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); |
e5f1efb9 GM |
41 | if (ret >= 0) |
42 | buf->update_needed = false; | |
5b78e513 LPC |
43 | } else { |
44 | kfifo_reset_out(&buf->kf); | |
45 | } | |
0894d80d | 46 | mutex_unlock(&buf->user_lock); |
5b78e513 | 47 | |
b174baf4 JC |
48 | return ret; |
49 | } | |
b174baf4 | 50 | |
869871b5 | 51 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
b174baf4 | 52 | { |
869871b5 LPC |
53 | struct iio_kfifo *kf = iio_to_kfifo(r); |
54 | kf->update_needed = true; | |
b174baf4 JC |
55 | return 0; |
56 | } | |
b174baf4 | 57 | |
869871b5 | 58 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
b174baf4 | 59 | { |
869871b5 LPC |
60 | if (r->bytes_per_datum != bpd) { |
61 | r->bytes_per_datum = bpd; | |
62 | iio_mark_update_needed_kfifo(r); | |
63 | } | |
b174baf4 JC |
64 | return 0; |
65 | } | |
b174baf4 | 66 | |
14555b14 | 67 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
b174baf4 | 68 | { |
7c388ec1 JC |
69 | /* Avoid an invalid state */ |
70 | if (length < 2) | |
71 | length = 2; | |
b174baf4 JC |
72 | if (r->length != length) { |
73 | r->length = length; | |
869871b5 | 74 | iio_mark_update_needed_kfifo(r); |
b174baf4 JC |
75 | } |
76 | return 0; | |
77 | } | |
b174baf4 | 78 | |
14555b14 | 79 | static int iio_store_to_kfifo(struct iio_buffer *r, |
5d65d920 | 80 | const void *data) |
b174baf4 JC |
81 | { |
82 | int ret; | |
83 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
c559afbf JC |
84 | ret = kfifo_in(&kf->kf, data, 1); |
85 | if (ret != 1) | |
b174baf4 | 86 | return -EBUSY; |
b174baf4 JC |
87 | return 0; |
88 | } | |
b174baf4 | 89 | |
14555b14 | 90 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
b26a2188 | 91 | size_t n, char __user *buf) |
b174baf4 JC |
92 | { |
93 | int ret, copied; | |
94 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
95 | ||
0894d80d LPC |
96 | if (mutex_lock_interruptible(&kf->user_lock)) |
97 | return -ERESTARTSYS; | |
8fe64955 | 98 | |
0894d80d LPC |
99 | if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) |
100 | ret = -EINVAL; | |
101 | else | |
102 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); | |
0894d80d LPC |
103 | mutex_unlock(&kf->user_lock); |
104 | if (ret < 0) | |
105 | return ret; | |
106 | ||
b174baf4 JC |
107 | return copied; |
108 | } | |
5565a450 | 109 | |
37d34556 | 110 | static size_t iio_kfifo_buf_data_available(struct iio_buffer *r) |
355c1a14 LPC |
111 | { |
112 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
37d34556 | 113 | size_t samples; |
355c1a14 LPC |
114 | |
115 | mutex_lock(&kf->user_lock); | |
37d34556 | 116 | samples = kfifo_len(&kf->kf); |
355c1a14 LPC |
117 | mutex_unlock(&kf->user_lock); |
118 | ||
37d34556 | 119 | return samples; |
355c1a14 LPC |
120 | } |
121 | ||
9e69c935 LPC |
122 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
123 | { | |
f6c23f48 LPC |
124 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
125 | ||
0894d80d | 126 | mutex_destroy(&kf->user_lock); |
f6c23f48 LPC |
127 | kfifo_free(&kf->kf); |
128 | kfree(kf); | |
9e69c935 LPC |
129 | } |
130 | ||
7e632344 | 131 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
5565a450 JC |
132 | .store_to = &iio_store_to_kfifo, |
133 | .read_first_n = &iio_read_first_n_kfifo, | |
355c1a14 | 134 | .data_available = iio_kfifo_buf_data_available, |
5565a450 | 135 | .request_update = &iio_request_update_kfifo, |
5565a450 | 136 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
5565a450 | 137 | .set_length = &iio_set_length_kfifo, |
9e69c935 | 138 | .release = &iio_kfifo_buffer_release, |
225d59ad LPC |
139 | |
140 | .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED, | |
5565a450 | 141 | }; |
7e632344 | 142 | |
7ab374a0 | 143 | struct iio_buffer *iio_kfifo_allocate(void) |
7e632344 LPC |
144 | { |
145 | struct iio_kfifo *kf; | |
146 | ||
7ab374a0 | 147 | kf = kzalloc(sizeof(*kf), GFP_KERNEL); |
7e632344 LPC |
148 | if (!kf) |
149 | return NULL; | |
7ab374a0 | 150 | |
7e632344 LPC |
151 | kf->update_needed = true; |
152 | iio_buffer_init(&kf->buffer); | |
7e632344 | 153 | kf->buffer.access = &kfifo_access_funcs; |
7c388ec1 | 154 | kf->buffer.length = 2; |
0894d80d | 155 | mutex_init(&kf->user_lock); |
7ab374a0 | 156 | |
7e632344 LPC |
157 | return &kf->buffer; |
158 | } | |
159 | EXPORT_SYMBOL(iio_kfifo_allocate); | |
160 | ||
161 | void iio_kfifo_free(struct iio_buffer *r) | |
162 | { | |
9e69c935 | 163 | iio_buffer_put(r); |
7e632344 LPC |
164 | } |
165 | EXPORT_SYMBOL(iio_kfifo_free); | |
5565a450 | 166 | |
780103fe KW |
167 | static void devm_iio_kfifo_release(struct device *dev, void *res) |
168 | { | |
169 | iio_kfifo_free(*(struct iio_buffer **)res); | |
170 | } | |
171 | ||
172 | static int devm_iio_kfifo_match(struct device *dev, void *res, void *data) | |
173 | { | |
174 | struct iio_buffer **r = res; | |
175 | ||
176 | if (WARN_ON(!r || !*r)) | |
177 | return 0; | |
178 | ||
179 | return *r == data; | |
180 | } | |
181 | ||
182 | /** | |
183 | * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate() | |
184 | * @dev: Device to allocate kfifo buffer for | |
185 | * | |
186 | * RETURNS: | |
187 | * Pointer to allocated iio_buffer on success, NULL on failure. | |
188 | */ | |
189 | struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev) | |
190 | { | |
191 | struct iio_buffer **ptr, *r; | |
192 | ||
193 | ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL); | |
194 | if (!ptr) | |
195 | return NULL; | |
196 | ||
197 | r = iio_kfifo_allocate(); | |
198 | if (r) { | |
199 | *ptr = r; | |
200 | devres_add(dev, ptr); | |
201 | } else { | |
202 | devres_free(ptr); | |
203 | } | |
204 | ||
205 | return r; | |
206 | } | |
207 | EXPORT_SYMBOL(devm_iio_kfifo_allocate); | |
208 | ||
209 | /** | |
210 | * devm_iio_fifo_free - Resource-managed iio_kfifo_free() | |
211 | * @dev: Device the buffer belongs to | |
212 | * @r: The buffer associated with the device | |
213 | */ | |
214 | void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r) | |
215 | { | |
216 | WARN_ON(devres_release(dev, devm_iio_kfifo_release, | |
217 | devm_iio_kfifo_match, r)); | |
218 | } | |
219 | EXPORT_SYMBOL(devm_iio_kfifo_free); | |
220 | ||
b174baf4 | 221 | MODULE_LICENSE("GPL"); |