ADIS16480_REG_Z_ACCEL_SCALE		ADIS16480_REG(0x02, 0x0E)
+#define ADIS16480_REG_X_GYRO_BIAS		ADIS16480_REG(0x02, 0x10)
+#define ADIS16480_REG_Y_GYRO_BIAS		ADIS16480_REG(0x02, 0x14)
+#define ADIS16480_REG_Z_GYRO_BIAS		ADIS16480_REG(0x02, 0x18)
+#define ADIS16480_REG_X_ACCEL_BIAS		ADIS16480_REG(0x02, 0x1C)
+#define ADIS16480_REG_Y_ACCEL_BIAS		ADIS16480_REG(0x02, 0x20)
+#define ADIS16480_REG_Z_ACCEL_BIAS		ADIS16480_REG(0x02, 0x24)
+#define ADIS16480_REG_X_HARD_IRON		ADIS16480_REG(0x02, 0x28)
+#define ADIS16480_REG_Y_HARD_IRON		ADIS16480_REG(0x02, 0x2A)
+#define ADIS16480_REG_Z_HARD_IRON		ADIS16480_REG(0x02, 0x2C)
+#define ADIS16480_REG_BAROM_BIAS		ADIS16480_REG(0x02, 0x40)
+#define ADIS16480_REG_FLASH_CNT			ADIS16480_REG(0x02, 0x7C)
+
+#define ADIS16480_REG_GLOB_CMD			ADIS16480_REG(0x03, 0x02)
+#define ADIS16480_REG_FNCTIO_CTRL		ADIS16480_REG(0x03, 0x06)
+#define ADIS16480_REG_GPIO_CTRL			ADIS16480_REG(0x03, 0x08)
+#define ADIS16480_REG_CONFIG			ADIS16480_REG(0x03, 0x0A)
+#define ADIS16480_REG_DEC_RATE			ADIS16480_REG(0x03, 0x0C)
+#define ADIS16480_REG_SLP_CNT			ADIS16480_REG(0x03, 0x10)
+#define ADIS16480_REG_FILTER_BNK0		ADIS16480_REG(0x03, 0x16)
+#define ADIS16480_REG_FILTER_BNK1		ADIS16480_REG(0x03, 0x18)
+#define ADIS16480_REG_ALM_CNFG0			ADIS16480_REG(0x03, 0x20)
+#define ADIS16480_REG_ALM_CNFG1			ADIS16480_REG(0x03, 0x22)
+#define ADIS16480_REG_ALM_CNFG2			ADIS16480_REG(0x03, 0x24)
+#define ADIS16480_REG_XG_ALM_MAGN		ADIS16480_REG(0x03, 0x28)
+#define ADIS16480_REG_YG_ALM_MAGN		ADIS16480_REG(0x03, 0x2A)
+#define ADIS16480_REG_ZG_ALM_MAGN		ADIS16480_REG(0x03, 0x2C)
+#define ADIS16480_REG_XA_ALM_MAGN		ADIS16480_REG(0x03, 0x2E)
+#define ADIS16480_REG_YA_ALM_MAGN		ADIS16480_REG(0x03, 0x30)
+#define ADIS16480_REG_ZA_ALM_MAGN		ADIS16480_REG(0x03, 0x32)
+#define ADIS16480_REG_XM_ALM_MAGN		ADIS16480_REG(0x03, 0x34)
+#define ADIS16480_REG_YM_ALM_MAGN		ADIS16480_REG(0x03, 0x36)
+#define ADIS16480_REG_ZM_ALM_MAGN		ADIS16480_REG(0x03, 0x38)
+#define ADIS16480_REG_BR_ALM_MAGN		ADIS16480_REG(0x03, 0x3A)
+#define ADIS16480_REG_FIRM_REV			ADIS16480_REG(0x03, 0x78)
+#define ADIS16480_REG_FIRM_DM			ADIS16480_REG(0x03, 0x7A)
+#define ADIS16480_REG_FIRM_Y			ADIS16480_REG(0x03, 0x7C)
+
+#define ADIS16480_REG_SERIAL_NUM		ADIS16480_REG(0x04, 0x20)
+
+/* Each filter coefficent bank spans two pages */
+#define ADIS16480_FIR_COEF(page) (x < 60 ? ADIS16480_REG(page, (x) + 8) : \
+		ADIS16480_REG((page) + 1, (x) - 60 + 8))
+#define ADIS16480_FIR_COEF_A(x)			ADIS16480_FIR_COEF(0x05, (x))
+#define ADIS16480_FIR_COEF_B(x)			ADIS16480_FIR_COEF(0x07, (x))
+#define ADIS16480_FIR_COEF_C(x)			ADIS16480_FIR_COEF(0x09, (x))
+#define ADIS16480_FIR_COEF_D(x)			ADIS16480_FIR_COEF(0x0B, (x))
+
+struct adis16480_chip_info {
+	unsigned int num_channels;
+	const struct iio_chan_spec *channels;
+};
+
+struct adis16480 {
+	const struct adis16480_chip_info *chip_info;
+
+	struct adis adis;
+};
+
+#ifdef CONFIG_DEBUG_FS
+
+static ssize_t adis16480_show_firmware_revision(struct file *file,
