| /* |
| * ColdFire UART emulation. |
| * |
| * Copyright (c) 2007 CodeSourcery. |
| * |
| * This code is licensed under the GPL |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "hw/irq.h" |
| #include "hw/sysbus.h" |
| #include "qemu/module.h" |
| #include "qapi/error.h" |
| #include "hw/m68k/mcf.h" |
| #include "hw/qdev-properties.h" |
| #include "hw/qdev-properties-system.h" |
| #include "chardev/char-fe.h" |
| #include "qom/object.h" |
| |
| struct mcf_uart_state { |
| SysBusDevice parent_obj; |
| |
| MemoryRegion iomem; |
| uint8_t mr[2]; |
| uint8_t sr; |
| uint8_t isr; |
| uint8_t imr; |
| uint8_t bg1; |
| uint8_t bg2; |
| uint8_t fifo[4]; |
| uint8_t tb; |
| int current_mr; |
| int fifo_len; |
| int tx_enabled; |
| int rx_enabled; |
| qemu_irq irq; |
| CharBackend chr; |
| }; |
| |
| #define TYPE_MCF_UART "mcf-uart" |
| OBJECT_DECLARE_SIMPLE_TYPE(mcf_uart_state, MCF_UART) |
| |
| /* UART Status Register bits. */ |
| #define MCF_UART_RxRDY 0x01 |
| #define MCF_UART_FFULL 0x02 |
| #define MCF_UART_TxRDY 0x04 |
| #define MCF_UART_TxEMP 0x08 |
| #define MCF_UART_OE 0x10 |
| #define MCF_UART_PE 0x20 |
| #define MCF_UART_FE 0x40 |
| #define MCF_UART_RB 0x80 |
| |
| /* Interrupt flags. */ |
| #define MCF_UART_TxINT 0x01 |
| #define MCF_UART_RxINT 0x02 |
| #define MCF_UART_DBINT 0x04 |
| #define MCF_UART_COSINT 0x80 |
| |
| /* UMR1 flags. */ |
| #define MCF_UART_BC0 0x01 |
| #define MCF_UART_BC1 0x02 |
| #define MCF_UART_PT 0x04 |
| #define MCF_UART_PM0 0x08 |
| #define MCF_UART_PM1 0x10 |
| #define MCF_UART_ERR 0x20 |
| #define MCF_UART_RxIRQ 0x40 |
| #define MCF_UART_RxRTS 0x80 |
| |
| static void mcf_uart_update(mcf_uart_state *s) |
| { |
| s->isr &= ~(MCF_UART_TxINT | MCF_UART_RxINT); |
| if (s->sr & MCF_UART_TxRDY) |
| s->isr |= MCF_UART_TxINT; |
| if ((s->sr & ((s->mr[0] & MCF_UART_RxIRQ) |
| ? MCF_UART_FFULL : MCF_UART_RxRDY)) != 0) |
| s->isr |= MCF_UART_RxINT; |
| |
| qemu_set_irq(s->irq, (s->isr & s->imr) != 0); |
| } |
| |
| uint64_t mcf_uart_read(void *opaque, hwaddr addr, |
| unsigned size) |
| { |
| mcf_uart_state *s = (mcf_uart_state *)opaque; |
| switch (addr & 0x3f) { |
| case 0x00: |
| return s->mr[s->current_mr]; |
| case 0x04: |
| return s->sr; |
| case 0x0c: |
| { |
| uint8_t val; |
| int i; |
| |
| if (s->fifo_len == 0) |
| return 0; |
| |
| val = s->fifo[0]; |
| s->fifo_len--; |
| for (i = 0; i < s->fifo_len; i++) |
| s->fifo[i] = s->fifo[i + 1]; |
| s->sr &= ~MCF_UART_FFULL; |
| if (s->fifo_len == 0) |
| s->sr &= ~MCF_UART_RxRDY; |
| mcf_uart_update(s); |
| qemu_chr_fe_accept_input(&s->chr); |
| return val; |
| } |
| case 0x10: |
| /* TODO: Implement IPCR. */ |
| return 0; |
| case 0x14: |
| return s->isr; |
| case 0x18: |
| return s->bg1; |
| case 0x1c: |
| return s->bg2; |
| default: |
| return 0; |
| } |
| } |
| |
| /* Update TxRDY flag and set data if present and enabled. */ |
| static void mcf_uart_do_tx(mcf_uart_state *s) |
| { |
| if (s->tx_enabled && (s->sr & MCF_UART_TxEMP) == 0) { |
| /* XXX this blocks entire thread. Rewrite to use |
| * qemu_chr_fe_write and background I/O callbacks */ |
| qemu_chr_fe_write_all(&s->chr, (unsigned char *)&s->tb, 1); |
| s->sr |= MCF_UART_TxEMP; |
| } |
| if (s->tx_enabled) { |
| s->sr |= MCF_UART_TxRDY; |
| } else { |
| s->sr &= ~MCF_UART_TxRDY; |
| } |
| } |
| |
| static void mcf_do_command(mcf_uart_state *s, uint8_t cmd) |
| { |
| /* Misc command. */ |
| switch ((cmd >> 4) & 7) { |
| case 0: /* No-op. */ |
| break; |
| case 1: /* Reset mode register pointer. */ |
| s->current_mr = 0; |
| break; |
| case 2: /* Reset receiver. */ |
| s->rx_enabled = 0; |
