Commit | Line | Data |
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b174baf4 JC |
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> | |
06458e27 | 8 | #include <linux/iio/kfifo_buf.h> |
b174baf4 | 9 | |
a710cc77 | 10 | struct iio_kfifo { |
14555b14 | 11 | struct iio_buffer buffer; |
a710cc77 | 12 | struct kfifo kf; |
a710cc77 | 13 | int update_needed; |
a710cc77 JC |
14 | }; |
15 | ||
14555b14 | 16 | #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
5565a450 | 17 | |
b174baf4 JC |
18 | static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, |
19 | int bytes_per_datum, int length) | |
20 | { | |
21 | if ((length == 0) || (bytes_per_datum == 0)) | |
22 | return -EINVAL; | |
23 | ||
14555b14 | 24 | __iio_update_buffer(&buf->buffer, bytes_per_datum, length); |
b174baf4 JC |
25 | return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL); |
26 | } | |
27 | ||
14555b14 | 28 | static int iio_request_update_kfifo(struct iio_buffer *r) |
b174baf4 JC |
29 | { |
30 | int ret = 0; | |
31 | struct iio_kfifo *buf = iio_to_kfifo(r); | |
32 | ||
b174baf4 JC |
33 | if (!buf->update_needed) |
34 | goto error_ret; | |
b174baf4 | 35 | kfifo_free(&buf->kf); |
14555b14 JC |
36 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, |
37 | buf->buffer.length); | |
b174baf4 | 38 | error_ret: |
b174baf4 JC |
39 | return ret; |
40 | } | |
b174baf4 | 41 | |
14555b14 | 42 | static int iio_get_length_kfifo(struct iio_buffer *r) |
b174baf4 JC |
43 | { |
44 | return r->length; | |
45 | } | |
b174baf4 | 46 | |
14555b14 | 47 | static IIO_BUFFER_ENABLE_ATTR; |
14555b14 | 48 | static IIO_BUFFER_LENGTH_ATTR; |
b174baf4 JC |
49 | |
50 | static struct attribute *iio_kfifo_attributes[] = { | |
51 | &dev_attr_length.attr, | |
b174baf4 JC |
52 | &dev_attr_enable.attr, |
53 | NULL, | |
54 | }; | |
55 | ||
56 | static struct attribute_group iio_kfifo_attribute_group = { | |
57 | .attrs = iio_kfifo_attributes, | |
1aa04278 | 58 | .name = "buffer", |
b174baf4 JC |
59 | }; |
60 | ||
14555b14 | 61 | static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) |
b174baf4 JC |
62 | { |
63 | return r->bytes_per_datum; | |
64 | } | |
b174baf4 | 65 | |
869871b5 | 66 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
b174baf4 | 67 | { |
869871b5 LPC |
68 | struct iio_kfifo *kf = iio_to_kfifo(r); |
69 | kf->update_needed = true; | |
b174baf4 JC |
70 | return 0; |
71 | } | |
b174baf4 | 72 | |
869871b5 | 73 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
b174baf4 | 74 | { |
869871b5 LPC |
75 | if (r->bytes_per_datum != bpd) { |
76 | r->bytes_per_datum = bpd; | |
77 | iio_mark_update_needed_kfifo(r); | |
78 | } | |
b174baf4 JC |
79 | return 0; |
80 | } | |
b174baf4 | 81 | |
14555b14 | 82 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
b174baf4 JC |
83 | { |
84 | if (r->length != length) { | |
85 | r->length = length; | |
869871b5 | 86 | iio_mark_update_needed_kfifo(r); |
b174baf4 JC |
87 | } |
88 | return 0; | |
89 | } | |
b174baf4 | 90 | |
14555b14 | 91 | static int iio_store_to_kfifo(struct iio_buffer *r, |
5565a450 JC |
92 | u8 *data, |
93 | s64 timestamp) | |
b174baf4 JC |
94 | { |
95 | int ret; | |
96 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
b174baf4 | 97 | ret = kfifo_in(&kf->kf, data, r->bytes_per_datum); |
4c3d1535 | 98 | if (ret != r->bytes_per_datum) |
b174baf4 | 99 | return -EBUSY; |
b174baf4 JC |
100 | return 0; |
101 | } | |
b174baf4 | 102 | |
14555b14 | 103 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
b26a2188 | 104 | size_t n, char __user *buf) |
b174baf4 JC |
105 | { |
106 | int ret, copied; | |
107 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
108 | ||
8fe64955 LPC |
109 | if (n < r->bytes_per_datum) |
110 | return -EINVAL; | |
111 | ||
112 | n = rounddown(n, r->bytes_per_datum); | |
113 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); | |
b174baf4 JC |
114 | |
115 | return copied; | |
116 | } | |
5565a450 | 117 | |
7e632344 | 118 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
5565a450 JC |
119 | .store_to = &iio_store_to_kfifo, |
120 | .read_first_n = &iio_read_first_n_kfifo, | |
5565a450 JC |
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, | |
126 | }; | |
7e632344 LPC |
127 | |
128 | struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) | |
129 | { | |
130 | struct iio_kfifo *kf; | |
131 | ||
132 | kf = kzalloc(sizeof *kf, GFP_KERNEL); | |
133 | if (!kf) | |
134 | return NULL; | |
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; | |
139 | ||
140 | return &kf->buffer; | |
141 | } | |
142 | EXPORT_SYMBOL(iio_kfifo_allocate); | |
143 | ||
144 | void iio_kfifo_free(struct iio_buffer *r) | |
145 | { | |
146 | kfree(iio_to_kfifo(r)); | |
147 | } | |
148 | EXPORT_SYMBOL(iio_kfifo_free); | |
5565a450 | 149 | |
b174baf4 | 150 | MODULE_LICENSE("GPL"); |