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/*
* Mach Operating System
* Copyright (c) 1993,1992 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* File: frc.c
* Author: Alessandro Forin, Carnegie Mellon University
* Date: 3/92
*
* Generic, mappable free running counter driver.
*/
#include <frc.h>
#if NFRC > 0
#include <mach/std_types.h>
#include <chips/busses.h>
#include <device/device_types.h>
/*
* Machine defines
* All you need to do to get this working on a
* random box is to define one macro and provide
* the correct virtual address.
*/
#include <platforms.h>
#ifdef DECSTATION
#define btop(x) mips_btop(x)
#endif /* DECSTATION */
/*
* Autoconf info
*/
static vm_offset_t frc_std[NFRC] = { 0 };
static vm_size_t frc_offset[NFRC] = { 0 };
static struct bus_device *frc_info[NFRC];
static int frc_probe(vm_offset_t,struct bus_ctlr *);
static void frc_attach(struct bus_device *);
struct bus_driver frc_driver =
{ frc_probe, 0, frc_attach, 0, frc_std, "frc", frc_info, };
/*
* Externally visible functions
*/
io_return_t frc_openclose(int,int); /* user */
vm_offset_t frc_mmap(int,vm_offset_t,vm_prot_t);
void frc_set_address(int,vm_size_t);
/*
* FRC's in kernel virtual memory. For in-kernel timestamps.
*/
vm_offset_t frc_address[NFRC];
/* machine-specific setups */
void
frc_set_address(
int unit,
vm_size_t offset)
{
if (unit < NFRC) {
frc_offset[unit] = offset;
}
}
/*
* Probe chip to see if it is there
*/
static frc_probe (
vm_offset_t reg,
struct bus_ctlr *ui)
{
/* see if something present at the given address */
if (check_memory(reg, 0)) {
frc_address[ui->unit] = 0;
return 0;
}
frc_std[ui->unit] = (vm_offset_t) reg;
printf("[mappable] ");
return 1;
}
static void
frc_attach (
struct bus_device *ui)
{
if (ui->unit < NFRC) {
frc_address[ui->unit] =
(vm_offset_t) frc_std[ui->unit] + frc_offset[ui->unit];
printf(": free running counter %d at kernel vaddr 0x%x",
ui->unit, frc_address[ui->unit]);
}
else
panic("frc: unknown unit number"); /* shouldn't happen */
}
int frc_intr()
{
/* we do not expect interrupts */
panic("frc_intr");
}
io_return_t
frc_openclose(
int dev,
int flag)
{
if (frc_std[dev])
return D_SUCCESS;
else
return D_NO_SUCH_DEVICE;
}
vm_offset_t
frc_mmap(
int dev,
vm_offset_t off,
vm_prot_t prot)
{
vm_offset_t addr;
if ((prot & VM_PROT_WRITE) || (off >= PAGE_SIZE) )
return (-1);
addr = (vm_offset_t) frc_std[dev] + frc_offset[dev];
return btop(pmap_extract(pmap_kernel(), addr));
}
#endif
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