qemu/hw/i2c/versatile_i2c.c

112 lines
3.2 KiB
C

/*
* ARM SBCon two-wire serial bus interface (I2C bitbang)
* a.k.a. 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 "qemu/osdep.h"
#include "hw/i2c/arm_sbcon_i2c.h"
#include "hw/registerfields.h"
#include "qemu/log.h"
#include "qemu/module.h"
#define VERSATILE_I2C(obj) \
OBJECT_CHECK(VersatileI2CState, (obj), TYPE_VERSATILE_I2C)
typedef ArmSbconI2CState VersatileI2CState;
REG32(CONTROL_GET, 0)
REG32(CONTROL_SET, 0)
REG32(CONTROL_CLR, 4)
#define SCL BIT(0)
#define SDA BIT(1)
static uint64_t versatile_i2c_read(void *opaque, hwaddr offset,
unsigned size)
{
VersatileI2CState *s = (VersatileI2CState *)opaque;
switch (offset) {
case A_CONTROL_SET:
return (s->out & 1) | (s->in << 1);
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
return -1;
}
}
static void versatile_i2c_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
VersatileI2CState *s = (VersatileI2CState *)opaque;
switch (offset) {
case A_CONTROL_SET:
s->out |= value & 3;
break;
case A_CONTROL_CLR:
s->out &= ~value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
}
bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SCL, (s->out & SCL) != 0);
s->in = bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SDA, (s->out & SDA) != 0);
}
static const MemoryRegionOps versatile_i2c_ops = {
.read = versatile_i2c_read,
.write = versatile_i2c_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void versatile_i2c_init(Object *obj)
{
DeviceState *dev = DEVICE(obj);
VersatileI2CState *s = VERSATILE_I2C(obj);
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
I2CBus *bus;
bus = i2c_init_bus(dev, "i2c");
bitbang_i2c_init(&s->bitbang, bus);
memory_region_init_io(&s->iomem, obj, &versatile_i2c_ops, s,
"arm_sbcon_i2c", 0x1000);
sysbus_init_mmio(sbd, &s->iomem);
}
static const TypeInfo versatile_i2c_info = {
.name = TYPE_VERSATILE_I2C,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(VersatileI2CState),
.instance_init = versatile_i2c_init,
};
static void versatile_i2c_register_types(void)
{
type_register_static(&versatile_i2c_info);
}
type_init(versatile_i2c_register_types)