qemu/hw/versatile_i2c.c

106 lines
3.0 KiB
C

/*
* ARM Versatile I2C controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Copyright (c) 2012 Oskar Andero <oskar.andero@gmail.com>
*
* This file is derived from hw/realview.c by Paul Brook
*
* 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
* of the License, or (at your option) any later version.
*
* 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 "sysbus.h"
#include "bitbang_i2c.h"
typedef struct {
SysBusDevice busdev;
MemoryRegion iomem;
bitbang_i2c_interface *bitbang;
int out;
int in;
} VersatileI2CState;
static uint64_t versatile_i2c_read(void *opaque, target_phys_addr_t offset,
unsigned size)
{
VersatileI2CState *s = (VersatileI2CState *)opaque;
if (offset == 0) {
return (s->out & 1) | (s->in << 1);
} else {
hw_error("%s: Bad offset 0x%x\n", __func__, (int)offset);
return -1;
}
}
static void versatile_i2c_write(void *opaque, target_phys_addr_t offset,
uint64_t value, unsigned size)
{
VersatileI2CState *s = (VersatileI2CState *)opaque;
switch (offset) {
case 0:
s->out |= value & 3;
break;
case 4:
s->out &= ~value;
break;
default:
hw_error("%s: Bad offset 0x%x\n", __func__, (int)offset);
}
bitbang_i2c_set(s->bitbang, BITBANG_I2C_SCL, (s->out & 1) != 0);
s->in = bitbang_i2c_set(s->bitbang, BITBANG_I2C_SDA, (s->out & 2) != 0);
}
static const MemoryRegionOps versatile_i2c_ops = {
.read = versatile_i2c_read,
.write = versatile_i2c_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static int versatile_i2c_init(SysBusDevice *dev)
{
VersatileI2CState *s = FROM_SYSBUS(VersatileI2CState, dev);
i2c_bus *bus;
bus = i2c_init_bus(&dev->qdev, "i2c");
s->bitbang = bitbang_i2c_init(bus);
memory_region_init_io(&s->iomem, &versatile_i2c_ops, s,
"versatile_i2c", 0x1000);
sysbus_init_mmio(dev, &s->iomem);
return 0;
}
static void versatile_i2c_class_init(ObjectClass *klass, void *data)
{
SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
k->init = versatile_i2c_init;
}
static const TypeInfo versatile_i2c_info = {
.name = "versatile_i2c",
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(VersatileI2CState),
.class_init = versatile_i2c_class_init,
};
static void versatile_i2c_register_types(void)
{
type_register_static(&versatile_i2c_info);
}
type_init(versatile_i2c_register_types)