| /* Ring buffer |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA |
| */ |
| #include "ringbuffer.h" |
| #include "trace.h" |
| #include "utils.h" |
| |
| /* WARNING: Since console output is internally using this ringbuffer to implement |
| * buffered writes, we cannot use any TRACE_*() or printf() style functions here, |
| * as it would create infinite recursion! */ |
| |
| void rbuf_reset(volatile ringbuf * rb) |
| { |
| unsigned long state; |
| |
| local_irq_save(state); |
| rb->ird = 0; |
| rb->iwr = 0; |
| local_irq_restore(state); |
| } |
| |
| uint8_t rbuf_read(volatile ringbuf * rb) |
| { |
| unsigned long state; |
| uint8_t val; |
| |
| local_irq_save(state); |
| val = rb->buf[rb->ird]; |
| rb->ird = (rb->ird + 1) % RING_BUFLEN; |
| local_irq_restore(state); |
| |
| return val; |
| } |
| |
| uint8_t rbuf_peek(volatile ringbuf * rb) |
| { |
| return rb->buf[rb->ird]; |
| } |
| |
| bool rbuf_is_empty(volatile ringbuf * rb) |
| { |
| return rb->ird == rb->iwr; |
| } |
| |
| static bool __rbuf_is_full(volatile ringbuf * rb) |
| { |
| return rb->ird == (rb->iwr + 1) % RING_BUFLEN; |
| } |
| |
| bool rbuf_is_full(volatile ringbuf * rb) |
| { |
| unsigned long state; |
| bool rc; |
| |
| local_irq_save(state); |
| rc = rb->ird == (rb->iwr + 1) % RING_BUFLEN; |
| local_irq_restore(state); |
| |
| return rc; |
| } |
| |
| int rbuf_write(volatile ringbuf * rb, uint8_t item) |
| { |
| unsigned long state; |
| |
| local_irq_save(state); |
| if (!__rbuf_is_full(rb)) { |
| rb->buf[rb->iwr] = item; |
| rb->iwr = (rb->iwr + 1) % RING_BUFLEN; |
| local_irq_restore(state); |
| return 0; |
| } else { |
| local_irq_restore(state); |
| return -1; |
| } |
| } |
| |
| |