299 lines
6.9 KiB
C
299 lines
6.9 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
#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 <linux/iio/iio.h>
|
||
|
|
#include <linux/iio/buffer.h>
|
||
|
|
#include <linux/iio/kfifo_buf.h>
|
||
|
|
#include <linux/iio/buffer_impl.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/poll.h>
|
||
|
|
|
||
|
|
struct iio_kfifo {
|
||
|
|
struct iio_buffer buffer;
|
||
|
|
struct kfifo kf;
|
||
|
|
struct mutex user_lock;
|
||
|
|
int update_needed;
|
||
|
|
};
|
||
|
|
|
||
|
|
#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
|
||
|
|
|
||
|
|
static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
|
||
|
|
size_t bytes_per_datum, unsigned int length)
|
||
|
|
{
|
||
|
|
if ((length == 0) || (bytes_per_datum == 0))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Make sure we don't overflow an unsigned int after kfifo rounds up to
|
||
|
|
* the next power of 2.
|
||
|
|
*/
|
||
|
|
if (roundup_pow_of_two(length) > UINT_MAX / bytes_per_datum)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
|
||
|
|
bytes_per_datum, 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->user_lock);
|
||
|
|
if (buf->update_needed) {
|
||
|
|
kfifo_free(&buf->kf);
|
||
|
|
ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
|
||
|
|
buf->buffer.length);
|
||
|
|
if (ret >= 0)
|
||
|
|
buf->update_needed = false;
|
||
|
|
} else {
|
||
|
|
kfifo_reset_out(&buf->kf);
|
||
|
|
}
|
||
|
|
mutex_unlock(&buf->user_lock);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
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_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
|
||
|
|
{
|
||
|
|
if (r->bytes_per_datum != bpd) {
|
||
|
|
r->bytes_per_datum = bpd;
|
||
|
|
iio_mark_update_needed_kfifo(r);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int iio_set_length_kfifo(struct iio_buffer *r, unsigned int length)
|
||
|
|
{
|
||
|
|
/* Avoid an invalid state */
|
||
|
|
if (length < 2)
|
||
|
|
length = 2;
|
||
|
|
if (r->length != length) {
|
||
|
|
r->length = length;
|
||
|
|
iio_mark_update_needed_kfifo(r);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int iio_store_to_kfifo(struct iio_buffer *r,
|
||
|
|
const void *data)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
ret = kfifo_in(&kf->kf, data, 1);
|
||
|
|
if (ret != 1)
|
||
|
|
return -EBUSY;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int iio_read_kfifo(struct iio_buffer *r, size_t n, char __user *buf)
|
||
|
|
{
|
||
|
|
int ret, copied;
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
|
||
|
|
if (mutex_lock_interruptible(&kf->user_lock))
|
||
|
|
return -ERESTARTSYS;
|
||
|
|
|
||
|
|
if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
|
||
|
|
ret = -EINVAL;
|
||
|
|
else
|
||
|
|
ret = kfifo_to_user(&kf->kf, buf, n, &copied);
|
||
|
|
mutex_unlock(&kf->user_lock);
|
||
|
|
if (ret < 0)
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
return copied;
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t iio_kfifo_buf_data_available(struct iio_buffer *r)
|
||
|
|
{
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
size_t samples;
|
||
|
|
|
||
|
|
mutex_lock(&kf->user_lock);
|
||
|
|
samples = kfifo_len(&kf->kf);
|
||
|
|
mutex_unlock(&kf->user_lock);
|
||
|
|
|
||
|
|
return samples;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
|
||
|
|
{
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(buffer);
|
||
|
|
|
||
|
|
mutex_destroy(&kf->user_lock);
|
||
|
|
kfifo_free(&kf->kf);
|
||
|
|
kfree(kf);
|
||
|
|
}
|
||
|
|
|
||
|
|
static size_t iio_kfifo_buf_space_available(struct iio_buffer *r)
|
||
|
|
{
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
size_t avail;
|
||
|
|
|
||
|
|
mutex_lock(&kf->user_lock);
|
||
|
|
avail = kfifo_avail(&kf->kf);
|
||
|
|
mutex_unlock(&kf->user_lock);
|
||
|
|
|
||
|
|
return avail;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int iio_kfifo_remove_from(struct iio_buffer *r, void *data)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
|
||
|
|
if (kfifo_size(&kf->kf) < 1)
|
||
|
|
return -EBUSY;
|
||
|
|
|
||
|
|
ret = kfifo_out(&kf->kf, data, 1);
|
||
|
|
if (ret != 1)
|
||
|
|
return -EBUSY;
|
||
|
|
|
||
|
|
wake_up_interruptible_poll(&r->pollq, EPOLLOUT | EPOLLWRNORM);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int iio_kfifo_write(struct iio_buffer *r, size_t n,
|
||
|
|
const char __user *buf)
