Initial import

1 files changed, 1209 insertions, 0 deletions

diff --git a/drivers/staging/iio/accel/sca3000_core.c b/drivers/staging/iio/accel/sca3000_core.c
new file mode 100644
index 000000000..b614f272b
--- /dev/null
+++ b/drivers/staging/iio/accel/sca3000_core.c
@@ -0,0 +1,1209 @@
+/*
+ * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI
+ *
+ * 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.
+ *
+ * Copyright (c) 2009 Jonathan Cameron <jic23@kernel.org>
+ *
+ * See industrialio/accels/sca3000.h for comments.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/buffer.h>
+
+#include "sca3000.h"
+
+enum sca3000_variant {
+	d01,
+	e02,
+	e04,
+	e05,
+};
+
+/*
+ * Note where option modes are not defined, the chip simply does not
+ * support any.
+ * Other chips in the sca3000 series use i2c and are not included here.
+ *
+ * Some of these devices are only listed in the family data sheet and
+ * do not actually appear to be available.
+ */
+static const struct sca3000_chip_info sca3000_spi_chip_info_tbl[] = {
+	[d01] = {
+		.scale = 7357,
+		.temp_output = true,
+		.measurement_mode_freq = 250,
+		.option_mode_1 = SCA3000_OP_MODE_BYPASS,
+		.option_mode_1_freq = 250,
+		.mot_det_mult_xz = {50, 100, 200, 350, 650, 1300},
+		.mot_det_mult_y = {50, 100, 150, 250, 450, 850, 1750},
+	},
+	[e02] = {
+		.scale = 9810,
+		.measurement_mode_freq = 125,
+		.option_mode_1 = SCA3000_OP_MODE_NARROW,
+		.option_mode_1_freq = 63,
+		.mot_det_mult_xz = {100, 150, 300, 550, 1050, 2050},
+		.mot_det_mult_y = {50, 100, 200, 350, 700, 1350, 2700},
+	},
+	[e04] = {
+		.scale = 19620,
+		.measurement_mode_freq = 100,
+		.option_mode_1 = SCA3000_OP_MODE_NARROW,
+		.option_mode_1_freq = 50,
+		.option_mode_2 = SCA3000_OP_MODE_WIDE,
+		.option_mode_2_freq = 400,
+		.mot_det_mult_xz = {200, 300, 600, 1100, 2100, 4100},
+		.mot_det_mult_y = {100, 200, 400, 7000, 1400, 2700, 54000},
+	},
+	[e05] = {
+		.scale = 61313,
+		.measurement_mode_freq = 200,
+		.option_mode_1 = SCA3000_OP_MODE_NARROW,
+		.option_mode_1_freq = 50,
+		.option_mode_2 = SCA3000_OP_MODE_WIDE,
+		.option_mode_2_freq = 400,
+		.mot_det_mult_xz = {600, 900, 1700, 3200, 6100, 11900},
+		.mot_det_mult_y = {300, 600, 1200, 2000, 4100, 7800, 15600},
+	},
+};
+
+int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val)
+{
+	st->tx[0] = SCA3000_WRITE_REG(address);
+	st->tx[1] = val;
+	return spi_write(st->us, st->tx, 2);
+}
+
+int sca3000_read_data_short(struct sca3000_state *st,
+			    uint8_t reg_address_high,
+			    int len)
+{
+	struct spi_transfer xfer[2] = {
+		{
+			.len = 1,
+			.tx_buf = st->tx,
+		}, {
+			.len = len,
+			.rx_buf = st->rx,
+		}
+	};
+	st->tx[0] = SCA3000_READ_REG(reg_address_high);
+
+	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
+}
+
+/**
+ * sca3000_reg_lock_on() test if the ctrl register lock is on
+ *
+ * Lock must be held.
+ **/
+static int sca3000_reg_lock_on(struct sca3000_state *st)
+{
+	int ret;
+
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_STATUS, 1);
+	if (ret < 0)
+		return ret;
+
+	return !(st->rx[0] & SCA3000_LOCKED);
+}
+
+/**
+ * __sca3000_unlock_reg_lock() unlock the control registers
+ *
+ * Note the device does not appear to support doing this in a single transfer.
+ * This should only ever be used as part of ctrl reg read.
