| Message ID | 20210201145105.20459-11-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: core,buffer: add support for multiple IIO buffers per IIO device | expand |
On Mon, 1 Feb 2021 16:51:04 +0200 Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > With this change, calling iio_device_attach_buffer() will actually attach > more buffers. > Right now this doesn't do any validation of whether a buffer is attached > twice; maybe that can be added later (if needed). Attaching a buffer more > than once should yield noticeably bad results. > > The first buffer is the legacy buffer, so a reference is kept to it. > > At this point, accessing the data for the extra buffers (that are added > after the first one) isn't possible yet. > > The iio_device_attach_buffer() is also changed to return an error code, > which for now is -ENOMEM if the array could not be realloc-ed for more > buffers. > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> A few minor comments inline. Thanks, J > --- > drivers/iio/industrialio-buffer.c | 80 +++++++++++++++++++++++++------ > include/linux/iio/buffer.h | 4 +- > include/linux/iio/buffer_impl.h | 3 ++ > include/linux/iio/iio-opaque.h | 4 ++ > 4 files changed, 74 insertions(+), 17 deletions(-) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index 692f721588e2..a69bb705d173 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1445,11 +1445,21 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > return ret; > } > > +static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > +{ > + bitmap_free(buffer->scan_mask); > + kfree(buffer->buffer_group.name); > + kfree(buffer->buffer_group.attrs); > + iio_free_chan_devattr_list(&buffer->buffer_attr_list); > +} > + > int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > { > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > const struct iio_chan_spec *channels; > - int i; > + int unwind_idx; > + int ret, i; > > channels = indio_dev->channels; > if (channels) { > @@ -1463,27 +1473,45 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > if (!buffer) > return 0; > > - return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > -} > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i); > + if (ret) { > + unwind_idx = i; Gut feeling would be to use i instead of introducing unwind_idx, but it doesn't really matter if you prefer this. > + goto error_unwind_sysfs_and_mask; > + } > + } > > -static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > -{ > - bitmap_free(buffer->scan_mask); > - kfree(buffer->buffer_group.name); > - kfree(buffer->buffer_group.attrs); > - iio_free_chan_devattr_list(&buffer->buffer_attr_list); could you put this move in a precursor patch. It's making a mess of the diff and hence this harder to review than it should be. > + return 0; > + > +error_unwind_sysfs_and_mask: > + for (; unwind_idx >= 0; unwind_idx--) { > + buffer = iio_dev_opaque->attached_buffers[unwind_idx]; > + __iio_buffer_free_sysfs_and_mask(buffer); > + } > + kfree(iio_dev_opaque->attached_buffers); > + iio_dev_opaque->attached_buffers = NULL; > + return ret; > } > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > { > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > + int i; > > if (!buffer) > return; > > iio_buffer_unregister_legacy_sysfs_groups(indio_dev); > > - __iio_buffer_free_sysfs_and_mask(buffer); > + for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + __iio_buffer_free_sysfs_and_mask(buffer); > + } > + > + kfree(iio_dev_opaque->attached_buffers); > + iio_dev_opaque->attached_buffers = NULL; For places where we set freed pointers to NULL, I'd like a comment on why. Usually it makes me a bit worried we are doing something less than tidy. > } > > /** > @@ -1601,13 +1629,35 @@ EXPORT_SYMBOL_GPL(iio_buffer_put); > * @indio_dev: The device the buffer should be attached to > * @buffer: The buffer to attach to the device > * > + * Return 0 if successful, negative if error. > + * > * This function attaches a buffer to a IIO device. The buffer stays attached to > - * the device until the device is freed. The function should only be called at > - * most once per device. > + * the device until the device is freed. For legacy reasons, the first attached > + * buffer will also be assigned to 'indio_dev->buffer'. > */ > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > - struct iio_buffer *buffer) > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > + struct iio_buffer *buffer) > { > - indio_dev->buffer = iio_buffer_get(buffer); > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > + struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; > + unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; > + > + cnt++; > + > + new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); > + if (!new) > + return -ENOMEM; > + iio_dev_opaque->attached_buffers = new; > + > + buffer = iio_buffer_get(buffer); > + > + /* first buffer is legacy; attach it to the IIO device directly */ > + if (!indio_dev->buffer) > + indio_dev->buffer = buffer; > + > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > + iio_dev_opaque->attached_buffers_cnt = cnt; > + > + return 0; > } > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h > index 8febc23f5f26..b6928ac5c63d 100644 > --- a/include/linux/iio/buffer.h > +++ b/include/linux/iio/buffer.h > @@ -41,7 +41,7 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, > bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, > const