iio:common: Add STMicroelectronics common library

This patch add a generic library for STMicroelectronics 3-axis sensors.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/common/Kconfig

@@ -3,3 +3,4 @@
 #
 
 source "drivers/iio/common/hid-sensors/Kconfig"
+source "drivers/iio/common/st_sensors/Kconfig"

drivers/iio/common/Makefile

@@ -7,3 +7,4 @@
 #
 
 obj-y += hid-sensors/
+obj-y += st_sensors/

drivers/iio/common/st_sensors/Kconfig

+#
+# STMicroelectronics sensors common library
+#
+
+config IIO_ST_SENSORS_I2C
+	tristate
+
+config IIO_ST_SENSORS_SPI
+	tristate
+
+config IIO_ST_SENSORS_CORE
+	tristate
+	select IIO_ST_SENSORS_I2C if I2C
+	select IIO_ST_SENSORS_SPI if SPI_MASTER

drivers/iio/common/st_sensors/Makefile

+#
+# Makefile for the STMicroelectronics sensor common modules.
+#
+
+obj-$(CONFIG_IIO_ST_SENSORS_I2C) += st_sensors_i2c.o
+obj-$(CONFIG_IIO_ST_SENSORS_SPI) += st_sensors_spi.o
+obj-$(CONFIG_IIO_ST_SENSORS_CORE) += st_sensors.o
+st_sensors-y := st_sensors_core.o
+st_sensors-$(CONFIG_IIO_BUFFER) += st_sensors_buffer.o
+st_sensors-$(CONFIG_IIO_TRIGGER) += st_sensors_trigger.o

drivers/iio/common/st_sensors/st_sensors_buffer.c

+/*
+ * STMicroelectronics sensors buffer library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/interrupt.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/irqreturn.h>
+
+#include <linux/iio/common/st_sensors.h>
+
+
+int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
+{
+	int i, n = 0, len;
+	u8 addr[ST_SENSORS_NUMBER_DATA_CHANNELS];
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	for (i = 0; i < ST_SENSORS_NUMBER_DATA_CHANNELS; i++) {
+		if (test_bit(i, indio_dev->active_scan_mask)) {
+			addr[n] = indio_dev->channels[i].address;
+			n++;
+		}
+	}
+	switch (n) {
+	case 1:
+		len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+			addr[0], ST_SENSORS_BYTE_FOR_CHANNEL, buf,
+			sdata->multiread_bit);
+		break;
+	case 2:
+		if ((addr[1] - addr[0]) == ST_SENSORS_BYTE_FOR_CHANNEL) {
+			len = sdata->tf->read_multiple_byte(&sdata->tb,
+					sdata->dev, addr[0],
+					ST_SENSORS_BYTE_FOR_CHANNEL*n,
+					buf, sdata->multiread_bit);
+		} else {
+			u8 rx_array[ST_SENSORS_BYTE_FOR_CHANNEL*
+				    ST_SENSORS_NUMBER_DATA_CHANNELS];
+			len = sdata->tf->read_multiple_byte(&sdata->tb,
+				sdata->dev, addr[0],
+				ST_SENSORS_BYTE_FOR_CHANNEL*
+				ST_SENSORS_NUMBER_DATA_CHANNELS,
+				rx_array, sdata->multiread_bit);
+			if (len < 0)
+				goto read_data_channels_error;
+
+			for (i = 0; i < n * ST_SENSORS_NUMBER_DATA_CHANNELS;
+									i++) {
+				if (i < n)
+					buf[i] = rx_array[i];
+				else
+					buf[i] = rx_array[n + i];
+			}
+			len = ST_SENSORS_BYTE_FOR_CHANNEL*n;
+		}
+		break;
+	case 3:
+		len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+			addr[0], ST_SENSORS_BYTE_FOR_CHANNEL*
+			ST_SENSORS_NUMBER_DATA_CHANNELS,
+			buf, sdata->multiread_bit);
+		break;
+	default:
+		len = -EINVAL;
+		goto read_data_channels_error;
+	}
+	if (len != ST_SENSORS_BYTE_FOR_CHANNEL*n) {
+		len = -EIO;
+		goto read_data_channels_error;
+	}
+
+read_data_channels_error:
+	return len;
+}
+EXPORT_SYMBOL(st_sensors_get_buffer_element);
+
+irqreturn_t st_sensors_trigger_handler(int irq, void *p)
+{
+	int len;
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
+	if (len < 0)
+		goto st_sensors_get_buffer_element_error;
+
+	if (indio_dev->scan_timestamp)
+		*(s64 *)((u8 *)sdata->buffer_data +
+				ALIGN(len, sizeof(s64))) = pf->timestamp;
+
+	iio_push_to_buffers(indio_dev, sdata->buffer_data);
+
+st_sensors_get_buffer_element_error:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(st_sensors_trigger_handler);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer");
+MODULE_LICENSE("GPL v2");

