aboutsummaryrefslogtreecommitdiff
path: root/hw/lm32_uart.c
diff options
context:
space:
mode:
authorMichael Walle <michael@walle.cc>2011-02-17 23:45:11 +0100
committerEdgar E. Iglesias <edgar.iglesias@gmail.com>2011-03-07 13:42:36 +0100
commit770ae5713af30e42492581fd53000a1b4a92a3c7 (patch)
tree3f66778402ea05fdc1a854035ff90f46b0a3956c /hw/lm32_uart.c
parentea7924dcc4000643ad767fa106a15acb9f8e055b (diff)
lm32: uart model
This patch add support for the LatticeMico32 UART. Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Diffstat (limited to 'hw/lm32_uart.c')
-rw-r--r--hw/lm32_uart.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/hw/lm32_uart.c b/hw/lm32_uart.c
new file mode 100644
index 0000000000..e225087b99
--- /dev/null
+++ b/hw/lm32_uart.c
@@ -0,0 +1,288 @@
+/*
+ * QEMU model of the LatticeMico32 UART block.
+ *
+ * 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/>.
+ *
+ *
+ * Specification available at:
+ * http://www.latticesemi.com/documents/mico32uart.pdf
+ */
+
+
+#include "hw.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "qemu-char.h"
+#include "qemu-error.h"
+
+enum {
+ R_RXTX = 0,
+ R_IER,
+ R_IIR,
+ R_LCR,
+ R_MCR,
+ R_LSR,
+ R_MSR,
+ R_DIV,
+ R_MAX
+};
+
+enum {
+ IER_RBRI = (1<<0),
+ IER_THRI = (1<<1),
+ IER_RLSI = (1<<2),
+ IER_MSI = (1<<3),
+};
+
+enum {
+ IIR_STAT = (1<<0),
+ IIR_ID0 = (1<<1),
+ IIR_ID1 = (1<<2),
+};
+
+enum {
+ LCR_WLS0 = (1<<0),
+ LCR_WLS1 = (1<<1),
+ LCR_STB = (1<<2),
+ LCR_PEN = (1<<3),
+ LCR_EPS = (1<<4),
+ LCR_SP = (1<<5),
+ LCR_SB = (1<<6),
+};
+
+enum {
+ MCR_DTR = (1<<0),
+ MCR_RTS = (1<<1),
+};
+
+enum {
+ LSR_DR = (1<<0),
+ LSR_OE = (1<<1),
+ LSR_PE = (1<<2),
+ LSR_FE = (1<<3),
+ LSR_BI = (1<<4),
+ LSR_THRE = (1<<5),
+ LSR_TEMT = (1<<6),
+};
+
+enum {
+ MSR_DCTS = (1<<0),
+ MSR_DDSR = (1<<1),
+ MSR_TERI = (1<<2),
+ MSR_DDCD = (1<<3),
+ MSR_CTS = (1<<4),
+ MSR_DSR = (1<<5),
+ MSR_RI = (1<<6),
+ MSR_DCD = (1<<7),
+};
+
+struct LM32UartState {
+ SysBusDevice busdev;
+ CharDriverState *chr;
+ qemu_irq irq;
+
+ uint32_t regs[R_MAX];
+};
+typedef struct LM32UartState LM32UartState;
+
+static void uart_update_irq(LM32UartState *s)
+{
+ unsigned int irq;
+
+ if ((s->regs[R_LSR] & (LSR_OE | LSR_PE | LSR_FE | LSR_BI))
+ && (s->regs[R_IER] & IER_RLSI)) {
+ irq = 1;
+ s->regs[R_IIR] = IIR_ID1 | IIR_ID0;
+ } else if ((s->regs[R_LSR] & LSR_DR) && (s->regs[R_IER] & IER_RBRI)) {
+ irq = 1;
+ s->regs[R_IIR] = IIR_ID1;
+ } else if ((s->regs[R_LSR] & LSR_THRE) && (s->regs[R_IER] & IER_THRI)) {
+ irq = 1;
+ s->regs[R_IIR] = IIR_ID0;
+ } else if ((s->regs[R_MSR] & 0x0f) && (s->regs[R_IER] & IER_MSI)) {
+ irq = 1;
+ s->regs[R_IIR] = 0;
+ } else {
+ irq = 0;
+ s->regs[R_IIR] = IIR_STAT;
+ }
+
+ trace_lm32_uart_irq_state(irq);
+ qemu_set_irq(s->irq, irq);
+}
+
+static uint32_t uart_read(void *opaque, target_phys_addr_t addr)
+{
+ LM32UartState *s = opaque;
+ uint32_t r = 0;
+
+ addr >>= 2;
+ switch (addr) {
+ case R_RXTX:
+ r = s->regs[R_RXTX];
+ s->regs[R_LSR] &= ~LSR_DR;
