Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 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> |
Jonathan Cameron | 06458e2 | 2012-04-25 15:54:58 +0100 | [diff] [blame] | 8 | #include <linux/iio/kfifo_buf.h> |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 9 | #include <linux/sched.h> |
Lars-Peter Clausen | 623c334 | 2013-09-15 16:31:00 +0100 | [diff] [blame] | 10 | #include <linux/poll.h> |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 11 | |
Jonathan Cameron | a710cc7 | 2011-08-30 12:32:43 +0100 | [diff] [blame] | 12 | struct iio_kfifo { |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 13 | struct iio_buffer buffer; |
Jonathan Cameron | a710cc7 | 2011-08-30 12:32:43 +0100 | [diff] [blame] | 14 | struct kfifo kf; |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 15 | struct mutex user_lock; |
Jonathan Cameron | a710cc7 | 2011-08-30 12:32:43 +0100 | [diff] [blame] | 16 | int update_needed; |
Jonathan Cameron | a710cc7 | 2011-08-30 12:32:43 +0100 | [diff] [blame] | 17 | }; |
| 18 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 19 | #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 20 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 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 | |
Martin Kelly | 8978f15 | 2018-03-26 14:27:52 -0700 | [diff] [blame] | 27 | /* |
| 28 | * Make sure we don't overflow an unsigned int after kfifo rounds up to |
| 29 | * the next power of 2. |
| 30 | */ |
| 31 | if (roundup_pow_of_two(length) > UINT_MAX / bytes_per_datum) |
| 32 | return -EINVAL; |
| 33 | |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 34 | return __kfifo_alloc((struct __kfifo *)&buf->kf, length, |
| 35 | bytes_per_datum, GFP_KERNEL); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 36 | } |
| 37 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 38 | static int iio_request_update_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 39 | { |
| 40 | int ret = 0; |
| 41 | struct iio_kfifo *buf = iio_to_kfifo(r); |
| 42 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 43 | mutex_lock(&buf->user_lock); |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 44 | if (buf->update_needed) { |
| 45 | kfifo_free(&buf->kf); |
| 46 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 47 | buf->buffer.length); |
Gabriele Mazzotta | e5f1efb | 2015-05-02 14:31:16 +0200 | [diff] [blame] | 48 | if (ret >= 0) |
| 49 | buf->update_needed = false; |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 50 | } else { |
| 51 | kfifo_reset_out(&buf->kf); |
| 52 | } |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 53 | mutex_unlock(&buf->user_lock); |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 54 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 55 | return ret; |
| 56 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 57 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 58 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 59 | { |
| 60 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 61 | kf->update_needed = true; |
| 62 | return 0; |
| 63 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 64 | |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 65 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
| 66 | { |
| 67 | if (r->bytes_per_datum != bpd) { |
| 68 | r->bytes_per_datum = bpd; |
| 69 | iio_mark_update_needed_kfifo(r); |
| 70 | } |
| 71 | return 0; |
| 72 | } |
| 73 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 74 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 75 | { |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 76 | /* Avoid an invalid state */ |
| 77 | if (length < 2) |
| 78 | length = 2; |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 79 | if (r->length != length) { |
| 80 | r->length = length; |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 81 | iio_mark_update_needed_kfifo(r); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 82 | } |
| 83 | return 0; |
| 84 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 85 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 86 | static int iio_store_to_kfifo(struct iio_buffer *r, |
Lars-Peter Clausen | 5d65d92 | 2013-09-15 17:50:00 +0100 | [diff] [blame] | 87 | const void *data) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 88 | { |
| 89 | int ret; |
| 90 | struct iio_kfifo *kf = iio_to_kfifo(r); |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 91 | ret = kfifo_in(&kf->kf, data, 1); |
| 92 | if (ret != 1) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 93 | return -EBUSY; |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 94 | return 0; |
| 95 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 96 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 97 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
Jonathan Cameron | b26a218 | 2011-05-18 14:41:02 +0100 | [diff] [blame] | 98 | size_t n, char __user *buf) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 99 | { |
| 100 | int ret, copied; |
| 101 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 102 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 103 | if (mutex_lock_interruptible(&kf->user_lock)) |
| 104 | return -ERESTARTSYS; |
Lars-Peter Clausen | 8fe6495 | 2011-12-12 09:33:14 +0100 | [diff] [blame] | 105 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 106 | if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) |
| 107 | ret = -EINVAL; |
| 108 | else |
| 109 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 110 | mutex_unlock(&kf->user_lock); |
| 111 | if (ret < 0) |
