Added a FIFO API that can be used to create and operate byte FIFOs. Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwa...@petalogix.com> ---
hw/Makefile.objs | 1 + hw/fifo.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ hw/fifo.h | 47 ++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+), 0 deletions(-) create mode 100644 hw/fifo.c create mode 100644 hw/fifo.h diff --git a/hw/Makefile.objs b/hw/Makefile.objs index 6dfebd2..dcb0bcd 100644 --- a/hw/Makefile.objs +++ b/hw/Makefile.objs @@ -15,6 +15,7 @@ hw-obj-$(CONFIG_ECC) += ecc.o hw-obj-$(CONFIG_NAND) += nand.o hw-obj-$(CONFIG_PFLASH_CFI01) += pflash_cfi01.o hw-obj-$(CONFIG_PFLASH_CFI02) += pflash_cfi02.o +hw-obj-y += fifo.o hw-obj-$(CONFIG_M48T59) += m48t59.o hw-obj-$(CONFIG_ESCC) += escc.o diff --git a/hw/fifo.c b/hw/fifo.c new file mode 100644 index 0000000..366dae4 --- /dev/null +++ b/hw/fifo.c @@ -0,0 +1,78 @@ +/* + * Generic FIFO component, implemented as a circular buffer. + * + * Copyright (c) 2012 Peter A. G. Crosthwaite + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "fifo.h" + +void fifo8_create(Fifo8 *fifo, uint32_t capacity) +{ + fifo->data = g_new(uint8_t, capacity); + fifo->capacity = capacity; + fifo->head = 0; + fifo->num = 0; +} + +void fifo8_destroy(Fifo8 *fifo) +{ + g_free(fifo->data); +} + +void fifo8_push(Fifo8 *fifo, uint8_t data) +{ + if (fifo->num == fifo->capacity) { + abort(); + } + fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; + fifo->num++; +} + +uint8_t fifo8_pop(Fifo8 *fifo) +{ + uint8_t ret; + + if (fifo->num == 0) { + abort(); + } + ret = fifo->data[fifo->head++]; + fifo->head %= fifo->capacity; + fifo->num--; + return ret; +} + +void fifo8_reset(Fifo8 *fifo) +{ + fifo->num = 0; +} + +bool fifo8_is_empty(Fifo8 *fifo) +{ + return (fifo->num == 0); +} + +bool fifo8_is_full(Fifo8 *fifo) +{ + return (fifo->num == fifo->capacity); +} + +const VMStateDescription vmstate_fifo8 = { + .name = "SSISlave", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), + VMSTATE_UINT32(head, Fifo8), + VMSTATE_UINT32(num, Fifo8), + VMSTATE_END_OF_LIST() + } +}; diff --git a/hw/fifo.h b/hw/fifo.h new file mode 100644 index 0000000..3fb09ff --- /dev/null +++ b/hw/fifo.h @@ -0,0 +1,47 @@ +#ifndef FIFO_H +#define FIFO_H + +#include "hw.h" + +typedef struct { + /* All fields are private */ + uint8_t *data; + uint32_t capacity; + uint32_t head; + uint32_t num; +} Fifo8; + +/* create a fifo of the specified size */ + +void fifo8_create(Fifo8 *, uint32_t); + +/* cleanup a fifo */ + +void fifo8_destroy(Fifo8 *); + +/* push a data byte to the fifo. Behaviour is undefined if the fifo is full */ + +void fifo8_push(Fifo8 *, uint8_t); + +/* pop a data byte from the fifo. Behviour is undefined if the fifo is empty */ + +uint8_t fifo8_pop(Fifo8 *); + +/* reset (empty) the fifo */ + +void fifo8_reset(Fifo8 *); + +bool fifo8_is_empty(Fifo8 *); +bool fifo8_is_full(Fifo8 *); + +extern const VMStateDescription vmstate_fifo8; + +#define VMSTATE_FIFO8(_field, _state) { \ + .name = (stringify(_field)), \ + .size = sizeof(Fifo8), \ + .vmsd = &vmstate_fifo8, \ + .flags = VMS_STRUCT, \ + .offset = vmstate_offset_value(_state, _field, Fifo8), \ +} + +#endif /* FIFO_H */ -- 1.7.0.4
