iio:accel: Add STMicroelectronics accelerometers driver

This patch adds a generic accelerometer driver for STMicroelectronics
accelerometers, currently it supports:
LSM303DLH, LSM303DLHC, LIS3DH, LSM330D, LSM330DL, LSM330DLC,
LIS331DLH, LSM303DL, LSM303DLM, LSM330.

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/accel/Kconfig

@@ -21,4 +21,35 @@ config KXSD9
 	  Say yes here to build support for the Kionix KXSD9 accelerometer.
 	  Currently this only supports the device via an SPI interface.
 
+config IIO_ST_ACCEL_3AXIS
+	tristate "STMicroelectronics accelerometers 3-Axis Driver"
+	depends on (I2C || SPI_MASTER) && SYSFS
+	select IIO_ST_SENSORS_CORE
+	select IIO_ST_ACCEL_I2C_3AXIS if (I2C)
+	select IIO_ST_ACCEL_SPI_3AXIS if (SPI_MASTER)
+	select IIO_TRIGGERED_BUFFER if (IIO_BUFFER)
+	select IIO_ST_ACCEL_BUFFER if (IIO_TRIGGERED_BUFFER)
+	help
+	  Say yes here to build support for STMicroelectronics accelerometers:
+	  LSM303DLH, LSM303DLHC, LIS3DH, LSM330D, LSM330DL, LSM330DLC,
+	  LIS331DLH, LSM303DL, LSM303DLM, LSM330.
+
+	  This driver can also be built as a module. If so, will be created
+	  these modules:
+	  - st_accel (core functions for the driver [it is mandatory]);
+	  - st_accel_i2c (necessary for the I2C devices [optional*]);
+	  - st_accel_spi (necessary for the SPI devices [optional*]);
+
+	  (*) one of these is necessary to do something.
+
+config IIO_ST_ACCEL_I2C_3AXIS
+	tristate
+	depends on IIO_ST_ACCEL_3AXIS
+	depends on IIO_ST_SENSORS_I2C
+
+config IIO_ST_ACCEL_SPI_3AXIS
+	tristate
+	depends on IIO_ST_ACCEL_3AXIS
+	depends on IIO_ST_SENSORS_SPI
+
 endmenu

drivers/iio/accel/Makefile

@@ -3,4 +3,12 @@
 #
 
 obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
+
+obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
+st_accel-y := st_accel_core.o
+st_accel-$(CONFIG_IIO_BUFFER) += st_accel_buffer.o
+
+obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
+obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
+
 obj-$(CONFIG_KXSD9)	+= kxsd9.o

drivers/iio/accel/st_accel.h

@@ -0,0 +1,47 @@
+/*
+ * STMicroelectronics accelerometers driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ * v. 1.0.0
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_ACCEL_H
+#define ST_ACCEL_H
+
+#include <linux/types.h>
+#include <linux/iio/common/st_sensors.h>
+
+#define LSM303DLHC_ACCEL_DEV_NAME	"lsm303dlhc_accel"
+#define LIS3DH_ACCEL_DEV_NAME		"lis3dh"
+#define LSM330D_ACCEL_DEV_NAME		"lsm330d_accel"
+#define LSM330DL_ACCEL_DEV_NAME		"lsm330dl_accel"
+#define LSM330DLC_ACCEL_DEV_NAME	"lsm330dlc_accel"
+#define LIS331DLH_ACCEL_DEV_NAME	"lis331dlh"
+#define LSM303DL_ACCEL_DEV_NAME		"lsm303dl_accel"
+#define LSM303DLH_ACCEL_DEV_NAME	"lsm303dlh_accel"
+#define LSM303DLM_ACCEL_DEV_NAME	"lsm303dlm_accel"
+#define LSM330_ACCEL_DEV_NAME		"lsm330_accel"
+
+int st_accel_common_probe(struct iio_dev *indio_dev);
+void st_accel_common_remove(struct iio_dev *indio_dev);
+
+#ifdef CONFIG_IIO_BUFFER
+int st_accel_allocate_ring(struct iio_dev *indio_dev);
+void st_accel_deallocate_ring(struct iio_dev *indio_dev);
+int st_accel_trig_set_state(struct iio_trigger *trig, bool state);
+#define ST_ACCEL_TRIGGER_SET_STATE (&st_accel_trig_set_state)
+#else /* CONFIG_IIO_BUFFER */
+static inline int st_accel_allocate_ring(struct iio_dev *indio_dev)
+{
+	return 0;
+}
+static inline void st_accel_deallocate_ring(struct iio_dev *indio_dev)
+{
+}
+#define ST_ACCEL_TRIGGER_SET_STATE NULL
+#endif /* CONFIG_IIO_BUFFER */
+
+#endif /* ST_ACCEL_H */

drivers/iio/accel/st_accel_buffer.c

@@ -0,0 +1,114 @@
+/*
+ * STMicroelectronics accelerometers driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <linux/iio/common/st_sensors.h>
+#include "st_accel.h"
+
+int st_accel_trig_set_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = trig->private_data;
+
+	return st_sensors_set_dataready_irq(indio_dev, state);
+}
+
+static int st_accel_buffer_preenable(struct iio_dev *indio_dev)
+{
+	int err;
+
+	err = st_sensors_set_enable(indio_dev, true);
+	if (err < 0)
+		goto st_accel_set_enable_error;
+
+	err = iio_sw_buffer_preenable(indio_dev);
+
+st_accel_set_enable_error:
+	return err;
+}
+
+static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
+{
+	int err;
+	struct st_sensor_data *adata = iio_priv(indio_dev);
+
+	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
+	if (adata->buffer_data == NULL) {
+		err = -ENOMEM;
+		goto allocate_memory_error;
+	}
+
+	err = st_sensors_set_axis_enable(indio_dev,
+					(u8)indio_dev->active_scan_mask[0]);
+	if (err < 0)
+		goto st_accel_buffer_postenable_error;
+
+	err = iio_triggered_buffer_postenable(indio_dev);
+	if (err < 0)
+		goto st_accel_buffer_postenable_error;
+
+	return err;
+
+st_accel_buffer_postenable_error:
+	kfree(adata->buffer_data);
+allocate_memory_error:
+	return err;
+}
+
+static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
+{
+	int err;
+	struct st_sensor_data *adata = iio_priv(indio_dev);
+
+	err = iio_triggered_buffer_predisable(indio_dev);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
+
+	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
+
+	err = st_sensors_set_enable(indio_dev, false);
+
+st_accel_buffer_predisable_error:
+	kfree(adata->buffer_data);
+	return err;
+}
+
+static const struct iio_buffer_setup_ops st_accel_buffer_setup_ops = {
+	.preenable = &st_accel_buffer_preenable,
+	.postenable = &st_accel_buffer_postenable,
+	.predisable = &st_accel_buffer_predisable,
+};
+
+int st_accel_allocate_ring(struct iio_dev *indio_dev)
+{
+	return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+		&st_sensors_trigger_handler, &st_accel_buffer_setup_ops);
+}
+
+void st_accel_deallocate_ring(struct iio_dev *indio_dev)
+{
+	iio_triggered_buffer_cleanup(indio_dev);
+}
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics accelerometers buffer");
+MODULE_LICENSE("GPL v2");