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author | Jonathan Cameron <jic23@kernel.org> | 2012-04-25 14:54:59 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-25 18:11:38 (GMT) |
commit | a980e046098b0a40eaff5e4e7fcde6cf035b7c06 (patch) | |
tree | 23375fc2bba39f088974cf621f7abf006d43d087 /drivers/iio/kfifo_buf.c | |
parent | 06458e277eac2b8761b0a04d3c808d57be281a2e (diff) | |
download | linux-fsl-qoriq-a980e046098b0a40eaff5e4e7fcde6cf035b7c06.tar.xz |
IIO: Move the core files to drivers/iio
Take the core support + the kfifo buffer implentation out of
staging. Whilst we are far from done in improving this subsystem
it is now at a stage where the userspae interfaces (provided by
the core) can be considered stable.
Drivers will follow over a longer time scale.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio/kfifo_buf.c')
-rw-r--r-- | drivers/iio/kfifo_buf.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c new file mode 100644 index 0000000..6bf9d05 --- /dev/null +++ b/drivers/iio/kfifo_buf.c @@ -0,0 +1,150 @@ +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/workqueue.h> +#include <linux/kfifo.h> +#include <linux/mutex.h> +#include <linux/iio/kfifo_buf.h> + +struct iio_kfifo { + struct iio_buffer buffer; + struct kfifo kf; + int update_needed; +}; + +#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) + +static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, + int bytes_per_datum, int length) +{ + if ((length == 0) || (bytes_per_datum == 0)) + return -EINVAL; + + __iio_update_buffer(&buf->buffer, bytes_per_datum, length); + return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL); +} + +static int iio_request_update_kfifo(struct iio_buffer *r) +{ + int ret = 0; + struct iio_kfifo *buf = iio_to_kfifo(r); + + if (!buf->update_needed) + goto error_ret; + kfifo_free(&buf->kf); + ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, + buf->buffer.length); +error_ret: + return ret; +} + +static int iio_get_length_kfifo(struct iio_buffer *r) +{ + return r->length; +} + +static IIO_BUFFER_ENABLE_ATTR; +static IIO_BUFFER_LENGTH_ATTR; + +static struct attribute *iio_kfifo_attributes[] = { + &dev_attr_length.attr, + &dev_attr_enable.attr, + NULL, +}; + +static struct attribute_group iio_kfifo_attribute_group = { + .attrs = iio_kfifo_attributes, + .name = "buffer", +}; + +static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) +{ + return r->bytes_per_datum; +} + +static int iio_mark_update_needed_kfifo(struct iio_buffer *r) +{ + struct iio_kfifo *kf = iio_to_kfifo(r); + kf->update_needed = true; + return 0; +} + +static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) +{ + if (r->bytes_per_datum != bpd) { + r->bytes_per_datum = bpd; + iio_mark_update_needed_kfifo(r); + } + return 0; +} + +static int iio_set_length_kfifo(struct iio_buffer *r, int length) +{ + if (r->length != length) { + r->length = length; + iio_mark_update_needed_kfifo(r); + } + return 0; +} + +static int iio_store_to_kfifo(struct iio_buffer *r, + u8 *data, + s64 timestamp) +{ + int ret; + struct iio_kfifo *kf = iio_to_kfifo(r); + ret = kfifo_in(&kf->kf, data, r->bytes_per_datum); + if (ret != r->bytes_per_datum) + return -EBUSY; + return 0; +} + +static int iio_read_first_n_kfifo(struct iio_buffer *r, + size_t n, char __user *buf) +{ + int ret, copied; + struct iio_kfifo *kf = iio_to_kfifo(r); + + if (n < r->bytes_per_datum) + return -EINVAL; + + n = rounddown(n, r->bytes_per_datum); + ret = kfifo_to_user(&kf->kf, buf, n, &copied); + + return copied; +} + +static const struct iio_buffer_access_funcs kfifo_access_funcs = { + .store_to = &iio_store_to_kfifo, + .read_first_n = &iio_read_first_n_kfifo, + .request_update = &iio_request_update_kfifo, + .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo, + .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, + .get_length = &iio_get_length_kfifo, + .set_length = &iio_set_length_kfifo, +}; + +struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) +{ + struct iio_kfifo *kf; + + kf = kzalloc(sizeof *kf, GFP_KERNEL); + if (!kf) + return NULL; + kf->update_needed = true; + iio_buffer_init(&kf->buffer); + kf->buffer.attrs = &iio_kfifo_attribute_group; + kf->buffer.access = &kfifo_access_funcs; + + return &kf->buffer; +} +EXPORT_SYMBOL(iio_kfifo_allocate); + +void iio_kfifo_free(struct iio_buffer *r) +{ + kfree(iio_to_kfifo(r)); +} +EXPORT_SYMBOL(iio_kfifo_free); + +MODULE_LICENSE("GPL"); |