drivers/iio/common/st_sensors/st_sensors_core.c

+/*
+ * STMicroelectronics sensors core library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <asm/unaligned.h>
+
+#include <linux/iio/common/st_sensors.h>
+
+
+#define ST_SENSORS_WAI_ADDRESS		0x0f
+
+static int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
+						u8 reg_addr, u8 mask, u8 data)
+{
+	int err;
+	u8 new_data;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	err = sdata->tf->read_byte(&sdata->tb, sdata->dev, reg_addr, &new_data);
+	if (err < 0)
+		goto st_sensors_write_data_with_mask_error;
+
+	new_data = ((new_data & (~mask)) | ((data << __ffs(mask)) & mask));
+	err = sdata->tf->write_byte(&sdata->tb, sdata->dev, reg_addr, new_data);
+
+st_sensors_write_data_with_mask_error:
+	return err;
+}
+
+int st_sensors_get_sampling_frequency_avl(struct iio_dev *indio_dev, char *buf)
+{
+	int i, len = 0;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	mutex_lock(&indio_dev->mlock);
+	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
+		if (sdata->sensor->odr.odr_avl[i].hz == 0)
+			break;
+
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+					sdata->sensor->odr.odr_avl[i].hz);
+	}
+	mutex_unlock(&indio_dev->mlock);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+EXPORT_SYMBOL(st_sensors_get_sampling_frequency_avl);
+
+int st_sensors_get_scale_avl(struct iio_dev *indio_dev, char *buf)
+{
+	int i, len = 0;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	mutex_lock(&indio_dev->mlock);
+	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
+		if (sdata->sensor->fs.fs_avl[i].num == 0)
+			break;
+
+		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+					sdata->sensor->fs.fs_avl[i].gain);
+	}
+	mutex_unlock(&indio_dev->mlock);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+EXPORT_SYMBOL(st_sensors_get_scale_avl);
+
+static int st_sensors_match_odr(struct st_sensors *sensor,
+			unsigned int odr, struct st_sensor_odr_avl *odr_out)
+{
+	int i, ret = -EINVAL;
+
+	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
+		if (sensor->odr.odr_avl[i].hz == 0)
+			goto st_sensors_match_odr_error;
+
+		if (sensor->odr.odr_avl[i].hz == odr) {
+			odr_out->hz = sensor->odr.odr_avl[i].hz;
+			odr_out->value = sensor->odr.odr_avl[i].value;
+			ret = 0;
+			break;
+		}
+	}
+
+st_sensors_match_odr_error:
+	return ret;
+}
+
+int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr)
+{
+	int err;
+	struct st_sensor_odr_avl odr_out;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	err = st_sensors_match_odr(sdata->sensor, odr, &odr_out);
+	if (err < 0)
+		goto st_sensors_match_odr_error;
+
+	if ((sdata->sensor->odr.addr == sdata->sensor->pw.addr) &&
+			(sdata->sensor->odr.mask == sdata->sensor->pw.mask)) {
+		if (sdata->enabled == true) {
+			err = st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor->odr.addr,
+				sdata->sensor->odr.mask,
+				odr_out.value);
+		} else {
+			err = 0;
+		}
+	} else {
+		err = st_sensors_write_data_with_mask(indio_dev,
+			sdata->sensor->odr.addr, sdata->sensor->odr.mask,
+			odr_out.value);
+	}
+	if (err >= 0)
+		sdata->odr = odr_out.hz;
+
+st_sensors_match_odr_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_set_odr);
+
+static int st_sensors_match_fs(struct st_sensors *sensor,
+					unsigned int fs, int *index_fs_avl)
+{
+	int i, ret = -EINVAL;
+
+	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
+		if (sensor->fs.fs_avl[i].num == 0)
+			goto st_sensors_match_odr_error;
+
+		if (sensor->fs.fs_avl[i].num == fs) {
+			*index_fs_avl = i;
+			ret = 0;
+			break;
+		}
+	}
+
+st_sensors_match_odr_error:
+	return ret;
+}
+
+static int st_sensors_set_fullscale(struct iio_dev *indio_dev, unsigned int fs)
+{