+ * Lock must be held before calling this
+ **/
+static int __sca3000_unlock_reg_lock(struct sca3000_state *st)
+{
+	struct spi_transfer xfer[3] = {
+		{
+			.len = 2,
+			.cs_change = 1,
+			.tx_buf = st->tx,
+		}, {
+			.len = 2,
+			.cs_change = 1,
+			.tx_buf = st->tx + 2,
+		}, {
+			.len = 2,
+			.tx_buf = st->tx + 4,
+		},
+	};
+	st->tx[0] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
+	st->tx[1] = 0x00;
+	st->tx[2] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
+	st->tx[3] = 0x50;
+	st->tx[4] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK);
+	st->tx[5] = 0xA0;
+
+	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
+}
+
+/**
+ * sca3000_write_ctrl_reg() write to a lock protect ctrl register
+ * @sel: selects which registers we wish to write to
+ * @val: the value to be written
+ *
+ * Certain control registers are protected against overwriting by the lock
+ * register and use a shared write address. This function allows writing of
+ * these registers.
+ * Lock must be held.
+ **/
+static int sca3000_write_ctrl_reg(struct sca3000_state *st,
+				  uint8_t sel,
+				  uint8_t val)
+{
+
+	int ret;
+
+	ret = sca3000_reg_lock_on(st);
+	if (ret < 0)
+		goto error_ret;
+	if (ret) {
+		ret = __sca3000_unlock_reg_lock(st);
+		if (ret)
+			goto error_ret;
+	}
+
+	/* Set the control select register */
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, sel);
+	if (ret)
+		goto error_ret;
+
+	/* Write the actual value into the register */
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_DATA, val);
+
+error_ret:
+	return ret;
+}
+
+/**
+ * sca3000_read_ctrl_reg() read from lock protected control register.
+ *
+ * Lock must be held.
+ **/
+static int sca3000_read_ctrl_reg(struct sca3000_state *st,
+				 u8 ctrl_reg)
+{
+	int ret;
+
+	ret = sca3000_reg_lock_on(st);
+	if (ret < 0)
+		goto error_ret;
+	if (ret) {
+		ret = __sca3000_unlock_reg_lock(st);
+		if (ret)
+			goto error_ret;
+	}
+	/* Set the control select register */
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, ctrl_reg);
+	if (ret)
+		goto error_ret;
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_CTRL_DATA, 1);
+	if (ret)
+		goto error_ret;
+	else
+		return st->rx[0];
+error_ret:
+	return ret;
+}
+
+/**
+ * sca3000_show_rev() - sysfs interface to read the chip revision number
+ **/
+static ssize_t sca3000_show_rev(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	int len = 0, ret;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_REVID, 1);
+	if (ret < 0)
+		goto error_ret;
+	len += sprintf(buf + len,
+		       "major=%d, minor=%d\n",
+		       st->rx[0] & SCA3000_REVID_MAJOR_MASK,
+		       st->rx[0] & SCA3000_REVID_MINOR_MASK);
+error_ret:
+	mutex_unlock(&st->lock);
+
+	return ret ? ret : len;
+}
+
+/**
+ * sca3000_show_available_measurement_modes() display available modes
+ *
+ * This is all read from chip specific data in the driver. Not all
+ * of the sca3000 series support modes other than normal.
