diff options
Diffstat (limited to 'include/linux/iio/iio.h')
| -rw-r--r-- | include/linux/iio/iio.h | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 07a0e8132e88..d11668f14a3e 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -7,9 +7,11 @@ #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> +#include <linux/minmax.h> #include <linux/slab.h> #include <linux/iio/types.h> /* IIO TODO LIST */ @@ -659,8 +661,8 @@ void iio_device_unregister(struct iio_dev *indio_dev); int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev, struct module *this_mod); int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp); -int iio_device_claim_direct_mode(struct iio_dev *indio_dev); -void iio_device_release_direct_mode(struct iio_dev *indio_dev); +bool __iio_device_claim_direct(struct iio_dev *indio_dev); +void __iio_device_release_direct(struct iio_dev *indio_dev); /* * Helper functions that allow claim and release of direct mode @@ -671,9 +673,7 @@ void iio_device_release_direct_mode(struct iio_dev *indio_dev); */ static inline bool iio_device_claim_direct(struct iio_dev *indio_dev) { - int ret = iio_device_claim_direct_mode(indio_dev); - - if (ret) + if (!__iio_device_claim_direct(indio_dev)) return false; __acquire(iio_dev); @@ -683,7 +683,7 @@ static inline bool iio_device_claim_direct(struct iio_dev *indio_dev) static inline void iio_device_release_direct(struct iio_dev *indio_dev) { - iio_device_release_direct_mode(indio_dev); + __iio_device_release_direct(indio_dev); __release(indio_dev); } @@ -777,8 +777,45 @@ static inline void *iio_device_get_drvdata(const struct iio_dev *indio_dev) * to in turn include IIO_DMA_MINALIGN'd elements such as buffers which * must not share cachelines with the rest of the structure, thus making * them safe for use with non-coherent DMA. + * + * A number of drivers also use this on buffers that include a 64-bit timestamp + * that is used with iio_push_to_buffer_with_ts(). Therefore, in the case where + * DMA alignment is not sufficient for proper timestamp alignment, we align to + * 8 bytes instead. + */ +#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_DMA_MINALIGN ARCH_DMA_MINALIGN +#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 */ |