+	int err, i;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	err = st_sensors_match_fs(sdata->sensor, fs, &i);
+	if (err < 0)
+		goto st_accel_set_fullscale_error;
+
+	err = st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor->fs.addr,
+				sdata->sensor->fs.mask,
+				sdata->sensor->fs.fs_avl[i].value);
+	if (err < 0)
+		goto st_accel_set_fullscale_error;
+
+	sdata->current_fullscale = (struct st_sensor_fullscale_avl *)
+						&sdata->sensor->fs.fs_avl[i];
+	return err;
+
+st_accel_set_fullscale_error:
+	dev_err(&indio_dev->dev, "failed to set new fullscale.\n");
+	return err;
+}
+
+int st_sensors_set_enable(struct iio_dev *indio_dev, bool enable)
+{
+	bool found;
+	u8 tmp_value;
+	int err = -EINVAL;
+	struct st_sensor_odr_avl odr_out;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	if (enable) {
+		found = false;
+		tmp_value = sdata->sensor->pw.value_on;
+		if ((sdata->sensor->odr.addr == sdata->sensor->pw.addr) &&
+			(sdata->sensor->odr.mask == sdata->sensor->pw.mask)) {
+			err = st_sensors_match_odr(sdata->sensor,
+							sdata->odr, &odr_out);
+			if (err < 0)
+				goto set_enable_error;
+			tmp_value = odr_out.value;
+			found = true;
+		}
+		err = st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor->pw.addr,
+				sdata->sensor->pw.mask, tmp_value);
+		if (err < 0)
+			goto set_enable_error;
+
+		sdata->enabled = true;
+
+		if (found)
+			sdata->odr = odr_out.hz;
+	} else {
+		err = st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor->pw.addr,
+				sdata->sensor->pw.mask,
+				sdata->sensor->pw.value_off);
+		if (err < 0)
+			goto set_enable_error;
+
+		sdata->enabled = false;
+	}
+
+set_enable_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_set_enable);
+
+int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	return st_sensors_write_data_with_mask(indio_dev,
+				sdata->sensor->enable_axis.addr,
+				sdata->sensor->enable_axis.mask, axis_enable);
+}
+EXPORT_SYMBOL(st_sensors_set_axis_enable);
+
+int st_sensors_init_sensor(struct iio_dev *indio_dev)
+{
+	int err;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	mutex_init(&sdata->tb.buf_lock);
+
+	err = st_sensors_set_enable(indio_dev, false);
+	if (err < 0)
+		goto init_error;
+
+	err = st_sensors_set_fullscale(indio_dev,
+						sdata->current_fullscale->num);
+	if (err < 0)
+		goto init_error;
+
+	err = st_sensors_set_odr(indio_dev, sdata->odr);
+	if (err < 0)
+		goto init_error;
+
+	/* set BDU */
+	err = st_sensors_write_data_with_mask(indio_dev,
+			sdata->sensor->bdu.addr, sdata->sensor->bdu.mask, true);
+	if (err < 0)
+		goto init_error;
+
+	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
+
+init_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_init_sensor);
+
+int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
+{
+	int err;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	/* Enable/Disable the interrupt generator 1. */
+	if (sdata->sensor->drdy_irq.ig1.en_addr > 0) {
+		err = st_sensors_write_data_with_mask(indio_dev,
+			sdata->sensor->drdy_irq.ig1.en_addr,
+			sdata->sensor->drdy_irq.ig1.en_mask, (int)enable);
+		if (err < 0)
+			goto st_accel_set_dataready_irq_error;
+	}
+
+	/* Enable/Disable the interrupt generator for data ready. */
+	err = st_sensors_write_data_with_mask(indio_dev,
+			sdata->sensor->drdy_irq.addr,
+			sdata->sensor->drdy_irq.mask, (int)enable);
+
+st_accel_set_dataready_irq_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_set_dataready_irq);
+
+int st_sensors_set_fullscale_by_gain(struct iio_dev *indio_dev, int scale)
+{
+	int err = -EINVAL, i;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
+		if ((sdata->sensor->fs.fs_avl[i].gain == scale) &&
+				(sdata->sensor->fs.fs_avl[i].gain != 0)) {
+			err = 0;
+			break;
+		}
+	}
+	if (err < 0)
+		goto st_sensors_match_scale_error;
+
