1 #include <linux/slab.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/device.h>
5 #include <linux/workqueue.h>
6 #include <linux/kfifo.h>
7 #include <linux/mutex.h>
8 #include <linux/iio/kfifo_buf.h>
11 struct iio_buffer buffer;
16 #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
18 static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
19 int bytes_per_datum, int length)
21 if ((length == 0) || (bytes_per_datum == 0))
24 __iio_update_buffer(&buf->buffer, bytes_per_datum, length);
25 return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL);
28 static int iio_request_update_kfifo(struct iio_buffer *r)
31 struct iio_kfifo *buf = iio_to_kfifo(r);
33 if (!buf->update_needed)
36 ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
42 static int iio_get_length_kfifo(struct iio_buffer *r)
47 static IIO_BUFFER_ENABLE_ATTR;
48 static IIO_BUFFER_LENGTH_ATTR;
50 static struct attribute *iio_kfifo_attributes[] = {
51 &dev_attr_length.attr,
52 &dev_attr_enable.attr,
56 static struct attribute_group iio_kfifo_attribute_group = {
57 .attrs = iio_kfifo_attributes,
61 static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
63 return r->bytes_per_datum;
66 static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
68 struct iio_kfifo *kf = iio_to_kfifo(r);
69 kf->update_needed = true;
73 static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
75 if (r->bytes_per_datum != bpd) {
76 r->bytes_per_datum = bpd;
77 iio_mark_update_needed_kfifo(r);
82 static int iio_set_length_kfifo(struct iio_buffer *r, int length)
84 if (r->length != length) {
86 iio_mark_update_needed_kfifo(r);
91 static int iio_store_to_kfifo(struct iio_buffer *r,
96 struct iio_kfifo *kf = iio_to_kfifo(r);
97 ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
98 if (ret != r->bytes_per_datum)
103 static int iio_read_first_n_kfifo(struct iio_buffer *r,
104 size_t n, char __user *buf)
107 struct iio_kfifo *kf = iio_to_kfifo(r);
109 if (n < r->bytes_per_datum)
112 n = rounddown(n, r->bytes_per_datum);
113 ret = kfifo_to_user(&kf->kf, buf, n, &copied);
118 static const struct iio_buffer_access_funcs kfifo_access_funcs = {
119 .store_to = &iio_store_to_kfifo,
120 .read_first_n = &iio_read_first_n_kfifo,
121 .request_update = &iio_request_update_kfifo,
122 .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo,
123 .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
124 .get_length = &iio_get_length_kfifo,
125 .set_length = &iio_set_length_kfifo,
128 struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
130 struct iio_kfifo *kf;
132 kf = kzalloc(sizeof *kf, GFP_KERNEL);
135 kf->update_needed = true;
136 iio_buffer_init(&kf->buffer);
137 kf->buffer.attrs = &iio_kfifo_attribute_group;
138 kf->buffer.access = &kfifo_access_funcs;
142 EXPORT_SYMBOL(iio_kfifo_allocate);
144 void iio_kfifo_free(struct iio_buffer *r)
146 kfree(iio_to_kfifo(r));
148 EXPORT_SYMBOL(iio_kfifo_free);
150 MODULE_LICENSE("GPL");