+		char __user *userbuf, size_t count, loff_t *ppos)
+{
+	struct adis16480 *adis16480 = file->private_data;
+	char buf[6];
+	size_t len;
+	u16 rev;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16480->adis, ADIS16480_REG_FIRM_REV, &rev);
+	if (ret < 0)
+		return ret;
+
+	len = snprintf(buf, sizeof(buf), "%x.%x\n", rev >> 8, rev & 0xff);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
+}
+
+static const struct file_operations adis16480_firmware_revision_fops = {
+	.open = simple_open,
+	.read = adis16480_show_firmware_revision,
+	.llseek = default_llseek,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t adis16480_show_firmware_date(struct file *file,
+		char __user *userbuf, size_t count, loff_t *ppos)
+{
+	struct adis16480 *adis16480 = file->private_data;
+	u16 md, year;
+	char buf[12];
+	size_t len;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16480->adis, ADIS16480_REG_FIRM_Y, &year);
+	if (ret < 0)
+		return ret;
+
+	ret = adis_read_reg_16(&adis16480->adis, ADIS16480_REG_FIRM_DM, &md);
+	if (ret < 0)
+		return ret;
+
+	len = snprintf(buf, sizeof(buf), "%.2x-%.2x-%.4x\n",
+			md >> 8, md & 0xff, year);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
+}
+
+static const struct file_operations adis16480_firmware_date_fops = {
+	.open = simple_open,
+	.read = adis16480_show_firmware_date,
+	.llseek = default_llseek,
+	.owner = THIS_MODULE,
+};
+
+static int adis16480_show_serial_number(void *arg, u64 *val)
+{
+	struct adis16480 *adis16480 = arg;
+	u16 serial;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16480->adis, ADIS16480_REG_SERIAL_NUM,
+		&serial);
+	if (ret < 0)
+		return ret;
+
+	*val = serial;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(adis16480_serial_number_fops,
+	adis16480_show_serial_number, NULL, "0x%.4llx\n");
+
+static int adis16480_show_product_id(void *arg, u64 *val)
+{
+	struct adis16480 *adis16480 = arg;
+	u16 prod_id;
+	int ret;
+
+	ret = adis_read_reg_16(&adis16480->adis, ADIS16480_REG_PROD_ID,
+		&prod_id);
+	if (ret < 0)
+		return ret;
+
+	*val = prod_id;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(adis16480_product_id_fops,
+	adis16480_show_product_id, NULL, "%llu\n");
+
+static int adis16480_show_flash_count(void *arg, u64 *val)
+{
+	struct adis16480 *adis16480 = arg;
+	u32 flash_count;
+	int ret;
+
+	ret = adis_read_reg_32(&adis16480->adis, ADIS16480_REG_FLASH_CNT,
+		&flash_count);
+	if (ret < 0)
+		return ret;
+
+	*val = flash_count;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(adis16480_flash_count_fops,
+	adis16480_show_flash_count, NULL, "%lld\n");
+
+static int adis16480_debugfs_init(struct iio_dev *indio_dev)
+{
+	struct adis16480 *adis16480 = iio_priv(indio_dev);
+
+	debugfs_create_file("firmware_revision", 0400,
+		indio_dev->debugfs_dentry, adis16480,
+		&adis16480_firmware_revision_fops);
+	debugfs_create_file("firmware_date", 0400, indio_dev->debugfs_dentry,
+		adis16480, &adis16480_firmware_date_fops);
+	debugfs_create_file("serial_number", 0400, indio_dev->debugfs_dentry,