+ **/
+static ssize_t
+sca3000_show_available_measurement_modes(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int len = 0;
+
+	len += sprintf(buf + len, "0 - normal mode");
+	switch (st->info->option_mode_1) {
+	case SCA3000_OP_MODE_NARROW:
+		len += sprintf(buf + len, ", 1 - narrow mode");
+		break;
+	case SCA3000_OP_MODE_BYPASS:
+		len += sprintf(buf + len, ", 1 - bypass mode");
+		break;
+	}
+	switch (st->info->option_mode_2) {
+	case SCA3000_OP_MODE_WIDE:
+		len += sprintf(buf + len, ", 2 - wide mode");
+		break;
+	}
+	/* always supported */
+	len += sprintf(buf + len, " 3 - motion detection\n");
+
+	return len;
+}
+
+/**
+ * sca3000_show_measurement_mode() sysfs read of current mode
+ **/
+static ssize_t
+sca3000_show_measurement_mode(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int len = 0, ret;
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+	/* mask bottom 2 bits - only ones that are relevant */
+	st->rx[0] &= 0x03;
+	switch (st->rx[0]) {
+	case SCA3000_MEAS_MODE_NORMAL:
+		len += sprintf(buf + len, "0 - normal mode\n");
+		break;
+	case SCA3000_MEAS_MODE_MOT_DET:
+		len += sprintf(buf + len, "3 - motion detection\n");
+		break;
+	case SCA3000_MEAS_MODE_OP_1:
+		switch (st->info->option_mode_1) {
+		case SCA3000_OP_MODE_NARROW:
+			len += sprintf(buf + len, "1 - narrow mode\n");
+			break;
+		case SCA3000_OP_MODE_BYPASS:
+			len += sprintf(buf + len, "1 - bypass mode\n");
+			break;
+		}
+		break;
+	case SCA3000_MEAS_MODE_OP_2:
+		switch (st->info->option_mode_2) {
+		case SCA3000_OP_MODE_WIDE:
+			len += sprintf(buf + len, "2 - wide mode\n");
+			break;
+		}
+		break;
+	}
+
+error_ret:
+	mutex_unlock(&st->lock);
+
+	return ret ? ret : len;
+}
+
+/**
+ * sca3000_store_measurement_mode() set the current mode
+ **/
+static ssize_t
+sca3000_store_measurement_mode(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf,
+			       size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret;
+	u8 mask = 0x03;
+	u8 val;
+
+	mutex_lock(&st->lock);
+	ret = kstrtou8(buf, 10, &val);
+	if (ret)
+		goto error_ret;
+	if (val > 3) {
+		ret = -EINVAL;
+		goto error_ret;
+	}
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+	st->rx[0] &= ~mask;
+	st->rx[0] |= (val & mask);
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, st->rx[0]);
+	if (ret)
+		goto error_ret;
+	mutex_unlock(&st->lock);
+
+	return len;
+
+error_ret:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+
+/*
+ * Not even vaguely standard attributes so defined here rather than
+ * in the relevant IIO core headers
+ */
+static IIO_DEVICE_ATTR(measurement_mode_available, S_IRUGO,
+		       sca3000_show_available_measurement_modes,
+		       NULL, 0);
+
+static IIO_DEVICE_ATTR(measurement_mode, S_IRUGO | S_IWUSR,
+		       sca3000_show_measurement_mode,
+		       sca3000_store_measurement_mode,
+		       0);
+
+/* More standard attributes */
+
+static IIO_DEVICE_ATTR(revision, S_IRUGO, sca3000_show_rev, NULL, 0);
+
+static const struct iio_event_spec sca3000_event = {
+	.type = IIO_EV_TYPE_MAG,
+	.dir = IIO_EV_DIR_RISING,
+	.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+};
+
+#define SCA3000_CHAN(index, mod)				\
+	{							\
+		.type = IIO_ACCEL,				\
+		.modified = 1,					\
+		.channel2 = mod,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
+		.address = index,				\
+		.scan_index = index,				\
+		.scan_type = {					\
+			.sign = 's',				\
+			.realbits = 11,				\
+			.storagebits = 16,			\
+			.shift = 5,				\
+		},						\
+		.event_spec = &sca3000_event,			\
+		.num_event_specs = 1,				\
+	 }
+
+static const struct iio_chan_spec sca3000_channels[] = {
+	SCA3000_CHAN(0, IIO_MOD_X),
+	SCA3000_CHAN(1, IIO_MOD_Y),
+	SCA3000_CHAN(2, IIO_MOD_Z),
+};
+
+static const struct iio_chan_spec sca3000_channels_with_temp[] = {
+	SCA3000_CHAN(0, IIO_MOD_X),
+	SCA3000_CHAN(1, IIO_MOD_Y),
+	SCA3000_CHAN(2, IIO_MOD_Z),
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_OFFSET),
+		/* No buffer support */
+		.scan_index = -1,
+	},
+};
+
+static u8 sca3000_addresses[3][3] = {
