Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 163 insertions, 34 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 71333140d42c..df919f44d513 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -37,11 +37,57 @@ static bool iio_buffer_is_active(struct iio_buffer *buf)
 	return !list_empty(&buf->buffer_list);
 }
 
-static bool iio_buffer_data_available(struct iio_buffer *buf)
+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, 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)) {
+		to_wait = min_t(size_t, to_wait, 1);
+		to_flush = 0;
+	}
+
+	avail = iio_buffer_data_available(buf);
+
+	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;
+}
+
 /**
  * iio_buffer_read_first_n_outer() - chrdev read for buffer access
  *
@@ -53,6 +99,9 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 {
 	struct iio_dev *indio_dev = filp->private_data;
 	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)
@@ -61,19 +110,28 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 	if (!rb || !rb->access->read_first_n)
 		return -EINVAL;
 
+	datum_size = rb->bytes_per_datum;
+
+	/*
+	 * If datum_size is 0 there will never be anything to read from the
+	 * buffer, so signal end of file now.
+	 */
+	if (!datum_size)
+		return 0;
+
+	to_read = min_t(size_t, n / datum_size, rb->watermark);
+
+	if (!(filp->f_flags & O_NONBLOCK))
+		to_wait = to_read;
+
 	do {
-		if (!iio_buffer_data_available(rb)) {
-			if (filp->f_flags & O_NONBLOCK)
-				return -EAGAIN;
+		ret = wait_event_interruptible(rb->pollq,
+			iio_buffer_ready(indio_dev, rb, to_wait, to_read));
+		if (ret)
+			return ret;
 
-			ret = wait_event_interruptible(rb->pollq,
-					iio_buffer_data_available(rb) ||
-					indio_dev->info == NULL);
-			if (ret)
-				return ret;
-			if (indio_dev->info == NULL)
-				return -ENODEV;
-		}
+		if (!indio_dev->info)
+			return -ENODEV;
 
 		ret = rb->access->read_first_n(rb, n, buf);
 		if (ret == 0 && (filp->f_flags & O_NONBLOCK))
@@ -96,9 +154,8 @@ unsigned int iio_buffer_poll(struct file *filp,
 		return -ENODEV;
 
 	poll_wait(filp, &rb->pollq, wait);
-	if (iio_buffer_data_available(rb))
+	if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
 		return POLLIN | POLLRDNORM;
-	/* need a way of knowing if there may be enough data... */
 	return 0;
 }
 
@@ -123,6 +180,7 @@ void iio_buffer_init(struct iio_buffer *buffer)
 	INIT_LIST_HEAD(&buffer->buffer_list);
 	init_waitqueue_head(&buffer->pollq);
 	kref_init(&buffer->ref);
+	buffer->watermark = 1;
 }
 EXPORT_SYMBOL(iio_buffer_init);
 
@@ -416,6 +474,11 @@ static ssize_t iio_buffer_write_length(struct device *dev,
 		buffer->access->set_length(buffer, val);
 		ret = 0;
 	}
+	if (ret)
+		goto out;
+	if (buffer->length && buffer->length < buffer->watermark)
+		buffer->watermark = buffer->length;
+out:
 	mutex_unlock(&indio_dev->mlock);
 
 	return ret ? ret : len;
@@ -472,6 +535,7 @@ static void iio_buffer_activate(struct iio_dev *indio_dev,
 static void iio_buffer_deactivate(struct iio_buffer *buffer)
 {
 	list_del_init(&buffer->buffer_list);
+	wake_up_interruptible(&buffer->pollq);
 	iio_buffer_put(buffer);
 }
 
@@ -629,19 +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;
 	}
@@ -754,12 +815,68 @@ done:
 
 static const char * const iio_scan_elements_group_name = "scan_elements";
 
+static ssize_t iio_buffer_show_watermark(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct iio_buffer *buffer = indio_dev->buffer;
+
+	return sprintf(buf, "%u\n", buffer->watermark);
+}
+
+static ssize_t iio_buffer_store_watermark(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf,
+					  size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct iio_buffer *buffer = indio_dev->buffer;
+	unsigned int val;
+	int ret;
+
+	ret = kstrtouint(buf, 10, &val);
+	if (ret)
+		return ret;
+	if (!val)
+		return -EINVAL;
+
+	mutex_lock(&indio_dev->mlock);
+
+	if (val > buffer->length) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (iio_buffer_is_active(indio_dev->buffer)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	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);
+
+	return ret ? ret : len;
+}
+
 static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
 		   iio_buffer_write_length);
 static struct device_attribute dev_attr_length_ro = __ATTR(length,
 	S_IRUGO, iio_buffer_read_length, NULL);
 static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
 		   iio_buffer_show_enable, iio_buffer_store_enable);
+static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
+		   iio_buffer_show_watermark, iio_buffer_store_watermark);
+
+static struct attribute *iio_buffer_attrs[] = {
+	&dev_attr_length.attr,
+	&dev_attr_enable.attr,
+	&dev_attr_watermark.attr,
+};
 
 int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
 {
@@ -778,21 +895,23 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
 			attrcount++;
 	}
 
-	buffer->buffer_group.name = "buffer";
-	buffer->buffer_group.attrs = kcalloc(attrcount + 3,
-			sizeof(*buffer->buffer_group.attrs), GFP_KERNEL);
-	if (!buffer->buffer_group.attrs)
+	attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
+		       sizeof(struct attribute *), GFP_KERNEL);
+	if (!attr)
 		return -ENOMEM;
 
-	if (buffer->access->set_length)
-		buffer->buffer_group.attrs[0] = &dev_attr_length.attr;
-	else
-		buffer->buffer_group.attrs[0] = &dev_attr_length_ro.attr;
-	buffer->buffer_group.attrs[1] = &dev_attr_enable.attr;
+	memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
+	if (!buffer->access->set_length)
+		attr[0] = &dev_attr_length_ro.attr;
+
 	if (buffer->attrs)
-		memcpy(&buffer->buffer_group.attrs[2], buffer->attrs,
-			sizeof(*&buffer->buffer_group.attrs) * attrcount);
-	buffer->buffer_group.attrs[attrcount+2] = NULL;
+		memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
+		       sizeof(struct attribute *) * attrcount);
+
+	attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL;
+
+	buffer->buffer_group.name = "buffer";
+	buffer->buffer_group.attrs = attr;
 
 	indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
 
@@ -937,8 +1056,18 @@ static const void *iio_demux(struct iio_buffer *buffer,
 static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
 {
 	const void *dataout = iio_demux(buffer, data);
+	int ret;
 
-	return buffer->access->store_to(buffer, dataout);
+	ret = buffer->access->store_to(buffer, dataout);
+	if (ret)
+		return ret;
+
+	/*
+	 * We can't just test for watermark to decide if we wake the poll queue
+	 * because read may request less samples than the watermark.
+	 */
+	wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
+	return 0;
 }
 
 static void iio_buffer_demux_free(struct iio_buffer *buffer)