iio: common: ssp_sensors: Add sensorhub iio commons

This patch adds common library for sensorhub iio drivers.

Signed-off-by: Karol Wrona <k.wrona@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/common/ssp_sensors/Kconfig

@@ -3,6 +3,16 @@
 #
 menu "SSP Sensor Common"
 
+config IIO_SSP_SENSORS_COMMONS
+	tristate "Commons for all SSP Sensor IIO drivers"
+	depends on IIO_SSP_SENSORHUB
+	select IIO_BUFFER
+	select IIO_KFIFO_BUF
+	help
+	  Say yes here to build commons for SSP sensors.
+	  To compile this as a module, choose M here: the module
+	  will be called ssp_iio.
+
 config IIO_SSP_SENSORHUB
 	tristate "Samsung Sensorhub driver"
 	depends on SPI

drivers/iio/common/ssp_sensors/Makefile

@@ -4,3 +4,5 @@
 
 sensorhub-objs				:= ssp_dev.o ssp_spi.o
 obj-$(CONFIG_IIO_SSP_SENSORHUB)		+= sensorhub.o
+
+obj-$(CONFIG_IIO_SSP_SENSORS_COMMONS) 	+= ssp_iio.o

drivers/iio/common/ssp_sensors/ssp_iio.c

@@ -0,0 +1,107 @@
+/*
+ *  Copyright (C) 2014, Samsung Electronics Co. Ltd. All Rights Reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#include <linux/iio/common/ssp_sensors.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "ssp_iio_sensor.h"
+
+/**
+ * ssp_common_buffer_postenable() - generic postenable callback for ssp buffer
+ *
+ * @indio_dev:		iio device
+ *
+ * Returns 0 or negative value in case of error
+ */
+int ssp_common_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct ssp_sensor_data *spd = iio_priv(indio_dev);
+	struct ssp_data *data = dev_get_drvdata(indio_dev->dev.parent->parent);
+
+	/* the allocation is made in post because scan size is known in this
+	 * moment
+	 * */
+	spd->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL | GFP_DMA);
+	if (!spd->buffer)
+		return -ENOMEM;
+
+	return ssp_enable_sensor(data, spd->type,
+				 ssp_get_sensor_delay(data, spd->type));
+}
+EXPORT_SYMBOL(ssp_common_buffer_postenable);
+
+/**
+ * ssp_common_buffer_postdisable() - generic postdisable callback for ssp buffer
+ *
+ * @indio_dev:		iio device
+ *
+ * Returns 0 or negative value in case of error
+ */
+int ssp_common_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	int ret;
+	struct ssp_sensor_data *spd = iio_priv(indio_dev);
+	struct ssp_data *data = dev_get_drvdata(indio_dev->dev.parent->parent);
+
+	ret = ssp_disable_sensor(data, spd->type);
+	if (ret < 0)
+		return ret;
+
+	kfree(spd->buffer);
+
+	return ret;
+}
+EXPORT_SYMBOL(ssp_common_buffer_postdisable);
+
+/**
+ * ssp_common_process_data() - Common process data callback for ssp sensors
+ *
+ * @indio_dev:		iio device
+ * @buf:		source buffer
+ * @len:		sensor data length
+ * @timestamp:		system timestamp
+ *
+ * Returns 0 or negative value in case of error
+ */
+int ssp_common_process_data(struct iio_dev *indio_dev, void *buf,
+			    unsigned int len, int64_t timestamp)
+{
+	__le32 time;
+	int64_t calculated_time;
+	struct ssp_sensor_data *spd = iio_priv(indio_dev);
+
+	if (indio_dev->scan_bytes == 0)
+		return 0;
+
+	/*
+	 * it always sends full set of samples, remember about available masks
+	 */
+	memcpy(spd->buffer, buf, len);
+
+	if (indio_dev->scan_timestamp) {
+		memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE);
+		calculated_time =
+			timestamp + (int64_t)le32_to_cpu(time) * 1000000;
+	}
+
+	return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer,
+						  calculated_time);
+}
+EXPORT_SYMBOL(ssp_common_process_data);
+
+MODULE_AUTHOR("Karol Wrona <k.wrona@samsung.com>");
+MODULE_DESCRIPTION("Samsung sensorhub commons");
+MODULE_LICENSE("GPL");

drivers/iio/common/ssp_sensors/ssp_iio_sensor.h

@@ -0,0 +1,70 @@
+#ifndef __SSP_IIO_SENSOR_H__
+#define __SSP_IIO_SENSOR_H__
+
+#define SSP_CHANNEL_AG(_type, _mod, _index) \
+{ \
+		.type = _type,\
+		.modified = 1,\
+		.channel2 = _mod,\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
+		.scan_index = _index,\
+		.scan_type = {\
+			.sign = 's',\
+			.realbits = 16,\
+			.storagebits = 16,\
+			.shift = 0,\
+			.endianness = IIO_LE,\
+		},\
+}
+
+/* It is defined here as it is a mixed timestamp */
+#define SSP_CHAN_TIMESTAMP(_si) {					\
+	.type = IIO_TIMESTAMP,						\
+	.channel = -1,							\
+	.scan_index = _si,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 64,						\
+		.storagebits = 64,					\
+		},							\
+}
+
+#define SSP_MS_PER_S			1000
+#define SSP_INVERTED_SCALING_FACTOR	1000000ULL
+
+#define SSP_FACTOR_WITH_MS \
+	(SSP_INVERTED_SCALING_FACTOR * SSP_MS_PER_S)
+
+int ssp_common_buffer_postenable(struct iio_dev *indio_dev);
+
+int ssp_common_buffer_postdisable(struct iio_dev *indio_dev);
+
+int ssp_common_process_data(struct iio_dev *indio_dev, void *buf,
+			    unsigned int len, int64_t timestamp);
+
+/* Converts time in ms to frequency */
+static inline void ssp_convert_to_freq(u32 time, int *integer_part,
+				       int *fractional)
+{
+	if (time == 0) {
+		*fractional = 0;
+		*integer_part = 0;
+		return;
+	}
+
+	*integer_part = SSP_FACTOR_WITH_MS / time;
+	*fractional = do_div(*integer_part, SSP_INVERTED_SCALING_FACTOR);
+}
+
+/* Converts frequency to time in ms */
+static inline int ssp_convert_to_time(int integer_part, int fractional)
+{
+	u64 value;
+
+	value = integer_part * SSP_INVERTED_SCALING_FACTOR + fractional;
+	if (value == 0)
+		return 0;
+
+	return div_u64(SSP_FACTOR_WITH_MS, value);
+}
+#endif /* __SSP_IIO_SENSOR_H__ */