+	err = st_sensors_set_fullscale(indio_dev,
+					sdata->sensor->fs.fs_avl[i].num);
+
+st_sensors_match_scale_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_set_fullscale_by_gain);
+
+static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
+							u8 ch_addr, int *data)
+{
+	int err;
+	u8 outdata[ST_SENSORS_BYTE_FOR_CHANNEL];
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	err = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+				ch_addr, ST_SENSORS_BYTE_FOR_CHANNEL,
+				outdata, sdata->multiread_bit);
+	if (err < 0)
+		goto read_error;
+
+	*data = (s16)get_unaligned_le16(outdata);
+
+read_error:
+	return err;
+}
+
+int st_sensors_read_info_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *ch, int *val)
+{
+	int err;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	mutex_lock(&indio_dev->mlock);
+	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+		err = -EBUSY;
+		goto read_error;
+	} else {
+		err = st_sensors_set_enable(indio_dev, true);
+		if (err < 0)
+			goto read_error;
+
+		msleep((sdata->sensor->bootime * 1000) / sdata->odr);
+		err = st_sensors_read_axis_data(indio_dev, ch->address, val);
+		if (err < 0)
+			goto read_error;
+
+		*val = *val >> ch->scan_type.shift;
+	}
+	mutex_unlock(&indio_dev->mlock);
+
+	return err;
+
+read_error:
+	mutex_unlock(&indio_dev->mlock);
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_read_info_raw);
+
+int st_sensors_check_device_support(struct iio_dev *indio_dev,
+			int num_sensors_list, const struct st_sensors *sensors)
+{
+	u8 wai;
+	int i, n, err;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
+					ST_SENSORS_DEFAULT_WAI_ADDRESS, &wai);
+	if (err < 0) {
+		dev_err(&indio_dev->dev, "failed to read Who-Am-I register.\n");
+		goto read_wai_error;
+	}
+
+	for (i = 0; i < num_sensors_list; i++) {
+		if (sensors[i].wai == wai)
+			break;
+	}
+	if (i == num_sensors_list)
+		goto device_not_supported;
+
+	for (n = 0; n < ARRAY_SIZE(sensors[i].sensors_supported); n++) {
+		if (strcmp(indio_dev->name,
+				&sensors[i].sensors_supported[n][0]) == 0)
+			break;
+	}
+	if (n == ARRAY_SIZE(sensors[i].sensors_supported)) {
+		dev_err(&indio_dev->dev, "device name and WhoAmI mismatch.\n");
+		goto sensor_name_mismatch;
+	}
+
+	sdata->sensor = (struct st_sensors *)&sensors[i];
+
+	return i;
+
+device_not_supported:
+	dev_err(&indio_dev->dev, "device not supported: WhoAmI (0x%x).\n", wai);
+sensor_name_mismatch:
+	err = -ENODEV;
+read_wai_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_check_device_support);
+
+ssize_t st_sensors_sysfs_get_sampling_frequency(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct st_sensor_data *adata = iio_priv(dev_get_drvdata(dev));
+
+	return sprintf(buf, "%d\n", adata->odr);
+}
+EXPORT_SYMBOL(st_sensors_sysfs_get_sampling_frequency);
+
+ssize_t st_sensors_sysfs_set_sampling_frequency(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	int err;
+	unsigned int odr;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+
+	err = kstrtoint(buf, 10, &odr);
+	if (err < 0)
+		goto conversion_error;
+
+	mutex_lock(&indio_dev->mlock);
+	err = st_sensors_set_odr(indio_dev, odr);
+	mutex_unlock(&indio_dev->mlock);
+
+conversion_error:
+	return err < 0 ? err : size;
+}
+EXPORT_SYMBOL(st_sensors_sysfs_set_sampling_frequency);
+
+ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+
+	return st_sensors_get_sampling_frequency_avl(indio_dev, buf);
+}
+EXPORT_SYMBOL(st_sensors_sysfs_sampling_frequency_avail);
+
+ssize_t st_sensors_sysfs_scale_avail(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+
+	return st_sensors_get_scale_avl(indio_dev, buf);
+}
+EXPORT_SYMBOL(st_sensors_sysfs_scale_avail);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors core");
+MODULE_LICENSE("GPL v2");

