Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / iio / imu / adis16400_buffer.c

diff --git a/kernel/drivers/iio/imu/adis16400_buffer.c b/kernel/drivers/iio/imu/adis16400_buffer.c
new file mode 100644 (file)
index 0000000..90c24a2
--- /dev/null
+++ b/kernel/drivers/iio/imu/adis16400_buffer.c
@@ -0,0 +1,100 @@
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "adis16400.h"
+
+int adis16400_update_scan_mode(struct iio_dev *indio_dev,
+       const unsigned long *scan_mask)
+{
+       struct adis16400_state *st = iio_priv(indio_dev);
+       struct adis *adis = &st->adis;
+       unsigned int burst_length;
+       u8 *tx;
+
+       if (st->variant->flags & ADIS16400_NO_BURST)
+               return adis_update_scan_mode(indio_dev, scan_mask);
+
+       kfree(adis->xfer);
+       kfree(adis->buffer);
+
+       /* All but the timestamp channel */
+       burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
+       if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
+               burst_length += sizeof(u16);
+
+       adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
+       if (!adis->xfer)
+               return -ENOMEM;
+
+       adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
+       if (!adis->buffer)
+               return -ENOMEM;
+
+       tx = adis->buffer + burst_length;
+       tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
+       tx[1] = 0;
+
+       adis->xfer[0].tx_buf = tx;
+       adis->xfer[0].bits_per_word = 8;
+       adis->xfer[0].len = 2;
+       adis->xfer[1].rx_buf = adis->buffer;
+       adis->xfer[1].bits_per_word = 8;
+       adis->xfer[1].len = burst_length;
+
+       spi_message_init(&adis->msg);
+       spi_message_add_tail(&adis->xfer[0], &adis->msg);
+       spi_message_add_tail(&adis->xfer[1], &adis->msg);
+
+       return 0;
+}
+
+irqreturn_t adis16400_trigger_handler(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct adis16400_state *st = iio_priv(indio_dev);
+       struct adis *adis = &st->adis;
+       u32 old_speed_hz = st->adis.spi->max_speed_hz;
+       void *buffer;
+       int ret;
+
+       if (!adis->buffer)
+               return -ENOMEM;
+
+       if (!(st->variant->flags & ADIS16400_NO_BURST) &&
+               st->adis.spi->max_speed_hz > ADIS16400_SPI_BURST) {
+               st->adis.spi->max_speed_hz = ADIS16400_SPI_BURST;
+               spi_setup(st->adis.spi);
+       }
+
+       ret = spi_sync(adis->spi, &adis->msg);
+       if (ret)
+               dev_err(&adis->spi->dev, "Failed to read data: %d\n", ret);
+
+       if (!(st->variant->flags & ADIS16400_NO_BURST)) {
+               st->adis.spi->max_speed_hz = old_speed_hz;
+               spi_setup(st->adis.spi);
+       }
+
+       if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
+               buffer = adis->buffer + sizeof(u16);
+       else
+               buffer = adis->buffer;
+
+       iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+               pf->timestamp);
+
+       iio_trigger_notify_done(indio_dev->trig);
+
+       return IRQ_HANDLED;
+}