LXR qemu/hw/char/etraxfs

   1/*
   2 * QEMU ETRAX System Emulator
   3 *
   4 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "qemu/osdep.h"
  26#include "hw/sysbus.h"
  27#include "chardev/char-fe.h"
  28#include "qemu/log.h"
  29
  30#define D(x)
  31
  32#define RW_TR_CTRL     (0x00 / 4)
  33#define RW_TR_DMA_EN   (0x04 / 4)
  34#define RW_REC_CTRL    (0x08 / 4)
  35#define RW_DOUT        (0x1c / 4)
  36#define RS_STAT_DIN    (0x20 / 4)
  37#define R_STAT_DIN     (0x24 / 4)
  38#define RW_INTR_MASK   (0x2c / 4)
  39#define RW_ACK_INTR    (0x30 / 4)
  40#define R_INTR         (0x34 / 4)
  41#define R_MASKED_INTR  (0x38 / 4)
  42#define R_MAX          (0x3c / 4)
  43
  44#define STAT_DAV     16
  45#define STAT_TR_IDLE 22
  46#define STAT_TR_RDY  24
  47
  48#define TYPE_ETRAX_FS_SERIAL "etraxfs,serial"
  49#define ETRAX_SERIAL(obj) \
  50    OBJECT_CHECK(ETRAXSerial, (obj), TYPE_ETRAX_FS_SERIAL)
  51
  52typedef struct ETRAXSerial {
  53    SysBusDevice parent_obj;
  54
  55    MemoryRegion mmio;
  56    CharBackend chr;
  57    qemu_irq irq;
  58
  59    int pending_tx;
  60
  61    uint8_t rx_fifo[16];
  62    unsigned int rx_fifo_pos;
  63    unsigned int rx_fifo_len;
  64
  65    /* Control registers.  */
  66    uint32_t regs[R_MAX];
  67} ETRAXSerial;
  68
  69static void ser_update_irq(ETRAXSerial *s)
  70{
  71
  72    if (s->rx_fifo_len) {
  73        s->regs[R_INTR] |= 8;
  74    } else {
  75        s->regs[R_INTR] &= ~8;
  76    }
  77
  78    s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK];
  79    qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]);
  80}
  81
  82static uint64_t
  83ser_read(void *opaque, hwaddr addr, unsigned int size)
  84{
  85    ETRAXSerial *s = opaque;
  86    uint32_t r = 0;
  87
  88    addr >>= 2;
  89    switch (addr)
  90    {
  91        case R_STAT_DIN:
  92            r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
  93            if (s->rx_fifo_len) {
  94                r |= 1 << STAT_DAV;
  95            }
  96            r |= 1 << STAT_TR_RDY;
  97            r |= 1 << STAT_TR_IDLE;
  98            break;
  99        case RS_STAT_DIN:
 100            r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
 101            if (s->rx_fifo_len) {
 102                r |= 1 << STAT_DAV;
 103                s->rx_fifo_len--;
 104            }
 105            r |= 1 << STAT_TR_RDY;
 106            r |= 1 << STAT_TR_IDLE;
 107            break;
 108        default:
 109            r = s->regs[addr];
 110            D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, r));
 111            break;
 112    }
 113    return r;
 114}
 115
 116static void
 117ser_write(void *opaque, hwaddr addr,
 118          uint64_t val64, unsigned int size)
 119{
 120    ETRAXSerial *s = opaque;
 121    uint32_t value = val64;
 122    unsigned char ch = val64;
 123
 124    D(qemu_log("%s " TARGET_FMT_plx "=%x\n",  __func__, addr, value));
 125    addr >>= 2;
 126    switch (addr)
 127    {
 128        case RW_DOUT:
 129            /* XXX this blocks entire thread. Rewrite to use
 130             * qemu_chr_fe_write and background I/O callbacks */
 131            qemu_chr_fe_write_all(&s->chr, &ch, 1);
 132            s->regs[R_INTR] |= 3;
 133            s->pending_tx = 1;
 134            s->regs[addr] = value;
 135            break;
 136        case RW_ACK_INTR:
 137            if (s->pending_tx) {
 138                value &= ~1;
 139                s->pending_tx = 0;