+	[0] = {SCA3000_REG_ADDR_X_MSB, SCA3000_REG_CTRL_SEL_MD_X_TH,
+	       SCA3000_MD_CTRL_OR_X},
+	[1] = {SCA3000_REG_ADDR_Y_MSB, SCA3000_REG_CTRL_SEL_MD_Y_TH,
+	       SCA3000_MD_CTRL_OR_Y},
+	[2] = {SCA3000_REG_ADDR_Z_MSB, SCA3000_REG_CTRL_SEL_MD_Z_TH,
+	       SCA3000_MD_CTRL_OR_Z},
+};
+
+static int sca3000_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val,
+			    int *val2,
+			    long mask)
+{
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret;
+	u8 address;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&st->lock);
+		if (chan->type == IIO_ACCEL) {
+			if (st->mo_det_use_count) {
+				mutex_unlock(&st->lock);
+				return -EBUSY;
+			}
+			address = sca3000_addresses[chan->address][0];
+			ret = sca3000_read_data_short(st, address, 2);
+			if (ret < 0) {
+				mutex_unlock(&st->lock);
+				return ret;
+			}
+			*val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF;
+			*val = ((*val) << (sizeof(*val)*8 - 13)) >>
+				(sizeof(*val)*8 - 13);
+		} else {
+			/* get the temperature when available */
+			ret = sca3000_read_data_short(st,
+				SCA3000_REG_ADDR_TEMP_MSB, 2);
+			if (ret < 0) {
+				mutex_unlock(&st->lock);
+				return ret;
+			}
+			*val = ((st->rx[0] & 0x3F) << 3) |
+			       ((st->rx[1] & 0xE0) >> 5);
+		}
+		mutex_unlock(&st->lock);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		if (chan->type == IIO_ACCEL)
+			*val2 = st->info->scale;
+		else /* temperature */
+			*val2 = 555556;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = -214;
+		*val2 = 600000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * sca3000_read_av_freq() sysfs function to get available frequencies
+ *
+ * The later modes are only relevant to the ring buffer - and depend on current
+ * mode. Note that data sheet gives rather wide tolerances for these so integer
+ * division will give good enough answer and not all chips have them specified
+ * at all.
+ **/
+static ssize_t sca3000_read_av_freq(struct device *dev,
+			     struct device_attribute *attr,
+			     char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int len = 0, ret, val;
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	val = st->rx[0];
+	mutex_unlock(&st->lock);
+	if (ret)
+		goto error_ret;
+
+	switch (val & 0x03) {
+	case SCA3000_MEAS_MODE_NORMAL:
+		len += sprintf(buf + len, "%d %d %d\n",
+			       st->info->measurement_mode_freq,
+			       st->info->measurement_mode_freq/2,
+			       st->info->measurement_mode_freq/4);
+		break;
+	case SCA3000_MEAS_MODE_OP_1:
+		len += sprintf(buf + len, "%d %d %d\n",
+			       st->info->option_mode_1_freq,
+			       st->info->option_mode_1_freq/2,
+			       st->info->option_mode_1_freq/4);
+		break;
+	case SCA3000_MEAS_MODE_OP_2:
+		len += sprintf(buf + len, "%d %d %d\n",
+			       st->info->option_mode_2_freq,
+			       st->info->option_mode_2_freq/2,
+			       st->info->option_mode_2_freq/4);
+		break;
+	}
+	return len;
+error_ret:
+	return ret;
+}
+/**
+ * __sca3000_get_base_freq() obtain mode specific base frequency
+ *
+ * lock must be held
+ **/
+static inline int __sca3000_get_base_freq(struct sca3000_state *st,
+					  const struct sca3000_chip_info *info,
+					  int *base_freq)
+{
+	int ret;
+
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+	switch (0x03 & st->rx[0]) {
+	case SCA3000_MEAS_MODE_NORMAL:
+		*base_freq = info->measurement_mode_freq;
+		break;
+	case SCA3000_MEAS_MODE_OP_1:
+		*base_freq = info->option_mode_1_freq;
+		break;
+	case SCA3000_MEAS_MODE_OP_2:
+		*base_freq = info->option_mode_2_freq;
+		break;
+	}
+error_ret:
+	return ret;
+}
+
+/**
+ * sca3000_read_frequency() sysfs interface to get the current frequency
+ **/
+static ssize_t sca3000_read_frequency(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret, len = 0, base_freq = 0, val;
+
+	mutex_lock(&st->lock);
+	ret = __sca3000_get_base_freq(st, st->info, &base_freq);
+	if (ret)
+		goto error_ret_mut;
+	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
+	mutex_unlock(&st->lock);
+	if (ret)
+		goto error_ret;
+	val = ret;