drivers/iio/common/st_sensors/st_sensors_i2c.c

+/*
+ * STMicroelectronics sensors i2c library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/iio/iio.h>
+
+#include <linux/iio/common/st_sensors_i2c.h>
+
+
+#define ST_SENSORS_I2C_MULTIREAD	0x80
+
+static unsigned int st_sensors_i2c_get_irq(struct iio_dev *indio_dev)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	return to_i2c_client(sdata->dev)->irq;
+}
+
+static int st_sensors_i2c_read_byte(struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 *res_byte)
+{
+	int err;
+
+	err = i2c_smbus_read_byte_data(to_i2c_client(dev), reg_addr);
+	if (err < 0)
+		goto st_accel_i2c_read_byte_error;
+
+	*res_byte = err & 0xff;
+
+st_accel_i2c_read_byte_error:
+	return err < 0 ? err : 0;
+}
+
+static int st_sensors_i2c_read_multiple_byte(
+		struct st_sensor_transfer_buffer *tb, struct device *dev,
+			u8 reg_addr, int len, u8 *data, bool multiread_bit)
+{
+	if (multiread_bit)
+		reg_addr |= ST_SENSORS_I2C_MULTIREAD;
+
+	return i2c_smbus_read_i2c_block_data(to_i2c_client(dev),
+							reg_addr, len, data);
+}
+
+static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 data)
+{
+	return i2c_smbus_write_byte_data(to_i2c_client(dev), reg_addr, data);
+}
+
+static const struct st_sensor_transfer_function st_sensors_tf_i2c = {
+	.read_byte = st_sensors_i2c_read_byte,
+	.write_byte = st_sensors_i2c_write_byte,
+	.read_multiple_byte = st_sensors_i2c_read_multiple_byte,
+};
+
+void st_sensors_i2c_configure(struct iio_dev *indio_dev,
+		struct i2c_client *client, struct st_sensor_data *sdata)
+{
+	i2c_set_clientdata(client, indio_dev);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = client->name;
+
+	sdata->tf = &st_sensors_tf_i2c;
+	sdata->get_irq_data_ready = st_sensors_i2c_get_irq;
+}
+EXPORT_SYMBOL(st_sensors_i2c_configure);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors i2c driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/common/st_sensors/st_sensors_spi.c

+/*
+ * STMicroelectronics sensors spi library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/iio/iio.h>
+
+#include <linux/iio/common/st_sensors_spi.h>
+
+
+#define ST_SENSORS_SPI_MULTIREAD	0xc0
+#define ST_SENSORS_SPI_READ		0x80
+
+static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	return to_spi_device(sdata->dev)->irq;
+}
+
+static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb,
+	struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit)
+{
+	struct spi_message msg;
+	int err;
+
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = tb->tx_buf,
+			.bits_per_word = 8,
+			.len = 1,
+		},
+		{
+			.rx_buf = tb->rx_buf,
+			.bits_per_word = 8,
+			.len = len,
+		}
+	};
+
+	mutex_lock(&tb->buf_lock);
+	if ((multiread_bit) && (len > 1))
+		tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD;
+	else
+		tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers[0], &msg);
+	spi_message_add_tail(&xfers[1], &msg);
+	err = spi_sync(to_spi_device(dev), &msg);
+	if (err)
+		goto acc_spi_read_error;
+
+	memcpy(data, tb->rx_buf, len*sizeof(u8));
+	mutex_unlock(&tb->buf_lock);
+	return len;
+
+acc_spi_read_error:
+	mutex_unlock(&tb->buf_lock);
+	return err;
+}
+
+static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 *res_byte)
+{
+	return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false);
+}
+
+static int st_sensors_spi_read_multiple_byte(
+	struct st_sensor_transfer_buffer *tb, struct device *dev,
+			u8 reg_addr, int len, u8 *data, bool multiread_bit)
+{
+	return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit);
+}
+
+static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 data)
+{
+	struct spi_message msg;
+	int err;
+
+	struct spi_transfer xfers = {
+		.tx_buf = tb->tx_buf,
+		.bits_per_word = 8,
+		.len = 2,
+	};
+
+	mutex_lock(&tb->buf_lock);
+	tb->tx_buf[0] = reg_addr;
+	tb->tx_buf[1] = data;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfers, &msg);
+	err = spi_sync(to_spi_device(dev), &msg);
+	mutex_unlock(&tb->buf_lock);
+
+	return err;
+}
+
+static const struct st_sensor_transfer_function st_sensors_tf_spi = {
+	.read_byte = st_sensors_spi_read_byte,
+	.write_byte = st_sensors_spi_write_byte,
+	.read_multiple_byte = st_sensors_spi_read_multiple_byte,
+};
+
+void st_sensors_spi_configure(struct iio_dev *indio_dev,
+			struct spi_device *spi, struct st_sensor_data *sdata)
+{
+	spi_set_drvdata(spi, indio_dev);
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi->modalias;
+
+	sdata->tf = &st_sensors_tf_spi;
+	sdata->get_irq_data_ready = st_sensors_spi_get_irq;
+}
+EXPORT_SYMBOL(st_sensors_spi_configure);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/common/st_sensors/st_sensors_trigger.c