+		adis16480, &adis16480_serial_number_fops);
+	debugfs_create_file("product_id", 0400, indio_dev->debugfs_dentry,
+		adis16480, &adis16480_product_id_fops);
+	debugfs_create_file("flash_count", 0400, indio_dev->debugfs_dentry,
+		adis16480, &adis16480_flash_count_fops);
+
+	return 0;
+}
+
+#else
+
+static int adis16480_debugfs_init(struct iio_dev *indio_dev)
+{
+	return 0;
+}
+
+#endif
+
+static int adis16480_set_freq(struct adis16480 *st, unsigned int freq)
+{
+	unsigned int t;
+
+	t = 2460000 / freq;
+	if (t > 2048)
+		t = 2048;
+
+	if (t != 0)
+		t--;
+
+	return adis_write_reg_16(&st->adis, ADIS16480_REG_DEC_RATE, t);
+}
+
+static int adis16480_get_freq(struct adis16480 *st, unsigned int *freq)
+{
+	uint16_t t;
+	int ret;
+
+	ret = adis_read_reg_16(&st->adis, ADIS16480_REG_DEC_RATE, &t);
+	if (ret < 0)
+		return ret;
+
+	*freq = 2460000 / (t + 1);
+
+	return 0;
+}
+
+static ssize_t adis16480_read_frequency(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adis16480 *st = iio_priv(indio_dev);
+	unsigned int freq;
+	int ret;
+
+	ret = adis16480_get_freq(st, &freq);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d.%.3d\n", freq / 1000, freq % 1000);
+}
+
+static ssize_t adis16480_write_frequency(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct adis16480 *st = iio_priv(indio_dev);
+	int freq_int, freq_fract;
+	long val;
+	int ret;
+
+	ret = iio_str_to_fixpoint(buf, 100, &freq_int, &freq_fract);
+	if (ret)
+		return ret;
+
+	val = freq_int * 1000 + freq_fract;
+
+	if (val <= 0)
+		return -EINVAL;
+
+	ret = adis16480_set_freq(st, val);
+
+	return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+			      adis16480_read_frequency,
+			      adis16480_write_frequency);
+
+enum {
+	ADIS16480_SCAN_GYRO_X,
+	ADIS16480_SCAN_GYRO_Y,
+	ADIS16480_SCAN_GYRO_Z,
+	ADIS16480_SCAN_ACCEL_X,
+	ADIS16480_SCAN_ACCEL_Y,
+	ADIS16480_SCAN_ACCEL_Z,
+	ADIS16480_SCAN_MAGN_X,
+	ADIS16480_SCAN_MAGN_Y,
+	ADIS16480_SCAN_MAGN_Z,
+	ADIS16480_SCAN_BARO,
+	ADIS16480_SCAN_TEMP,
+};
+
+static const unsigned int adis16480_calibbias_regs[] = {
+	[ADIS16480_SCAN_GYRO_X] = ADIS16480_REG_X_GYRO_BIAS,
+	[ADIS16480_SCAN_GYRO_Y] = ADIS16480_REG_Y_GYRO_BIAS,
+	[ADIS16480_SCAN_GYRO_Z] = ADIS16480_REG_Z_GYRO_BIAS,
+	[ADIS16480_SCAN_ACCEL_X] = ADIS16480_REG_X_ACCEL_BIAS,
+	[ADIS16480_SCAN_ACCEL_Y] = ADIS16480_REG_Y_ACCEL_BIAS,
+	[ADIS16480_SCAN_ACCEL_Z] = ADIS16480_REG_Z_ACCEL_BIAS,
+	[ADIS16480_SCAN_MAGN_X] = ADIS16480_REG_X_HARD_IRON,
+	[ADIS16480_SCAN_MAGN_Y] = ADIS16480_REG_Y_HARD_IRON,
+	[ADIS16480_SCAN_MAGN_Z] = ADIS16480_REG_Z_HARD_IRON,
+	[ADIS16480_SCAN_BARO] = ADIS16480_REG_BAROM_BIAS,
+};
+
+static const unsigned int adis16480_calibscale_regs[] = {
+	[ADIS16480_SCAN_GYRO_X] = ADIS16480_REG_X_GYRO_SCALE,
+	[ADIS16480_SCAN_GYRO_Y] = ADIS16480_REG_Y_GYRO_SCALE,
+	[ADIS16480_SCAN_GYRO_Z] = ADIS16480_REG_Z_GYRO_SCALE,
+	[ADIS16480_SCAN_ACCEL_X] = ADIS16480_REG_X_ACCEL_SCALE,
+	[ADIS16480_SCAN_ACCEL_Y] = ADIS16480_REG_Y_ACCEL_SCALE,
+	[ADIS16480_SCAN_ACCEL_Z] = ADIS16480_REG_Z_ACCEL_SCALE,
+};
