qemu/hw/grlib_apbuart.c

189 lines
5.3 KiB
C
Raw Normal View History

/*
* QEMU GRLIB APB UART Emulator
*
* Copyright (c) 2010-2011 AdaCore
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "sysbus.h"
#include "qemu-char.h"
#include "ptimer.h"
#include "trace.h"
#define UART_REG_SIZE 20 /* Size of memory mapped registers */
/* UART status register fields */
#define UART_DATA_READY (1 << 0)
#define UART_TRANSMIT_SHIFT_EMPTY (1 << 1)
#define UART_TRANSMIT_FIFO_EMPTY (1 << 2)
#define UART_BREAK_RECEIVED (1 << 3)
#define UART_OVERRUN (1 << 4)
#define UART_PARITY_ERROR (1 << 5)
#define UART_FRAMING_ERROR (1 << 6)
#define UART_TRANSMIT_FIFO_HALF (1 << 7)
#define UART_RECEIVE_FIFO_HALF (1 << 8)
#define UART_TRANSMIT_FIFO_FULL (1 << 9)
#define UART_RECEIVE_FIFO_FULL (1 << 10)
/* UART control register fields */
#define UART_RECEIVE_ENABLE (1 << 0)
#define UART_TRANSMIT_ENABLE (1 << 1)
#define UART_RECEIVE_INTERRUPT (1 << 2)
#define UART_TRANSMIT_INTERRUPT (1 << 3)
#define UART_PARITY_SELECT (1 << 4)
#define UART_PARITY_ENABLE (1 << 5)
#define UART_FLOW_CONTROL (1 << 6)
#define UART_LOOPBACK (1 << 7)
#define UART_EXTERNAL_CLOCK (1 << 8)
#define UART_RECEIVE_FIFO_INTERRUPT (1 << 9)
#define UART_TRANSMIT_FIFO_INTERRUPT (1 << 10)
#define UART_FIFO_DEBUG_MODE (1 << 11)
#define UART_OUTPUT_ENABLE (1 << 12)
#define UART_FIFO_AVAILABLE (1 << 31)
/* Memory mapped register offsets */
#define DATA_OFFSET 0x00
#define STATUS_OFFSET 0x04
#define CONTROL_OFFSET 0x08
#define SCALER_OFFSET 0x0C /* not supported */
#define FIFO_DEBUG_OFFSET 0x10 /* not supported */
typedef struct UART {
SysBusDevice busdev;
MemoryRegion iomem;
qemu_irq irq;
CharDriverState *chr;
/* registers */
uint32_t receive;
uint32_t status;
uint32_t control;
} UART;
static int grlib_apbuart_can_receive(void *opaque)
{
UART *uart = opaque;
return !!(uart->status & UART_DATA_READY);
}
static void grlib_apbuart_receive(void *opaque, const uint8_t *buf, int size)
{
UART *uart = opaque;
uart->receive = *buf;
uart->status |= UART_DATA_READY;
if (uart->control & UART_RECEIVE_INTERRUPT) {
qemu_irq_pulse(uart->irq);
}
}
static void grlib_apbuart_event(void *opaque, int event)
{
trace_grlib_apbuart_event(event);
}
static void
grlib_apbuart_write(void *opaque, target_phys_addr_t addr,
uint64_t value, unsigned size)
{
UART *uart = opaque;
unsigned char c = 0;
addr &= 0xff;
/* Unit registers */
switch (addr) {
case DATA_OFFSET:
c = value & 0xFF;
qemu_chr_fe_write(uart->chr, &c, 1);
return;
case STATUS_OFFSET:
/* Read Only */
return;
case CONTROL_OFFSET:
/* Not supported */
return;
case SCALER_OFFSET:
/* Not supported */
return;
default:
break;
}
trace_grlib_apbuart_writel_unknown(addr, value);
}
static bool grlib_apbuart_accepts(void *opaque, target_phys_addr_t addr,
unsigned size, bool is_write)
{
return is_write && size == 4;
}
static const MemoryRegionOps grlib_apbuart_ops = {
.write = grlib_apbuart_write,
.valid.accepts = grlib_apbuart_accepts,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static int grlib_apbuart_init(SysBusDevice *dev)
{
UART *uart = FROM_SYSBUS(typeof(*uart), dev);
qemu_chr_add_handlers(uart->chr,
grlib_apbuart_can_receive,
grlib_apbuart_receive,
grlib_apbuart_event,
uart);
sysbus_init_irq(dev, &uart->irq);
memory_region_init_io(&uart->iomem, &grlib_apbuart_ops, uart,
"uart", UART_REG_SIZE);
sysbus_init_mmio(dev, &uart->iomem);
return 0;
}
static SysBusDeviceInfo grlib_gptimer_info = {
.init = grlib_apbuart_init,
.qdev.name = "grlib,apbuart",
.qdev.size = sizeof(UART),
.qdev.props = (Property[]) {
DEFINE_PROP_CHR("chrdev", UART, chr),
DEFINE_PROP_END_OF_LIST()
}
};
static void grlib_gptimer_register(void)
{
sysbus_register_withprop(&grlib_gptimer_info);
}
device_init(grlib_gptimer_register)