qemu/hw/etraxfs_ser.c

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/*
* QEMU ETRAX System Emulator
*
* Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
*
* 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 <stdio.h>
#include <ctype.h>
#include "hw.h"
#include "qemu-char.h"
#define D(x)
#define RW_TR_CTRL 0x00
#define RW_TR_DMA_EN 0x04
#define RW_REC_CTRL 0x08
#define RW_DOUT 0x1c
#define RS_STAT_DIN 0x20
#define R_STAT_DIN 0x24
#define RW_INTR_MASK 0x2c
#define RW_ACK_INTR 0x30
#define R_INTR 0x34
#define R_MASKED_INTR 0x38
#define STAT_DAV 16
#define STAT_TR_IDLE 22
#define STAT_TR_RDY 24
struct etrax_serial_t
{
CPUState *env;
CharDriverState *chr;
qemu_irq *irq;
target_phys_addr_t base;
int pending_tx;
/* Control registers. */
uint32_t rw_tr_ctrl;
uint32_t rw_tr_dma_en;
uint32_t rw_rec_ctrl;
uint32_t rs_stat_din;
uint32_t r_stat_din;
uint32_t rw_intr_mask;
uint32_t rw_ack_intr;
uint32_t r_intr;
uint32_t r_masked_intr;
};
static void ser_update_irq(struct etrax_serial_t *s)
{
uint32_t o_irq = s->r_masked_intr;
s->r_intr &= ~(s->rw_ack_intr);
s->r_masked_intr = s->r_intr & s->rw_intr_mask;
if (o_irq != s->r_masked_intr) {
D(printf("irq_mask=%x r_intr=%x rmi=%x airq=%x \n",
s->rw_intr_mask, s->r_intr,
s->r_masked_intr, s->rw_ack_intr));
if (s->r_masked_intr)
qemu_irq_raise(s->irq[0]);
else
qemu_irq_lower(s->irq[0]);
}
s->rw_ack_intr = 0;
}
static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)
{
D(CPUState *env = opaque);
D(printf ("%s %x pc=%x\n", __func__, addr, env->pc));
return 0;
}
static uint32_t ser_readl (void *opaque, target_phys_addr_t addr)
{
struct etrax_serial_t *s = opaque;
D(CPUState *env = s->env);
uint32_t r = 0;
switch (addr & 0xfff)
{
case RW_TR_CTRL:
r = s->rw_tr_ctrl;
break;
case RW_TR_DMA_EN:
r = s->rw_tr_dma_en;
break;
case RS_STAT_DIN:
r = s->rs_stat_din;
/* clear dav. */
s->rs_stat_din &= ~(1 << STAT_DAV);
break;
case R_STAT_DIN:
r = s->rs_stat_din;
break;
case RW_ACK_INTR:
D(printf("load rw_ack_intr=%x\n", s->rw_ack_intr));
r = s->rw_ack_intr;
break;
case RW_INTR_MASK:
r = s->rw_intr_mask;
break;
case R_INTR:
D(printf("load r_intr=%x\n", s->r_intr));
r = s->r_intr;
break;
case R_MASKED_INTR:
D(printf("load r_maked_intr=%x\n", s->r_masked_intr));
r = s->r_masked_intr;
break;
default:
D(printf ("%s %x p=%x\n", __func__, addr, env->pc));
break;
}
return r;
}
static void
ser_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
{
D(struct etrax_serial_t *s = opaque);
D(CPUState *env = s->env);
D(printf ("%s %x %x pc=%x\n", __func__, addr, value, env->pc));
}
static void
ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
{
struct etrax_serial_t *s = opaque;
unsigned char ch = value;
D(CPUState *env = s->env);
switch (addr & 0xfff)
{
case RW_TR_CTRL:
D(printf("rw_tr_ctrl=%x\n", value));
s->rw_tr_ctrl = value;
break;
case RW_TR_DMA_EN:
D(printf("rw_tr_dma_en=%x\n", value));
s->rw_tr_dma_en = value;
break;
case RW_DOUT:
qemu_chr_write(s->chr, &ch, 1);
s->r_intr |= 1;
s->pending_tx = 1;
break;
case RW_ACK_INTR:
D(printf("rw_ack_intr=%x\n", value));
s->rw_ack_intr = value;
if (s->pending_tx && (s->rw_ack_intr & 1)) {
s->r_intr |= 1;
s->pending_tx = 0;
s->rw_ack_intr &= ~1;
}
break;
case RW_INTR_MASK:
D(printf("r_intr_mask=%x\n", value));
s->rw_intr_mask = value;
break;
default:
D(printf ("%s %x %x pc=%x\n",
__func__, addr, value, env->pc));
break;
}
ser_update_irq(s);
}
static CPUReadMemoryFunc *ser_read[] = {
&ser_readb,
&ser_readb,
&ser_readl,
};
static CPUWriteMemoryFunc *ser_write[] = {
&ser_writeb,
&ser_writeb,
&ser_writel,
};
static void serial_receive(void *opaque, const uint8_t *buf, int size)
{
struct etrax_serial_t *s = opaque;
s->r_intr |= 8;
s->rs_stat_din &= ~0xff;
s->rs_stat_din |= (buf[0] & 0xff);
s->rs_stat_din |= (1 << STAT_DAV); /* dav. */
ser_update_irq(s);
}
static int serial_can_receive(void *opaque)
{
struct etrax_serial_t *s = opaque;
int r;
/* Is the receiver enabled? */
r = s->rw_rec_ctrl & 1;
/* Pending rx data? */
r |= !(s->r_intr & 8);
return r;
}
static void serial_event(void *opaque, int event)
{
}
void etraxfs_ser_init(CPUState *env, qemu_irq *irq, CharDriverState *chr,
target_phys_addr_t base)
{
struct etrax_serial_t *s;
int ser_regs;
s = qemu_mallocz(sizeof *s);
if (!s)
return;
s->env = env;
s->irq = irq;
s->base = base;
s->chr = chr;
/* transmitter begins ready and idle. */
s->rs_stat_din |= (1 << STAT_TR_RDY);
s->rs_stat_din |= (1 << STAT_TR_IDLE);
qemu_chr_add_handlers(chr, serial_can_receive, serial_receive,
serial_event, s);
ser_regs = cpu_register_io_memory(0, ser_read, ser_write, s);
cpu_register_physical_memory (base, 0x3c, ser_regs);
}