+
+static int adis16480_set_calibbias(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int bias)
+{
+	unsigned int reg = adis16480_calibbias_regs[chan->scan_index];
+	struct adis16480 *st = iio_priv(indio_dev);
+
+	switch (chan->type) {
+	case IIO_MAGN:
+	case IIO_PRESSURE:
+		if (bias < -0x8000 || bias >= 0x8000)
+			return -EINVAL;
+		return adis_write_reg_16(&st->adis, reg, bias);
+	case IIO_ANGL_VEL:
+	case IIO_ACCEL:
+		return adis_write_reg_32(&st->adis, reg, bias);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static int adis16480_get_calibbias(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *bias)
+{
+	unsigned int reg = adis16480_calibbias_regs[chan->scan_index];
+	struct adis16480 *st = iio_priv(indio_dev);
+	uint16_t val16;
+	uint32_t val32;
+	int ret;
+
+	switch (chan->type) {
+	case IIO_MAGN:
+	case IIO_PRESSURE:
+		ret = adis_read_reg_16(&st->adis, reg, &val16);
+		*bias = sign_extend32(val16, 15);
+		break;
+	case IIO_ANGL_VEL:
+	case IIO_ACCEL:
+		ret = adis_read_reg_32(&st->adis, reg, &val32);
+		*bias = sign_extend32(val32, 31);
+		break;
+	default:
+			ret = -EINVAL;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return IIO_VAL_INT;
+}
+
+static int adis16480_set_calibscale(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int scale)
+{
+	unsigned int reg = adis16480_calibscale_regs[chan->scan_index];
+	struct adis16480 *st = iio_priv(indio_dev);
+
+	if (scale < -0x8000 || scale >= 0x8000)
+		return -EINVAL;
+
+	return adis_write_reg_16(&st->adis, reg, scale);
+}
+
+static int adis16480_get_calibscale(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *scale)
+{
+	unsigned int reg = adis16480_calibscale_regs[chan->scan_index];
+	struct adis16480 *st = iio_priv(indio_dev);
+	uint16_t val16;
+	int ret;
+
+	ret = adis_read_reg_16(&st->adis, reg, &val16);
+	if (ret < 0)
+		return ret;
+
+	*scale = sign_extend32(val16, 15);
+	return IIO_VAL_INT;
+}
+
+static const unsigned int adis16480_def_filter_freqs[] = {
+	310,
+	55,
+	275,
+	63,
+};
+
+static const unsigned int ad16480_filter_data[][2] = {
+	[ADIS16480_SCAN_GYRO_X]		= { ADIS16480_REG_FILTER_BNK0, 0 },
+	[ADIS16480_SCAN_GYRO_Y]		= { ADIS16480_REG_FILTER_BNK0, 3 },
+	[ADIS16480_SCAN_GYRO_Z]		= { ADIS16480_REG_FILTER_BNK0, 6 },
+	[ADIS16480_SCAN_ACCEL_X]	= { ADIS16480_REG_FILTER_BNK0, 9 },
+	[ADIS16480_SCAN_ACCEL_Y]	= { ADIS16480_REG_FILTER_BNK0, 12 },
+	[ADIS16480_SCAN_ACCEL_Z]	= { ADIS16480_REG_FILTER_BNK1, 0 },
+	[ADIS16480_SCAN_MAGN_X]		= { ADIS16480_REG_FILTER_BNK1, 3 },
+	[ADIS16480_SCAN_MAGN_Y]		= { ADIS16480_REG_FILTER_BNK1, 6 },
+	[ADIS16480_SCAN_MAGN_Z]		= { ADIS16480_REG_FILTER_BNK1, 9 },
+};
+
+static int adis16480_get_filter_freq(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *freq)
+{
+	struct adis16480 *st = iio_priv(indio_dev);
+	unsigned int enable_mask, offset, reg;
+	uint16_t val;
+	int ret;
+
+	reg = ad16480_filter_data[chan->scan_index][0];
+	offset = ad16480_filter_data[chan->scan_index][1];
+	enable_mask = BIT(offset + 2);
+