+	if (base_freq > 0)
+		switch (val & 0x03) {
+		case 0x00:
+		case 0x03:
+			len = sprintf(buf, "%d\n", base_freq);
+			break;
+		case 0x01:
+			len = sprintf(buf, "%d\n", base_freq/2);
+			break;
+		case 0x02:
+			len = sprintf(buf, "%d\n", base_freq/4);
+			break;
+	}
+
+	return len;
+error_ret_mut:
+	mutex_unlock(&st->lock);
+error_ret:
+	return ret;
+}
+
+/**
+ * sca3000_set_frequency() sysfs interface to set the current frequency
+ **/
+static ssize_t sca3000_set_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 sca3000_state *st = iio_priv(indio_dev);
+	int ret, base_freq = 0;
+	int ctrlval;
+	int val;
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&st->lock);
+	/* What mode are we in? */
+	ret = __sca3000_get_base_freq(st, st->info, &base_freq);
+	if (ret)
+		goto error_free_lock;
+
+	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
+	if (ret < 0)
+		goto error_free_lock;
+	ctrlval = ret;
+	/* clear the bits */
+	ctrlval &= ~0x03;
+
+	if (val == base_freq/2) {
+		ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_2;
+	} else if (val == base_freq/4) {
+		ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_4;
+	} else if (val != base_freq) {
+		ret = -EINVAL;
+		goto error_free_lock;
+	}
+	ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
+				     ctrlval);
+error_free_lock:
+	mutex_unlock(&st->lock);
+
+	return ret ? ret : len;
+}
+
+/*
+ * Should only really be registered if ring buffer support is compiled in.
+ * Does no harm however and doing it right would add a fair bit of complexity
+ */
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sca3000_read_av_freq);
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+			      sca3000_read_frequency,
+			      sca3000_set_frequency);
+
+/**
+ * sca3000_read_thresh() - query of a threshold
+ **/
+static int sca3000_read_thresh(struct iio_dev *indio_dev,
+			       const struct iio_chan_spec *chan,
+			       enum iio_event_type type,
+			       enum iio_event_direction dir,
+			       enum iio_event_info info,
+			       int *val, int *val2)
+{
+	int ret, i;
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int num = chan->channel2;
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_ctrl_reg(st, sca3000_addresses[num][1]);
+	mutex_unlock(&st->lock);
+	if (ret < 0)
+		return ret;
+	*val = 0;
+	if (num == 1)
+		for_each_set_bit(i, (unsigned long *)&ret,
+				 ARRAY_SIZE(st->info->mot_det_mult_y))
+			*val += st->info->mot_det_mult_y[i];
+	else
+		for_each_set_bit(i, (unsigned long *)&ret,
+				 ARRAY_SIZE(st->info->mot_det_mult_xz))
+			*val += st->info->mot_det_mult_xz[i];
+
+	return IIO_VAL_INT;
+}
+
+/**
+ * sca3000_write_thresh() control of threshold
+ **/
+static int sca3000_write_thresh(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir,
+				enum iio_event_info info,
+				int val, int val2)
+{
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int num = chan->channel2;
+	int ret;
+	int i;
+	u8 nonlinear = 0;
+
+	if (num == 1) {
+		i = ARRAY_SIZE(st->info->mot_det_mult_y);
+		while (i > 0)
+			if (val >= st->info->mot_det_mult_y[--i]) {
+				nonlinear |= (1 << i);
+				val -= st->info->mot_det_mult_y[i];
+			}
+	} else {
+		i = ARRAY_SIZE(st->info->mot_det_mult_xz);
+		while (i > 0)
+			if (val >= st->info->mot_det_mult_xz[--i]) {
+				nonlinear |= (1 << i);
+				val -= st->info->mot_det_mult_xz[i];
+			}
+	}
+
+	mutex_lock(&st->lock);
+	ret = sca3000_write_ctrl_reg(st, sca3000_addresses[num][1], nonlinear);
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static struct attribute *sca3000_attributes[] = {
+	&iio_dev_attr_revision.dev_attr.attr,
+	&iio_dev_attr_measurement_mode_available.dev_attr.attr,
+	&iio_dev_attr_measurement_mode.dev_attr.attr,
+	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group sca3000_attribute_group = {
+	.attrs = sca3000_attributes,
+};
+
+/**
+ * sca3000_event_handler() - handling ring and non ring events
+ *
+ * Ring related interrupt handler. Depending on event, push to
+ * the ring buffer event chrdev or the event one.
