| #include <linux/slab.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/device.h> |
| #include <linux/workqueue.h> |
| #include <linux/kfifo.h> |
| #include <linux/mutex.h> |
| |
| #include "kfifo_buf.h" |
| |
| struct iio_kfifo { |
| struct iio_buffer buffer; |
| struct kfifo kf; |
| int use_count; |
| int update_needed; |
| struct mutex use_lock; |
| }; |
| |
| #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
| |
| static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, |
| int bytes_per_datum, int length) |
| { |
| if ((length == 0) || (bytes_per_datum == 0)) |
| return -EINVAL; |
| |
| __iio_update_buffer(&buf->buffer, bytes_per_datum, length); |
| return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL); |
| } |
| |
| static int iio_request_update_kfifo(struct iio_buffer *r) |
| { |
| int ret = 0; |
| struct iio_kfifo *buf = iio_to_kfifo(r); |
| |
| mutex_lock(&buf->use_lock); |
| if (!buf->update_needed) |
| goto error_ret; |
| if (buf->use_count) { |
| ret = -EAGAIN; |
| goto error_ret; |
| } |
| kfifo_free(&buf->kf); |
| ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, |
| buf->buffer.length); |
| error_ret: |
| mutex_unlock(&buf->use_lock); |
| return ret; |
| } |
| |
| static void iio_mark_kfifo_in_use(struct iio_buffer *r) |
| { |
| struct iio_kfifo *buf = iio_to_kfifo(r); |
| mutex_lock(&buf->use_lock); |
| buf->use_count++; |
| mutex_unlock(&buf->use_lock); |
| } |
| |
| static void iio_unmark_kfifo_in_use(struct iio_buffer *r) |
| { |
| struct iio_kfifo *buf = iio_to_kfifo(r); |
| mutex_lock(&buf->use_lock); |
| buf->use_count--; |
| mutex_unlock(&buf->use_lock); |
| } |
| |
| static int iio_get_length_kfifo(struct iio_buffer *r) |
| { |
| return r->length; |
| } |
| |
| static inline void __iio_init_kfifo(struct iio_kfifo *kf) |
| { |
| mutex_init(&kf->use_lock); |
| } |
| |
| static IIO_BUFFER_ENABLE_ATTR; |
| static IIO_BUFFER_BYTES_PER_DATUM_ATTR; |
| static IIO_BUFFER_LENGTH_ATTR; |
| |
| static struct attribute *iio_kfifo_attributes[] = { |
| &dev_attr_length.attr, |
| &dev_attr_bytes_per_datum.attr, |
| &dev_attr_enable.attr, |
| NULL, |
| }; |
| |
| static struct attribute_group iio_kfifo_attribute_group = { |
| .attrs = iio_kfifo_attributes, |
| .name = "buffer", |
| }; |
| |
| struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) |
| { |
| struct iio_kfifo *kf; |
| |
| kf = kzalloc(sizeof *kf, GFP_KERNEL); |
| if (!kf) |
| return NULL; |
| kf->update_needed = true; |
| iio_buffer_init(&kf->buffer, indio_dev); |
| kf->buffer.attrs = &iio_kfifo_attribute_group; |
| __iio_init_kfifo(kf); |
| |
| return &kf->buffer; |
| } |
| EXPORT_SYMBOL(iio_kfifo_allocate); |
| |
| static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r) |
| { |
| return r->bytes_per_datum; |
| } |
| |
| static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
| { |
| if (r->bytes_per_datum != bpd) { |
| r->bytes_per_datum = bpd; |
| if (r->access->mark_param_change) |
| r->access->mark_param_change(r); |
| } |
| return 0; |
| } |
| |
| static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
| { |
| struct iio_kfifo *kf = iio_to_kfifo(r); |
| kf->update_needed = true; |
| return 0; |
| } |
| |
| static int iio_set_length_kfifo(struct iio_buffer *r, int length) |
| { |
| if (r->length != length) { |
| r->length = length; |
| if (r->access->mark_param_change) |
| r->access->mark_param_change(r); |
| } |
| return 0; |
| } |
| |
| void iio_kfifo_free(struct iio_buffer *r) |
| { |
| kfree(iio_to_kfifo(r)); |
| } |
| EXPORT_SYMBOL(iio_kfifo_free); |
| |
| static int iio_store_to_kfifo(struct iio_buffer *r, |
| u8 *data, |
| s64 timestamp) |
| { |
| int ret; |
| struct iio_kfifo *kf = iio_to_kfifo(r); |
| u8 *datal = kmalloc(r->bytes_per_datum, GFP_KERNEL); |
| memcpy(datal, data, r->bytes_per_datum - sizeof(timestamp)); |
| memcpy(datal + r->bytes_per_datum - sizeof(timestamp), |
| ×tamp, sizeof(timestamp)); |
| ret = kfifo_in(&kf->kf, data, r->bytes_per_datum); |
| if (ret != r->bytes_per_datum) { |
| kfree(datal); |
| return -EBUSY; |
| } |
| kfree(datal); |
| return 0; |
| } |
| |
| static int iio_read_first_n_kfifo(struct iio_buffer *r, |
| size_t n, char __user *buf) |
| { |
| int ret, copied; |
| struct iio_kfifo *kf = iio_to_kfifo(r); |
| |
| ret = kfifo_to_user(&kf->kf, buf, r->bytes_per_datum*n, &copied); |
| |
| return copied; |
| } |
| |
| const struct iio_buffer_access_funcs kfifo_access_funcs = { |
| .mark_in_use = &iio_mark_kfifo_in_use, |
| .unmark_in_use = &iio_unmark_kfifo_in_use, |
| .store_to = &iio_store_to_kfifo, |
| .read_first_n = &iio_read_first_n_kfifo, |
| .mark_param_change = &iio_mark_update_needed_kfifo, |
| .request_update = &iio_request_update_kfifo, |
| .get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo, |
| .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
| .get_length = &iio_get_length_kfifo, |
| .set_length = &iio_set_length_kfifo, |
| }; |
| EXPORT_SYMBOL(kfifo_access_funcs); |
| |
| MODULE_LICENSE("GPL"); |