+	ret = adis_read_reg_16(&st->adis, reg, &val);
+	if (ret < 0)
+		return ret;
+
+	if (!(val & enable_mask))
+		*freq = 0;
+	else
+		*freq = adis16480_def_filter_freqs[(val >> offset) & 0x3];
+
+	return IIO_VAL_INT;
+}
+
+static int adis16480_set_filter_freq(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int freq)
+{
+	struct adis16480 *st = iio_priv(indio_dev);
+	unsigned int enable_mask, offset, reg;
+	unsigned int diff, best_diff;
+	unsigned int i, best_freq;
+	uint16_t val;
+	int ret;
+
+	reg = ad16480_filter_data[chan->scan_index][0];
+	offset = ad16480_filter_data[chan->scan_index][1];
+	enable_mask = BIT(offset + 2);
+
+	ret = adis_read_reg_16(&st->adis, reg, &val);
+	if (ret < 0)
+		return ret;
+
+	if (freq == 0) {
+		val &= ~enable_mask;
+	} else {
+		best_freq = 0;
+		best_diff = 310;
+		for (i = 0; i < ARRAY_SIZE(adis16480_def_filter_freqs); i++) {
+			if (adis16480_def_filter_freqs[i] >= freq) {
+				diff = adis16480_def_filter_freqs[i] - freq;
+				if (diff < best_diff) {
+					best_diff = diff;
+					best_freq = i;
+				}
+			}
+		}
+
+		val &= ~(0x3 << offset);
+		val |= best_freq << offset;
+		val |= enable_mask;
+	}
+
+	return adis_write_reg_16(&st->adis, reg, val);
+}
+
+static int adis16480_read_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *val, int *val2, long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		return adis_single_conversion(indio_dev, chan, 0, val);
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*val = 0;
+			*val2 = IIO_DEGREE_TO_RAD(20000); /* 0.02 degree/sec */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_ACCEL:
+			*val = 0;
+			*val2 = IIO_G_TO_M_S_2(800); /* 0.8 mg */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_MAGN:
+			*val = 0;
+			*val2 = 100; /* 0.0001 gauss */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_TEMP:
+			*val = 5;
+			*val2 = 650000; /* 5.65 milli degree Celsius */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_PRESSURE:
+			*val = 0;
+			*val2 = 4000; /* 40ubar = 0.004 kPa */
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		/* Only the temperature channel has a offset */
+		*val = 4425; /* 25 degree Celsius = 0x0000 */
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		return adis16480_get_calibbias(indio_dev, chan, val);
+	case IIO_CHAN_INFO_CALIBSCALE:
+		return adis16480_get_calibscale(indio_dev, chan, val);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return adis16480_get_filter_freq(indio_dev, chan, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int adis16480_write_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int val, int val2, long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		return adis16480_set_calibbias(indio_dev, chan, val);
+	case IIO_CHAN_INFO_CALIBSCALE:
+		return adis16480_set_calibscale(indio_dev, chan, val);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		return adis16480_set_filter_freq(indio_dev, chan, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+#define ADIS16480_MOD_CHANNEL(_type, _mod, _address, _si, _info, _bits) \
