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path: root/drivers/iio/industrialio-buffer.c
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Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
-rw-r--r--drivers/iio/industrialio-buffer.c58
1 files changed, 45 insertions, 13 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index a24b2e0..df919f4 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -42,18 +42,47 @@ static size_t iio_buffer_data_available(struct iio_buffer *buf)
return buf->access->data_available(buf);
}
+static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
+ struct iio_buffer *buf, size_t required)
+{
+ if (!indio_dev->info->hwfifo_flush_to_buffer)
+ return -ENODEV;
+
+ return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
+}
+
static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
- size_t to_wait)
+ size_t to_wait, int to_flush)
{
+ size_t avail;
+ int flushed = 0;
+
/* wakeup if the device was unregistered */
if (!indio_dev->info)
return true;
/* drain the buffer if it was disabled */
- if (!iio_buffer_is_active(buf))
+ if (!iio_buffer_is_active(buf)) {
to_wait = min_t(size_t, to_wait, 1);
+ to_flush = 0;
+ }
+
+ avail = iio_buffer_data_available(buf);
- if (iio_buffer_data_available(buf) >= to_wait)
+ if (avail >= to_wait) {
+ /* force a flush for non-blocking reads */
+ if (!to_wait && !avail && to_flush)
+ iio_buffer_flush_hwfifo(indio_dev, buf, to_flush);
+ return true;
+ }
+
+ if (to_flush)
+ flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
+ to_wait - avail);
+ if (flushed <= 0)
+ return false;
+
+ if (avail + flushed >= to_wait)
return true;
return false;
@@ -72,6 +101,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
struct iio_buffer *rb = indio_dev->buffer;
size_t datum_size;
size_t to_wait = 0;
+ size_t to_read;
int ret;
if (!indio_dev->info)
@@ -89,12 +119,14 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
if (!datum_size)
return 0;
+ to_read = min_t(size_t, n / datum_size, rb->watermark);
+
if (!(filp->f_flags & O_NONBLOCK))
- to_wait = min_t(size_t, n / datum_size, rb->watermark);
+ to_wait = to_read;
do {
ret = wait_event_interruptible(rb->pollq,
- iio_buffer_ready(indio_dev, rb, to_wait));
+ iio_buffer_ready(indio_dev, rb, to_wait, to_read));
if (ret)
return ret;
@@ -122,7 +154,7 @@ unsigned int iio_buffer_poll(struct file *filp,
return -ENODEV;
poll_wait(filp, &rb->pollq, wait);
- if (iio_buffer_ready(indio_dev, rb, rb->watermark))
+ if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
return POLLIN | POLLRDNORM;
return 0;
}
@@ -661,19 +693,16 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
}
}
/* Definitely possible for devices to support both of these. */
- if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
- if (!indio_dev->trig) {
- printk(KERN_INFO "Buffer not started: no trigger\n");
- ret = -EINVAL;
- /* Can only occur on first buffer */
- goto error_run_postdisable;
- }
+ if ((indio_dev->modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
} else if (indio_dev->modes & INDIO_BUFFER_SOFTWARE) {
indio_dev->currentmode = INDIO_BUFFER_SOFTWARE;
} else { /* Should never be reached */
+ /* Can only occur on first buffer */
+ if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+ pr_info("Buffer not started: no trigger\n");
ret = -EINVAL;
goto error_run_postdisable;
}
@@ -825,6 +854,9 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
}
buffer->watermark = val;
+
+ if (indio_dev->info->hwfifo_set_watermark)
+ indio_dev->info->hwfifo_set_watermark(indio_dev, val);
out:
mutex_unlock(&indio_dev->mlock);
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