+/*
+ * STMicroelectronics sensors trigger library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/interrupt.h>
+
+#include <linux/iio/common/st_sensors.h>
+
+
+int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
+				const struct iio_trigger_ops *trigger_ops)
+{
+	int err;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	sdata->trig = iio_trigger_alloc("%s-trigger", indio_dev->name);
+	if (sdata->trig == NULL) {
+		err = -ENOMEM;
+		dev_err(&indio_dev->dev, "failed to allocate iio trigger.\n");
+		goto iio_trigger_alloc_error;
+	}
+
+	err = request_threaded_irq(sdata->get_irq_data_ready(indio_dev),
+			iio_trigger_generic_data_rdy_poll,
+			NULL,
+			IRQF_TRIGGER_RISING,
+			sdata->trig->name,
+			sdata->trig);
+	if (err)
+		goto request_irq_error;
+
+	sdata->trig->private_data = indio_dev;
+	sdata->trig->ops = trigger_ops;
+	sdata->trig->dev.parent = sdata->dev;
+
+	err = iio_trigger_register(sdata->trig);
+	if (err < 0) {
+		dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
+		goto iio_trigger_register_error;
+	}
+	indio_dev->trig = sdata->trig;
+
+	return 0;
+
+iio_trigger_register_error:
+	free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
+request_irq_error:
+	iio_trigger_free(sdata->trig);
+iio_trigger_alloc_error:
+	return err;
+}
+EXPORT_SYMBOL(st_sensors_allocate_trigger);
+
+void st_sensors_deallocate_trigger(struct iio_dev *indio_dev)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+
+	iio_trigger_unregister(sdata->trig);
+	free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
+	iio_trigger_free(sdata->trig);
+}
+EXPORT_SYMBOL(st_sensors_deallocate_trigger);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger");
+MODULE_LICENSE("GPL v2");

