Root/
| 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> |
| 8 | #include <linux/iio/kfifo_buf.h> |
| 9 | |
| 10 | struct iio_kfifo { |
| 11 | struct iio_buffer buffer; |
| 12 | struct kfifo kf; |
| 13 | int update_needed; |
| 14 | }; |
| 15 | |
| 16 | #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
| 17 | |
| 18 | static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, |
| 19 | int bytes_per_datum, int length) |
| 20 | { |
| 21 | if ((length == 0) || (bytes_per_datum == 0)) |
| 22 | return -EINVAL; |
| 23 | |
| 24 | __iio_update_buffer(&buf->buffer, bytes_per_datum, length); |
| 25 | return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL); |
| 26 | } |
| 27 | |
| 28 | static int iio_request_update_kfifo(struct iio_buffer *r) |
| 29 | { |
| 30 | int ret = 0; |
| 31 | struct iio_kfifo *buf = iio_to_kfifo(r); |
| 32 | |
| 33 | if (!buf->update_needed) |
| 34 | goto error_ret; |
| 35 | kfifo_free(&buf->kf); |
| 36 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, |
| 37 | buf->buffer.length); |
| 38 | error_ret: |
| 39 | return ret; |
| 40 | } |
| 41 | |
| 42 | static int iio_get_length_kfifo(struct iio_buffer *r) |
| 43 | { |
| 44 | return r->length; |
| 45 | } |
| 46 | |
| 47 | static IIO_BUFFER_ENABLE_ATTR; |
| 48 | static IIO_BUFFER_LENGTH_ATTR; |
| 49 | |
| 50 | static struct attribute *iio_kfifo_attributes[] = { |
| 51 | &dev_attr_length.attr, |
| 52 | &dev_attr_enable.attr, |
| 53 | NULL, |
| 54 | }; |
| 55 | |
| 56 | static struct attribute_group iio_kfifo_attribute_group = { |
| 57 | .attrs = iio_kfifo_attributes, |
| 58 | .name = "buffer", |
| 59 | }; |
| 60 | |
| 61 | static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) |
| 62 | { |
| 63 | return r->bytes_per_datum; |
| 64 | } |
| 65 | |
| 66 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
| 67 | { |
| 68 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 69 | kf->update_needed = true; |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
| 74 | { |
| 75 | if (r->bytes_per_datum != bpd) { |
| 76 | r->bytes_per_datum = bpd; |
| 77 | iio_mark_update_needed_kfifo(r); |
| 78 | } |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
| 83 | { |
| 84 | if (r->length != length) { |
| 85 | r->length = length; |
| 86 | iio_mark_update_needed_kfifo(r); |
| 87 | } |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static int iio_store_to_kfifo(struct iio_buffer *r, |
| 92 | u8 *data, |
| 93 | s64 timestamp) |
| 94 | { |
| 95 | int ret; |
| 96 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 97 | ret = kfifo_in(&kf->kf, data, r->bytes_per_datum); |
| 98 | if (ret != r->bytes_per_datum) |
| 99 | return -EBUSY; |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
| 104 | size_t n, char __user *buf) |
| 105 | { |
| 106 | int ret, copied; |
| 107 | struct iio_kfifo *kf = iio_to_kfifo(r); |
| 108 | |
| 109 | if (n < r->bytes_per_datum) |
| 110 | return -EINVAL; |
| 111 | |
| 112 | n = rounddown(n, r->bytes_per_datum); |
| 113 | ret = kfifo_to_user(&kf->kf, buf, n, &copied); |
| 114 | |
| 115 | return copied; |
| 116 | } |
| 117 | |
| 118 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
| 119 | .store_to = &iio_store_to_kfifo, |
| 120 | .read_first_n = &iio_read_first_n_kfifo, |
| 121 | .request_update = &iio_request_update_kfifo, |
| 122 | .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo, |
| 123 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
| 124 | .get_length = &iio_get_length_kfifo, |
| 125 | .set_length = &iio_set_length_kfifo, |
| 126 | }; |
| 127 | |
| 128 | struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) |
| 129 | { |
| 130 | struct iio_kfifo *kf; |
| 131 | |
| 132 | kf = kzalloc(sizeof *kf, GFP_KERNEL); |
| 133 | if (!kf) |
| 134 | return NULL; |
| 135 | kf->update_needed = true; |
| 136 | iio_buffer_init(&kf->buffer); |
| 137 | kf->buffer.attrs = &iio_kfifo_attribute_group; |
| 138 | kf->buffer.access = &kfifo_access_funcs; |
| 139 | |
| 140 | return &kf->buffer; |
| 141 | } |
| 142 | EXPORT_SYMBOL(iio_kfifo_allocate); |
| 143 | |
| 144 | void iio_kfifo_free(struct iio_buffer *r) |
| 145 | { |
| 146 | kfree(iio_to_kfifo(r)); |
| 147 | } |
| 148 | EXPORT_SYMBOL(iio_kfifo_free); |
| 149 | |
| 150 | MODULE_LICENSE("GPL"); |
| 151 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9