| 112 | return ret; |
| 113 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 114 | return copied; |
| 115 | } |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 116 | |
Josselin Costanzi | 37d3455 | 2015-03-22 20:33:38 +0200 | [diff] [blame] | 117 | static size_t iio_kfifo_buf_data_available(struct iio_buffer *r) |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 118 | { |
| 119 | struct iio_kfifo *kf = iio_to_kfifo(r); |
Josselin Costanzi | 37d3455 | 2015-03-22 20:33:38 +0200 | [diff] [blame] | 120 | size_t samples; |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 121 | |
| 122 | mutex_lock(&kf->user_lock); |
Josselin Costanzi | 37d3455 | 2015-03-22 20:33:38 +0200 | [diff] [blame] | 123 | samples = kfifo_len(&kf->kf); |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 124 | mutex_unlock(&kf->user_lock); |
| 125 | |
Josselin Costanzi | 37d3455 | 2015-03-22 20:33:38 +0200 | [diff] [blame] | 126 | return samples; |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 127 | } |
| 128 | |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 129 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
| 130 | { |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 131 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
| 132 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 133 | mutex_destroy(&kf->user_lock); |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 134 | kfifo_free(&kf->kf); |
| 135 | kfree(kf); |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 136 | } |
| 137 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 138 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 139 | .store_to = &iio_store_to_kfifo, |
| 140 | .read_first_n = &iio_read_first_n_kfifo, |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 141 | .data_available = iio_kfifo_buf_data_available, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 142 | .request_update = &iio_request_update_kfifo, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 143 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 144 | .set_length = &iio_set_length_kfifo, |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 145 | .release = &iio_kfifo_buffer_release, |
Lars-Peter Clausen | 225d59a | 2015-05-29 18:14:21 +0200 | [diff] [blame] | 146 | |
| 147 | .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 148 | }; |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 149 | |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame] | 150 | struct iio_buffer *iio_kfifo_allocate(void) |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 151 | { |
| 152 | struct iio_kfifo *kf; |
| 153 | |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame] | 154 | kf = kzalloc(sizeof(*kf), GFP_KERNEL); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 155 | if (!kf) |
| 156 | return NULL; |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame] | 157 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 158 | kf->update_needed = true; |
| 159 | iio_buffer_init(&kf->buffer); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 160 | kf->buffer.access = &kfifo_access_funcs; |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 161 | kf->buffer.length = 2; |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 162 | mutex_init(&kf->user_lock); |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame] | 163 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 164 | return &kf->buffer; |
| 165 | } |
| 166 | EXPORT_SYMBOL(iio_kfifo_allocate); |
| 167 | |
| 168 | void iio_kfifo_free(struct iio_buffer *r) |
| 169 | { |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 170 | iio_buffer_put(r); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 171 | } |
| 172 | EXPORT_SYMBOL(iio_kfifo_free); |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 173 | |
Karol Wrona | 780103f | 2014-12-19 18:39:25 +0100 | [diff] [blame] | 174 | static void devm_iio_kfifo_release(struct device *dev, void *res) |
| 175 | { |
| 176 | iio_kfifo_free(*(struct iio_buffer **)res); |
| 177 | } |
| 178 | |
| 179 | static int devm_iio_kfifo_match(struct device *dev, void *res, void *data) |
| 180 | { |
| 181 | struct iio_buffer **r = res; |
| 182 | |
| 183 | if (WARN_ON(!r || !*r)) |
| 184 | return 0; |
| 185 | |
| 186 | return *r == data; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate() |
| 191 | * @dev: Device to allocate kfifo buffer for |
| 192 | * |
| 193 | * RETURNS: |
| 194 | * Pointer to allocated iio_buffer on success, NULL on failure. |
| 195 | */ |
| 196 | struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev) |
| 197 | { |
| 198 | struct iio_buffer **ptr, *r; |
| 199 | |
| 200 | ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL); |
| 201 | if (!ptr) |
| 202 | return NULL; |
| 203 | |
| 204 | r = iio_kfifo_allocate(); |
| 205 | if (r) { |
| 206 | *ptr = r; |
| 207 | devres_add(dev, ptr); |
| 208 | } else { |
| 209 | devres_free(ptr); |
| 210 | } |
| 211 | |
| 212 | return r; |
| 213 | } |
| 214 | EXPORT_SYMBOL(devm_iio_kfifo_allocate); |
| 215 | |
| 216 | /** |
| 217 | * devm_iio_fifo_free - Resource-managed iio_kfifo_free() |
| 218 | * @dev: Device the buffer belongs to |
| 219 | * @r: The buffer associated with the device |
| 220 | */ |
| 221 | void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r) |
| 222 | { |
| 223 | WARN_ON(devres_release(dev, devm_iio_kfifo_release, |
| 224 | devm_iio_kfifo_match, r)); |
| 225 | } |
| 226 | EXPORT_SYMBOL(devm_iio_kfifo_free); |
| 227 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 228 | MODULE_LICENSE("GPL"); |