hw/lm32_juart.c

   1 /*
   2  *  LatticeMico32 JTAG UART model.
   3  *
   4  *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "hw.h"
  21 #include "sysbus.h"
  22 #include "trace.h"
  23 #include "qemu-char.h"
  24
  25 #include "lm32_juart.h"
  26
  27 enum {
  28     LM32_JUART_MIN_SAVE_VERSION = 0,
  29     LM32_JUART_CURRENT_SAVE_VERSION = 0,
  30     LM32_JUART_MAX_SAVE_VERSION = 0,
  31 };
  32
  33 enum {
  34     JTX_FULL = (1<<8),
  35 };
  36
  37 enum {
  38     JRX_FULL = (1<<8),
  39 };
  40
  41 struct LM32JuartState {
  42     SysBusDevice busdev;
  43     CharDriverState *chr;
  44
  45     uint32_t jtx;
  46     uint32_t jrx;
  47 };
  48 typedef struct LM32JuartState LM32JuartState;
  49
  50 uint32_t lm32_juart_get_jtx(DeviceState *d)
  51 {
  52     LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
  53
  54     trace_lm32_juart_get_jtx(s->jtx);
  55     return s->jtx;
  56 }
  57
  58 uint32_t lm32_juart_get_jrx(DeviceState *d)
  59 {
  60     LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
  61
  62     trace_lm32_juart_get_jrx(s->jrx);
  63     return s->jrx;
  64 }
  65
  66 void lm32_juart_set_jtx(DeviceState *d, uint32_t jtx)
  67 {
  68     LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
  69     unsigned char ch = jtx & 0xff;
  70
  71     trace_lm32_juart_set_jtx(s->jtx);
  72
  73     s->jtx = jtx;
  74     if (s->chr) {
  75         qemu_chr_fe_write(s->chr, &ch, 1);
  76     }
  77 }
  78
  79 void lm32_juart_set_jrx(DeviceState *d, uint32_t jtx)
  80 {
  81     LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
  82
  83     trace_lm32_juart_set_jrx(s->jrx);
  84     s->jrx &= ~JRX_FULL;
  85 }
  86
  87 static void juart_rx(void *opaque, const uint8_t *buf, int size)
  88 {
  89     LM32JuartState *s = opaque;
  90
  91     s->jrx = *buf | JRX_FULL;
  92 }
  93
  94 static int juart_can_rx(void *opaque)
  95 {
  96     LM32JuartState *s = opaque;
  97
  98     return !(s->jrx & JRX_FULL);
  99 }
 100
 101 static void juart_event(void *opaque, int event)
 102 {
 103 }
 104
 105 static void juart_reset(DeviceState *d)
 106 {
 107     LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
 108
 109     s->jtx = 0;
 110     s->jrx = 0;
 111 }
 112
 113 static int lm32_juart_init(SysBusDevice *dev)
 114 {
 115     LM32JuartState *s = FROM_SYSBUS(typeof(*s), dev);
 116
 117     s->chr = qdev_init_chardev(&dev->qdev);
 118     if (s->chr) {
 119         qemu_chr_add_handlers(s->chr, juart_can_rx, juart_rx, juart_event, s);
 120     }
 121
 122     return 0;
 123 }
 124
 125 static const VMStateDescription vmstate_lm32_juart = {
 126     .name = "lm32-juart",
 127     .version_id = 1,
 128     .minimum_version_id = 1,
 129     .minimum_version_id_old = 1,
 130     .fields      = (VMStateField[]) {
 131         VMSTATE_UINT32(jtx, LM32JuartState),
 132         VMSTATE_UINT32(jrx, LM32JuartState),
 133         VMSTATE_END_OF_LIST()
 134     }
 135 };
 136
 137 static SysBusDeviceInfo lm32_juart_info = {
 138     .init = lm32_juart_init,
 139     .qdev.name  = "lm32-juart",
 140     .qdev.size  = sizeof(LM32JuartState),
 141     .qdev.vmsd  = &vmstate_lm32_juart,
 142     .qdev.reset = juart_reset,
 143 };
 144
 145 static void lm32_juart_register(void)
 146 {
 147     sysbus_register_withprop(&lm32_juart_info);
 148 }
 149
 150 device_init(lm32_juart_register)