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Diffstat (limited to 'include/linux/mmtimer.h')
| -rw-r--r-- | include/linux/mmtimer.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/include/linux/mmtimer.h b/include/linux/mmtimer.h new file mode 100644 index 000000000000..6b5855016a4e --- /dev/null +++ b/include/linux/mmtimer.h @@ -0,0 +1,140 @@ +/* + * Intel Multimedia Timer device interface + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2001-2003 Silicon Graphics, Inc. All rights reserved. + * + * This file should define an interface compatible with the IA-PC Multimedia + * Timers Draft Specification (rev. 0.97) from Intel. Note that some + * hardware may not be able to safely export its registers to userspace, + * so the ioctl interface should support all necessary functionality. + * + * 11/01/01 - jbarnes - initial revision + * 9/10/04 - Christoph Lameter - remove interrupt support + */ + +#ifndef _LINUX_MMTIMER_H +#define _LINUX_MMTIMER_H + +/* name of the device, usually in /dev */ +#define MMTIMER_NAME "mmtimer" +#define MMTIMER_FULLNAME "/dev/mmtimer" +#define MMTIMER_DESC "IA-PC Multimedia Timer" +#define MMTIMER_VERSION "1.0" + +/* + * Breakdown of the ioctl's available. An 'optional' next to the command + * indicates that supporting this command is optional, while 'required' + * commands must be implemented if conformance is desired. + * + * MMTIMER_GETOFFSET - optional + * Should return the offset (relative to the start of the page where the + * registers are mapped) for the counter in question. + * + * MMTIMER_GETRES - required + * The resolution of the clock in femto (10^-15) seconds + * + * MMTIMER_GETFREQ - required + * Frequency of the clock in Hz + * + * MMTIMER_GETBITS - required + * Number of bits in the clock's counter + * + * MMTIMER_MMAPAVAIL - required + * Returns nonzero if the registers can be mmap'd into userspace, 0 otherwise + * + * MMTIMER_GETCOUNTER - required + * Gets the current value in the counter + */ +#define MMTIMER_IOCTL_BASE 'm' + +#define MMTIMER_GETOFFSET _IO(MMTIMER_IOCTL_BASE, 0) +#define MMTIMER_GETRES _IOR(MMTIMER_IOCTL_BASE, 1, unsigned long) +#define MMTIMER_GETFREQ _IOR(MMTIMER_IOCTL_BASE, 2, unsigned long) +#define MMTIMER_GETBITS _IO(MMTIMER_IOCTL_BASE, 4) +#define MMTIMER_MMAPAVAIL _IO(MMTIMER_IOCTL_BASE, 6) +#define MMTIMER_GETCOUNTER _IOR(MMTIMER_IOCTL_BASE, 9, unsigned long) + +/* + * An mmtimer verification program. WARNINGs are ok, but ERRORs indicate + * that the device doesn't fully support the interface defined here. + */ +#ifdef _MMTIMER_TEST_PROGRAM + +#include <stdio.h> +#include <unistd.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#include <sys/ioctl.h> + +#include "mmtimer.h" + +int main(int argc, char *argv[]) +{ + int result, fd; + unsigned long val = 0; + unsigned long i; + + if((fd = open("/dev/"MMTIMER_NAME, O_RDONLY)) == -1) { + printf("failed to open /dev/%s", MMTIMER_NAME); + return 1; + } + + /* + * Can we mmap in the counter? + */ + if((result = ioctl(fd, MMTIMER_MMAPAVAIL, 0)) == 1) { + printf("mmap available\n"); + /* ... so try getting the offset for each clock */ + if((result = ioctl(fd, MMTIMER_GETOFFSET, 0)) != -ENOSYS) + printf("offset: %d\n", result); + else + printf("WARNING: offset unavailable for clock\n"); + } + else + printf("WARNING: mmap unavailable\n"); + + /* + * Get the resolution in femtoseconds + */ + if((result = ioctl(fd, MMTIMER_GETRES, &val)) != -ENOSYS) + printf("resolution: %ld femtoseconds\n", val); + else + printf("ERROR: failed to get resolution\n"); + + /* + * Get the frequency in Hz + */ + if((result = ioctl(fd, MMTIMER_GETFREQ, &val)) != -ENOSYS) + if(val < 10000000) /* less than 10 MHz? */ + printf("ERROR: frequency only %ld MHz, should be >= 10 MHz\n", val/1000000); + else + printf("frequency: %ld MHz\n", val/1000000); + else + printf("ERROR: failed to get frequency\n"); + + /* + * How many bits in the counter? + */ + if((result = ioctl(fd, MMTIMER_GETBITS, 0)) != -ENOSYS) + printf("bits in counter: %d\n", result); + else + printf("ERROR: can't get number of bits in counter\n"); + + if((result = ioctl(fd, MMTIMER_GETCOUNTER, &val)) != -ENOSYS) + printf("counter value: %ld\n", val); + else + printf("ERROR: can't get counter value\n"); + + return 0; +} + +#endif /* _MMTIMER_TEST_PROGRM */ + +#endif /* _LINUX_MMTIMER_H */ |