/*
* QEMU SCI/SCIF serial port emulation
*
* Copyright (c) 2007 Magnus Damm
*
* Based on serial.c - QEMU 16450 UART emulation
* Copyright (c) 2003-2004 Fabrice Bellard
*
* 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 "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/sh4/sh.h"
#include "chardev/char-fe.h"
#include "exec/address-spaces.h"
#include "qapi/error.h"
//#define DEBUG_SERIAL
#define SH_SERIAL_FLAG_TEND (1 << 0)
#define SH_SERIAL_FLAG_TDE (1 << 1)
#define SH_SERIAL_FLAG_RDF (1 << 2)
#define SH_SERIAL_FLAG_BRK (1 << 3)
#define SH_SERIAL_FLAG_DR (1 << 4)
#define SH_RX_FIFO_LENGTH (16)
typedef struct {
MemoryRegion iomem;
MemoryRegion iomem_p4;
MemoryRegion iomem_a7;
uint8_t smr;
uint8_t brr;
uint8_t scr;
uint8_t dr; /* ftdr / tdr */
uint8_t sr; /* fsr / ssr */
uint16_t fcr;
uint8_t sptr;
uint8_t rx_fifo[SH_RX_FIFO_LENGTH]; /* frdr / rdr */
uint8_t rx_cnt;
uint8_t rx_tail;
uint8_t rx_head;
int freq;
int feat;
int flags;
int rtrg;
CharBackend chr;
qemu_irq eri;
qemu_irq rxi;
qemu_irq txi;
qemu_irq tei;
qemu_irq bri;
} sh_serial_state;
static void sh_serial_clear_fifo(sh_serial_state * s)
{
memset(s->rx_fifo, 0, SH_RX_FIFO_LENGTH);
s->rx_cnt = 0;
s->rx_head = 0;
s->rx_tail = 0;
}
static void sh_serial_write(void *opaque, hwaddr offs,
uint64_t val, unsigned size)
{
sh_serial_state *s = opaque;
unsigned char ch;
#ifdef DEBUG_SERIAL
printf("sh_serial: write offs=0x%02x val=0x%02x\n",
offs, val);
#endif
switch(offs) {
case 0x00: /* SMR */
s->smr = val & ((s->feat & SH_SERIAL_FEAT_SCIF) ? 0x7b : 0xff);
return;
case 0x04: /* BRR */
s->brr = val;
return;
case 0x08: /* SCR */
/* TODO : For SH7751, SCIF mask should be 0xfb. */
s->scr = val & ((s->feat & SH_SERIAL_FEAT_SCIF) ? 0xfa : 0xff);
if (!(val & (1 << 5)))
s->flags |= SH_SERIAL_FLAG_TEND;
if ((s->feat & SH_SERIAL_FEAT_SCIF) && s->txi) {
qemu_set_irq(s->txi, val & (1 << 7));
}
if (!(val & (1 << 6))) {
qemu_set_irq(s->rxi, 0);
}
return;
case 0x0c: /* FTDR / TDR */
if (qemu_chr_fe_backend_connected(&s->chr)) {
ch = val;
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
qemu_chr_fe_write_all(&s->chr, &ch, 1);
}
s->dr = val;
s->flags &= ~SH_SERIAL_FLAG_TDE;
return;
#if 0
case 0x14: /* FRDR / RDR */
ret = 0;
break;
#endif
}
if (s->feat & SH_SERIAL_FEAT_SCIF) {
switch(offs) {
case 0x10: /* FSR */
if (!(val & (1 << 6)))
s->flags &= ~SH_SERIAL_FLAG_TEND;
if (!(val & (1 << 5)))
s->flags &= ~SH_SERIAL_FLAG_TDE;
if (!(val & (1 << 4)))
s->flags &= ~SH_SERIAL_FLAG_BRK;
if (!(val & (1 << 1)))
s->flags &= ~SH_SERIAL_FLAG_RDF;
if (!(val & (1 << 0)))
s->flags &= ~SH_SERIAL_FLAG_DR;
if (!(val & (1 << 1)) || !(val & (1 << 0))) {
if (s->rxi) {
qemu_set_irq(s->rxi, 0);
}
}
return;
case 0x18: /* FCR */
s->fcr = val;
switch ((val >> 6) & 3) {
case 0:
s->rtrg = 1;
break;
case 1:
s->rtrg = 4;
break;
case 2:
s->rtrg = 8;
break;
case 3:
s->rtrg = 14;
break;
}
if (val & (1 << 1)) {
sh_serial_clear_fifo(s);
s->sr &= ~(1 << 1);
}
return;
case 0x20: /* SPTR */
s->sptr = val & 0xf3;
return;
case 0x24: /* LSR */
return;
}
}
else {
switch(offs) {
#if 0
case 0x0c:
ret = s->dr;
break;
case 0x10:
ret = 0;
break;
#endif
case 0x1c:
s->sptr = val & 0x8f;
return;
}
}
fprintf(stderr, "sh_serial: unsupported write to 0x%02"
HWADDR_PRIx "\n", offs);
abort();
}
static uint64_t sh_serial_read(void *opaque, hwaddr offs,
unsigned size)
{
sh_serial_state *s = opaque;
uint32_t ret = ~0;
#if 0
switch(offs) {
case 0x00:
ret = s->smr;
break;
case 0x04:
ret = s->brr;
break;
case 0x08:
ret = s->scr;
break;
case 0x14:
ret = 0;
break;
}
