diff options
Diffstat (limited to 'drivers/staging/iio/kfifo_buf.c')
| -rw-r--r-- | drivers/staging/iio/kfifo_buf.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/drivers/staging/iio/kfifo_buf.c b/drivers/staging/iio/kfifo_buf.c new file mode 100644 index 0000000..a56c0cb --- /dev/null +++ b/drivers/staging/iio/kfifo_buf.c @@ -0,0 +1,196 @@ +#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" + +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_ring_buffer(&buf->ring, bytes_per_datum, length); + return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL); +} + +int iio_request_update_kfifo(struct iio_ring_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->ring.bytes_per_datum, + buf->ring.length); +error_ret: + mutex_unlock(&buf->use_lock); + return ret; +} +EXPORT_SYMBOL(iio_request_update_kfifo); + +void iio_mark_kfifo_in_use(struct iio_ring_buffer *r) +{ + struct iio_kfifo *buf = iio_to_kfifo(r); + mutex_lock(&buf->use_lock); + buf->use_count++; + mutex_unlock(&buf->use_lock); +} +EXPORT_SYMBOL(iio_mark_kfifo_in_use); + +void iio_unmark_kfifo_in_use(struct iio_ring_buffer *r) +{ + struct iio_kfifo *buf = iio_to_kfifo(r); + mutex_lock(&buf->use_lock); + buf->use_count--; + mutex_unlock(&buf->use_lock); +} +EXPORT_SYMBOL(iio_unmark_kfifo_in_use); + +int iio_get_length_kfifo(struct iio_ring_buffer *r) +{ + return r->length; +} +EXPORT_SYMBOL(iio_get_length_kfifo); + +static inline void __iio_init_kfifo(struct iio_kfifo *kf) +{ + mutex_init(&kf->use_lock); +} + +static IIO_RING_ENABLE_ATTR; +static IIO_RING_BYTES_PER_DATUM_ATTR; +static IIO_RING_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, +}; + +static const struct attribute_group *iio_kfifo_attribute_groups[] = { + &iio_kfifo_attribute_group, + NULL +}; + +static void iio_kfifo_release(struct device *dev) +{ + struct iio_ring_buffer *r = to_iio_ring_buffer(dev); + struct iio_kfifo *kf = iio_to_kfifo(r); + kfifo_free(&kf->kf); + kfree(kf); +} + +static struct device_type iio_kfifo_type = { + .release = iio_kfifo_release, + .groups = iio_kfifo_attribute_groups, +}; + +struct iio_ring_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev) +{ + struct iio_kfifo *kf; + + kf = kzalloc(sizeof *kf, GFP_KERNEL); + if (!kf) + return NULL; + iio_ring_buffer_init(&kf->ring, indio_dev); + __iio_init_kfifo(kf); + kf->ring.dev.type = &iio_kfifo_type; + device_initialize(&kf->ring.dev); + kf->ring.dev.parent = &indio_dev->dev; + kf->ring.dev.bus = &iio_bus_type; + dev_set_drvdata(&kf->ring.dev, (void *)&(kf->ring)); + + return &kf->ring; +} +EXPORT_SYMBOL(iio_kfifo_allocate); + +int iio_get_bytes_per_datum_kfifo(struct iio_ring_buffer *r) +{ + return r->bytes_per_datum; +} +EXPORT_SYMBOL(iio_get_bytes_per_datum_kfifo); + +int iio_set_bytes_per_datum_kfifo(struct iio_ring_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; +} +EXPORT_SYMBOL(iio_set_bytes_per_datum_kfifo); + +int iio_mark_update_needed_kfifo(struct iio_ring_buffer *r) +{ + struct iio_kfifo *kf = iio_to_kfifo(r); + kf->update_needed = true; + return 0; +} +EXPORT_SYMBOL(iio_mark_update_needed_kfifo); + +int iio_set_length_kfifo(struct iio_ring_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; +} +EXPORT_SYMBOL(iio_set_length_kfifo); + +void iio_kfifo_free(struct iio_ring_buffer *r) +{ + if (r) + iio_put_ring_buffer(r); +} +EXPORT_SYMBOL(iio_kfifo_free); + +int iio_store_to_kfifo(struct iio_ring_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; +} +EXPORT_SYMBOL(iio_store_to_kfifo); + +int iio_rip_kfifo(struct iio_ring_buffer *r, + size_t count, char __user *buf, int *deadoffset) +{ + int ret, copied; + struct iio_kfifo *kf = iio_to_kfifo(r); + + *deadoffset = 0; + ret = kfifo_to_user(&kf->kf, buf, r->bytes_per_datum*count, &copied); + + return copied; +} +EXPORT_SYMBOL(iio_rip_kfifo); +MODULE_LICENSE("GPL"); |