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> |
7c388ec1 | 9 | #include <linux/sched.h> |
623c334c | 10 | #include <linux/poll.h> |
b174baf4 | 11 | |
a710cc77 | 12 | struct iio_kfifo { |
14555b14 | 13 | struct iio_buffer buffer; |
a710cc77 | 14 | struct kfifo kf; |
0894d80d | 15 | struct mutex user_lock; |
a710cc77 | 16 | int update_needed; |
a710cc77 JC |
17 | }; |
18 | ||
14555b14 | 19 | #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
5565a450 | 20 | |
b174baf4 JC |
21 | static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, |
22 | int bytes_per_datum, int length) | |
23 | { | |
24 | if ((length == 0) || (bytes_per_datum == 0)) | |
25 | return -EINVAL; | |
26 | ||
c559afbf JC |
27 | return __kfifo_alloc((struct __kfifo *)&buf->kf, length, |
28 | bytes_per_datum, GFP_KERNEL); | |
b174baf4 JC |
29 | } |
30 | ||
14555b14 | 31 | static int iio_request_update_kfifo(struct iio_buffer *r) |
b174baf4 JC |
32 | { |
33 | int ret = 0; | |
34 | struct iio_kfifo *buf = iio_to_kfifo(r); | |
35 | ||
0894d80d | 36 | mutex_lock(&buf->user_lock); |
5b78e513 LPC |
37 | if (buf->update_needed) { |
38 | kfifo_free(&buf->kf); | |
39 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, | |
14555b14 | 40 | buf->buffer.length); |
cb6fbfa1 | 41 | buf->update_needed = false; |
5b78e513 LPC |
42 | } else { |
43 | kfifo_reset_out(&buf->kf); | |
44 | } | |
0894d80d | 45 | mutex_unlock(&buf->user_lock); |
5b78e513 | 46 | |
b174baf4 JC |
47 | return ret; |
48 | } | |
b174baf4 | 49 | |
14555b14 | 50 | static int iio_get_length_kfifo(struct iio_buffer *r) |
b174baf4 JC |
51 | { |
52 | return r->length; | |
53 | } | |
b174baf4 | 54 | |
14555b14 | 55 | static IIO_BUFFER_ENABLE_ATTR; |
14555b14 | 56 | static IIO_BUFFER_LENGTH_ATTR; |
b174baf4 JC |
57 | |
58 | static struct attribute *iio_kfifo_attributes[] = { | |
59 | &dev_attr_length.attr, | |
b174baf4 JC |
60 | &dev_attr_enable.attr, |
61 | NULL, | |
62 | }; | |
63 | ||
64 | static struct attribute_group iio_kfifo_attribute_group = { | |
65 | .attrs = iio_kfifo_attributes, | |
1aa04278 | 66 | .name = "buffer", |
b174baf4 JC |
67 | }; |
68 | ||
14555b14 | 69 | static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) |
b174baf4 JC |
70 | { |
71 | return r->bytes_per_datum; | |
72 | } | |
b174baf4 | 73 | |
869871b5 | 74 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
b174baf4 | 75 | { |
869871b5 LPC |
76 | struct iio_kfifo *kf = iio_to_kfifo(r); |
77 | kf->update_needed = true; | |
b174baf4 JC |
78 | return 0; |
79 | } | |
b174baf4 | 80 | |
869871b5 | 81 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
b174baf4 | 82 | { |
869871b5 LPC |
83 | if (r->bytes_per_datum != bpd) { |
84 | r->bytes_per_datum = bpd; | |
85 | iio_mark_update_needed_kfifo(r); | |
86 | } | |
b174baf4 JC |
87 | return 0; |
88 | } | |
b174baf4 | 89 | |
14555b14 | 90 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
b174baf4 | 91 | { |
7c388ec1 JC |
92 | /* Avoid an invalid state */ |
93 | if (length < 2) | |
94 | length = 2; | |
b174baf4 JC |
95 | if (r->length != length) { |
96 | r->length = length; | |
869871b5 | 97 | iio_mark_update_needed_kfifo(r); |
b174baf4 JC |
98 | } |
99 | return 0; | |
100 | } | |
b174baf4 | 101 | |
14555b14 | 102 | static int iio_store_to_kfifo(struct iio_buffer *r, |
