os161/kern/dev/lamebus/lrandom.c
2015-12-23 00:50:04 +00:00

86 lines
2.5 KiB
C

/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
* The President and Fellows of Harvard College.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Driver for LAMEbus random generator card
*/
#include <types.h>
#include <lib.h>
#include <uio.h>
#include <platform/bus.h>
#include <lamebus/lrandom.h>
#include "autoconf.h"
/* Registers (offsets within slot) */
#define LR_REG_RAND 0 /* random register */
/* Constants */
#define LR_RANDMAX 0xffffffff
int
config_lrandom(struct lrandom_softc *lr, int lrandomno)
{
(void)lrandomno;
(void)lr;
return 0;
}
uint32_t
lrandom_random(void *devdata)
{
struct lrandom_softc *lr = devdata;
return bus_read_register(lr->lr_bus, lr->lr_buspos, LR_REG_RAND);
}
uint32_t
lrandom_randmax(void *devdata)
{
(void)devdata;
return LR_RANDMAX;
}
int
lrandom_read(void *devdata, struct uio *uio)
{
struct lrandom_softc *lr = devdata;
uint32_t val;
int result;
while (uio->uio_resid > 0) {
val = bus_read_register(lr->lr_bus, lr->lr_buspos,
LR_REG_RAND);
result = uiomove(&val, sizeof(val), uio);
if (result) {
return result;
}
}
return 0;
}