+ *
+ * This function is complicated by the fact that the devices can signify ring
+ * and non ring events via the same interrupt line and they can only
+ * be distinguished via a read of the relevant status register.
+ **/
+static irqreturn_t sca3000_event_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret, val;
+	s64 last_timestamp = iio_get_time_ns();
+
+	/*
+	 * Could lead if badly timed to an extra read of status reg,
+	 * but ensures no interrupt is missed.
+	 */
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1);
+	val = st->rx[0];
+	mutex_unlock(&st->lock);
+	if (ret)
+		goto done;
+
+	sca3000_ring_int_process(val, indio_dev->buffer);
+
+	if (val & SCA3000_INT_STATUS_FREE_FALL)
+		iio_push_event(indio_dev,
+			       IIO_MOD_EVENT_CODE(IIO_ACCEL,
+						  0,
+						  IIO_MOD_X_AND_Y_AND_Z,
+						  IIO_EV_TYPE_MAG,
+						  IIO_EV_DIR_FALLING),
+			       last_timestamp);
+
+	if (val & SCA3000_INT_STATUS_Y_TRIGGER)
+		iio_push_event(indio_dev,
+			       IIO_MOD_EVENT_CODE(IIO_ACCEL,
+						  0,
+						  IIO_MOD_Y,
+						  IIO_EV_TYPE_MAG,
+						  IIO_EV_DIR_RISING),
+			       last_timestamp);
+
+	if (val & SCA3000_INT_STATUS_X_TRIGGER)
+		iio_push_event(indio_dev,
+			       IIO_MOD_EVENT_CODE(IIO_ACCEL,
+						  0,
+						  IIO_MOD_X,
+						  IIO_EV_TYPE_MAG,
+						  IIO_EV_DIR_RISING),
+			       last_timestamp);
+
+	if (val & SCA3000_INT_STATUS_Z_TRIGGER)
+		iio_push_event(indio_dev,
+			       IIO_MOD_EVENT_CODE(IIO_ACCEL,
+						  0,
+						  IIO_MOD_Z,
+						  IIO_EV_TYPE_MAG,
+						  IIO_EV_DIR_RISING),
+			       last_timestamp);
+
+done:
+	return IRQ_HANDLED;
+}
+
+/**
+ * sca3000_read_event_config() what events are enabled
+ **/
+static int sca3000_read_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir)
+{
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret;
+	u8 protect_mask = 0x03;
+	int num = chan->channel2;
+
+	/* read current value of mode register */
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+
+	if ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET)
+		ret = 0;
+	else {
+		ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
+		if (ret < 0)
+			goto error_ret;
+		/* only supporting logical or's for now */
+		ret = !!(ret & sca3000_addresses[num][2]);
+	}
+error_ret:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+/**
+ * sca3000_query_free_fall_mode() is free fall mode enabled
+ **/
+static ssize_t sca3000_query_free_fall_mode(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf)
+{
+	int ret;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int val;
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	val = st->rx[0];
+	mutex_unlock(&st->lock);
+	if (ret < 0)
+		return ret;
+	return sprintf(buf, "%d\n", !!(val & SCA3000_FREE_FALL_DETECT));
+}
+
+/**
+ * sca3000_set_free_fall_mode() simple on off control for free fall int
+ *
+ * In these chips the free fall detector should send an interrupt if
+ * the device falls more than 25cm.  This has not been tested due
+ * to fragile wiring.
+ **/
+static ssize_t sca3000_set_free_fall_mode(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf,
+					  size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct sca3000_state *st = iio_priv(indio_dev);
+	u8 val;
+	int ret;
+	u8 protect_mask = SCA3000_FREE_FALL_DETECT;
+
+	mutex_lock(&st->lock);
+	ret = kstrtou8(buf, 10, &val);
+	if (ret)
+		goto error_ret;
+
+	/* read current value of mode register */
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+
+	/* if off and should be on */
+	if (val && !(st->rx[0] & protect_mask))
+		ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
+					(st->rx[0] | SCA3000_FREE_FALL_DETECT));
+	/* if on and should be off */
+	else if (!val && (st->rx[0] & protect_mask))
+		ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
+					(st->rx[0] & ~protect_mask));
+error_ret:
+	mutex_unlock(&st->lock);
+
+	return ret ? ret : len;
+}
+
+/**
+ * sca3000_write_event_config() simple on off control for motion detector
+ *
+ * This is a per axis control, but enabling any will result in the
+ * motion detector unit being enabled.