5d65d920 | 103 | const void *data) |
b174baf4 JC |
104 | { |
105 | int ret; | |
106 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
c559afbf JC |
107 | ret = kfifo_in(&kf->kf, data, 1); |
108 | if (ret != 1) | |
b174baf4 | 109 | return -EBUSY; |
355c1a14 | 110 | |
623c334c | 111 | wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM); |
c559afbf | 112 | |
b174baf4 JC |
113 | return 0; |
114 | } | |
b174baf4 | 115 | |
14555b14 | 116 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
b26a2188 | 117 | size_t n, char __user *buf) |
b174baf4 JC |
118 | { |
119 | int ret, copied; | |
120 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
121 | ||
0894d80d LPC |
122 | if (mutex_lock_interruptible(&kf->user_lock)) |
123 | return -ERESTARTSYS; | |
8fe64955 | 124 | |
0894d80d LPC |
125 | if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) |
126 | ret = -EINVAL; | |
127 | else | |
128 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); | |
0894d80d LPC |
129 | mutex_unlock(&kf->user_lock); |
130 | if (ret < 0) | |
131 | return ret; | |
132 | ||
b174baf4 JC |
133 | return copied; |
134 | } | |
5565a450 | 135 | |
355c1a14 LPC |
136 | static bool iio_kfifo_buf_data_available(struct iio_buffer *r) |
137 | { | |
138 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
139 | bool empty; | |
140 | ||
141 | mutex_lock(&kf->user_lock); | |
142 | empty = kfifo_is_empty(&kf->kf); | |
143 | mutex_unlock(&kf->user_lock); | |
144 | ||
145 | return !empty; | |
146 | } | |
147 | ||
9e69c935 LPC |
148 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
149 | { | |
f6c23f48 LPC |
150 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
151 | ||
0894d80d | 152 | mutex_destroy(&kf->user_lock); |
f6c23f48 LPC |
153 | kfifo_free(&kf->kf); |
154 | kfree(kf); | |
9e69c935 LPC |
155 | } |
156 | ||
7e632344 | 157 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
5565a450 JC |
158 | .store_to = &iio_store_to_kfifo, |
159 | .read_first_n = &iio_read_first_n_kfifo, | |
355c1a14 | 160 | .data_available = iio_kfifo_buf_data_available, |
5565a450 JC |
161 | .request_update = &iio_request_update_kfifo, |
162 | .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo, | |
163 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, | |
164 | .get_length = &iio_get_length_kfifo, | |
165 | .set_length = &iio_set_length_kfifo, | |
9e69c935 | 166 | .release = &iio_kfifo_buffer_release, |
5565a450 | 167 | }; |
7e632344 LPC |
168 | |
169 | struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) | |
170 | { | |
171 | struct iio_kfifo *kf; | |
172 | ||
173 | kf = kzalloc(sizeof *kf, GFP_KERNEL); | |
174 | if (!kf) | |
175 | return NULL; | |
176 | kf->update_needed = true; | |
177 | iio_buffer_init(&kf->buffer); | |
178 | kf->buffer.attrs = &iio_kfifo_attribute_group; | |
179 | kf->buffer.access = &kfifo_access_funcs; | |
7c388ec1 | 180 | kf->buffer.length = 2; |
0894d80d | 181 | mutex_init(&kf->user_lock); |
7e632344 LPC |
182 | return &kf->buffer; |
183 | } | |
184 | EXPORT_SYMBOL(iio_kfifo_allocate); | |
185 | ||
186 | void iio_kfifo_free(struct iio_buffer *r) | |
187 | { | |
9e69c935 | 188 | iio_buffer_put(r); |
7e632344 LPC |
189 | } |
190 | EXPORT_SYMBOL(iio_kfifo_free); | |
5565a450 | 191 | |
b174baf4 | 192 | MODULE_LICENSE("GPL"); |