diff options
| -rw-r--r-- | include/linux/iio/iio.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index a574f22398e4..d11668f14a3e 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -7,6 +7,7 @@ #ifndef _INDUSTRIAL_IO_H_ #define _INDUSTRIAL_IO_H_ +#include <linux/align.h> #include <linux/device.h> #include <linux/cdev.h> #include <linux/compiler_types.h> @@ -784,6 +785,37 @@ static inline void *iio_device_get_drvdata(const struct iio_dev *indio_dev) */ #define IIO_DMA_MINALIGN MAX(ARCH_DMA_MINALIGN, sizeof(s64)) +#define __IIO_DECLARE_BUFFER_WITH_TS(type, name, count) \ + type name[ALIGN((count), sizeof(s64) / sizeof(type)) + sizeof(s64) / sizeof(type)] + +/** + * IIO_DECLARE_BUFFER_WITH_TS() - Declare a buffer with timestamp + * @type: element type of the buffer + * @name: identifier name of the buffer + * @count: number of elements in the buffer + * + * Declares a buffer that is safe to use with iio_push_to_buffer_with_ts(). In + * addition to allocating enough space for @count elements of @type, it also + * allocates space for a s64 timestamp at the end of the buffer and ensures + * proper alignment of the timestamp. + */ +#define IIO_DECLARE_BUFFER_WITH_TS(type, name, count) \ + __IIO_DECLARE_BUFFER_WITH_TS(type, name, count) __aligned(sizeof(s64)) + +/** + * IIO_DECLARE_DMA_BUFFER_WITH_TS() - Declare a DMA-aligned buffer with timestamp + * @type: element type of the buffer + * @name: identifier name of the buffer + * @count: number of elements in the buffer + * + * Same as IIO_DECLARE_BUFFER_WITH_TS(), but is uses __aligned(IIO_DMA_MINALIGN) + * to ensure that the buffer doesn't share cachelines with anything that comes + * before it in a struct. This should not be used for stack-allocated buffers + * as stack memory cannot generally be used for DMA. + */ +#define IIO_DECLARE_DMA_BUFFER_WITH_TS(type, name, count) \ + __IIO_DECLARE_BUFFER_WITH_TS(type, name, count) __aligned(IIO_DMA_MINALIGN) + struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv); /* The information at the returned address is guaranteed to be cacheline aligned */ |