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authorDenis Ciocca <denis.ciocca@gmail.com>2013-01-25 23:44:00 +0000
committerJonathan Cameron <jic23@kernel.org>2013-01-31 17:56:43 +0000
commit23491b513bcd3dfe4ddb94547d73d9deb94eda44 (patch)
tree2f7628041f42e3df88716253e8ca820b2ec884a1 /drivers/iio/common/st_sensors/st_sensors_spi.c
parent085494ac2039433a5df9fdd6fb653579e18b8c71 (diff)
downloadvexpress-lsk-23491b513bcd3dfe4ddb94547d73d9deb94eda44.tar.gz
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>
Diffstat (limited to 'drivers/iio/common/st_sensors/st_sensors_spi.c')
-rw-r--r--drivers/iio/common/st_sensors/st_sensors_spi.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/iio/common/st_sensors/st_sensors_spi.c b/drivers/iio/common/st_sensors/st_sensors_spi.c
new file mode 100644
index 00000000000..f0aa2f10522
--- /dev/null
+++ b/drivers/iio/common/st_sensors/st_sensors_spi.c
@@ -0,0 +1,128 @@
+/*
+ * 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");