historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/hw/timer/omap_synctimer.c
2024-01-16 11:20:27 -06:00

110 lines
3.1 KiB
C

/*
* TI OMAP2 32kHz sync timer emulation.
*
* Copyright (C) 2007-2008 Nokia Corporation
* Written by Andrzej Zaborowski <andrew@openedhand.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 or
* (at your option) any later version of the License.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/timer.h"
#include "hw/arm/omap.h"
struct omap_synctimer_s {
MemoryRegion iomem;
uint32_t val;
uint16_t readh;
};
/* 32-kHz Sync Timer of the OMAP2 */
static uint32_t omap_synctimer_read(struct omap_synctimer_s *s) {
return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 0x8000,
NANOSECONDS_PER_SECOND);
}
void omap_synctimer_reset(struct omap_synctimer_s *s)
{
s->val = omap_synctimer_read(s);
}
static uint32_t omap_synctimer_readw(void *opaque, hwaddr addr)
{
struct omap_synctimer_s *s = (struct omap_synctimer_s *) opaque;
switch (addr) {
case 0x00: /* 32KSYNCNT_REV */
return 0x21;
case 0x10: /* CR */
return omap_synctimer_read(s) - s->val;
}
OMAP_BAD_REG(addr);
return 0;
}
static uint32_t omap_synctimer_readh(void *opaque, hwaddr addr)
{
struct omap_synctimer_s *s = (struct omap_synctimer_s *) opaque;
uint32_t ret;
if (addr & 2)
return s->readh;
else {
ret = omap_synctimer_readw(opaque, addr);
s->readh = ret >> 16;
return ret & 0xffff;
}
}
static uint64_t omap_synctimer_readfn(void *opaque, hwaddr addr,
unsigned size)
{
switch (size) {
case 1:
return omap_badwidth_read32(opaque, addr);
case 2:
return omap_synctimer_readh(opaque, addr);
case 4:
return omap_synctimer_readw(opaque, addr);
default:
g_assert_not_reached();
}
}
static void omap_synctimer_writefn(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
OMAP_BAD_REG(addr);
}
static const MemoryRegionOps omap_synctimer_ops = {
.read = omap_synctimer_readfn,
.write = omap_synctimer_writefn,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
.endianness = DEVICE_NATIVE_ENDIAN,
};
struct omap_synctimer_s *omap_synctimer_init(struct omap_target_agent_s *ta,
struct omap_mpu_state_s *mpu, omap_clk fclk, omap_clk iclk)
{
struct omap_synctimer_s *s = g_malloc0(sizeof(*s));
omap_synctimer_reset(s);
memory_region_init_io(&s->iomem, NULL, &omap_synctimer_ops, s, "omap.synctimer",
omap_l4_region_size(ta, 0));
omap_l4_attach(ta, 0, &s->iomem);
return s;
}