lm32: juart model

This patch adds the JTAG UART model. It is accessed through special control
registers and opcodes. Therefore the translation uses callbacks to this
model.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>

2 files changed, 161 insertions, 0 deletions

diff --git a/hw/lm32_juart.c b/hw/lm32_juart.c
new file mode 100644
index 0000000..fddcf7e
--- /dev/null
+++ b/hw/lm32_juart.c
@@ -0,0 +1,150 @@
+/*
+ *  LatticeMico32 JTAG UART model.
+ *
+ *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "qemu-char.h"
+
+#include "lm32_juart.h"
+
+enum {
+    LM32_JUART_MIN_SAVE_VERSION = 0,
+    LM32_JUART_CURRENT_SAVE_VERSION = 0,
+    LM32_JUART_MAX_SAVE_VERSION = 0,
+};
+
+enum {
+    JTX_FULL = (1<<8),
+};
+
+enum {
+    JRX_FULL = (1<<8),
+};
+
+struct LM32JuartState {
+    SysBusDevice busdev;
+    CharDriverState *chr;
+
+    uint32_t jtx;
+    uint32_t jrx;
+};
+typedef struct LM32JuartState LM32JuartState;
+
+uint32_t lm32_juart_get_jtx(DeviceState *d)
+{
+    LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
+
+    trace_lm32_juart_get_jtx(s->jtx);
+    return s->jtx;
+}
+
+uint32_t lm32_juart_get_jrx(DeviceState *d)
+{
+    LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
+
+    trace_lm32_juart_get_jrx(s->jrx);
+    return s->jrx;
+}
+
+void lm32_juart_set_jtx(DeviceState *d, uint32_t jtx)
+{
+    LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
+    unsigned char ch = jtx & 0xff;
+
+    trace_lm32_juart_set_jtx(s->jtx);
+
+    s->jtx = jtx;
+    if (s->chr) {
+        qemu_chr_write(s->chr, &ch, 1);
+    }
+}
+
+void lm32_juart_set_jrx(DeviceState *d, uint32_t jtx)
+{
+    LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
+
+    trace_lm32_juart_set_jrx(s->jrx);
+    s->jrx &= ~JRX_FULL;
+}
+
+static void juart_rx(void *opaque, const uint8_t *buf, int size)
+{
+    LM32JuartState *s = opaque;
+
+    s->jrx = *buf | JRX_FULL;
+}
+
+static int juart_can_rx(void *opaque)
+{
+    LM32JuartState *s = opaque;
+
+    return !(s->jrx & JRX_FULL);
+}
+
+static void juart_event(void *opaque, int event)
+{
+}
+
+static void juart_reset(DeviceState *d)
+{
+    LM32JuartState *s = container_of(d, LM32JuartState, busdev.qdev);
+
+    s->jtx = 0;
+    s->jrx = 0;
+}
+
+static int lm32_juart_init(SysBusDevice *dev)
+{
+    LM32JuartState *s = FROM_SYSBUS(typeof(*s), dev);
+
+    s->chr = qdev_init_chardev(&dev->qdev);
+    if (s->chr) {
+        qemu_chr_add_handlers(s->chr, juart_can_rx, juart_rx, juart_event, s);
+    }
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_lm32_juart = {
+    .name = "lm32-juart",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField[]) {
+        VMSTATE_UINT32(jtx, LM32JuartState),
+        VMSTATE_UINT32(jrx, LM32JuartState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static SysBusDeviceInfo lm32_juart_info = {
+    .init = lm32_juart_init,
+    .qdev.name  = "lm32-juart",
+    .qdev.size  = sizeof(LM32JuartState),
+    .qdev.vmsd  = &vmstate_lm32_juart,
+    .qdev.reset = juart_reset,
+};
+
+static void lm32_juart_register(void)
+{
+    sysbus_register_withprop(&lm32_juart_info);
+}
+
+device_init(lm32_juart_register)
diff --git a/hw/lm32_juart.h b/hw/lm32_juart.h
new file mode 100644
index 0000000..67fc586
--- /dev/null
+++ b/hw/lm32_juart.h
@@ -0,0 +1,11 @@
+#ifndef QEMU_HW_LM32_JUART_H
+#define QEMU_HW_LM32_JUART_H
+
+#include "qemu-common.h"
+
+uint32_t lm32_juart_get_jtx(DeviceState *d);
+uint32_t lm32_juart_get_jrx(DeviceState *d);
+void lm32_juart_set_jtx(DeviceState *d, uint32_t jtx);
+void lm32_juart_set_jrx(DeviceState *d, uint32_t jrx);
+
+#endif /* QEMU_HW_LM32_JUART_H */