+	{ \
+		.type = (_type), \
+		.modified = 1, \
+		.channel2 = (_mod), \
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+			IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT | \
+			IIO_CHAN_INFO_SCALE_SHARED_BIT | \
+			_info, \
+		.address = (_address), \
+		.scan_index = (_si), \
+		.scan_type = { \
+			.sign = 's', \
+			.realbits = (_bits), \
+			.storagebits = (_bits), \
+			.endianness = IIO_BE, \
+		}, \
+	}
+
+#define ADIS16480_GYRO_CHANNEL(_mod) \
+	ADIS16480_MOD_CHANNEL(IIO_ANGL_VEL, IIO_MOD_ ## _mod, \
+	ADIS16480_REG_ ## _mod ## _GYRO_OUT, ADIS16480_SCAN_GYRO_ ## _mod, \
+	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT | \
+	IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT, \
+	32)
+
+#define ADIS16480_ACCEL_CHANNEL(_mod) \
+	ADIS16480_MOD_CHANNEL(IIO_ACCEL, IIO_MOD_ ## _mod, \
+	ADIS16480_REG_ ## _mod ## _ACCEL_OUT, ADIS16480_SCAN_ACCEL_ ## _mod, \
+	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT | \
+	IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT, \
+	32)
+
+#define ADIS16480_MAGN_CHANNEL(_mod) \
+	ADIS16480_MOD_CHANNEL(IIO_MAGN, IIO_MOD_ ## _mod, \
+	ADIS16480_REG_ ## _mod ## _MAGN_OUT, ADIS16480_SCAN_MAGN_ ## _mod, \
+	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT, \
+	16)
+
+#define ADIS16480_PRESSURE_CHANNEL() \
+	{ \
+		.type = IIO_PRESSURE, \
+		.indexed = 1, \
+		.channel = 0, \
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+			IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT | \
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \
+		.address = ADIS16480_REG_BAROM_OUT, \
+		.scan_index = ADIS16480_SCAN_BARO, \
+		.scan_type = { \
+			.sign = 's', \
+			.realbits = 32, \
+			.storagebits = 32, \
+			.endianness = IIO_BE, \
+		}, \
+	}
+
+#define ADIS16480_TEMP_CHANNEL() { \
+		.type = IIO_TEMP, \
+		.indexed = 1, \
+		.channel = 0, \
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT | \
+			IIO_CHAN_INFO_OFFSET_SEPARATE_BIT, \
+		.address = ADIS16480_REG_TEMP_OUT, \
+		.scan_index = ADIS16480_SCAN_TEMP, \
+		.scan_type = { \
+			.sign = 's', \
+			.realbits = 16, \
+			.storagebits = 16, \
+			.endianness = IIO_BE, \
+		}, \
+	}
+
+static const struct iio_chan_spec adis16480_channels[] = {
+	ADIS16480_GYRO_CHANNEL(X),
+	ADIS16480_GYRO_CHANNEL(Y),
+	ADIS16480_GYRO_CHANNEL(Z),
+	ADIS16480_ACCEL_CHANNEL(X),
+	ADIS16480_ACCEL_CHANNEL(Y),
+	ADIS16480_ACCEL_CHANNEL(Z),
+	ADIS16480_MAGN_CHANNEL(X),
+	ADIS16480_MAGN_CHANNEL(Y),
+	ADIS16480_MAGN_CHANNEL(Z),
+	ADIS16480_PRESSURE_CHANNEL(),
+	ADIS16480_TEMP_CHANNEL(),
+	IIO_CHAN_SOFT_TIMESTAMP(11)
+};
+
+static const struct iio_chan_spec adis16485_channels[] = {
+	ADIS16480_GYRO_CHANNEL(X),
+	ADIS16480_GYRO_CHANNEL(Y),
+	ADIS16480_GYRO_CHANNEL(Z),
+	ADIS16480_ACCEL_CHANNEL(X),
+	ADIS16480_ACCEL_CHANNEL(Y),
+	ADIS16480_ACCEL_CHANNEL(Z),
+	ADIS16480_TEMP_CHANNEL(),
+	IIO_CHAN_SOFT_TIMESTAMP(7)
+};
+
+enum adis16480_variant {
+	ADIS16375,
+	ADIS16480,
+	ADIS16485,
+	ADIS16488,
+};
+
