From 1546d6718dc92b27935931ee4e4c2e9893ef3066 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Thu, 7 Oct 2021 08:00:31 +0000 Subject: [PATCH] iio: kfifo-buffer: Add output buffer support Add output buffer support to the kfifo buffer implementation. The implementation is straight forward and mostly just wraps the kfifo API to provide the required operations. Signed-off-by: Lars-Peter Clausen Signed-off-by: Alexandru Ardelean Signed-off-by: Mihail Chindris Link: https://lore.kernel.org/r/20211007080035.2531-3-mihail.chindris@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/buffer/kfifo_buf.c | 50 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c index 516eb3465de1..416d35a61ae2 100644 --- a/drivers/iio/buffer/kfifo_buf.c +++ b/drivers/iio/buffer/kfifo_buf.c @@ -138,10 +138,60 @@ static void iio_kfifo_buffer_release(struct iio_buffer *buffer) 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, -- 2.11.0