+ * N.B. enabling motion detector stops normal data acquisition.
+ * There is a complexity in knowing which mode to return to when
+ * this mode is disabled.  Currently normal mode is assumed.
+ **/
+static int sca3000_write_event_config(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir,
+				      int state)
+{
+	struct sca3000_state *st = iio_priv(indio_dev);
+	int ret, ctrlval;
+	u8 protect_mask = 0x03;
+	int num = chan->channel2;
+
+	mutex_lock(&st->lock);
+	/*
+	 * First read the motion detector config to find out if
+	 * this axis is on
+	 */
+	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
+	if (ret < 0)
+		goto exit_point;
+	ctrlval = ret;
+	/* if off and should be on */
+	if (state && !(ctrlval & sca3000_addresses[num][2])) {
+		ret = sca3000_write_ctrl_reg(st,
+					     SCA3000_REG_CTRL_SEL_MD_CTRL,
+					     ctrlval |
+					     sca3000_addresses[num][2]);
+		if (ret)
+			goto exit_point;
+		st->mo_det_use_count++;
+	} else if (!state && (ctrlval & sca3000_addresses[num][2])) {
+		ret = sca3000_write_ctrl_reg(st,
+					     SCA3000_REG_CTRL_SEL_MD_CTRL,
+					     ctrlval &
+					     ~(sca3000_addresses[num][2]));
+		if (ret)
+			goto exit_point;
+		st->mo_det_use_count--;
+	}
+
+	/* read current value of mode register */
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto exit_point;
+	/* if off and should be on */
+	if ((st->mo_det_use_count)
+	    && ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET))
+		ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
+					(st->rx[0] & ~protect_mask)
+					| SCA3000_MEAS_MODE_MOT_DET);
+	/* if on and should be off */
+	else if (!(st->mo_det_use_count)
+		 && ((st->rx[0] & protect_mask) == SCA3000_MEAS_MODE_MOT_DET))
+		ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
+					(st->rx[0] & ~protect_mask));
+exit_point:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+/* Free fall detector related event attribute */
+static IIO_DEVICE_ATTR_NAMED(accel_xayaz_mag_falling_en,
+			     in_accel_x&y&z_mag_falling_en,
+			     S_IRUGO | S_IWUSR,
+			     sca3000_query_free_fall_mode,
+			     sca3000_set_free_fall_mode,
+			     0);
+
+static IIO_CONST_ATTR_NAMED(accel_xayaz_mag_falling_period,
+			    in_accel_x&y&z_mag_falling_period,
+			    "0.226");
+
+static struct attribute *sca3000_event_attributes[] = {
+	&iio_dev_attr_accel_xayaz_mag_falling_en.dev_attr.attr,
+	&iio_const_attr_accel_xayaz_mag_falling_period.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group sca3000_event_attribute_group = {
+	.attrs = sca3000_event_attributes,
+	.name = "events",
+};
+
+/**
+ * sca3000_clean_setup() get the device into a predictable state
+ *
+ * Devices use flash memory to store many of the register values
+ * and hence can come up in somewhat unpredictable states.
+ * Hence reset everything on driver load.
