aboutsummaryrefslogtreecommitdiff
path: root/hw/char/etraxfs_ser.c
diff options
context:
space:
mode:
Diffstat (limited to 'hw/char/etraxfs_ser.c')
-rw-r--r--hw/char/etraxfs_ser.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/hw/char/etraxfs_ser.c b/hw/char/etraxfs_ser.c
new file mode 100644
index 0000000000..b7499d775b
--- /dev/null
+++ b/hw/char/etraxfs_ser.c
@@ -0,0 +1,246 @@
+/*
+ * QEMU ETRAX System Emulator
+ *
+ * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "hw/sysbus.h"
+#include "char/char.h"
+#include "qemu/log.h"
+
+#define D(x)
+
+#define RW_TR_CTRL (0x00 / 4)
+#define RW_TR_DMA_EN (0x04 / 4)
+#define RW_REC_CTRL (0x08 / 4)
+#define RW_DOUT (0x1c / 4)
+#define RS_STAT_DIN (0x20 / 4)
+#define R_STAT_DIN (0x24 / 4)
+#define RW_INTR_MASK (0x2c / 4)
+#define RW_ACK_INTR (0x30 / 4)
+#define R_INTR (0x34 / 4)
+#define R_MASKED_INTR (0x38 / 4)
+#define R_MAX (0x3c / 4)
+
+#define STAT_DAV 16
+#define STAT_TR_IDLE 22
+#define STAT_TR_RDY 24
+
+struct etrax_serial
+{
+ SysBusDevice busdev;
+ MemoryRegion mmio;
+ CharDriverState *chr;
+ qemu_irq irq;
+
+ int pending_tx;
+
+ uint8_t rx_fifo[16];
+ unsigned int rx_fifo_pos;
+ unsigned int rx_fifo_len;
+
+ /* Control registers. */
+ uint32_t regs[R_MAX];
+};
+
+static void ser_update_irq(struct etrax_serial *s)
+{
+
+ if (s->rx_fifo_len) {
+ s->regs[R_INTR] |= 8;
+ } else {
+ s->regs[R_INTR] &= ~8;
+ }
+
+ s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK];
+ qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]);
+}
+
+static uint64_t
+ser_read(void *opaque, hwaddr addr, unsigned int size)
+{
+ struct etrax_serial *s = opaque;
+ uint32_t r = 0;
+
+ addr >>= 2;
+ switch (addr)
+ {
+ case R_STAT_DIN:
+ r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
+ if (s->rx_fifo_len) {
+ r |= 1 << STAT_DAV;
+ }
+ r |= 1 << STAT_TR_RDY;
+ r |= 1 << STAT_TR_IDLE;
+ break;
+ case RS_STAT_DIN:
+ r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15];
+ if (s->rx_fifo_len) {
+ r |= 1 << STAT_DAV;
+ s->rx_fifo_len--;
+ }
+ r |= 1 << STAT_TR_RDY;
+ r |= 1 << STAT_TR_IDLE;
+ break;
+ default:
+ r = s->regs[addr];
+ D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, r));
+ break;
+ }
+ return r;
+}
+
+static void
+ser_write(void *opaque, hwaddr addr,
+ uint64_t val64, unsigned int size)
+{
+ struct etrax_serial *s = opaque;
+ uint32_t value = val64;
+ unsigned char ch = val64;
+
+ D(qemu_log("%s " TARGET_FMT_plx "=%x\n", __func__, addr, value));
+ addr >>= 2;
+ switch (addr)
+ {
+ case RW_DOUT:
+ qemu_chr_fe_write(s->chr, &ch, 1);
+ s->regs[R_INTR] |= 3;
+ s->pending_tx = 1;
+ s->regs[addr] = value;
+ break;
+ case RW_ACK_INTR:
+ if (s->pending_tx) {
+ value &= ~1;
+ s->pending_tx = 0;
+ D(qemu_log("fixedup value=%x r_intr=%x\n",
+ value, s->regs[R_INTR]));
+ }
+ s->regs[addr] = value;
+ s->regs[R_INTR] &= ~value;
+ D(printf("r_intr=%x\n", s->regs[R_INTR]));
+ break;
+ default:
+ s->regs[addr] = value;
+ break;
+ }
+ ser_update_irq(s);
+}
+
+static const MemoryRegionOps ser_ops = {
+ .read = ser_read,
+ .write = ser_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+ .valid = {
+ .min_access_size = 4,
+ .max_access_size = 4
+ }
+};
+
+static void serial_receive(void *opaque, const uint8_t *buf, int size)
+{
+ struct etrax_serial *s = opaque;
+ int i;
+
+ /* Got a byte. */
+ if (s->rx_fifo_len >= 16) {
+ qemu_log("WARNING: UART dropped char.\n");
+ return;
+ }
+
+ for (i = 0; i < size; i++) {
+ s->rx_fifo[s->rx_fifo_pos] = buf[i];
+ s->rx_fifo_pos++;
+ s->rx_fifo_pos &= 15;
+ s->rx_fifo_len++;
+ }
+
+ ser_update_irq(s);
+}
+
+static int serial_can_receive(void *opaque)
+{
+ struct etrax_serial *s = opaque;
+ int r;
+
+ /* Is the receiver enabled? */
+ if (!(s->regs[RW_REC_CTRL] & (1 << 3))) {
+ return 0;
+ }
+
+ r = sizeof(s->rx_fifo) - s->rx_fifo_len;
+ return r;
+}
+
+static void serial_event(void *opaque, int event)
+{
+
+}
+
+static void etraxfs_ser_reset(DeviceState *d)
+{
+ struct etrax_serial *s = container_of(d, typeof(*s), busdev.qdev);
+
+ /* transmitter begins ready and idle. */
+ s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY);
+ s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE);
+
+ s->regs[RW_REC_CTRL] = 0x10000;
+
+}
+
+static int etraxfs_ser_init(SysBusDevice *dev)
+{
+ struct etrax_serial *s = FROM_SYSBUS(typeof (*s), dev);
+
+ sysbus_init_irq(dev, &s->irq);
+ memory_region_init_io(&s->mmio, &ser_ops, s, "etraxfs-serial", R_MAX * 4);
+ sysbus_init_mmio(dev, &s->mmio);
+
+ s->chr = qemu_char_get_next_serial();
+ if (s->chr)
+ qemu_chr_add_handlers(s->chr,
+ serial_can_receive, serial_receive,
+ serial_event, s);
+ return 0;
+}
+
+static void etraxfs_ser_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+ k->init = etraxfs_ser_init;
+ dc->reset = etraxfs_ser_reset;
+}
+
+static const TypeInfo etraxfs_ser_info = {
+ .name = "etraxfs,serial",
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(struct etrax_serial),
+ .class_init = etraxfs_ser_class_init,
+};
+
+static void etraxfs_serial_register_types(void)
+{
+ type_register_static(&etraxfs_ser_info);
+}
+
+type_init(etraxfs_serial_register_types)
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-26 01:57:33 +0000