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 | } |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 45 | r->stufftoread = false; |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 46 | mutex_unlock(&buf->user_lock); |
Lars-Peter Clausen | 5b78e51 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 47 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 48 | return ret; |
| 49 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 50 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 51 | static int iio_get_length_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 52 | { |
| 53 | return r->length; |
| 54 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 55 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 56 | static IIO_BUFFER_ENABLE_ATTR; |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 57 | static IIO_BUFFER_LENGTH_ATTR; |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 58 | |
| 59 | static struct attribute *iio_kfifo_attributes[] = { |
| 60 | &dev_attr_length.attr, |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 61 | &dev_attr_enable.attr, |
| 62 | NULL, |
| 63 | }; |
| 64 | |
| 65 | static struct attribute_group iio_kfifo_attribute_group = { |
| 66 | .attrs = iio_kfifo_attributes, |
Jonathan Cameron | 1aa0427 | 2011-08-30 12:32:47 +0100 | [diff] [blame] | 67 | .name = "buffer", |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 68 | }; |
| 69 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 70 | static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 71 | { |
| 72 | return r->bytes_per_datum; |
| 73 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 74 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 75 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 76 | { |
| 77 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 78 | kf->update_needed = true; |
| 79 | return 0; |
| 80 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 81 | |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 82 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
| 83 | { |
| 84 | if (r->bytes_per_datum != bpd) { |
| 85 | r->bytes_per_datum = bpd; |
| 86 | iio_mark_update_needed_kfifo(r); |
| 87 | } |
| 88 | return 0; |
| 89 | } |
| 90 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 91 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 92 | { |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 93 | /* Avoid an invalid state */ |
| 94 | if (length < 2) |
| 95 | length = 2; |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 96 | if (r->length != length) { |
| 97 | r->length = length; |
Lars-Peter Clausen | 869871b | 2011-12-19 15:23:48 +0100 | [diff] [blame] | 98 | iio_mark_update_needed_kfifo(r); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 99 | } |
| 100 | return 0; |
| 101 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 102 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 103 | static int iio_store_to_kfifo(struct iio_buffer *r, |
Lars-Peter Clausen | 5d65d92 | 2013-09-15 17:50:00 +0100 | [diff] [blame] | 104 | const void *data) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 105 | { |
| 106 | int ret; |
| 107 | struct iio_kfifo *kf = iio_to_kfifo(r); |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 108 | ret = kfifo_in(&kf->kf, data, 1); |
| 109 | if (ret != 1) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 110 | return -EBUSY; |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 111 | r->stufftoread = true; |
Lars-Peter Clausen | 623c334 | 2013-09-15 16:31:00 +0100 | [diff] [blame] | 112 | wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM); |
Jonathan Cameron | c559afb | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 113 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 114 | return 0; |
| 115 | } |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 116 | |
Jonathan Cameron | 14555b1 | 2011-09-21 11:15:57 +0100 | [diff] [blame] | 117 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
Jonathan Cameron | b26a218 | 2011-05-18 14:41:02 +0100 | [diff] [blame] | 118 | size_t n, char __user *buf) |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 119 | { |
| 120 | int ret, copied; |
| 121 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 122 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 123 | if (mutex_lock_interruptible(&kf->user_lock)) |
| 124 | return -ERESTARTSYS; |
Lars-Peter Clausen | 8fe6495 | 2011-12-12 09:33:14 +0100 | [diff] [blame] | 125 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 126 | if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf)) |
| 127 | ret = -EINVAL; |
| 128 | else |
| 129 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 130 | |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 131 | if (kfifo_is_empty(&kf->kf)) |
| 132 | r->stufftoread = false; |
| 133 | /* verify it is still empty to avoid race */ |
| 134 | if (!kfifo_is_empty(&kf->kf)) |
| 135 | r->stufftoread = true; |
| 136 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 137 | mutex_unlock(&kf->user_lock); |
| 138 | if (ret < 0) |
| 139 | return ret; |
| 140 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 141 | return copied; |
| 142 | } |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 143 | |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 144 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
| 145 | { |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 146 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
| 147 | |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 148 | mutex_destroy(&kf->user_lock); |
Lars-Peter Clausen | f6c23f4 | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 149 | kfifo_free(&kf->kf); |
| 150 | kfree(kf); |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 151 | } |
| 152 | |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 153 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 154 | .store_to = &iio_store_to_kfifo, |
| 155 | .read_first_n = &iio_read_first_n_kfifo, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 156 | .request_update = &iio_request_update_kfifo, |
| 157 | .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo, |
| 158 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
| 159 | .get_length = &iio_get_length_kfifo, |
| 160 | .set_length = &iio_set_length_kfifo, |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 161 | .release = &iio_kfifo_buffer_release, |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 162 | }; |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 163 | |
| 164 | struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) |
| 165 | { |
| 166 | struct iio_kfifo *kf; |
| 167 | |
| 168 | kf = kzalloc(sizeof *kf, GFP_KERNEL); |
| 169 | if (!kf) |
| 170 | return NULL; |
| 171 | kf->update_needed = true; |
| 172 | iio_buffer_init(&kf->buffer); |
| 173 | kf->buffer.attrs = &iio_kfifo_attribute_group; |
| 174 | kf->buffer.access = &kfifo_access_funcs; |
Jonathan Cameron | 7c388ec | 2012-06-30 13:52:00 +0100 | [diff] [blame] | 175 | kf->buffer.length = 2; |
Lars-Peter Clausen | 0894d80d | 2013-10-15 09:30:00 +0100 | [diff] [blame] | 176 | mutex_init(&kf->user_lock); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 177 | return &kf->buffer; |
| 178 | } |
| 179 | EXPORT_SYMBOL(iio_kfifo_allocate); |
| 180 | |
| 181 | void iio_kfifo_free(struct iio_buffer *r) |
| 182 | { |
Lars-Peter Clausen | 9e69c93 | 2013-10-04 12:06:00 +0100 | [diff] [blame] | 183 | iio_buffer_put(r); |
Lars-Peter Clausen | 7e63234 | 2012-01-03 11:02:51 +0100 | [diff] [blame] | 184 | } |
| 185 | EXPORT_SYMBOL(iio_kfifo_free); |
Jonathan Cameron | 5565a45 | 2011-05-18 14:42:24 +0100 | [diff] [blame] | 186 | |
Jonathan Cameron | b174baf | 2011-02-11 13:09:10 +0000 | [diff] [blame] | 187 | MODULE_LICENSE("GPL"); |