+static const struct adis16480_chip_info adis16480_chip_info[] = {
+	[ADIS16375] = {
+		.channels = adis16485_channels,
+		.num_channels = ARRAY_SIZE(adis16485_channels),
+	},
+	[ADIS16480] = {
+		.channels = adis16480_channels,
+		.num_channels = ARRAY_SIZE(adis16480_channels),
+	},
+	[ADIS16485] = {
+		.channels = adis16485_channels,
+		.num_channels = ARRAY_SIZE(adis16485_channels),
+	},
+	[ADIS16488] = {
+		.channels = adis16480_channels,
+		.num_channels = ARRAY_SIZE(adis16480_channels),
+	},
+};
+
+static struct attribute *adis16480_attributes[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group adis16480_attribute_group = {
+	.attrs = adis16480_attributes,
+};
+
+static const struct iio_info adis16480_info = {
+	.attrs = &adis16480_attribute_group,
+	.read_raw = &adis16480_read_raw,
+	.write_raw = &adis16480_write_raw,
+	.update_scan_mode = adis_update_scan_mode,
+	.driver_module = THIS_MODULE,
+};
+
+static int adis16480_stop_device(struct iio_dev *indio_dev)
+{
+	struct adis16480 *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = adis_write_reg_16(&st->adis, ADIS16480_REG_SLP_CNT, BIT(9));
+	if (ret)
+		dev_err(&indio_dev->dev,
+			"Could not power down device: %d\n", ret);
+
+	return ret;
+}
+
+static int adis16480_enable_irq(struct adis *adis, bool enable)
+{
+	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
+		enable ? BIT(3) : 0);
+}
+
+static int adis16480_initial_setup(struct iio_dev *indio_dev)
+{
+	struct adis16480 *st = iio_priv(indio_dev);
+	uint16_t prod_id;
+	unsigned int device_id;
+	int ret;
+
+	adis_reset(&st->adis);
+	msleep(70);
+
+	ret = adis_write_reg_16(&st->adis, ADIS16480_REG_GLOB_CMD, BIT(1));
+	if (ret)
+		return ret;
+	msleep(30);
+
+	ret = adis_check_status(&st->adis);
+	if (ret)
+		return ret;
+
+	ret = adis_read_reg_16(&st->adis, ADIS16480_REG_PROD_ID, &prod_id);
+	if (ret)
+		return ret;
+
+	sscanf(indio_dev->name, "adis%u\n", &device_id);
+
+	if (prod_id != device_id)
+		dev_warn(&indio_dev->dev, "Device ID(%u) and product ID(%u) do not match.",
+				device_id, prod_id);
+
+	return 0;
+}
+
+#define ADIS16480_DIAG_STAT_XGYRO_FAIL 0
+#define ADIS16480_DIAG_STAT_YGYRO_FAIL 1
+#define ADIS16480_DIAG_STAT_ZGYRO_FAIL 2
+#define ADIS16480_DIAG_STAT_XACCL_FAIL 3
+#define ADIS16480_DIAG_STAT_YACCL_FAIL 4
+#define ADIS16480_DIAG_STAT_ZACCL_FAIL 5
+#define ADIS16480_DIAG_STAT_XMAGN_FAIL 8
+#define ADIS16480_DIAG_STAT_YMAGN_FAIL 9
+#define ADIS16480_DIAG_STAT_ZMAGN_FAIL 10
+#define ADIS16480_DIAG_STAT_BARO_FAIL 11
+
+static const char * const adis16480_status_error_msgs[] = {
+	[ADIS16480_DIAG_STAT_XGYRO_FAIL] = "X-axis gyroscope self-test failure",
+	[ADIS16480_DIAG_STAT_YGYRO_FAIL] = "Y-axis gyroscope self-test failure",
+	[ADIS16480_DIAG_STAT_ZGYRO_FAIL] = "Z-axis gyroscope self-test failure",
+	[ADIS16480_DIAG_STAT_XACCL_FAIL] = "X-axis accelerometer self-test failure",
+	[ADIS16480_DIAG_STAT_YACCL_FAIL] = "Y-axis accelerometer self-test failure",
+	[ADIS16480_DIAG_STAT_ZACCL_FAIL] = "Z-axis accelerometer self-test failure",
