hw/char/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/hw.h"
  21 #include "hw/sysbus.h"
  22 #include "trace.h"
  23 #include "sysemu/char.h"
  24
  25 #include "hw/char/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 #define LM32_JUART(obj) OBJECT_CHECK(LM32JuartState, (obj), TYPE_LM32_JUART)
  42
  43 struct LM32JuartState {
  44     SysBusDevice parent_obj;
  45
  46     CharDriverState *chr;
  47
  48     uint32_t jtx;
  49     uint32_t jrx;
  50 };
  51 typedef struct LM32JuartState LM32JuartState;
  52
  53 uint32_t lm32_juart_get_jtx(DeviceState *d)
  54 {
  55     LM32JuartState *s = LM32_JUART(d);
  56
  57     trace_lm32_juart_get_jtx(s->jtx);
  58     return s->jtx;
  59 }
  60
  61 uint32_t lm32_juart_get_jrx(DeviceState *d)
  62 {
  63     LM32JuartState *s = LM32_JUART(d);
  64
  65     trace_lm32_juart_get_jrx(s->jrx);
  66     return s->jrx;
  67 }
  68
  69 void lm32_juart_set_jtx(DeviceState *d, uint32_t jtx)
  70 {
  71     LM32JuartState *s = LM32_JUART(d);
  72     unsigned char ch = jtx & 0xff;
  73
  74     trace_lm32_juart_set_jtx(s->jtx);
  75
  76     s->jtx = jtx;
  77     if (s->chr) {
  78         qemu_chr_fe_write(s->chr, &ch, 1);
  79     }
  80 }
  81
  82 void lm32_juart_set_jrx(DeviceState *d, uint32_t jtx)
  83 {
  84     LM32JuartState *s = LM32_JUART(d);
  85
  86     trace_lm32_juart_set_jrx(s->jrx);
  87     s->jrx &= ~JRX_FULL;
  88 }
  89
  90 static void juart_rx(void *opaque, const uint8_t *buf, int size)
  91 {
  92     LM32JuartState *s = opaque;
  93
  94     s->jrx = *buf | JRX_FULL;
  95 }
  96
  97 static int juart_can_rx(void *opaque)
  98 {
  99     LM32JuartState *s = opaque;
 100
 101     return !(s->jrx & JRX_FULL);
 102 }
 103
 104 static void juart_event(void *opaque, int event)
 105 {
 106 }
 107
 108 static void juart_reset(DeviceState *d)
 109 {
 110     LM32JuartState *s = LM32_JUART(d);
 111
 112     s->jtx = 0;
 113     s->jrx = 0;
 114 }
 115
 116 static int lm32_juart_init(SysBusDevice *dev)
 117 {
 118     LM32JuartState *s = LM32_JUART(dev);
 119
 120     s->chr = qemu_char_get_next_serial();
 121     if (s->chr) {
 122         qemu_chr_add_handlers(s->chr, juart_can_rx, juart_rx, juart_event, s);
 123     }
 124
 125     return 0;
 126 }
 127
 128 static const VMStateDescription vmstate_lm32_juart = {
 129     .name = "lm32-juart",
 130     .version_id = 1,
 131     .minimum_version_id = 1,
 132     .minimum_version_id_old = 1,
 133     .fields      = (VMStateField[]) {
 134         VMSTATE_UINT32(jtx, LM32JuartState),
 135         VMSTATE_UINT32(jrx, LM32JuartState),
 136         VMSTATE_END_OF_LIST()
 137     }
 138 };
 139
 140 static void lm32_juart_class_init(ObjectClass *klass, void *data)
 141 {
 142     DeviceClass *dc = DEVICE_CLASS(klass);
 143     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 144
 145     k->init = lm32_juart_init;
 146     dc->reset = juart_reset;
 147     dc->vmsd = &vmstate_lm32_juart;
 148 }
 149
 150 static const TypeInfo lm32_juart_info = {
 151     .name          = TYPE_LM32_JUART,
 152     .parent        = TYPE_SYS_BUS_DEVICE,
 153     .instance_size = sizeof(LM32JuartState),
 154     .class_init    = lm32_juart_class_init,
 155 };
 156
 157 static void lm32_juart_register_types(void)
 158 {
 159     type_register_static(&lm32_juart_info);
 160 }
 161
 162 type_init(lm32_juart_register_types)