Commit | Line | Data |
---|---|---|
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 | |
869871b5 | 50 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
b174baf4 | 51 | { |
869871b5 LPC |
52 | struct iio_kfifo *kf = iio_to_kfifo(r); |
53 | kf->update_needed = true; | |
b174baf4 JC |
54 | return 0; |
55 | } | |
b174baf4 | 56 | |
869871b5 | 57 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
b174baf4 | 58 | { |
869871b5 LPC |
59 | if (r->bytes_per_datum != bpd) { |
60 | r->bytes_per_datum = bpd; | |
61 | iio_mark_update_needed_kfifo(r); | |
62 | } | |
b174baf4 JC |
63 | return 0; |
64 | } | |
b174baf4 | 65 | |
14555b14 | 66 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
b174baf4 | 67 | { |
7c388ec1 JC |
68 | /* Avoid an invalid state */ |
69 | if (length < 2) | |
70 | length = 2; | |
b174baf4 JC |
71 | if (r->length != length) { |
72 | r->length = length; | |
869871b5 | 73 | iio_mark_update_needed_kfifo(r); |
b174baf4 JC |
74 | } |
75 | return 0; | |
76 | } | |
b174baf4 | 77 | |
14555b14 | 78 | static int iio_store_to_kfifo(struct iio_buffer *r, |
5d65d920 | 79 | const void *data) |
b174baf4 JC |
80 | { |
81 | int ret; | |
82 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
c559afbf JC |
83 | ret = kfifo_in(&kf->kf, data, 1); |
84 | if (ret != 1) | |
b174baf4 | 85 | return -EBUSY; |
355c1a14 | 86 | |
623c334c | 87 | wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM); |
c559afbf | 88 | |
b174baf4 JC |
89 | return 0; |
90 | } | |
b174baf4 | 91 | |
14555b14 | 92 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
b26a2188 | 93 | size_t n, char __user *buf) |
b174baf4 JC |
94 | { |
95 | int ret, copied; | |
96 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
97 | ||
0894d80d LPC |
98 | if (mutex_lock_interruptible(&kf->user_lock)) |
99 | return -ERESTARTSYS; | |
8fe64955 | 100 | |
0894d80d LPC |
101 | if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) |
102 | ret = -EINVAL; | |
103 | else | |
104 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); | |
0894d80d LPC |
105 | mutex_unlock(&kf->user_lock); |
106 | if (ret < 0) | |
107 | return ret; | |
108 | ||
b174baf4 JC |
109 | return copied; |
110 | } | |
5565a450 | 111 | |
355c1a14 LPC |
112 | static bool iio_kfifo_buf_data_available(struct iio_buffer *r) |
113 | { | |
114 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
115 | bool empty; | |
116 | ||
117 | mutex_lock(&kf->user_lock); | |
118 | empty = kfifo_is_empty(&kf->kf); | |
119 | mutex_unlock(&kf->user_lock); | |
120 | ||
121 | return !empty; | |
122 | } | |
123 | ||
9e69c935 LPC |
124 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
125 | { | |
f6c23f48 LPC |
126 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
127 | ||
0894d80d | 128 | mutex_destroy(&kf->user_lock); |
f6c23f48 LPC |
129 | kfifo_free(&kf->kf); |
130 | kfree(kf); | |
9e69c935 LPC |
131 | } |
132 | ||
7e632344 | 133 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
5565a450 JC |
134 | .store_to = &iio_store_to_kfifo, |
135 | .read_first_n = &iio_read_first_n_kfifo, | |
355c1a14 | 136 | .data_available = iio_kfifo_buf_data_available, |
5565a450 | 137 | .request_update = &iio_request_update_kfifo, |
5565a450 | 138 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
5565a450 | 139 | .set_length = &iio_set_length_kfifo, |
9e69c935 | 140 | .release = &iio_kfifo_buffer_release, |
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"); |