This source file includes following definitions.
- __iio_allocate_kfifo
- iio_request_update_kfifo
- iio_mark_update_needed_kfifo
- iio_set_bytes_per_datum_kfifo
- iio_set_length_kfifo
- iio_store_to_kfifo
- iio_read_first_n_kfifo
- iio_kfifo_buf_data_available
- iio_kfifo_buffer_release
- iio_kfifo_allocate
- iio_kfifo_free
- devm_iio_kfifo_release
- devm_iio_kfifo_match
- devm_iio_kfifo_allocate
- devm_iio_kfifo_free
1
2 #include <linux/slab.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/device.h>
6 #include <linux/workqueue.h>
7 #include <linux/kfifo.h>
8 #include <linux/mutex.h>
9 #include <linux/iio/iio.h>
10 #include <linux/iio/buffer.h>
11 #include <linux/iio/kfifo_buf.h>
12 #include <linux/iio/buffer_impl.h>
13 #include <linux/sched.h>
14 #include <linux/poll.h>
15
16 struct iio_kfifo {
17 struct iio_buffer buffer;
18 struct kfifo kf;
19 struct mutex user_lock;
20 int update_needed;
21 };
22
23 #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
24
25 static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
26 size_t bytes_per_datum, unsigned int length)
27 {
28 if ((length == 0) || (bytes_per_datum == 0))
29 return -EINVAL;
30
31
32
33
34
35 if (roundup_pow_of_two(length) > UINT_MAX / bytes_per_datum)
36 return -EINVAL;
37
38 return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
39 bytes_per_datum, GFP_KERNEL);
40 }
41
42 static int iio_request_update_kfifo(struct iio_buffer *r)
43 {
44 int ret = 0;
45 struct iio_kfifo *buf = iio_to_kfifo(r);
46
47 mutex_lock(&buf->user_lock);
48 if (buf->update_needed) {
49 kfifo_free(&buf->kf);
50 ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
51 buf->buffer.length);
52 if (ret >= 0)
53 buf->update_needed = false;
54 } else {
55 kfifo_reset_out(&buf->kf);
56 }
57 mutex_unlock(&buf->user_lock);
58
59 return ret;
60 }
61
62 static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
63 {
64 struct iio_kfifo *kf = iio_to_kfifo(r);
65 kf->update_needed = true;
66 return 0;
67 }
68
69 static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
70 {
71 if (r->bytes_per_datum != bpd) {
72 r->bytes_per_datum = bpd;
73 iio_mark_update_needed_kfifo(r);
74 }
75 return 0;
76 }
77
78 static int iio_set_length_kfifo(struct iio_buffer *r, unsigned int length)
79 {
80
81 if (length < 2)
82 length = 2;
83 if (r->length != length) {
84 r->length = length;
85 iio_mark_update_needed_kfifo(r);
86 }
87 return 0;
88 }
89
90 static int iio_store_to_kfifo(struct iio_buffer *r,
91 const void *data)
92 {
93 int ret;
94 struct iio_kfifo *kf = iio_to_kfifo(r);
95 ret = kfifo_in(&kf->kf, data, 1);
96 if (ret != 1)
97 return -EBUSY;
98 return 0;
99 }
100
101 static int iio_read_first_n_kfifo(struct iio_buffer *r,
102 size_t n, char __user *buf)
103 {
104 int ret, copied;
105 struct iio_kfifo *kf = iio_to_kfifo(r);
106
107 if (mutex_lock_interruptible(&kf->user_lock))
108 return -ERESTARTSYS;
109
110 if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
111 ret = -EINVAL;
112 else
113 ret = kfifo_to_user(&kf->kf, buf, n, &copied);
114 mutex_unlock(&kf->user_lock);
115 if (ret < 0)
116 return ret;
117
118 return copied;
119 }
120
121 static size_t iio_kfifo_buf_data_available(struct iio_buffer *r)
122 {
123 struct iio_kfifo *kf = iio_to_kfifo(r);
124 size_t samples;
125
126 mutex_lock(&kf->user_lock);
127 samples = kfifo_len(&kf->kf);
128 mutex_unlock(&kf->user_lock);
129
130 return samples;
131 }
132
133 static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
134 {
135 struct iio_kfifo *kf = iio_to_kfifo(buffer);
136
137 mutex_destroy(&kf->user_lock);
138 kfifo_free(&kf->kf);
139 kfree(kf);
140 }
141
142 static const struct iio_buffer_access_funcs kfifo_access_funcs = {
143 .store_to = &iio_store_to_kfifo,
144 .read_first_n = &iio_read_first_n_kfifo,
145 .data_available = iio_kfifo_buf_data_available,
146 .request_update = &iio_request_update_kfifo,
147 .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
148 .set_length = &iio_set_length_kfifo,
149 .release = &iio_kfifo_buffer_release,
150
151 .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
152 };
153
154 struct iio_buffer *iio_kfifo_allocate(void)
155 {
156 struct iio_kfifo *kf;
157
158 kf = kzalloc(sizeof(*kf), GFP_KERNEL);
159 if (!kf)
160 return NULL;
161
162 kf->update_needed = true;
163 iio_buffer_init(&kf->buffer);
164 kf->buffer.access = &kfifo_access_funcs;
165 kf->buffer.length = 2;
166 mutex_init(&kf->user_lock);
167
168 return &kf->buffer;
169 }
170 EXPORT_SYMBOL(iio_kfifo_allocate);
171
172 void iio_kfifo_free(struct iio_buffer *r)
173 {
174 iio_buffer_put(r);
175 }
176 EXPORT_SYMBOL(iio_kfifo_free);
177
178 static void devm_iio_kfifo_release(struct device *dev, void *res)
179 {
180 iio_kfifo_free(*(struct iio_buffer **)res);
181 }
182
183 static int devm_iio_kfifo_match(struct device *dev, void *res, void *data)
184 {
185 struct iio_buffer **r = res;
186
187 if (WARN_ON(!r || !*r))
188 return 0;
189
190 return *r == data;
191 }
192
193
194
195
196
197
198
199
200 struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
201 {
202 struct iio_buffer **ptr, *r;
203
204 ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
205 if (!ptr)
206 return NULL;
207
208 r = iio_kfifo_allocate();
209 if (r) {
210 *ptr = r;
211 devres_add(dev, ptr);
212 } else {
213 devres_free(ptr);
214 }
215
216 return r;
217 }
218 EXPORT_SYMBOL(devm_iio_kfifo_allocate);
219
220
221
222
223
224
225 void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r)
226 {
227 WARN_ON(devres_release(dev, devm_iio_kfifo_release,
228 devm_iio_kfifo_match, r));
229 }
230 EXPORT_SYMBOL(devm_iio_kfifo_free);
231
232 MODULE_LICENSE("GPL");