include/linux/iio/common/st_sensors.h

+/*
+ * STMicroelectronics sensors library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_SENSORS_H
+#define ST_SENSORS_H
+
+#include <linux/i2c.h>
+#include <linux/spi/spi.h>
+#include <linux/irqreturn.h>
+#include <linux/iio/trigger.h>
+
+#define ST_SENSORS_TX_MAX_LENGTH		2
+#define ST_SENSORS_RX_MAX_LENGTH		6
+
+#define ST_SENSORS_ODR_LIST_MAX			10
+#define ST_SENSORS_FULLSCALE_AVL_MAX		10
+
+#define ST_SENSORS_NUMBER_ALL_CHANNELS		4
+#define ST_SENSORS_NUMBER_DATA_CHANNELS		3
+#define ST_SENSORS_ENABLE_ALL_AXIS		0x07
+#define ST_SENSORS_BYTE_FOR_CHANNEL		2
+#define ST_SENSORS_SCAN_X			0
+#define ST_SENSORS_SCAN_Y			1
+#define ST_SENSORS_SCAN_Z			2
+#define ST_SENSORS_DEFAULT_12_REALBITS		12
+#define ST_SENSORS_DEFAULT_16_REALBITS		16
+#define ST_SENSORS_DEFAULT_POWER_ON_VALUE	0x01
+#define ST_SENSORS_DEFAULT_POWER_OFF_VALUE	0x00
+#define ST_SENSORS_DEFAULT_WAI_ADDRESS		0x0f
+#define ST_SENSORS_DEFAULT_AXIS_ADDR		0x20
+#define ST_SENSORS_DEFAULT_AXIS_MASK		0x07
+#define ST_SENSORS_DEFAULT_AXIS_N_BIT		3
+
+#define ST_SENSORS_MAX_NAME			17
+#define ST_SENSORS_MAX_4WAI			7
+
+#define ST_SENSORS_LSM_CHANNELS(device_type, index, mod, endian, bits, addr) \
+{ \
+	.type = device_type, \
+	.modified = 1, \
+	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \
+	.scan_index = index, \
+	.channel2 = mod, \
+	.address = addr, \
+	.scan_type = { \
+		.sign = 's', \
+		.realbits = bits, \
+		.shift = 16 - bits, \
+		.storagebits = 16, \
+		.endianness = endian, \
+	}, \
+}
+
+#define ST_SENSOR_DEV_ATTR_SAMP_FREQ() \
+		IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, \
+			st_sensors_sysfs_get_sampling_frequency, \
+			st_sensors_sysfs_set_sampling_frequency)
+
+#define ST_SENSORS_DEV_ATTR_SAMP_FREQ_AVAIL() \
+		IIO_DEV_ATTR_SAMP_FREQ_AVAIL( \
+			st_sensors_sysfs_sampling_frequency_avail)
+
+#define ST_SENSORS_DEV_ATTR_SCALE_AVAIL(name) \
+		IIO_DEVICE_ATTR(name, S_IRUGO, \
+			st_sensors_sysfs_scale_avail, NULL , 0);
+
+struct st_sensor_odr_avl {
+	unsigned int hz;
+	u8 value;
+};
+
+struct st_sensor_odr {
+	u8 addr;
+	u8 mask;
+	struct st_sensor_odr_avl odr_avl[ST_SENSORS_ODR_LIST_MAX];
+};
+
+struct st_sensor_power {
+	u8 addr;
+	u8 mask;
+	u8 value_off;
+	u8 value_on;
+};
+
+struct st_sensor_axis {
+	u8 addr;
+	u8 mask;
+};
+
+struct st_sensor_fullscale_avl {
+	unsigned int num;
+	u8 value;
+	unsigned int gain;
+	unsigned int gain2;
+};
+
+struct st_sensor_fullscale {
+	u8 addr;
+	u8 mask;
+	struct st_sensor_fullscale_avl fs_avl[ST_SENSORS_FULLSCALE_AVL_MAX];
+};
+
+/**
+ * struct st_sensor_bdu - ST sensor device block data update
+ * @addr: address of the register.
+ * @mask: mask to write the block data update flag.
+ */
+struct st_sensor_bdu {
+	u8 addr;
+	u8 mask;
+};
+
+/**
+ * struct st_sensor_data_ready_irq - ST sensor device data-ready interrupt
+ * @addr: address of the register.
+ * @mask: mask to write the on/off value.
+ * struct ig1 - represents the Interrupt Generator 1 of sensors.
+ * @en_addr: address of the enable ig1 register.
+ * @en_mask: mask to write the on/off value for enable.
+ */
+struct st_sensor_data_ready_irq {
+	u8 addr;
+	u8 mask;
+	struct {
+		u8 en_addr;
+		u8 en_mask;
+	} ig1;
+};
+
+/**
+ * struct st_sensor_transfer_buffer - ST sensor device I/O buffer
+ * @buf_lock: Mutex to protect rx and tx buffers.
+ * @tx_buf: Buffer used by SPI transfer function to send data to the sensors.
+ *	This buffer is used to avoid DMA not-aligned issue.
+ * @rx_buf: Buffer used by SPI transfer to receive data from sensors.
+ *	This buffer is used to avoid DMA not-aligned issue.
+ */
+struct st_sensor_transfer_buffer {
+	struct mutex buf_lock;
+	u8 rx_buf[ST_SENSORS_RX_MAX_LENGTH];
+	u8 tx_buf[ST_SENSORS_TX_MAX_LENGTH] ____cacheline_aligned;
+};
+
+/**
+ * struct st_sensor_transfer_function - ST sensor device I/O function
+ * @read_byte: Function used to read one byte.
+ * @write_byte: Function used to write one byte.
+ * @read_multiple_byte: Function used to read multiple byte.
+ */
+struct st_sensor_transfer_function {
+	int (*read_byte) (struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 *res_byte);
+	int (*write_byte) (struct st_sensor_transfer_buffer *tb,
+				struct device *dev, u8 reg_addr, u8 data);
+	int (*read_multiple_byte) (struct st_sensor_transfer_buffer *tb,
+		struct device *dev, u8 reg_addr, int len, u8 *data,
+							bool multiread_bit);
+};
+
+/**
+ * struct st_sensors - ST sensors list
+ * @wai: Contents of WhoAmI register.
