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[/] [ao486/] [trunk/] [syn/] [components/] [sd_card/] [software/] [exe_bsp/] [drivers/] [src/] [altera_avalon_jtag_uart_read.c] - Rev 2
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/****************************************************************************** * * * License Agreement * * * * Copyright (c) 2006 Altera Corporation, San Jose, California, USA. * * All rights reserved. * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the "Software"), * * to deal in the Software without restriction, including without limitation * * the rights to use, copy, modify, merge, publish, distribute, sublicense, * * and/or sell copies of the Software, and to permit persons to whom the * * Software is furnished to do so, subject to the following conditions: * * * * The above copyright notice and this permission notice shall be included in * * all copies or substantial portions of the Software. * * * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * * DEALINGS IN THE SOFTWARE. * * * * This agreement shall be governed in all respects by the laws of the State * * of California and by the laws of the United States of America. * * * ******************************************************************************/ #include <string.h> #include <fcntl.h> #include <errno.h> #include <limits.h> #include <sys/stat.h> #include "sys/alt_irq.h" #include "sys/alt_alarm.h" #include "sys/ioctl.h" #include "alt_types.h" #include "altera_avalon_jtag_uart_regs.h" #include "altera_avalon_jtag_uart.h" #include "sys/alt_log_printf.h" #ifdef __ucosii__ #include "includes.h" #endif /* __ucosii__ */ #ifdef ALTERA_AVALON_JTAG_UART_SMALL /* ----------------------------------------------------------- */ /* ----------------------- SMALL DRIVER ---------------------- */ /* ----------------------------------------------------------- */ /* Read routine. The small version blocks until it has at least one byte * available, it then returns as much as is immediately available without * waiting any more. It's performance will be very poor without * interrupts. */ int altera_avalon_jtag_uart_read(altera_avalon_jtag_uart_state* sp, char* buffer, int space, int flags) { unsigned int base = sp->base; char * ptr = buffer; char * end = buffer + space; while (ptr < end) { unsigned int data = IORD_ALTERA_AVALON_JTAG_UART_DATA(base); if (data & ALTERA_AVALON_JTAG_UART_DATA_RVALID_MSK) *ptr++ = (data & ALTERA_AVALON_JTAG_UART_DATA_DATA_MSK) >> ALTERA_AVALON_JTAG_UART_DATA_DATA_OFST; else if (ptr != buffer) break; else if(flags & O_NONBLOCK) break; } if (ptr != buffer) return ptr - buffer; else if (flags & O_NONBLOCK) return -EWOULDBLOCK; else return -EIO; } #else /* !ALTERA_AVALON_JTAG_UART_SMALL */ /* ----------------------------------------------------------- */ /* ----------------------- FAST DRIVER ----------------------- */ /* ----------------------------------------------------------- */ int altera_avalon_jtag_uart_read(altera_avalon_jtag_uart_state* sp, char * buffer, int space, int flags) { char * ptr = buffer; alt_irq_context context; unsigned int n; /* * When running in a multi threaded environment, obtain the "read_lock" * semaphore. This ensures that reading from the device is thread-safe. */ ALT_SEM_PEND (sp->read_lock, 0); while (space > 0) { unsigned int in, out; /* Read as much data as possible */ do { in = sp->rx_in; out = sp->rx_out; if (in >= out) n = in - out; else n = ALTERA_AVALON_JTAG_UART_BUF_LEN - out; if (n == 0) break; /* No more data available */ if (n > space) n = space; memcpy(ptr, sp->rx_buf + out, n); ptr += n; space -= n; sp->rx_out = (out + n) % ALTERA_AVALON_JTAG_UART_BUF_LEN; } while (space > 0); /* If we read any data then return it */ if (ptr != buffer) break; /* If in non-blocking mode then return error */ if (flags & O_NONBLOCK) break; #ifdef __ucosii__ /* OS Present: Pend on a flag if the OS is running, otherwise spin */ if(OSRunning == OS_TRUE) { /* * When running in a multi-threaded mode, we pend on the read event * flag set and timeout event flag set in the isr. This avoids wasting CPU * cycles waiting in this thread, when we could be doing something more * profitable elsewhere. */ ALT_FLAG_PEND (sp->events, ALT_JTAG_UART_READ_RDY | ALT_JTAG_UART_TIMEOUT, OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME, 0); } else { /* Spin until more data arrives or until host disconnects */ while (in == sp->rx_in && sp->host_inactive < sp->timeout) ; } #else /* No OS: Always spin */ while (in == sp->rx_in && sp->host_inactive < sp->timeout) ; #endif /* __ucosii__ */ if (in == sp->rx_in) break; } /* * Now that access to the circular buffer is complete, release the read * semaphore so that other threads can access the buffer. */ ALT_SEM_POST (sp->read_lock); if (ptr != buffer) { /* If we read any data then there is space in the buffer so enable interrupts */ context = alt_irq_disable_all(); sp->irq_enable |= ALTERA_AVALON_JTAG_UART_CONTROL_RE_MSK; IOWR_ALTERA_AVALON_JTAG_UART_CONTROL(sp->base, sp->irq_enable); alt_irq_enable_all(context); } if (ptr != buffer) return ptr - buffer; else if (flags & O_NONBLOCK) return -EWOULDBLOCK; else return -EIO; } #endif /* ALTERA_AVALON_JTAG_UART_SMALL */