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-rw-r--r--qemu/hw/char/lm32_uart.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/qemu/hw/char/lm32_uart.c b/qemu/hw/char/lm32_uart.c
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+++ b/qemu/hw/char/lm32_uart.c
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+/*
+ * 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/hw.h"
+#include "hw/sysbus.h"
+#include "trace.h"
+#include "sysemu/char.h"
+#include "qemu/error-report.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),
+};
+
+#define TYPE_LM32_UART "lm32-uart"
+#define LM32_UART(obj) OBJECT_CHECK(LM32UartState, (obj), TYPE_LM32_UART)
+
+struct LM32UartState {
+ SysBusDevice parent_obj;
+
+ MemoryRegion iomem;
+ 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 uint64_t uart_read(void *opaque, hwaddr addr,
+ unsigned size)
+{
+ 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);
+ qemu_chr_accept_input(s->chr);
+ 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 unknown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+
+ trace_lm32_uart_memory_read(addr << 2, r);
+ return r;
+}
+
+static void uart_write(void *opaque, hwaddr addr,
+ uint64_t value, unsigned size)
+{
+ 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_fe_write_all(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 unknown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+ uart_update_irq(s);
+}
+
+static const MemoryRegionOps uart_ops = {
+ .read = uart_read,
+ .write = uart_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+ .valid = {
+ .min_access_size = 4,
+ .max_access_size = 4,
+ },
+};
+
+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 = LM32_UART(d);
+ 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 = LM32_UART(dev);
+
+ sysbus_init_irq(dev, &s->irq);
+
+ memory_region_init_io(&s->iomem, OBJECT(s), &uart_ops, s,
+ "uart", R_MAX * 4);
+ sysbus_init_mmio(dev, &s->iomem);
+
+ /* FIXME use a qdev chardev prop instead of qemu_char_get_next_serial() */
+ s->chr = qemu_char_get_next_serial();
+ 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,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_ARRAY(regs, LM32UartState, R_MAX),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void lm32_uart_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+ k->init = lm32_uart_init;
+ dc->reset = uart_reset;
+ dc->vmsd = &vmstate_lm32_uart;
+ /* Reason: init() method uses qemu_char_get_next_serial() */
+ dc->cannot_instantiate_with_device_add_yet = true;
+}
+
+static const TypeInfo lm32_uart_info = {
+ .name = TYPE_LM32_UART,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(LM32UartState),
+ .class_init = lm32_uart_class_init,
+};
+
+static void lm32_uart_register_types(void)
+{
+ type_register_static(&lm32_uart_info);
+}
+
+type_init(lm32_uart_register_types)