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 "qemu/osdep.h"
  21 #include "hw/hw.h"
  22 #include "hw/sysbus.h"
  23 #include "trace.h"
  24 #include "sysemu/char.h"
  25
  26 #include "hw/char/lm32_juart.h"
  27
  28 enum {
  29     LM32_JUART_MIN_SAVE_VERSION = 0,
  30     LM32_JUART_CURRENT_SAVE_VERSION = 0,
  31     LM32_JUART_MAX_SAVE_VERSION = 0,
  32 };
  33
  34 enum {
  35     JTX_FULL = (1<<8),
  36 };
  37
  38 enum {
  39     JRX_FULL = (1<<8),
  40 };
  41
  42 #define LM32_JUART(obj) OBJECT_CHECK(LM32JuartState, (obj), TYPE_LM32_JUART)
  43
  44 struct LM32JuartState {
  45     SysBusDevice parent_obj;
  46
  47     CharBackend chr;
  48
  49     uint32_t jtx;
  50     uint32_t jrx;
  51 };
  52 typedef struct LM32JuartState LM32JuartState;
  53
  54 uint32_t lm32_juart_get_jtx(DeviceState *d)
  55 {
  56     LM32JuartState *s = LM32_JUART(d);
  57
  58     trace_lm32_juart_get_jtx(s->jtx);
  59     return s->jtx;
  60 }
  61
  62 uint32_t lm32_juart_get_jrx(DeviceState *d)
  63 {
  64     LM32JuartState *s = LM32_JUART(d);
  65
  66     trace_lm32_juart_get_jrx(s->jrx);
  67     return s->jrx;
  68 }
  69
  70 void lm32_juart_set_jtx(DeviceState *d, uint32_t jtx)
  71 {
  72     LM32JuartState *s = LM32_JUART(d);
  73     unsigned char ch = jtx & 0xff;
  74
  75     trace_lm32_juart_set_jtx(s->jtx);
  76
  77     s->jtx = jtx;
  78     if (s->chr.chr) {
  79         /* XXX this blocks entire thread. Rewrite to use
  80          * qemu_chr_fe_write and background I/O callbacks */
  81         qemu_chr_fe_write_all(&s->chr, &ch, 1);
  82     }
  83 }
  84
  85 void lm32_juart_set_jrx(DeviceState *d, uint32_t jtx)
  86 {
  87     LM32JuartState *s = LM32_JUART(d);
  88
  89     trace_lm32_juart_set_jrx(s->jrx);
  90     s->jrx &= ~JRX_FULL;
  91 }
  92
  93 static void juart_rx(void *opaque, const uint8_t *buf, int size)
  94 {
  95     LM32JuartState *s = opaque;
  96
  97     s->jrx = *buf | JRX_FULL;
  98 }
  99
 100 static int juart_can_rx(void *opaque)
 101 {
 102     LM32JuartState *s = opaque;
 103
 104     return !(s->jrx & JRX_FULL);
 105 }
 106
 107 static void juart_event(void *opaque, int event)
 108 {
 109 }
 110
 111 static void juart_reset(DeviceState *d)
 112 {
 113     LM32JuartState *s = LM32_JUART(d);
 114
 115     s->jtx = 0;
 116     s->jrx = 0;
 117 }
 118
 119 static void lm32_juart_realize(DeviceState *dev, Error **errp)
 120 {
 121     LM32JuartState *s = LM32_JUART(dev);
 122
 123     if (s->chr.chr) {
 124         qemu_chr_fe_set_handlers(&s->chr, juart_can_rx, juart_rx,
 125                                  juart_event, s, NULL);
 126     }
 127 }
 128
 129 static const VMStateDescription vmstate_lm32_juart = {
 130     .name = "lm32-juart",
 131     .version_id = 1,
 132     .minimum_version_id = 1,
 133     .fields = (VMStateField[]) {
 134         VMSTATE_UINT32(jtx, LM32JuartState),
 135         VMSTATE_UINT32(jrx, LM32JuartState),
 136         VMSTATE_END_OF_LIST()
 137     }
 138 };
 139
 140 static Property lm32_juart_properties[] = {
 141     DEFINE_PROP_CHR("chardev", LM32JuartState, chr),
 142     DEFINE_PROP_END_OF_LIST(),
 143 };
 144
 145 static void lm32_juart_class_init(ObjectClass *klass, void *data)
 146 {
 147     DeviceClass *dc = DEVICE_CLASS(klass);
 148
 149     dc->reset = juart_reset;
 150     dc->vmsd = &vmstate_lm32_juart;
 151     dc->props = lm32_juart_properties;
 152     dc->realize = lm32_juart_realize;
 153 }
 154
 155 static const TypeInfo lm32_juart_info = {
 156     .name          = TYPE_LM32_JUART,
 157     .parent        = TYPE_SYS_BUS_DEVICE,
 158     .instance_size = sizeof(LM32JuartState),
 159     .class_init    = lm32_juart_class_init,
 160 };
 161
 162 static void lm32_juart_register_types(void)
 163 {
 164     type_register_static(&lm32_juart_info);
 165 }
 166
 167 type_init(lm32_juart_register_types)