+ * @sensors_supported: List of supported sensors by struct itself.
+ * @ch: IIO channels for the sensor.
+ * @odr: Output data rate register and ODR list available.
+ * @pw: Power register of the sensor.
+ * @enable_axis: Enable one or more axis of the sensor.
+ * @fs: Full scale register and full scale list available.
+ * @bdu: Block data update register.
+ * @drdy_irq: Data ready register of the sensor.
+ * @multi_read_bit: Use or not particular bit for [I2C/SPI] multi-read.
+ * @bootime: samples to discard when sensor passing from power-down to power-up.
+ */
+struct st_sensors {
+	u8 wai;
+	char sensors_supported[ST_SENSORS_MAX_4WAI][ST_SENSORS_MAX_NAME];
+	struct iio_chan_spec *ch;
+	struct st_sensor_odr odr;
+	struct st_sensor_power pw;
+	struct st_sensor_axis enable_axis;
+	struct st_sensor_fullscale fs;
+	struct st_sensor_bdu bdu;
+	struct st_sensor_data_ready_irq drdy_irq;
+	bool multi_read_bit;
+	unsigned int bootime;
+};
+
+/**
+ * struct st_sensor_data - ST sensor device status
+ * @dev: Pointer to instance of struct device (I2C or SPI).
+ * @trig: The trigger in use by the core driver.
+ * @sensor: Pointer to the current sensor struct in use.
+ * @current_fullscale: Maximum range of measure by the sensor.
+ * @enabled: Status of the sensor (false->off, true->on).
+ * @multiread_bit: Use or not particular bit for [I2C/SPI] multiread.
+ * @buffer_data: Data used by buffer part.
+ * @odr: Output data rate of the sensor [Hz].
+ * @get_irq_data_ready: Function to get the IRQ used for data ready signal.
+ * @tf: Transfer function structure used by I/O operations.
+ * @tb: Transfer buffers and mutex used by I/O operations.
+ */
+struct st_sensor_data {
+	struct device *dev;
+	struct iio_trigger *trig;
+	struct st_sensors *sensor;
+	struct st_sensor_fullscale_avl *current_fullscale;
+
+	bool enabled;
+	bool multiread_bit;
+
+	char *buffer_data;
+
+	unsigned int odr;
+
+	unsigned int (*get_irq_data_ready) (struct iio_dev *indio_dev);
+
+	const struct st_sensor_transfer_function *tf;
+	struct st_sensor_transfer_buffer tb;
+};
+
+#ifdef CONFIG_IIO_BUFFER
+int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
+				const struct iio_trigger_ops *trigger_ops);
+
+void st_sensors_deallocate_trigger(struct iio_dev *indio_dev);
+
+irqreturn_t st_sensors_trigger_handler(int irq, void *p);
+
+int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf);
+#endif
+
+int st_sensors_init_sensor(struct iio_dev *indio_dev);
+
+int st_sensors_set_enable(struct iio_dev *indio_dev, bool enable);
+
+int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable);
+
+int st_sensors_get_sampling_frequency_avl(struct iio_dev *indio_dev, char *buf);
+
+int st_sensors_get_scale_avl(struct iio_dev *indio_dev, char *buf);
+
+int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr);
+
+int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable);
+
+int st_sensors_set_fullscale_by_gain(struct iio_dev *indio_dev, int scale);
+
+int st_sensors_read_info_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *ch, int *val);
+
+int st_sensors_check_device_support(struct iio_dev *indio_dev,
+			int num_sensors_list, const struct st_sensors *sensors);
+
+ssize_t st_sensors_sysfs_get_sampling_frequency(struct device *dev,
+				struct device_attribute *attr, char *buf);
+
+ssize_t st_sensors_sysfs_set_sampling_frequency(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size);
+
+ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
+				struct device_attribute *attr, char *buf);
+
+ssize_t st_sensors_sysfs_scale_avail(struct device *dev,
+				struct device_attribute *attr, char *buf);
+
+#endif /* ST_SENSORS_H */

include/linux/iio/common/st_sensors_i2c.h

+/*
+ * STMicroelectronics sensors i2c library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_SENSORS_I2C_H
+#define ST_SENSORS_I2C_H
+
+#include <linux/i2c.h>
+#include <linux/iio/common/st_sensors.h>
+
+void st_sensors_i2c_configure(struct iio_dev *indio_dev,
+		struct i2c_client *client, struct st_sensor_data *sdata);
+
+#endif /* ST_SENSORS_I2C_H */

include/linux/iio/common/st_sensors_spi.h

+/*
+ * STMicroelectronics sensors spi library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_SENSORS_SPI_H
+#define ST_SENSORS_SPI_H
+
+#include <linux/spi/spi.h>
+#include <linux/iio/common/st_sensors.h>
+
+void st_sensors_spi_configure(struct iio_dev *indio_dev,
+			struct spi_device *spi, struct st_sensor_data *sdata);
+
+#endif /* ST_SENSORS_SPI_H */