| /** |
| * @file mecirc_buf.h |
| * |
| * @brief Meilhaus circular buffer implementation. |
| * @note Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de) |
| * @author Guenter Gebhardt |
| * @author Krzysztof Gantzke (k.gantzke@meilhaus.de) |
| */ |
| |
| /* |
| * Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de) |
| * |
| * This file 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., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #ifndef _MECIRC_BUF_H_ |
| #define _MECIRC_BUF_H_ |
| |
| # ifdef __KERNEL__ |
| |
| # ifdef BOSCH |
| |
| typedef struct me_circ_buf { |
| unsigned int mask; |
| // unsigned int count; |
| uint32_t *buf; |
| int volatile head; |
| int volatile tail; |
| } me_circ_buf_t; |
| |
| static inline int me_circ_buf_values(me_circ_buf_t * buf) |
| { |
| // return ((buf->head - buf->tail) & (buf->count - 1)); |
| return ((buf->head - buf->tail) & (buf->mask)); |
| } |
| |
| static inline int me_circ_buf_space(me_circ_buf_t * buf) |
| { |
| // return ((buf->tail - (buf->head + 1)) & (buf->count - 1)); |
| return ((buf->tail - (buf->head + 1)) & (buf->mask)); |
| } |
| |
| static inline int me_circ_buf_values_to_end(me_circ_buf_t * buf) |
| { |
| int end; |
| int n; |
| // end = buf->count - buf->tail; |
| // n = (buf->head + end) & (buf->count - 1); |
| end = buf->mask + 1 - buf->tail; |
| n = (buf->head + end) & (buf->mask); |
| return (n < end) ? n : end; |
| } |
| |
| static inline int me_circ_buf_space_to_end(me_circ_buf_t * buf) |
| { |
| int end; |
| int n; |
| |
| // end = buf->count - 1 - buf->head; |
| // n = (end + buf->tail) & (buf->count - 1); |
| end = buf->mask - buf->head; |
| n = (end + buf->tail) & (buf->mask); |
| return (n <= end) ? n : (end + 1); |
| } |
| |
| #define _CBUFF_32b_t |
| |
| # else //~BOSCH |
| /// @note buf->mask = buf->count-1 = ME4600_AI_CIRC_BUF_COUNT-1 |
| |
| # ifdef _CBUFF_32b_t |
| //32 bit |
| typedef struct me_circ_buf_32b { |
| int volatile head; |
| int volatile tail; |
| unsigned int mask; //buffor size-1 must be 2^n-1 to work |
| uint32_t *buf; |
| } me_circ_buf_t; |
| # else |
| //16 bit |
| typedef struct me_circ_buf_16b { |
| int volatile head; |
| int volatile tail; |
| unsigned int mask; //buffor size-1 must be 2^n-1 to work |
| uint16_t *buf; |
| } me_circ_buf_t; |
| # endif //_CBUFF_32b_t |
| |
| /** How many values is in buffer */ |
| static inline int me_circ_buf_values(me_circ_buf_t * buf) |
| { |
| return ((buf->head - buf->tail) & (buf->mask)); |
| } |
| |
| /** How many space left */ |
| static inline int me_circ_buf_space(me_circ_buf_t * buf) |
| { |
| return ((buf->tail - (buf->head + 1)) & (buf->mask)); |
| } |
| |
| /** How many values can be read from buffor in one chunck. */ |
| static inline int me_circ_buf_values_to_end(me_circ_buf_t * buf) |
| { |
| return (buf->tail <= |
| buf->head) ? (buf->head - buf->tail) : (buf->mask - buf->tail + |
| 1); |
| } |
| |
| /** How many values can be write to buffer in one chunck. */ |
| static inline int me_circ_buf_space_to_end(me_circ_buf_t * buf) |
| { |
| return (buf->tail <= |
| buf->head) ? (buf->mask - buf->head + 1) : (buf->tail - |
| buf->head - 1); |
| } |
| |
| # endif //BOSCH |
| # endif //__KERNEL__ |
| #endif //_MECIRC_BUF_H_ |