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 | |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 27 | return __kfifo_alloc((struct __kfifo *)&buf->kf, length, |
| 28 | bytes_per_datum, GFP_KERNEL); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 29 | } |
| 30 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 31 | static int iio_request_update_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 32 | { |
| 33 | int ret = 0; |
| 34 | struct iio_kfifo *buf = iio_to_kfifo(r); |
| 35 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 36 | mutex_lock(&buf->user_lock); |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 37 | if (buf->update_needed) { |
| 38 | kfifo_free(&buf->kf); |
| 39 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 40 | buf->buffer.length); |
Lars-Peter Clausen | cb6fbfa | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 41 | buf->update_needed = false; |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 42 | } else { |
| 43 | kfifo_reset_out(&buf->kf); |
| 44 | } |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 45 | mutex_unlock(&buf->user_lock); |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 46 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 47 | return ret; |
| 48 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 49 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 50 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 51 | { |
| 52 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 53 | kf->update_needed = true; |
| 54 | return 0; |
| 55 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 56 | |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 57 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
| 58 | { |
| 59 | if (r->bytes_per_datum != bpd) { |
| 60 | r->bytes_per_datum = bpd; |
| 61 | iio_mark_update_needed_kfifo(r); |
| 62 | } |
| 63 | return 0; |
| 64 | } |
| 65 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 66 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 67 | { |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 68 | /* Avoid an invalid state */ |
| 69 | if (length < 2) |
| 70 | length = 2; |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 71 | if (r->length != length) { |
| 72 | r->length = length; |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 73 | iio_mark_update_needed_kfifo(r); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 74 | } |
| 75 | return 0; |
| 76 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 77 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 78 | static int iio_store_to_kfifo(struct iio_buffer *r, |
Lars-Peter Clausen | 5d65d92 | 2013-09-15 17:50:00 +0100 | [diff] [blame] | 79 | const void *data) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 80 | { |
| 81 | int ret; |
| 82 | struct iio_kfifo *kf = iio_to_kfifo(r); |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 83 | ret = kfifo_in(&kf->kf, data, 1); |
| 84 | if (ret != 1) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 85 | return -EBUSY; |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 86 | |
Lars-Peter Clausen | 623c334 | 2013-09-15 16:31:00 +0100 | [diff] [blame] | 87 | wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM); |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 88 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 89 | return 0; |
| 90 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 91 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 92 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
Jonathan Cameron | b26a218 | 2011-05-18 14:41:02 +0100 | [diff] [blame] | 93 | size_t n, char __user *buf) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 94 | { |
| 95 | int ret, copied; |
| 96 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 97 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 98 | if (mutex_lock_interruptible(&kf->user_lock)) |
| 99 | return -ERESTARTSYS; |
Lars-Peter Clausen | 8fe6495 | 2011-12-12 09:33:14 +0100 | [diff] [blame] | 100 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 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); |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 105 | mutex_unlock(&kf->user_lock); |
| 106 | if (ret < 0) |
| 107 | return ret; |
| 108 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 109 | return copied; |
| 110 | } |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 111 | |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 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 | |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 124 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
| 125 | { |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 126 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
| 127 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 128 | mutex_destroy(&kf->user_lock); |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 129 | kfifo_free(&kf->kf); |
| 130 | kfree(kf); |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 131 | } |
| 132 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 133 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 134 | .store_to = &iio_store_to_kfifo, |
| 135 | .read_first_n = &iio_read_first_n_kfifo, |
Lars-Peter Clausen | 355c1a1 | 2013-11-25 14:56:00 +0000 | [diff] [blame] | 136 | .data_available = iio_kfifo_buf_data_available, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 137 | .request_update = &iio_request_update_kfifo, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 138 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 139 | .set_length = &iio_set_length_kfifo, |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 140 | .release = &iio_kfifo_buffer_release, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 141 | }; |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 142 | |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame^] | 143 | struct iio_buffer *iio_kfifo_allocate(void) |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 144 | { |
| 145 | struct iio_kfifo *kf; |
| 146 | |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame^] | 147 | kf = kzalloc(sizeof(*kf), GFP_KERNEL); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 148 | if (!kf) |
| 149 | return NULL; |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame^] | 150 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 151 | kf->update_needed = true; |
| 152 | iio_buffer_init(&kf->buffer); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 153 | kf->buffer.access = &kfifo_access_funcs; |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 154 | kf->buffer.length = 2; |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 155 | mutex_init(&kf->user_lock); |
Karol Wrona | 7ab374a | 2014-12-19 18:39:24 +0100 | [diff] [blame^] | 156 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 157 | return &kf->buffer; |
| 158 | } |
| 159 | EXPORT_SYMBOL(iio_kfifo_allocate); |
| 160 | |
| 161 | void iio_kfifo_free(struct iio_buffer *r) |
| 162 | { |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 163 | iio_buffer_put(r); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 164 | } |
| 165 | EXPORT_SYMBOL(iio_kfifo_free); |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 166 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 167 | MODULE_LICENSE("GPL"); |