2011-02-11 06:09:10 -07:00
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/workqueue.h>
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#include <linux/kfifo.h>
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#include <linux/mutex.h>
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2012-04-25 08:54:58 -06:00
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#include <linux/iio/kfifo_buf.h>
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2012-06-30 06:52:00 -06:00
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#include <linux/sched.h>
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2011-02-11 06:09:10 -07:00
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2011-08-30 05:32:43 -06:00
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struct iio_kfifo {
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2011-09-21 04:15:57 -06:00
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struct iio_buffer buffer;
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2011-08-30 05:32:43 -06:00
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struct kfifo kf;
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int update_needed;
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};
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2011-09-21 04:15:57 -06:00
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#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
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2011-05-18 07:42:24 -06:00
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2011-02-11 06:09:10 -07:00
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static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
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int bytes_per_datum, int length)
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{
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if ((length == 0) || (bytes_per_datum == 0))
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return -EINVAL;
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2011-09-21 04:15:57 -06:00
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__iio_update_buffer(&buf->buffer, bytes_per_datum, length);
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2012-06-30 06:52:00 -06:00
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return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
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bytes_per_datum, GFP_KERNEL);
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2011-02-11 06:09:10 -07:00
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}
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2011-09-21 04:15:57 -06:00
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static int iio_request_update_kfifo(struct iio_buffer *r)
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2011-02-11 06:09:10 -07:00
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{
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int ret = 0;
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struct iio_kfifo *buf = iio_to_kfifo(r);
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if (!buf->update_needed)
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goto error_ret;
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kfifo_free(&buf->kf);
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2011-09-21 04:15:57 -06:00
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ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
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buf->buffer.length);
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2012-06-30 06:52:00 -06:00
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r->stufftoread = false;
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2011-02-11 06:09:10 -07:00
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error_ret:
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return ret;
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}
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2011-09-21 04:15:57 -06:00
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static int iio_get_length_kfifo(struct iio_buffer *r)
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2011-02-11 06:09:10 -07:00
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{
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return r->length;
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}
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2011-09-21 04:15:57 -06:00
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static IIO_BUFFER_ENABLE_ATTR;
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static IIO_BUFFER_LENGTH_ATTR;
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2011-02-11 06:09:10 -07:00
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static struct attribute *iio_kfifo_attributes[] = {
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&dev_attr_length.attr,
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&dev_attr_enable.attr,
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NULL,
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};
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static struct attribute_group iio_kfifo_attribute_group = {
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.attrs = iio_kfifo_attributes,
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2011-08-30 05:32:47 -06:00
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.name = "buffer",
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2011-02-11 06:09:10 -07:00
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};
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2011-09-21 04:15:57 -06:00
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static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
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2011-02-11 06:09:10 -07:00
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{
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return r->bytes_per_datum;
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}
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2011-12-19 07:23:48 -07:00
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static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
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2011-02-11 06:09:10 -07:00
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{
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2011-12-19 07:23:48 -07:00
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struct iio_kfifo *kf = iio_to_kfifo(r);
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kf->update_needed = true;
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2011-02-11 06:09:10 -07:00
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return 0;
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}
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2011-12-19 07:23:48 -07:00
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static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
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2011-02-11 06:09:10 -07:00
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{
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2011-12-19 07:23:48 -07:00
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if (r->bytes_per_datum != bpd) {
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r->bytes_per_datum = bpd;
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iio_mark_update_needed_kfifo(r);
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}
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2011-02-11 06:09:10 -07:00
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return 0;
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}
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2011-09-21 04:15:57 -06:00
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static int iio_set_length_kfifo(struct iio_buffer *r, int length)
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2011-02-11 06:09:10 -07:00
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{
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2012-06-30 06:52:00 -06:00
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/* Avoid an invalid state */
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if (length < 2)
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length = 2;
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2011-02-11 06:09:10 -07:00
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if (r->length != length) {
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r->length = length;
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2011-12-19 07:23:48 -07:00
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iio_mark_update_needed_kfifo(r);
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2011-02-11 06:09:10 -07:00
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}
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return 0;
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}
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2011-09-21 04:15:57 -06:00
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static int iio_store_to_kfifo(struct iio_buffer *r,
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2012-09-04 06:38:00 -06:00
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u8 *data)
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2011-02-11 06:09:10 -07:00
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{
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int ret;
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struct iio_kfifo *kf = iio_to_kfifo(r);
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2012-06-30 06:52:00 -06:00
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ret = kfifo_in(&kf->kf, data, 1);
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if (ret != 1)
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2011-02-11 06:09:10 -07:00
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return -EBUSY;
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2012-06-30 06:52:00 -06:00
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r->stufftoread = true;
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wake_up_interruptible(&r->pollq);
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2012-06-30 06:52:00 -06:00
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2011-02-11 06:09:10 -07:00
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return 0;
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}
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2011-09-21 04:15:57 -06:00
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static int iio_read_first_n_kfifo(struct iio_buffer *r,
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2011-05-18 07:41:02 -06:00
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size_t n, char __user *buf)
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2011-02-11 06:09:10 -07:00
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{
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int ret, copied;
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struct iio_kfifo *kf = iio_to_kfifo(r);
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2012-08-27 11:40:04 -06:00
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if (n < r->bytes_per_datum || r->bytes_per_datum == 0)
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2011-12-12 01:33:14 -07:00
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return -EINVAL;
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ret = kfifo_to_user(&kf->kf, buf, n, &copied);
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2012-08-27 11:40:04 -06:00
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if (ret < 0)
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return ret;
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2011-02-11 06:09:10 -07:00
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2012-06-30 06:52:00 -06:00
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if (kfifo_is_empty(&kf->kf))
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r->stufftoread = false;
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/* verify it is still empty to avoid race */
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if (!kfifo_is_empty(&kf->kf))
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r->stufftoread = true;
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2011-02-11 06:09:10 -07:00
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return copied;
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}
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2011-05-18 07:42:24 -06:00
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2012-01-03 03:02:51 -07:00
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static const struct iio_buffer_access_funcs kfifo_access_funcs = {
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2011-05-18 07:42:24 -06:00
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.store_to = &iio_store_to_kfifo,
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.read_first_n = &iio_read_first_n_kfifo,
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.request_update = &iio_request_update_kfifo,
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.get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo,
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.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
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.get_length = &iio_get_length_kfifo,
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.set_length = &iio_set_length_kfifo,
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};
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2012-01-03 03:02:51 -07:00
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struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
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{
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struct iio_kfifo *kf;
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kf = kzalloc(sizeof *kf, GFP_KERNEL);
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if (!kf)
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return NULL;
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kf->update_needed = true;
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iio_buffer_init(&kf->buffer);
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kf->buffer.attrs = &iio_kfifo_attribute_group;
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kf->buffer.access = &kfifo_access_funcs;
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2012-06-30 06:52:00 -06:00
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kf->buffer.length = 2;
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2012-01-03 03:02:51 -07:00
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return &kf->buffer;
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}
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EXPORT_SYMBOL(iio_kfifo_allocate);
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void iio_kfifo_free(struct iio_buffer *r)
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{
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kfree(iio_to_kfifo(r));
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}
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EXPORT_SYMBOL(iio_kfifo_free);
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2011-05-18 07:42:24 -06:00
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2011-02-11 06:09:10 -07:00
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MODULE_LICENSE("GPL");
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