From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 drivers/iio/common/st_sensors/st_sensors_buffer.c | 128 ++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 drivers/iio/common/st_sensors/st_sensors_buffer.c

(limited to 'drivers/iio/common/st_sensors/st_sensors_buffer.c')

diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
new file mode 100644
index 000000000..e18bc6782
--- /dev/null
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -0,0 +1,128 @@
+/*
+ * 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)
+{
+	u8 *addr;
+	int i, n = 0, len;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+	unsigned int num_data_channels = sdata->num_data_channels;
+	unsigned int byte_for_channel =
+			indio_dev->channels[0].scan_type.storagebits >> 3;
+
+	addr = kmalloc(num_data_channels, GFP_KERNEL);
+	if (!addr) {
+		len = -ENOMEM;
+		goto st_sensors_get_buffer_element_error;
+	}
+
+	for (i = 0; i < num_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], byte_for_channel, buf, sdata->multiread_bit);
+		break;
+	case 2:
+		if ((addr[1] - addr[0]) == byte_for_channel) {
+			len = sdata->tf->read_multiple_byte(&sdata->tb,
+				sdata->dev, addr[0], byte_for_channel * n,
+				buf, sdata->multiread_bit);
+		} else {
+			u8 *rx_array;
+			rx_array = kmalloc(byte_for_channel * num_data_channels,
+					   GFP_KERNEL);
+			if (!rx_array) {
+				len = -ENOMEM;
+				goto st_sensors_free_memory;
+			}
+
+			len = sdata->tf->read_multiple_byte(&sdata->tb,
+				sdata->dev, addr[0],
+				byte_for_channel * num_data_channels,
+				rx_array, sdata->multiread_bit);
+			if (len < 0) {
+				kfree(rx_array);
+				goto st_sensors_free_memory;
+			}
+
+			for (i = 0; i < n * byte_for_channel; i++) {
+				if (i < n)
+					buf[i] = rx_array[i];
+				else
+					buf[i] = rx_array[n + i];
+			}
+			kfree(rx_array);
+			len = byte_for_channel * n;
+		}
+		break;
+	case 3:
+		len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+			addr[0], byte_for_channel * num_data_channels,
+			buf, sdata->multiread_bit);
+		break;
+	default:
+		len = -EINVAL;
+		goto st_sensors_free_memory;
+	}
+	if (len != byte_for_channel * n) {
+		len = -EIO;
+		goto st_sensors_free_memory;
+	}
+
+st_sensors_free_memory:
+	kfree(addr);
+st_sensors_get_buffer_element_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;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
+		pf->timestamp);
+
+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");
-- 
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