unsigned long *mask); > > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > - struct iio_buffer *buffer); > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > + struct iio_buffer *buffer); > > #endif /* _IIO_BUFFER_GENERIC_H_ */ > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > index 41044320e581..768b90c64412 100644 > --- a/include/linux/iio/buffer_impl.h > +++ b/include/linux/iio/buffer_impl.h > @@ -112,6 +112,9 @@ struct iio_buffer { > /* @demux_bounce: Buffer for doing gather from incoming scan. */ > void *demux_bounce; > > + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ > + struct list_head attached_entry; > + > /* @buffer_list: Entry in the devices list of current buffers. */ > struct list_head buffer_list; > > diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h > index 3e4c3cd248fd..c909835b6247 100644 > --- a/include/linux/iio/iio-opaque.h > +++ b/include/linux/iio/iio-opaque.h > @@ -7,6 +7,8 @@ > * struct iio_dev_opaque - industrial I/O device opaque information > * @indio_dev: public industrial I/O device information > * @event_interface: event chrdevs associated with interrupt lines > + * @attached_buffers: array of buffers statically attached by the driver > + * @attached_buffers_cnt: number of buffers in the array of statically attached buffers > * @buffer_list: list of all buffers currently attached > * @channel_attr_list: keep track of automatically created channel > * attributes > @@ -24,6 +26,8 @@ > struct iio_dev_opaque { > struct iio_dev indio_dev; > struct iio_event_interface *event_interface; > + struct iio_buffer **attached_buffers; > + unsigned int attached_buffers_cnt; > struct list_head buffer_list; > struct list_head channel_attr_list; > struct attribute_group chan_attr_group;
On Thu, Feb 4, 2021 at 8:39 PM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > On Mon, 1 Feb 2021 16:51:04 +0200 > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > > > With this change, calling iio_device_attach_buffer() will actually attach > > more buffers. > > Right now this doesn't do any validation of whether a buffer is attached > > twice; maybe that can be added later (if needed). Attaching a buffer more > > than once should yield noticeably bad results. > > > > The first buffer is the legacy buffer, so a reference is kept to it. > > > > At this point, accessing the data for the extra buffers (that are added > > after the first one) isn't possible yet. > > > > The iio_device_attach_buffer() is also changed to return an error code, > > which for now is -ENOMEM if the array could not be realloc-ed for more > > buffers. > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > A few minor comments inline. > > Thanks, > > J > > --- > > drivers/iio/industrialio-buffer.c | 80 +++++++++++++++++++++++++------ > > include/linux/iio/buffer.h | 4 +- > > include/linux/iio/buffer_impl.h | 3 ++ > > include/linux/iio/iio-opaque.h | 4 ++ > > 4 files changed, 74 insertions(+), 17 deletions(-) > > > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > > index 692f721588e2..a69bb705d173 100644 > > --- a/drivers/iio/industrialio-buffer.c > > +++ b/drivers/iio/industrialio-buffer.c > > @@ -1445,11 +1445,21 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > > return ret; > > } > > > > +static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > +{ > > + bitmap_free(buffer->scan_mask); > > + kfree(buffer->buffer_group.name); > > + kfree(buffer->buffer_group.attrs); > > + iio_free_chan_devattr_list(&buffer->buffer_attr_list); > > +} > > + > > int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > { > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > struct iio_buffer *buffer = indio_dev->buffer; > > const struct iio_chan_spec *channels; > > - int i; > > + int unwind_idx; > > + int ret, i; > > > > channels = indio_dev->channels; > > if (channels) { > > @@ -1463,27 +1473,45 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > if (!buffer) > > return 0; > > > > - return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > > -} > > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > > + buffer = iio_dev_opaque->attached_buffers[i]; > > + ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i); > > + if (ret) { > > + unwind_idx = i; > Gut feeling would be to use i instead of introducing unwind_idx, but it > doesn't really matter if you prefer this. I thought about leaving 'i' here, but then in the next patch a block/patch is added that makes using 'i' less obvious/clean. So, unwind_idx is clearer after more code is added after this block. > > > + goto error_unwind_sysfs_and_mask; > > + } > > + } > > > > -static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > -{ > > - bitmap_free(buffer->scan_mask); > > - kfree(buffer->buffer_group.name); > > - kfree(buffer->buffer_group.attrs); > > - iio_free_chan_devattr_list(&buffer->buffer_attr_list); > > could you put this move in a precursor patch. It's making a mess > of the diff and hence this harder to review than it should be. ack > > > + return 0; > > + > > +error_unwind_sysfs_and_mask: > > + for (; unwind_idx >= 0; unwind_idx--) { > > + buffer = iio_dev_opaque->attached_buffers[unwind_idx]; > > + __iio_buffer_free_sysfs_and_mask(buffer); > > + } > > + kfree(iio_dev_opaque->attached_buffers); > > + iio_dev_opaque->attached_buffers = NULL; > > + return