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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libbsp/] [powerpc/] [score603e/] [PCI_bus/] [PCI.c] - Rev 562
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/* * * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994, 1997. * On-Line Applications Research Corporation (OAR). * All rights assigned to U.S. Government, 1994. * * This material may be reproduced by or for the U.S. Government pursuant * to the copyright license under the clause at DFARS 252.227-7013. This * notice must appear in all copies of this file and its derivatives. * * $ld: */ #include <rtems.h> #include <assert.h> #include <stdio.h> #include <bsp.h> /* * Forced delay to get around timing problems with the UNIVERSE chip. The * two nops are used so that the delay works for varying clock frequencies, * up to 66 Mhz, with margin. Each nop averages about 1 1/2 clock ticks, * and since there are 2 nops, this routine takes about 3 clock ticks, * which on a worst case 66 Mhz board, is 45 nanosecond. This time period * is sufficient to guarantee a work-around to the UNIVERSE chip timing * problem. The problem is that when there are two successive accesses to * an UNIVERSE register, without sufficient delay, the second access will * not work correctly. */ void PCI_bus_delay () { asm(" nop"); asm(" nop"); } /* * PCI_bus_write */ void PCI_bus_write( volatile rtems_unsigned32 * _addr, /* IN */ rtems_unsigned32 _data /* IN */ ) { _data = Convert_Endian_32( _data ); *_addr = _data; } rtems_unsigned32 PCI_bus_read( volatile rtems_unsigned32 * _addr /* IN */ ) { rtems_unsigned32 data; data = *_addr; data = Convert_Endian_32( data ); return data; } /* * PCI Configuration Cycle Read/Write Access which is used to access all of * devices registers on the PCI bus. i.e.: Universe, Ethernet & PMC. */ rtems_unsigned32 Read_pci_device_register( rtems_unsigned32 address ) { rtems_unsigned32 data; /* * Write the PCI configuration address */ PCI_bus_write( (volatile rtems_unsigned32 *)SCORE603E_PCI_IO_CFG_ADDR, address ); /* * Delay needed when running out of DRAM */ PCI_bus_delay (); /* * read data */ data = PCI_bus_read( (volatile rtems_unsigned32 *)SCORE603E_PCI_IO_CFG_DATA ); return data; } void Write_pci_device_register( rtems_unsigned32 address, rtems_unsigned32 data ) { /* * Write the PCI configuration address */ PCI_bus_write( (volatile rtems_unsigned32 *)SCORE603E_PCI_IO_CFG_ADDR, address ); /* * Delay needed when running out of DRAM */ PCI_bus_delay (); /* * write data */ PCI_bus_write( (volatile rtems_unsigned32 *)SCORE603E_PCI_IO_CFG_DATA, data ); }
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