[deliverable/linux.git] / drivers / iio / kfifo_buf.c

#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/kfifo_buf.h>

struct iio_kfifo {
	struct iio_buffer buffer;
	struct kfifo kf;
	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,
				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);

	if (!buf->update_needed)
		goto error_ret;
	kfifo_free(&buf->kf);
	ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
				   buf->buffer.length);
error_ret:
	return ret;
}

static int iio_get_length_kfifo(struct iio_buffer *r)
{
	return r->length;
}

static IIO_BUFFER_ENABLE_ATTR;
static IIO_BUFFER_LENGTH_ATTR;

static struct attribute *iio_kfifo_attributes[] = {
	&dev_attr_length.attr,
	&dev_attr_enable.attr,
	NULL,
};

static struct attribute_group iio_kfifo_attribute_group = {
	.attrs = iio_kfifo_attributes,
	.name = "buffer",
};

static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
{
	return r->bytes_per_datum;
}

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, int length)
{
	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,
			      u8 *data,
			      s64 timestamp)
{
	int ret;
	struct iio_kfifo *kf = iio_to_kfifo(r);
	ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
	if (ret != r->bytes_per_datum)
		return -EBUSY;
	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);

	if (n < r->bytes_per_datum)
		return -EINVAL;

	n = rounddown(n, r->bytes_per_datum);
	ret = kfifo_to_user(&kf->kf, buf, n, &copied);

	return copied;
}

static const struct iio_buffer_access_funcs kfifo_access_funcs = {
	.store_to = &iio_store_to_kfifo,
	.read_first_n = &iio_read_first_n_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,
};

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);
	kf->buffer.attrs = &iio_kfifo_attribute_group;
	kf->buffer.access = &kfifo_access_funcs;

	return &kf->buffer;
}
EXPORT_SYMBOL(iio_kfifo_allocate);

void iio_kfifo_free(struct iio_buffer *r)
{
	kfree(iio_to_kfifo(r));
}
EXPORT_SYMBOL(iio_kfifo_free);

MODULE_LICENSE("GPL");
Commit	Line	Data
b174baf4 JC	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>
06458e27	8	#include <linux/iio/kfifo_buf.h>
b174baf4	9
a710cc77	10	struct iio_kfifo {
14555b14	11	struct iio_buffer buffer;
a710cc77	12	struct kfifo kf;
a710cc77	13	int update_needed;
a710cc77 JC	14	};
a710cc77 JC	15
14555b14	16	#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
5565a450	17
b174baf4 JC	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
14555b14	24	__iio_update_buffer(&buf->buffer, bytes_per_datum, length);
b174baf4 JC	25	return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL);
	26	}
	27
14555b14	28	static int iio_request_update_kfifo(struct iio_buffer *r)
b174baf4 JC	29	{
	30	int ret = 0;
	31	struct iio_kfifo *buf = iio_to_kfifo(r);
	32
b174baf4 JC	33	if (!buf->update_needed)
b174baf4 JC	34	goto error_ret;
b174baf4	35	kfifo_free(&buf->kf);
14555b14 JC	36	ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
14555b14 JC	37	buf->buffer.length);
b174baf4	38	error_ret:
b174baf4 JC	39	return ret;
b174baf4 JC	40	}
b174baf4	41
14555b14	42	static int iio_get_length_kfifo(struct iio_buffer *r)
b174baf4 JC	43	{
	44	return r->length;
	45	}
b174baf4	46
14555b14	47	static IIO_BUFFER_ENABLE_ATTR;
14555b14	48	static IIO_BUFFER_LENGTH_ATTR;
b174baf4 JC	49
	50	static struct attribute *iio_kfifo_attributes[] = {
	51	&dev_attr_length.attr,
b174baf4 JC	52	&dev_attr_enable.attr,
	53	NULL,
	54	};
	55
	56	static struct attribute_group iio_kfifo_attribute_group = {
	57	.attrs = iio_kfifo_attributes,
1aa04278	58	.name = "buffer",
b174baf4 JC	59	};
b174baf4 JC	60
14555b14	61	static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
b174baf4 JC	62	{
	63	return r->bytes_per_datum;
	64	}
b174baf4	65
869871b5	66	static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
b174baf4	67	{
869871b5 LPC	68	struct iio_kfifo *kf = iio_to_kfifo(r);
869871b5 LPC	69	kf->update_needed = true;
b174baf4 JC	70	return 0;
b174baf4 JC	71	}
b174baf4	72
869871b5	73	static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
b174baf4	74	{
869871b5 LPC	75	if (r->bytes_per_datum != bpd) {
	76	r->bytes_per_datum = bpd;
	77	iio_mark_update_needed_kfifo(r);
	78	}
b174baf4 JC	79	return 0;
b174baf4 JC	80	}
b174baf4	81
14555b14	82	static int iio_set_length_kfifo(struct iio_buffer *r, int length)
b174baf4 JC	83	{
	84	if (r->length != length) {
	85	r->length = length;
869871b5	86	iio_mark_update_needed_kfifo(r);
b174baf4 JC	87	}
	88	return 0;
	89	}
b174baf4	90
14555b14	91	static int iio_store_to_kfifo(struct iio_buffer *r,
5565a450 JC	92	u8 *data,
5565a450 JC	93	s64 timestamp)
b174baf4 JC	94	{
	95	int ret;
	96	struct iio_kfifo *kf = iio_to_kfifo(r);
b174baf4	97	ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
4c3d1535	98	if (ret != r->bytes_per_datum)
b174baf4	99	return -EBUSY;
b174baf4 JC	100	return 0;
b174baf4 JC	101	}
b174baf4	102
14555b14	103	static int iio_read_first_n_kfifo(struct iio_buffer *r,
b26a2188	104	size_t n, char __user *buf)
b174baf4 JC	105	{
	106	int ret, copied;
	107	struct iio_kfifo *kf = iio_to_kfifo(r);
	108
8fe64955 LPC	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);
b174baf4 JC	114
	115	return copied;
	116	}
5565a450	117
7e632344	118	static const struct iio_buffer_access_funcs kfifo_access_funcs = {
5565a450 JC	119	.store_to = &iio_store_to_kfifo,
5565a450 JC	120	.read_first_n = &iio_read_first_n_kfifo,
5565a450 JC	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	};
7e632344 LPC	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);
5565a450	149
b174baf4	150	MODULE_LICENSE("GPL");