diff options
| author | Mihail Chindris <mihail.chindris@analog.com> | 2021-10-07 08:00:30 +0000 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2021-10-19 08:30:44 +0100 |
| commit | 9eeee3b0bf190b4f677af27e24ba0cd1c030e49b (patch) | |
| tree | a30f4dcb58b2086aed34160d297c233fc76aaea2 /drivers/iio/iio_core.h | |
| parent | d6fa1406306d6608d50e974551c61ebbfa5e26d0 (diff) | |
iio: Add output buffer support
Currently IIO only supports buffer mode for capture devices like ADCs. Add
support for buffered mode for output devices like DACs.
The output buffer implementation is analogous to the input buffer
implementation. Instead of using read() to get data from the buffer write()
is used to copy data into the buffer.
poll() with POLLOUT will wakeup if there is space available.
Drivers can remove data from a buffer using iio_pop_from_buffer(), the
function can e.g. called from a trigger handler to write the data to
hardware.
A buffer can only be either a output buffer or an input, but not both. So,
for a device that has an ADC and DAC path, this will mean 2 IIO buffers
(one for each direction).
The direction of the buffer is decided by the new direction field of the
iio_buffer struct and should be set after allocating and before registering
it.
Co-developed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Co-developed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211007080035.2531-2-mihail.chindris@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/iio_core.h')
| -rw-r--r-- | drivers/iio/iio_core.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h index 8f4a9b264962..61e318431de9 100644 --- a/drivers/iio/iio_core.h +++ b/drivers/iio/iio_core.h @@ -68,12 +68,15 @@ __poll_t iio_buffer_poll_wrapper(struct file *filp, struct poll_table_struct *wait); ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf, size_t n, loff_t *f_ps); +ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf, + size_t n, loff_t *f_ps); int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev); void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev); #define iio_buffer_poll_addr (&iio_buffer_poll_wrapper) #define iio_buffer_read_outer_addr (&iio_buffer_read_wrapper) +#define iio_buffer_write_outer_addr (&iio_buffer_write_wrapper) void iio_disable_all_buffers(struct iio_dev *indio_dev); void iio_buffer_wakeup_poll(struct iio_dev *indio_dev); @@ -83,6 +86,7 @@ void iio_device_detach_buffers(struct iio_dev *indio_dev); #define iio_buffer_poll_addr NULL #define iio_buffer_read_outer_addr NULL +#define iio_buffer_write_outer_addr NULL static inline int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev) { |