+ **/
+static int sca3000_clean_setup(struct sca3000_state *st)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+	/* Ensure all interrupts have been acknowledged */
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1);
+	if (ret)
+		goto error_ret;
+
+	/* Turn off all motion detection channels */
+	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
+	if (ret < 0)
+		goto error_ret;
+	ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL,
+				     ret & SCA3000_MD_CTRL_PROT_MASK);
+	if (ret)
+		goto error_ret;
+
+	/* Disable ring buffer */
+	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
+	ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
+				     (ret & SCA3000_OUT_CTRL_PROT_MASK)
+				     | SCA3000_OUT_CTRL_BUF_X_EN
+				     | SCA3000_OUT_CTRL_BUF_Y_EN
+				     | SCA3000_OUT_CTRL_BUF_Z_EN
+				     | SCA3000_OUT_CTRL_BUF_DIV_4);
+	if (ret)
+		goto error_ret;
+	/* Enable interrupts, relevant to mode and set up as active low */
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
+	if (ret)
+		goto error_ret;
+	ret = sca3000_write_reg(st,
+				SCA3000_REG_ADDR_INT_MASK,
+				(ret & SCA3000_INT_MASK_PROT_MASK)
+				| SCA3000_INT_MASK_ACTIVE_LOW);
+	if (ret)
+		goto error_ret;
+	/*
+	 * Select normal measurement mode, free fall off, ring off
+	 * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5
+	 * as that occurs in one of the example on the datasheet
+	 */
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1);
+	if (ret)
+		goto error_ret;
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE,
+				(st->rx[0] & SCA3000_MODE_PROT_MASK));
+	st->bpse = 11;
+
+error_ret:
+	mutex_unlock(&st->lock);
+	return ret;
+}
+
+static const struct iio_info sca3000_info = {
+	.attrs = &sca3000_attribute_group,
+	.read_raw = &sca3000_read_raw,
+	.event_attrs = &sca3000_event_attribute_group,
+	.read_event_value = &sca3000_read_thresh,
+	.write_event_value = &sca3000_write_thresh,
+	.read_event_config = &sca3000_read_event_config,
+	.write_event_config = &sca3000_write_event_config,
+	.driver_module = THIS_MODULE,
+};
+
+static int sca3000_probe(struct spi_device *spi)
+{
+	int ret;
+	struct sca3000_state *st;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+	st->us = spi;
+	mutex_init(&st->lock);
+	st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi)
+					      ->driver_data];
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &sca3000_info;
+	if (st->info->temp_output) {
+		indio_dev->channels = sca3000_channels_with_temp;
+		indio_dev->num_channels =
+			ARRAY_SIZE(sca3000_channels_with_temp);
+	} else {
+		indio_dev->channels = sca3000_channels;
+		indio_dev->num_channels = ARRAY_SIZE(sca3000_channels);
+	}
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	sca3000_configure_ring(indio_dev);
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	if (spi->irq) {
+		ret = request_threaded_irq(spi->irq,
+					   NULL,
+					   &sca3000_event_handler,
+					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					   "sca3000",
+					   indio_dev);
+		if (ret)
+			goto error_unregister_dev;
+	}
+	sca3000_register_ring_funcs(indio_dev);
+	ret = sca3000_clean_setup(st);
+	if (ret)
+		goto error_free_irq;
+	return 0;
+
+error_free_irq:
+	if (spi->irq)
+		free_irq(spi->irq, indio_dev);
+error_unregister_dev:
+	iio_device_unregister(indio_dev);
+	return ret;
+}
+
+static int sca3000_stop_all_interrupts(struct sca3000_state *st)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+	ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1);
+	if (ret)
+		goto error_ret;
+	ret = sca3000_write_reg(st, SCA3000_REG_ADDR_INT_MASK,
+				(st->rx[0] &
+				 ~(SCA3000_INT_MASK_RING_THREE_QUARTER |
+				   SCA3000_INT_MASK_RING_HALF |
+				   SCA3000_INT_MASK_ALL_INTS)));
+error_ret:
+	mutex_unlock(&st->lock);
+	return ret;
+}
+
+static int sca3000_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct sca3000_state *st = iio_priv(indio_dev);
+
+	/* Must ensure no interrupts can be generated after this! */
+	sca3000_stop_all_interrupts(st);
+	if (spi->irq)
+		free_irq(spi->irq, indio_dev);
+	iio_device_unregister(indio_dev);
+	sca3000_unconfigure_ring(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id sca3000_id[] = {
+	{"sca3000_d01", d01},
+	{"sca3000_e02", e02},
+	{"sca3000_e04", e04},
+	{"sca3000_e05", e05},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, sca3000_id);
+
+static struct spi_driver sca3000_driver = {
+	.driver = {
+		.name = "sca3000",
+		.owner = THIS_MODULE,
+	},
+	.probe = sca3000_probe,
+	.remove = sca3000_remove,
+	.id_table = sca3000_id,
+};
+module_spi_driver(sca3000_driver);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("VTI SCA3000 Series Accelerometers SPI driver");
+MODULE_LICENSE("GPL v2");