+ uart_update_irq(s);
+ break;
+ case R_IIR:
+ case R_LSR:
+ case R_MSR:
+ r = s->regs[addr];
+ break;
+ case R_IER:
+ case R_LCR:
+ case R_MCR:
+ case R_DIV:
+ error_report("lm32_uart: read access to write only register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ default:
+ error_report("lm32_uart: read access to unkown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+
+ trace_lm32_uart_memory_read(addr << 2, r);
+ return r;
+}
+
+static void uart_write(void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+ LM32UartState *s = opaque;
+ unsigned char ch = value;
+
+ trace_lm32_uart_memory_write(addr, value);
+
+ addr >>= 2;
+ switch (addr) {
+ case R_RXTX:
+ if (s->chr) {
+ qemu_chr_write(s->chr, &ch, 1);
+ }
+ break;
+ case R_IER:
+ case R_LCR:
+ case R_MCR:
+ case R_DIV:
+ s->regs[addr] = value;
+ break;
+ case R_IIR:
+ case R_LSR:
+ case R_MSR:
+ error_report("lm32_uart: write access to read only register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ default:
+ error_report("lm32_uart: write access to unkown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+ uart_update_irq(s);
+}
+
+static CPUReadMemoryFunc * const uart_read_fn[] = {
+ NULL,
+ NULL,
+ &uart_read,
+};
+
+static CPUWriteMemoryFunc * const uart_write_fn[] = {
+ NULL,
+ NULL,
+ &uart_write,
+};
+
+static void uart_rx(void *opaque, const uint8_t *buf, int size)
+{
+ LM32UartState *s = opaque;
+
+ if (s->regs[R_LSR] & LSR_DR) {
+ s->regs[R_LSR] |= LSR_OE;
+ }
+
+ s->regs[R_LSR] |= LSR_DR;
+ s->regs[R_RXTX] = *buf;
+
+ uart_update_irq(s);
+}
+
+static int uart_can_rx(void *opaque)
+{
+ LM32UartState *s = opaque;
+
+ return !(s->regs[R_LSR] & LSR_DR);
+}
+
+static void uart_event(void *opaque, int event)
+{
+}
+
+static void uart_reset(DeviceState *d)
+{
+ LM32UartState *s = container_of(d, LM32UartState, busdev.qdev);
+ int i;
+
+ for (i = 0; i < R_MAX; i++) {
+ s->regs[i] = 0;
+ }
+
+ /* defaults */
+ s->regs[R_LSR] = LSR_THRE | LSR_TEMT;
+}
+
+static int lm32_uart_init(SysBusDevice *dev)
+{
+ LM32UartState *s = FROM_SYSBUS(typeof(*s), dev);
+ int uart_regs;
+
+ sysbus_init_irq(dev, &s->irq);
+
+ uart_regs = cpu_register_io_memory(uart_read_fn, uart_write_fn, s,
+ DEVICE_NATIVE_ENDIAN);
+ sysbus_init_mmio(dev, R_MAX * 4, uart_regs);
+
+ s->chr = qdev_init_chardev(&dev->qdev);
+ if (s->chr) {
+ qemu_chr_add_handlers(s->chr, uart_can_rx, uart_rx, uart_event, s);
+ }
+
+ return 0;
+}
+
+static const VMStateDescription vmstate_lm32_uart = {
+ .name = "lm32-uart",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_ARRAY(regs, LM32UartState, R_MAX),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static SysBusDeviceInfo lm32_uart_info = {
+ .init = lm32_uart_init,
+ .qdev.name = "lm32-uart",
+ .qdev.size = sizeof(LM32UartState),
+ .qdev.vmsd = &vmstate_lm32_uart,
+ .qdev.reset = uart_reset,
+};
+
+static void lm32_uart_register(void)
+{
+ sysbus_register_withprop(&lm32_uart_info);
+}
+
+device_init(lm32_uart_register)