[PATCH v2 1/2] iio: Move scan mask management to the core

From: Alexandru Ardelean
Date: Wed Apr 29 2020 - 11:17:47 EST


From: Lars-Peter Clausen <lars@xxxxxxxxxx>

Let the core handle the buffer scan mask management including allocation
and channel selection. Having this handled in a central place rather than
open-coding it all over the place will make it easier to change the
implementation (if needed).
At the very least, this change abstracts scan-mask management away from
buffer implementations.

Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---

Changelog v1 -> v2:
- split away from initial series; the `buffer->channel_mask` attribute
requires a bit more dicussion; or may even be dropped; just these 2
patches helps with diff-ing 2 trees, as applying patches between my
work tree & IIO has fewer conflicts
- return -EINVAL if masklength is 0 in iio_buffer_alloc_scanmask()
- convert 2nd parameter to `unsigned int masklength` in
iio_buffer_alloc_scanmask()

drivers/iio/buffer/industrialio-buffer-cb.c | 17 +++++-----
drivers/iio/industrialio-buffer.c | 36 +++++++++++++++------
drivers/iio/inkern.c | 15 +++++++++
include/linux/iio/consumer.h | 10 ++++++
4 files changed, 59 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c
index 47c96f7f4976..dc5bb2ab533a 100644
--- a/drivers/iio/buffer/industrialio-buffer-cb.c
+++ b/drivers/iio/buffer/industrialio-buffer-cb.c
@@ -34,7 +34,7 @@ static void iio_buffer_cb_release(struct iio_buffer *buffer)
{
struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);

- bitmap_free(cb_buff->buffer.scan_mask);
+ iio_buffer_free_scanmask(&cb_buff->buffer);
kfree(cb_buff);
}

@@ -72,27 +72,26 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
}

cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
- cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
- GFP_KERNEL);
- if (cb_buff->buffer.scan_mask == NULL) {
- ret = -ENOMEM;
+
+ ret = iio_buffer_alloc_scanmask(&cb_buff->buffer,
+ cb_buff->indio_dev->masklength);
+ if (ret)
goto error_release_channels;
- }
+
chan = &cb_buff->channels[0];
while (chan->indio_dev) {
if (chan->indio_dev != cb_buff->indio_dev) {
ret = -EINVAL;
goto error_free_scan_mask;
}
- set_bit(chan->channel->scan_index,
- cb_buff->buffer.scan_mask);
+ iio_buffer_channel_enable(&cb_buff->buffer, chan);
chan++;
}

return cb_buff;

error_free_scan_mask:
- bitmap_free(cb_buff->buffer.scan_mask);
+ iio_buffer_free_scanmask(&cb_buff->buffer);
error_release_channels:
iio_channel_release_all(cb_buff->channels);
error_free_cb_buff:
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index eae39eaf49af..c6b63f4474ff 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -208,6 +208,26 @@ void iio_buffer_init(struct iio_buffer *buffer)
}
EXPORT_SYMBOL(iio_buffer_init);

+int iio_buffer_alloc_scanmask(struct iio_buffer *buffer,
+ unsigned int masklength)
+{
+ if (!masklength)
+ return -EINVAL;
+
+ buffer->scan_mask = bitmap_zalloc(masklength, GFP_KERNEL);
+ if (buffer->scan_mask == NULL)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iio_buffer_alloc_scanmask);
+
+void iio_buffer_free_scanmask(struct iio_buffer *buffer)
+{
+ bitmap_free(buffer->scan_mask);
+}
+EXPORT_SYMBOL_GPL(iio_buffer_free_scanmask);
+
/**
* iio_buffer_set_attrs - Set buffer specific attributes
* @buffer: The buffer for which we are setting attributes
@@ -1306,14 +1326,10 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
indio_dev->scan_index_timestamp =
channels[i].scan_index;
}
- if (indio_dev->masklength && buffer->scan_mask == NULL) {
- buffer->scan_mask = bitmap_zalloc(indio_dev->masklength,
- GFP_KERNEL);
- if (buffer->scan_mask == NULL) {
- ret = -ENOMEM;
- goto error_cleanup_dynamic;
- }
- }
+
+ ret = iio_buffer_alloc_scanmask(buffer, indio_dev->masklength);
+ if (ret)
+ goto error_cleanup_dynamic;
}

buffer->scan_el_group.name = iio_scan_elements_group_name;
@@ -1334,7 +1350,7 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
return 0;

error_free_scan_mask:
- bitmap_free(buffer->scan_mask);
+ iio_buffer_free_scanmask(buffer);
error_cleanup_dynamic:
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
kfree(buffer->buffer_group.attrs);
@@ -1349,7 +1365,7 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
if (!buffer)
return;

- bitmap_free(buffer->scan_mask);
+ iio_buffer_free_scanmask(buffer);
kfree(buffer->buffer_group.attrs);
kfree(buffer->scan_el_group.attrs);
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index ede99e0d5371..f35cb9985edc 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -11,6 +11,7 @@

#include <linux/iio/iio.h>
#include "iio_core.h"
+#include <linux/iio/buffer_impl.h>
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>
@@ -857,6 +858,20 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);

+void iio_buffer_channel_enable(struct iio_buffer *buffer,
+ const struct iio_channel *chan)
+{
+ set_bit(chan->channel->scan_index, buffer->scan_mask);
+}
+EXPORT_SYMBOL_GPL(iio_buffer_channel_enable);
+
+void iio_buffer_channel_disable(struct iio_buffer *buffer,
+ const struct iio_channel *chan)
+{
+ clear_bit(chan->channel->scan_index, buffer->scan_mask);
+}
+EXPORT_SYMBOL_GPL(iio_buffer_channel_disable);
+
unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
{
const struct iio_chan_spec_ext_info *ext_info;
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index c4118dcb8e05..9fcd320c2fb4 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -12,6 +12,7 @@

struct iio_dev;
struct iio_chan_spec;
+struct iio_buffer;
struct device;

/**
@@ -342,6 +343,15 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val,
int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
int *processed, unsigned int scale);

+void iio_buffer_channel_enable(struct iio_buffer *buffer,
+ const struct iio_channel *chan);
+void iio_buffer_channel_disable(struct iio_buffer *buffer,
+ const struct iio_channel *chan);
+
+int iio_buffer_alloc_scanmask(struct iio_buffer *buffer,
+ unsigned int masklength);
+void iio_buffer_free_scanmask(struct iio_buffer *buffer);
+
/**
* iio_get_channel_ext_info_count() - get number of ext_info attributes
* connected to the channel.
--
2.17.1