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path: root/drivers/staging/iio/imu/adis16400_ring.c
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Diffstat (limited to 'drivers/staging/iio/imu/adis16400_ring.c')
-rw-r--r--drivers/staging/iio/imu/adis16400_ring.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/staging/iio/imu/adis16400_ring.c b/drivers/staging/iio/imu/adis16400_ring.c
index 5529b32bd2e3..5d94cdc2ea2d 100644
--- a/drivers/staging/iio/imu/adis16400_ring.c
+++ b/drivers/staging/iio/imu/adis16400_ring.c
@@ -6,6 +6,7 @@
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
+#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/list.h>
@@ -96,6 +97,54 @@ static void adis16400_poll_func_th(struct iio_dev *indio_dev)
*/
}
+/**
+ * adis16400_spi_read_burst() - read all data registers
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @rx: somewhere to pass back the value read (min size is 24 bytes)
+ **/
+static int adis16400_spi_read_burst(struct device *dev, u8 *rx)
+{
+ struct spi_message msg;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct adis16400_state *st = iio_dev_get_devdata(indio_dev);
+ u32 old_speed_hz = st->us->max_speed_hz;
+ int ret;
+
+ struct spi_transfer xfers[] = {
+ {
+ .tx_buf = st->tx,
+ .bits_per_word = 8,
+ .len = 2,
+ .cs_change = 0,
+ }, {
+ .rx_buf = rx,
+ .bits_per_word = 8,
+ .len = 24,
+ .cs_change = 1,
+ },
+ };
+
+ mutex_lock(&st->buf_lock);
+ st->tx[0] = ADIS16400_READ_REG(ADIS16400_GLOB_CMD);
+ st->tx[1] = 0;
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfers[0], &msg);
+ spi_message_add_tail(&xfers[1], &msg);
+
+ st->us->max_speed_hz = min(ADIS16400_SPI_BURST, old_speed_hz);
+ spi_setup(st->us);
+
+ ret = spi_sync(st->us, &msg);
+ if (ret)
+ dev_err(&st->us->dev, "problem when burst reading");
+
+ st->us->max_speed_hz = old_speed_hz;
+ spi_setup(st->us);
+ mutex_unlock(&st->buf_lock);
+ return ret;
+}
+
/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
* specific to be rolled into the core.
*/