|
||
|
|
{
|
||
|
|
struct iio_kfifo *kf = iio_to_kfifo(r);
|
||
|
|
int ret, copied;
|
||
|
|
|
||
|
|
mutex_lock(&kf->user_lock);
|
||
|
|
if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
|
||
|
|
ret = -EINVAL;
|
||
|
|
else
|
||
|
|
ret = kfifo_from_user(&kf->kf, buf, n, &copied);
|
||
|
|
mutex_unlock(&kf->user_lock);
|
||
|
|
if (ret)
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
return copied;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct iio_buffer_access_funcs kfifo_access_funcs = {
|
||
|
|
.store_to = &iio_store_to_kfifo,
|
||
|
|
.read = &iio_read_kfifo,
|
||
|
|
.data_available = iio_kfifo_buf_data_available,
|
||
|
|
.remove_from = &iio_kfifo_remove_from,
|
||
|
|
.write = &iio_kfifo_write,
|
||
|
|
.space_available = &iio_kfifo_buf_space_available,
|
||
|
|
.request_update = &iio_request_update_kfifo,
|
||
|
|
.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
|
||
|
|
.set_length = &iio_set_length_kfifo,
|
||
|
|
.release = &iio_kfifo_buffer_release,
|
||
|
|
|
||
|
|
.modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
|
||
|
|
};
|
||
|
|
|
||
|
|
struct iio_buffer *iio_kfifo_allocate(void)
|
||
|
|
{
|
||
|
|
struct iio_kfifo *kf;
|
||
|
|
|
||
|
|
kf = kzalloc(sizeof(*kf), GFP_KERNEL);
|
||
|
|
if (!kf)
|
||
|
|
return NULL;
|
||
|
|
|
||
|
|
kf->update_needed = true;
|
||
|
|
iio_buffer_init(&kf->buffer);
|
||
|
|
kf->buffer.access = &kfifo_access_funcs;
|
||
|
|
kf->buffer.length = 2;
|
||
|
|
mutex_init(&kf->user_lock);
|
||
|
|
|
||
|
|
return &kf->buffer;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(iio_kfifo_allocate);
|
||
|
|
|
||
|
|
void iio_kfifo_free(struct iio_buffer *r)
|
||
|
|
{
|
||
|
|
iio_buffer_put(r);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(iio_kfifo_free);
|
||
|
|
|
||
|
|
static void devm_iio_kfifo_release(struct device *dev, void *res)
|
||
|
|
{
|
||
|
|
iio_kfifo_free(*(struct iio_buffer **)res);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* devm_iio_kfifo_allocate - Resource-managed iio_kfifo_allocate()
|
||
|
|
* @dev: Device to allocate kfifo buffer for
|
||
|
|
*
|
||
|
|
* RETURNS:
|
||
|
|
* Pointer to allocated iio_buffer on success, NULL on failure.
|
||
|
|
*/
|
||
|
|
static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
|
||
|
|
{
|
||
|
|
struct iio_buffer **ptr, *r;
|
||
|
|
|
||
|
|
ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
|
||
|
|
if (!ptr)
|
||
|
|
return NULL;
|
||
|
|
|
||
|
|
r = iio_kfifo_allocate();
|
||
|
|
if (r) {
|
||
|
|
*ptr = r;
|
||
|
|
devres_add(dev, ptr);
|
||
|
|
} else {
|
||
|
|
devres_free(ptr);
|
||
|
|
}
|
||
|
|
|
||
|
|
return r;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* devm_iio_kfifo_buffer_setup_ext - Allocate a kfifo buffer & attach it to an IIO device
|
||
|
|
* @dev: Device object to which to attach the life-time of this kfifo buffer
|
||
|
|
* @indio_dev: The device the buffer should be attached to
|
||
|
|
* @mode_flags: The mode flags for this buffer (INDIO_BUFFER_SOFTWARE and/or
|
||
|
|
* INDIO_BUFFER_TRIGGERED).
|
||
|
|
* @setup_ops: The setup_ops required to configure the HW part of the buffer (optional)
|
||
|
|
* @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer
|
||
|
|
*
|
||
|
|
* This function allocates a kfifo buffer via devm_iio_kfifo_allocate() and
|
||
|
|
* attaches it to the IIO device via iio_device_attach_buffer().
|
||
|
|
* This is meant to be a bit of a short-hand/helper function as there are a few
|
||
|
|
* drivers that seem to do this.
|
||
|
|
*/
|
||
|
|
int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
|
||
|
|
struct iio_dev *indio_dev,
|
||
|
|
int mode_flags,
|
||
|
|
const struct iio_buffer_setup_ops *setup_ops,
|
||
|
|
const struct attribute **buffer_attrs)
|
||
|
|
{
|
||
|
|
struct iio_buffer *buffer;
|
||
|
|
|
||
|
|
if (!mode_flags)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
buffer = devm_iio_kfifo_allocate(dev);
|
||
|
|
if (!buffer)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
mode_flags &= kfifo_access_funcs.modes;
|
||
|
|
|
||
|
|
indio_dev->modes |= mode_flags;
|
||
|
|
indio_dev->setup_ops = setup_ops;
|
||
|
|
|
||
|
|
buffer->attrs = buffer_attrs;
|
||
|
|
|
||
|
|
return iio_device_attach_buffer(indio_dev, buffer);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(devm_iio_kfifo_buffer_setup_ext);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|