#endif
if (s->feat & SH_SERIAL_FEAT_SCIF) {
switch(offs) {
case 0x00: /* SMR */
ret = s->smr;
break;
case 0x08: /* SCR */
ret = s->scr;
break;
case 0x10: /* FSR */
ret = 0;
if (s->flags & SH_SERIAL_FLAG_TEND)
ret |= (1 << 6);
if (s->flags & SH_SERIAL_FLAG_TDE)
ret |= (1 << 5);
if (s->flags & SH_SERIAL_FLAG_BRK)
ret |= (1 << 4);
if (s->flags & SH_SERIAL_FLAG_RDF)
ret |= (1 << 1);
if (s->flags & SH_SERIAL_FLAG_DR)
ret |= (1 << 0);
if (s->scr & (1 << 5))
s->flags |= SH_SERIAL_FLAG_TDE | SH_SERIAL_FLAG_TEND;
break;
case 0x14:
if (s->rx_cnt > 0) {
ret = s->rx_fifo[s->rx_tail++];
s->rx_cnt--;
if (s->rx_tail == SH_RX_FIFO_LENGTH)
s->rx_tail = 0;
if (s->rx_cnt < s->rtrg)
s->flags &= ~SH_SERIAL_FLAG_RDF;
}
break;
case 0x18:
ret = s->fcr;
break;
case 0x1c:
ret = s->rx_cnt;
break;
case 0x20:
ret = s->sptr;
break;
case 0x24:
ret = 0;
break;
}
}
else {
switch(offs) {
#if 0
case 0x0c:
ret = s->dr;
break;
case 0x10:
ret = 0;
break;
case 0x14:
ret = s->rx_fifo[0];
break;
#endif
case 0x1c:
ret = s->sptr;
break;
}
}
#ifdef DEBUG_SERIAL
printf("sh_serial: read offs=0x%02x val=0x%x\n",
offs, ret);
#endif
if (ret & ~((1 << 16) - 1)) {
fprintf(stderr, "sh_serial: unsupported read from 0x%02"
HWADDR_PRIx "\n", offs);
abort();
}
return ret;
}
static int sh_serial_can_receive(sh_serial_state *s)
{
return s->scr & (1 << 4);
}
static void sh_serial_receive_break(sh_serial_state *s)
{
if (s->feat & SH_SERIAL_FEAT_SCIF)
s->sr |= (1 << 4);
}
static int sh_serial_can_receive1(void *opaque)
{
sh_serial_state *s = opaque;
return sh_serial_can_receive(s);
}
static void sh_serial_receive1(void *opaque, const uint8_t *buf, int size)
{
sh_serial_state *s = opaque;
if (s->feat & SH_SERIAL_FEAT_SCIF) {
int i;
for (i = 0; i < size; i++) {
if (s->rx_cnt < SH_RX_FIFO_LENGTH) {
s->rx_fifo[s->rx_head++] = buf[i];
if (s->rx_head == SH_RX_FIFO_LENGTH) {
s->rx_head = 0;
}
s->rx_cnt++;
if (s->rx_cnt >= s->rtrg) {
s->flags |= SH_SERIAL_FLAG_RDF;
if (s->scr & (1 << 6) && s->rxi) {
qemu_set_irq(s->rxi, 1);
}
}
}
}
} else {
s->rx_fifo[0] = buf[0];
}
}
static void sh_serial_event(void *opaque, int event)
{
sh_serial_state *s = opaque;
if (event == CHR_EVENT_BREAK)
sh_serial_receive_break(s);
}
static const MemoryRegionOps sh_serial_ops = {
.read = sh_serial_read,
.write = sh_serial_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
void sh_serial_init(MemoryRegion *sysmem,
hwaddr base, int feat,
uint32_t freq, Chardev *chr,
qemu_irq eri_source,
qemu_irq rxi_source,
qemu_irq txi_source,
qemu_irq tei_source,
qemu_irq bri_source)
{
sh_serial_state *s;
s = g_malloc0(sizeof(sh_serial_state));
s->feat = feat;
s->flags = SH_SERIAL_FLAG_TEND | SH_SERIAL_FLAG_TDE;
s->rtrg = 1;
s->smr = 0;
s->brr = 0xff;
s->scr = 1 << 5; /* pretend that TX is enabled so early printk works */
s->sptr = 0;
if (feat & SH_SERIAL_FEAT_SCIF) {
s->fcr = 0;
}
else {
s->dr = 0xff;
}
sh_serial_clear_fifo(s);
memory_region_init_io(&s->iomem, NULL, &sh_serial_ops, s,
"serial", 0x100000000ULL);
memory_region_init_alias(&s->iomem_p4, NULL, "serial-p4", &s->iomem,
0, 0x28);
memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
memory_region_init_alias(&s->iomem_a7, NULL, "serial-a7", &s->iomem,
0, 0x28);
memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
if (chr) {
qemu_chr_fe_init(&s->chr, chr, &error_abort);
qemu_chr_fe_set_handlers(&s->chr, sh_serial_can_receive1,
sh_serial_receive1,
sh_serial_event, NULL, s, NULL, true);
}
s->eri = eri_source;
s->rxi = rxi_source;
s->txi = txi_source;
s->tei = tei_source;
s->bri = bri_source;
}