 140                D(qemu_log("fixedup value=%x r_intr=%x\n",
 141                           value, s->regs[R_INTR]));
 142            }
 143            s->regs[addr] = value;
 144            s->regs[R_INTR] &= ~value;
 145            D(printf("r_intr=%x\n", s->regs[R_INTR]));
 146            break;
 147        default:
 148            s->regs[addr] = value;
 149            break;
 150    }
 151    ser_update_irq(s);
 152}
 153
 154static const MemoryRegionOps ser_ops = {
 155    .read = ser_read,
 156    .write = ser_write,
 157    .endianness = DEVICE_NATIVE_ENDIAN,
 158    .valid = {
 159        .min_access_size = 4,
 160        .max_access_size = 4
 161    }
 162};
 163
 164static Property etraxfs_ser_properties[] = {
 165    DEFINE_PROP_CHR("chardev", ETRAXSerial, chr),
 166    DEFINE_PROP_END_OF_LIST(),
 167};
 168
 169static void serial_receive(void *opaque, const uint8_t *buf, int size)
 170{
 171    ETRAXSerial *s = opaque;
 172    int i;
 173
 174    /* Got a byte.  */
 175    if (s->rx_fifo_len >= 16) {
 176        D(qemu_log("WARNING: UART dropped char.\n"));
 177        return;
 178    }
 179
 180    for (i = 0; i < size; i++) { 
 181        s->rx_fifo[s->rx_fifo_pos] = buf[i];
 182        s->rx_fifo_pos++;
 183        s->rx_fifo_pos &= 15;
 184        s->rx_fifo_len++;
 185    }
 186
 187    ser_update_irq(s);
 188}
 189
 190static int serial_can_receive(void *opaque)
 191{
 192    ETRAXSerial *s = opaque;
 193
 194    /* Is the receiver enabled?  */
 195    if (!(s->regs[RW_REC_CTRL] & (1 << 3))) {
 196        return 0;
 197    }
 198
 199    return sizeof(s->rx_fifo) - s->rx_fifo_len;
 200}
 201
 202static void serial_event(void *opaque, int event)
 203{
 204
 205}
 206
 207static void etraxfs_ser_reset(DeviceState *d)
 208{
 209    ETRAXSerial *s = ETRAX_SERIAL(d);
 210
 211    /* transmitter begins ready and idle.  */
 212    s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY);
 213    s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE);
 214
 215    s->regs[RW_REC_CTRL] = 0x10000;
 216
 217}
 218
 219static void etraxfs_ser_init(Object *obj)
 220{
 221    ETRAXSerial *s = ETRAX_SERIAL(obj);
 222    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
 223
 224    sysbus_init_irq(dev, &s->irq);
 225    memory_region_init_io(&s->mmio, obj, &ser_ops, s,
 226                          "etraxfs-serial", R_MAX * 4);
 227    sysbus_init_mmio(dev, &s->mmio);
 228}
 229
 230static void etraxfs_ser_realize(DeviceState *dev, Error **errp)
 231{
 232    ETRAXSerial *s = ETRAX_SERIAL(dev);
 233
 234    qemu_chr_fe_set_handlers(&s->chr,
 235                             serial_can_receive, serial_receive,
 236                             serial_event, NULL, s, NULL, true);
 237}
 238
 239static void etraxfs_ser_class_init(ObjectClass *klass, void *data)
 240{
 241    DeviceClass *dc = DEVICE_CLASS(klass);
 242
 243    dc->reset = etraxfs_ser_reset;
 244    dc->props = etraxfs_ser_properties;
 245    dc->realize = etraxfs_ser_realize;
 246}
 247
 248static const TypeInfo etraxfs_ser_info = {
 249    .name          = TYPE_ETRAX_FS_SERIAL,
 250    .parent        = TYPE_SYS_BUS_DEVICE,
 251    .instance_size = sizeof(ETRAXSerial),
 252    .instance_init = etraxfs_ser_init,
 253    .class_init    = etraxfs_ser_class_init,
 254};
 255
 256static void etraxfs_serial_register_types(void)
 257{
 258    type_register_static(&etraxfs_ser_info);
 259}
 260
 261type_init(etraxfs_serial_register_types)
 262