+	[ADIS16480_DIAG_STAT_XMAGN_FAIL] = "X-axis magnetometer self-test failure",
+	[ADIS16480_DIAG_STAT_YMAGN_FAIL] = "Y-axis magnetometer self-test failure",
+	[ADIS16480_DIAG_STAT_ZMAGN_FAIL] = "Z-axis magnetometer self-test failure",
+	[ADIS16480_DIAG_STAT_BARO_FAIL] = "Barometer self-test failure",
+};
+
+static const struct adis_data adis16480_data = {
+	.diag_stat_reg = ADIS16480_REG_DIAG_STS,
+	.glob_cmd_reg = ADIS16480_REG_GLOB_CMD,
+	.has_paging = true,
+
+	.read_delay = 5,
+	.write_delay = 5,
+
+	.status_error_msgs = adis16480_status_error_msgs,
+	.status_error_mask = BIT(ADIS16480_DIAG_STAT_XGYRO_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_YGYRO_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_ZGYRO_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_XACCL_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_YACCL_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_ZACCL_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_XMAGN_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_YMAGN_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_ZMAGN_FAIL) |
+		BIT(ADIS16480_DIAG_STAT_BARO_FAIL),
+
+	.enable_irq = adis16480_enable_irq,
+};
+
+static int adis16480_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct iio_dev *indio_dev;
+	struct adis16480 *st;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st = iio_priv(indio_dev);
+
+	st->chip_info = &adis16480_chip_info[id->driver_data];
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+	indio_dev->info = &adis16480_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = adis_init(&st->adis, indio_dev, spi, &adis16480_data);
+	if (ret)
+		goto error_free_dev;
+
+	ret = adis_setup_buffer_and_trigger(&st->adis, indio_dev, NULL);
+	if (ret)
+		goto error_free_dev;
+
+	ret = adis16480_initial_setup(indio_dev);
+	if (ret)
+		goto error_cleanup_buffer;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_stop_device;
+
+	adis16480_debugfs_init(indio_dev);
+
+	return 0;
+
+error_stop_device:
+	adis16480_stop_device(indio_dev);
+error_cleanup_buffer:
+	adis_cleanup_buffer_and_trigger(&st->adis, indio_dev);
+error_free_dev:
+	iio_device_free(indio_dev);
+	return ret;
+}
+
+static int adis16480_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct adis16480 *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	adis16480_stop_device(indio_dev);
+
+	adis_cleanup_buffer_and_trigger(&st->adis, indio_dev);
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id adis16480_ids[] = {
+	{ "adis16375", ADIS16375 },
+	{ "adis16480", ADIS16480 },
+	{ "adis16485", ADIS16485 },
+	{ "adis16488", ADIS16488 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, adis16480_ids);
+
+static struct spi_driver adis16480_driver = {
+	.driver = {
+		.name = "adis16480",
+		.owner = THIS_MODULE,
+	},
+	.id_table = adis16480_ids,
+	.probe = adis16480_probe,
+	.remove = adis16480_remove,
+};
+module_spi_driver(adis16480_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices ADIS16480 IMU driver");
+MODULE_LICENSE("GPL v2");