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139 lines
5.2 KiB
139 lines
5.2 KiB
/**************************************************************************** |
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* drivers/pipe/pipe_common.h |
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* |
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* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved. |
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* 3. Neither the name NuttX nor the names of its contributors may be |
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* used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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****************************************************************************/ |
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#ifndef __DRIVERS_PIPE_COMMON_H |
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#define __DRIVERS_PIPE_COMMON_H |
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/**************************************************************************** |
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* Included Files |
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****************************************************************************/ |
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#include <nuttx/config.h> |
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#include <sys/types.h> |
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#include <stdint.h> |
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#include <stdbool.h> |
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#include <poll.h> |
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#ifndef CONFIG_DEV_PIPE_SIZE |
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# define CONFIG_DEV_PIPE_SIZE 1024 |
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#endif |
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#if CONFIG_DEV_PIPE_SIZE > 0 |
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/**************************************************************************** |
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* Pre-processor Definitions |
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****************************************************************************/ |
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/* Maximum number of threads than can be waiting for POLL events */ |
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#ifndef CONFIG_DEV_PIPE_NPOLLWAITERS |
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# define CONFIG_DEV_PIPE_NPOLLWAITERS 2 |
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#endif |
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/* Maximum number of open's supported on pipe */ |
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#define CONFIG_DEV_PIPE_MAXUSER 255 |
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/**************************************************************************** |
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* Public Types |
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****************************************************************************/ |
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/* Make the buffer index as small as possible for the configured pipe size */ |
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#if CONFIG_DEV_PIPE_SIZE > 65535 |
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typedef uint32_t pipe_ndx_t; /* 32-bit index */ |
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#elif CONFIG_DEV_PIPE_SIZE > 255 |
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typedef uint16_t pipe_ndx_t; /* 16-bit index */ |
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#else |
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typedef uint8_t pipe_ndx_t; /* 8-bit index */ |
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#endif |
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/* This structure represents the state of one pipe. A reference to this |
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* structure is retained in the i_private field of the inode whenthe pipe/fifo |
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* device is registered. |
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*/ |
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struct pipe_dev_s |
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{ |
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sem_t d_bfsem; /* Used to serialize access to d_buffer and indices */ |
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sem_t d_rdsem; /* Empty buffer - Reader waits for data write */ |
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sem_t d_wrsem; /* Full buffer - Writer waits for data read */ |
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pipe_ndx_t d_wrndx; /* Index in d_buffer to save next byte written */ |
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pipe_ndx_t d_rdndx; /* Index in d_buffer to return the next byte read */ |
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uint8_t d_refs; /* References counts on pipe (limited to 255) */ |
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uint8_t d_nwriters; /* Number of reference counts for write access */ |
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uint8_t d_pipeno; /* Pipe minor number */ |
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uint8_t *d_buffer; /* Buffer allocated when device opened */ |
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/* The following is a list if poll structures of threads waiting for |
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* driver events. The 'struct pollfd' reference for each open is also |
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* retained in the f_priv field of the 'struct file'. |
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*/ |
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#ifndef CONFIG_DISABLE_POLL |
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struct pollfd *d_fds[CONFIG_DEV_PIPE_NPOLLWAITERS]; |
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#endif |
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}; |
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/**************************************************************************** |
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* Public Function Prototypes |
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****************************************************************************/ |
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#ifdef __cplusplus |
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# define EXTERN extern "C" |
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extern "C" { |
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#else |
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# define EXTERN extern |
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#endif |
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EXTERN FAR struct pipe_dev_s *pipecommon_allocdev(void); |
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EXTERN void pipecommon_freedev(FAR struct pipe_dev_s *dev); |
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EXTERN int pipecommon_open(FAR struct file *filep); |
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EXTERN int pipecommon_close(FAR struct file *filep); |
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EXTERN ssize_t pipecommon_read(FAR struct file *, FAR char *, size_t); |
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EXTERN ssize_t pipecommon_write(FAR struct file *, FAR const char *, size_t); |
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#ifndef CONFIG_DISABLE_POLL |
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EXTERN int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds, |
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bool setup); |
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#endif |
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#undef EXTERN |
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#ifdef __cplusplus |
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} |
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#endif |
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#endif /* CONFIG_DEV_PIPE_SIZE > 0 */ |
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#endif /* __DRIVERS_PIPE_COMMON_H */
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