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