ret; > > } > > > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > > { > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > struct iio_buffer *buffer = indio_dev->buffer; > > + int i; > > > > if (!buffer) > > return; > > > > iio_buffer_unregister_legacy_sysfs_groups(indio_dev); > > > > - __iio_buffer_free_sysfs_and_mask(buffer); > > + for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { > > + buffer = iio_dev_opaque->attached_buffers[i]; > > + __iio_buffer_free_sysfs_and_mask(buffer); > > + } > > + > > + kfree(iio_dev_opaque->attached_buffers); > > + iio_dev_opaque->attached_buffers = NULL; > > For places where we set freed pointers to NULL, I'd like a comment on why. > Usually it makes me a bit worried we are doing something less than tidy. ack; will remove; > > > } > > > > /** > > @@ -1601,13 +1629,35 @@ EXPORT_SYMBOL_GPL(iio_buffer_put); > > * @indio_dev: The device the buffer should be attached to > > * @buffer: The buffer to attach to the device > > * > > + * Return 0 if successful, negative if error. > > + * > > * This function attaches a buffer to a IIO device. The buffer stays attached to > > - * the device until the device is freed. The function should only be called at > > - * most once per device. > > + * the device until the device is freed. For legacy reasons, the first attached > > + * buffer will also be assigned to 'indio_dev->buffer'. > > */ > > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > > - struct iio_buffer *buffer) > > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > > + struct iio_buffer *buffer) > > { > > - indio_dev->buffer = iio_buffer_get(buffer); > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > + struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; > > + unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; > > + > > + cnt++; > > + > > + new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); > > + if (!new) > > + return -ENOMEM; > > + iio_dev_opaque->attached_buffers = new; > > + > > + buffer = iio_buffer_get(buffer); > > + > > + /* first buffer is legacy; attach it to the IIO device directly */ > > + if (!indio_dev->buffer) > > + indio_dev->buffer = buffer; > > + > > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > > + iio_dev_opaque->attached_buffers_cnt = cnt; > > + > > + return 0; > > } > > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > > diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h > > index 8febc23f5f26..b6928ac5c63d 100644 > > --- a/include/linux/iio/buffer.h > > +++ b/include/linux/iio/buffer.h > > @@ -41,7 +41,7 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, > > bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, > > const unsigned long *mask); > > > > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > > - struct iio_buffer *buffer); > > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > > + struct iio_buffer *buffer); > > > > #endif /* _IIO_BUFFER_GENERIC_H_ */ > > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > > index 41044320e581..768b90c64412 100644 > > --- a/include/linux/iio/buffer_impl.h > > +++ b/include/linux/iio/buffer_impl.h > > @@ -112,6 +112,9 @@ struct iio_buffer { > > /* @demux_bounce: Buffer for doing gather from incoming scan. */ > > void *demux_bounce; > > > > + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ > > + struct list_head attached_entry; > > + > > /* @buffer_list: Entry in the devices list of current buffers. */ > > struct list_head buffer_list; > > > > diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h > > index 3e4c3cd248fd..c909835b6247 100644 > > --- a/include/linux/iio/iio-opaque.h > > +++ b/include/linux/iio/iio-opaque.h > > @@ -7,6 +7,8 @@ > > * struct iio_dev_opaque - industrial I/O device opaque information > > * @indio_dev: public industrial I/O device information > > * @event_interface: event chrdevs associated with interrupt lines > > + * @attached_buffers: array of buffers statically attached by the driver > > + * @attached_buffers_cnt: number of buffers in the array of statically attached buffers > > * @buffer_list: list of all buffers currently attached > > * @channel_attr_list: keep track of automatically created channel > > * attributes > > @@ -24,6 +26,8 @@ > > struct iio_dev_opaque { > > struct iio_dev indio_dev; > > struct iio_event_interface *event_interface; > > + struct iio_buffer **attached_buffers; > > + unsigned int attached_buffers_cnt; > > struct list_head buffer_list; > > struct list_head channel_attr_list; > > struct attribute_group chan_attr_group; >
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 692f721588e2..a69bb705d173 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1445,11 +1445,21 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, return ret; } +static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) +{ + bitmap_free(buffer->scan_mask); + kfree(buffer->buffer_group.name); + kfree(buffer->buffer_group.attrs); + iio_free_chan_devattr_list(&buffer->buffer_attr_list); +} + int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) { + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = indio_dev->buffer; const struct iio_chan_spec *channels; - int i; + int unwind_idx; + int ret, i; channels = indio_dev->channels; if (channels) { @@ -1463,27 +1473,45 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) if (!buffer) return 0; - return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); -} + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { + buffer = iio_dev_opaque->attached_buffers[i]; + ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i); + if (ret) { + unwind_idx = i; + goto error_unwind_sysfs_and_mask; + } + } -static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) -{ - bitmap_free(buffer->scan_mask); - kfree(buffer->buffer_group.name); - kfree(buffer->buffer_group.attrs); - iio_free_chan_devattr_list(&buffer->buffer_attr_list); + return 0; + +error_unwind_sysfs_and_mask: + for (; unwind_idx >= 0; unwind_idx--) { + buffer = iio_dev_opaque->attached_buffers[unwind_idx]; + __iio_buffer_free_sysfs_and_mask(buffer); + } + kfree(iio_dev_opaque->attached_buffers); + iio_dev_opaque->attached_buffers = NULL; + return ret; } void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) { + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = indio_dev->buffer; + int i; if (!buffer) return; iio_buffer_unregister_legacy_sysfs_groups(indio_dev); - __iio_buffer_free_sysfs_and_mask(buffer); + for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { + buffer = iio_dev_opaque->attached_buffers[i]; + __iio_buffer_free_sysfs_and_mask(buffer); + } + + kfree(iio_dev_opaque->attached_buffers); + iio_dev_opaque->attached_buffers = NULL; } /** @@ -1601,13 +1629,35 @@ EXPORT_SYMBOL_GPL(iio_buffer_put); * @indio_dev: The device the buffer should be attached to * @buffer: The buffer to attach to the device * + * Return 0 if successful, negative if error. + * * This function attaches a buffer to a IIO device. The buffer stays attached to - * the device until the device is freed. The function should only be called at - * most once per device. + * the device until the device is freed. For legacy reasons, the first attached + * buffer will also be assigned to 'indio_dev->buffer'. */ -void iio_device_attach_buffer(struct iio_dev *indio_dev, - struct iio_buffer *buffer) +int iio_device_attach_buffer(struct iio_dev *indio_dev, + struct iio_buffer *buffer) { - indio_dev->buffer = iio_buffer_get(buffer); + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); + struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; + unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; + + cnt++; + + new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); + if (!new) + return -ENOMEM; + iio_dev_opaque->attached_buffers = new; + + buffer = iio_buffer_get(buffer); + + /* first buffer is legacy; attach it to the IIO device directly */ + if (!indio_dev->buffer) + indio_dev->buffer = buffer; + + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; + iio_dev_opaque->attached_buffers_cnt = cnt; + + return 0; } EXPORT_SYMBOL_GPL(iio_device_attach_buffer); diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h index 8febc23f5f26..b6928ac5c63d 100644 --- a/include/linux/iio/buffer.h +++ b/include/linux/iio/buffer.h @@ -41,7 +41,7 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, const unsigned long *mask); -void iio_device_attach_buffer(struct iio_dev *indio_dev, - struct iio_buffer *buffer); +int iio_device_attach_buffer(struct iio_dev *indio_dev, + struct iio_buffer *buffer); #endif /* _IIO_BUFFER_GENERIC_H_ */ diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index 41044320e581..768b90c64412 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -112,6 +112,9 @@ struct iio_buffer { /* @demux_bounce: Buffer for doing gather from incoming scan. */ void *demux_bounce; + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ + struct list_head attached_entry; + /* @buffer_list: Entry in the devices list of current buffers. */ struct list_head buffer_list; diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h index 3e4c3cd248fd..c909835b6247 100644 --- a/include/linux/iio/iio-opaque.h +++ b/include/linux/iio/iio-opaque.h @@ -7,6 +7,8 @@ * struct iio_dev_opaque - industrial I/O device opaque information * @indio_dev: public industrial I/O device information * @event_interface: event chrdevs associated with interrupt lines + * @attached_buffers: array of buffers statically attached by the driver + * @attached_buffers_cnt: number of buffers in the array of statically attached buffers * @buffer_list: list of all buffers currently attached * @channel_attr_list: keep track of automatically created channel * attributes @@ -24,6 +26,8 @@ struct iio_dev_opaque { struct iio_dev indio_dev; struct iio_event_interface *event_interface; + struct iio_buffer **attached_buffers; + unsigned int attached_buffers_cnt; struct list_head buffer_list; struct list_head channel_attr_list; struct attribute_group chan_attr_group;
With this change, calling iio_device_attach_buffer() will actually attach more buffers. Right now this doesn't do any validation of whether a buffer is attached twice; maybe that can be added later (if needed). Attaching a buffer more than once should yield noticeably bad results. The first buffer is the legacy buffer, so a reference is kept to it. At this point, accessing the data for the extra buffers (that are added after the first one) isn't possible yet. The iio_device_attach_buffer() is also changed to return an error code, which for now is -ENOMEM if the array could not be realloc-ed for more buffers. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- drivers/iio/industrialio-buffer.c | 80 +++++++++++++++++++++++++------ include/linux/iio/buffer.h | 4 +- include/linux/iio/buffer_impl.h | 3 ++ include/linux/iio/iio-opaque.h | 4 ++ 4 files changed, 74 insertions(+), 17 deletions(-)