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>
12 struct iio_buffer buffer;
17 #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
19 static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
20 int bytes_per_datum, int length)
22 if ((length == 0) || (bytes_per_datum == 0))
25 __iio_update_buffer(&buf->buffer, bytes_per_datum, length);
26 return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL);
29 static int iio_request_update_kfifo(struct iio_buffer *r)
32 struct iio_kfifo *buf = iio_to_kfifo(r);
34 if (!buf->update_needed)
37 ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
43 static int iio_get_length_kfifo(struct iio_buffer *r)
48 static IIO_BUFFER_ENABLE_ATTR;
49 static IIO_BUFFER_LENGTH_ATTR;
51 static struct attribute *iio_kfifo_attributes[] = {
52 &dev_attr_length.attr,
53 &dev_attr_enable.attr,
57 static struct attribute_group iio_kfifo_attribute_group = {
58 .attrs = iio_kfifo_attributes,
62 static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
64 return r->bytes_per_datum;
67 static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
69 struct iio_kfifo *kf = iio_to_kfifo(r);
70 kf->update_needed = true;
74 static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
76 if (r->bytes_per_datum != bpd) {
77 r->bytes_per_datum = bpd;
78 iio_mark_update_needed_kfifo(r);
83 static int iio_set_length_kfifo(struct iio_buffer *r, int length)
85 if (r->length != length) {
87 iio_mark_update_needed_kfifo(r);
92 static int iio_store_to_kfifo(struct iio_buffer *r,
97 struct iio_kfifo *kf = iio_to_kfifo(r);
98 ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
99 if (ret != r->bytes_per_datum)
104 static int iio_read_first_n_kfifo(struct iio_buffer *r,
105 size_t n, char __user *buf)
108 struct iio_kfifo *kf = iio_to_kfifo(r);
110 if (n < r->bytes_per_datum)
113 n = rounddown(n, r->bytes_per_datum);
114 ret = kfifo_to_user(&kf->kf, buf, n, &copied);
119 static const struct iio_buffer_access_funcs kfifo_access_funcs = {
120 .store_to = &iio_store_to_kfifo,
121 .read_first_n = &iio_read_first_n_kfifo,
122 .request_update = &iio_request_update_kfifo,
123 .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo,
124 .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
125 .get_length = &iio_get_length_kfifo,
126 .set_length = &iio_set_length_kfifo,
129 struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
131 struct iio_kfifo *kf;
133 kf = kzalloc(sizeof *kf, GFP_KERNEL);
136 kf->update_needed = true;
137 iio_buffer_init(&kf->buffer);
138 kf->buffer.attrs = &iio_kfifo_attribute_group;
139 kf->buffer.access = &kfifo_access_funcs;
143 EXPORT_SYMBOL(iio_kfifo_allocate);
145 void iio_kfifo_free(struct iio_buffer *r)
147 kfree(iio_to_kfifo(r));
149 EXPORT_SYMBOL(iio_kfifo_free);
151 MODULE_LICENSE("GPL");