| /* Copyright (C) 1998-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Phil Blundell, based on the Alpha version by |
| David Mosberger. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* I/O port access on the ARM is something of a fiction. What we do is to |
| map an appropriate area of /dev/mem into user space so that a program |
| can blast away at the hardware in such a way as to generate I/O cycles |
| on the bus. To insulate user code from dependencies on particular |
| hardware we don't allow calls to inb() and friends to be inlined, but |
| force them to come through code in here every time. Performance-critical |
| registers tend to be memory mapped these days so this should be no big |
| problem. */ |
| |
| /* Once upon a time this file used mprotect to enable and disable |
| access to particular areas of I/O space. Unfortunately the |
| mprotect syscall also has the side effect of enabling caching for |
| the area affected (this is a kernel limitation). So we now just |
| enable all the ports all of the time. */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <ctype.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| |
| #include <linux/version.h> |
| #include <sys/sysctl.h> |
| |
| #define PATH_ARM_SYSTYPE "/etc/arm_systype" |
| #define PATH_CPUINFO "/proc/cpuinfo" |
| |
| #define MAX_PORT 0x10000 |
| |
| static struct { |
| unsigned long int base; |
| unsigned long int io_base; |
| unsigned int shift; |
| unsigned int initdone; /* since all the above could be 0 */ |
| } io; |
| |
| #define IO_BASE_FOOTBRIDGE 0x7c000000 |
| #define IO_SHIFT_FOOTBRIDGE 0 |
| |
| static struct platform { |
| const char *name; |
| unsigned long int io_base; |
| unsigned int shift; |
| } platform[] = { |
| /* All currently supported platforms are in fact the same. :-) */ |
| {"Chalice-CATS", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, |
| {"DEC-EBSA285", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, |
| {"Corel-NetWinder", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, |
| {"Rebel-NetWinder", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, |
| }; |
| |
| #define IO_ADDR(port) (io.base + ((port) << io.shift)) |
| |
| /* |
| * Initialize I/O system. There are several ways to get the information |
| * we need. Each is tried in turn until one succeeds. |
| * |
| * 1. Sysctl (CTL_BUS, CTL_BUS_ISA, ISA_*). This is the preferred method |
| * but not all kernels support it. |
| * |
| * 2. Read the value (not the contents) of symlink PATH_ARM_SYSTYPE. |
| * - If it matches one of the entries in the table above, use the |
| * corresponding values. |
| * - If it begins with a number, assume this is a previously |
| * unsupported system and the values encode, in order, |
| * "<io_base>,<port_shift>". |
| * |
| * 3. Lookup the "system type" field in /proc/cpuinfo. Again, if it |
| * matches an entry in the platform[] table, use the corresponding |
| * values. |
| */ |
| |
| /* The Linux kernel headers renamed this constant between 2.5.26 and |
| 2.5.27. It was backported to 2.4 between 2.4.22 and 2.4.23. */ |
| #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,23) |
| # define BUS_ISA CTL_BUS_ISA |
| #endif |
| |
| static int |
| init_iosys (void) |
| { |
| char systype[256]; |
| int i, n; |
| static int iobase_name[] = { CTL_BUS, BUS_ISA, BUS_ISA_PORT_BASE }; |
| static int ioshift_name[] = { CTL_BUS, BUS_ISA, BUS_ISA_PORT_SHIFT }; |
| size_t len = sizeof(io.base); |
| |
| if (! __sysctl (iobase_name, 3, &io.io_base, &len, NULL, 0) |
| && ! __sysctl (ioshift_name, 3, &io.shift, &len, NULL, 0)) |
| { |
| io.initdone = 1; |
| return 0; |
| } |
| |
| n = __readlink (PATH_ARM_SYSTYPE, systype, sizeof (systype) - 1); |
| if (n > 0) |
| { |
| systype[n] = '\0'; |
| if (isdigit (systype[0])) |
| { |
| if (sscanf (systype, "%li,%i", &io.io_base, &io.shift) == 2) |
| { |
| io.initdone = 1; |
| return 0; |
| } |
| /* else we're likely going to fail with the system match below */ |
| } |
| } |
| else |
| { |
| FILE * fp; |
| |
| fp = fopen (PATH_CPUINFO, "rce"); |
| if (! fp) |
| return -1; |
| while ((n = fscanf (fp, "Hardware\t: %256[^\n]\n", systype)) |
| != EOF) |
| { |
| if (n == 1) |
| break; |
| else |
| fgets_unlocked (systype, 256, fp); |
| } |
| fclose (fp); |
| |
| if (n == EOF) |
| { |
| /* this can happen if the format of /proc/cpuinfo changes... */ |
| fprintf (stderr, |
| "ioperm: Unable to determine system type.\n" |
| "\t(May need " PATH_ARM_SYSTYPE " symlink?)\n"); |
| __set_errno (ENODEV); |
| return -1; |
| } |
| } |
| |
| /* translate systype name into i/o system: */ |
| for (i = 0; i < sizeof (platform) / sizeof (platform[0]); ++i) |
| { |
| if (strcmp (platform[i].name, systype) == 0) |
| { |
| io.shift = platform[i].shift; |
| io.io_base = platform[i].io_base; |
| io.initdone = 1; |
| return 0; |
| } |
| } |
| |
| /* systype is not a known platform name... */ |
| __set_errno (ENODEV); |
| return -1; |
| } |
| |
| int |
| _ioperm (unsigned long int from, unsigned long int num, int turn_on) |
| { |
| if (! io.initdone && init_iosys () < 0) |
| return -1; |
| |
| /* this test isn't as silly as it may look like; consider overflows! */ |
| if (from >= MAX_PORT || from + num > MAX_PORT) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| if (turn_on) |
| { |
| if (! io.base) |
| { |
| int fd; |
| |
| fd = __open ("/dev/mem", O_RDWR); |
| if (fd < 0) |
| return -1; |
| |
| io.base = |
| (unsigned long int) __mmap (0, MAX_PORT << io.shift, |
| PROT_READ | PROT_WRITE, |
| MAP_SHARED, fd, io.io_base); |
| __close (fd); |
| if ((long) io.base == -1) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| int |
| _iopl (unsigned int level) |
| { |
| if (level > 3) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| if (level) |
| { |
| return _ioperm (0, MAX_PORT, 1); |
| } |
| return 0; |
| } |
| |
| |
| void |
| _outb (unsigned char b, unsigned long int port) |
| { |
| *((volatile unsigned char *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| void |
| _outw (unsigned short b, unsigned long int port) |
| { |
| *((volatile unsigned short *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| void |
| _outl (unsigned int b, unsigned long int port) |
| { |
| *((volatile unsigned long *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| unsigned int |
| _inb (unsigned long int port) |
| { |
| return *((volatile unsigned char *)(IO_ADDR (port))); |
| } |
| |
| |
| unsigned int |
| _inw (unsigned long int port) |
| { |
| return *((volatile unsigned short *)(IO_ADDR (port))); |
| } |
| |
| |
| unsigned int |
| _inl (unsigned long int port) |
| { |
| return *((volatile unsigned long *)(IO_ADDR (port))); |
| } |
| |
| weak_alias (_ioperm, ioperm); |
| weak_alias (_iopl, iopl); |
| weak_alias (_inb, inb); |
| weak_alias (_inw, inw); |
| weak_alias (_inl, inl); |
| weak_alias (_outb, outb); |
| weak_alias (_outw, outw); |
| weak_alias (_outl, outl); |