| s->fifo_len = 0; |
| s->sr &= ~(MCF_UART_RxRDY | MCF_UART_FFULL); |
| break; |
| case 3: /* Reset transmitter. */ |
| s->tx_enabled = 0; |
| s->sr |= MCF_UART_TxEMP; |
| s->sr &= ~MCF_UART_TxRDY; |
| break; |
| case 4: /* Reset error status. */ |
| break; |
| case 5: /* Reset break-change interrupt. */ |
| s->isr &= ~MCF_UART_DBINT; |
| break; |
| case 6: /* Start break. */ |
| case 7: /* Stop break. */ |
| break; |
| } |
| |
| /* Transmitter command. */ |
| switch ((cmd >> 2) & 3) { |
| case 0: /* No-op. */ |
| break; |
| case 1: /* Enable. */ |
| s->tx_enabled = 1; |
| mcf_uart_do_tx(s); |
| break; |
| case 2: /* Disable. */ |
| s->tx_enabled = 0; |
| mcf_uart_do_tx(s); |
| break; |
| case 3: /* Reserved. */ |
| fprintf(stderr, "mcf_uart: Bad TX command\n"); |
| break; |
| } |
| |
| /* Receiver command. */ |
| switch (cmd & 3) { |
| case 0: /* No-op. */ |
| break; |
| case 1: /* Enable. */ |
| s->rx_enabled = 1; |
| break; |
| case 2: |
| s->rx_enabled = 0; |
| break; |
| case 3: /* Reserved. */ |
| fprintf(stderr, "mcf_uart: Bad RX command\n"); |
| break; |
| } |
| } |
| |
| void mcf_uart_write(void *opaque, hwaddr addr, |
| uint64_t val, unsigned size) |
| { |
| mcf_uart_state *s = (mcf_uart_state *)opaque; |
| switch (addr & 0x3f) { |
| case 0x00: |
| s->mr[s->current_mr] = val; |
| s->current_mr = 1; |
| break; |
| case 0x04: |
| /* CSR is ignored. */ |
| break; |
| case 0x08: /* Command Register. */ |
| mcf_do_command(s, val); |
| break; |
| case 0x0c: /* Transmit Buffer. */ |
| s->sr &= ~MCF_UART_TxEMP; |
| s->tb = val; |
| mcf_uart_do_tx(s); |
| break; |
| case 0x10: |
| /* ACR is ignored. */ |
| break; |
| case 0x14: |
| s->imr = val; |
| break; |
| default: |
| break; |
| } |
| mcf_uart_update(s); |
| } |
| |
| static void mcf_uart_reset(DeviceState *dev) |
| { |
| mcf_uart_state *s = MCF_UART(dev); |
| |
| s->fifo_len = 0; |
| s->mr[0] = 0; |
| s->mr[1] = 0; |
| s->sr = MCF_UART_TxEMP; |
| s->tx_enabled = 0; |
| s->rx_enabled = 0; |
| s->isr = 0; |
| s->imr = 0; |
| } |
| |
| static void mcf_uart_push_byte(mcf_uart_state *s, uint8_t data) |
| { |
| /* Break events overwrite the last byte if the fifo is full. */ |
| if (s->fifo_len == 4) |
| s->fifo_len--; |
| |
| s->fifo[s->fifo_len] = data; |
| s->fifo_len++; |
| s->sr |= MCF_UART_RxRDY; |
| if (s->fifo_len == 4) |
| s->sr |= MCF_UART_FFULL; |
| |
| mcf_uart_update(s); |
| } |
| |
| static void mcf_uart_event(void *opaque, QEMUChrEvent event) |
| { |
| mcf_uart_state *s = (mcf_uart_state *)opaque; |
| |
| switch (event) { |
| case CHR_EVENT_BREAK: |
| s->isr |= MCF_UART_DBINT; |
| mcf_uart_push_byte(s, 0); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static int mcf_uart_can_receive(void *opaque) |
| { |
| mcf_uart_state *s = (mcf_uart_state *)opaque; |
| |
| return s->rx_enabled && (s->sr & MCF_UART_FFULL) == 0; |
| } |
| |
| static void mcf_uart_receive(void *opaque, const uint8_t *buf, int size) |
| { |
| mcf_uart_state *s = (mcf_uart_state *)opaque; |
| |
| mcf_uart_push_byte(s, buf[0]); |
| } |
| |
| static const MemoryRegionOps mcf_uart_ops = { |
| .read = mcf_uart_read, |
| .write = mcf_uart_write, |
| .endianness = DEVICE_NATIVE_ENDIAN, |
| }; |
| |
| static void mcf_uart_instance_init(Object *obj) |
| { |
| SysBusDevice *dev = SYS_BUS_DEVICE(obj); |
| mcf_uart_state *s = MCF_UART(dev); |
| |
| memory_region_init_io(&s->iomem, obj, &mcf_uart_ops, s, "uart", 0x40); |
| sysbus_init_mmio(dev, &s->iomem); |
| |
| sysbus_init_irq(dev, &s->irq); |
| } |
| |
| static void mcf_uart_realize(DeviceState *dev, Error **errp) |
| { |
| mcf_uart_state *s = MCF_UART(dev); |
| |
| qemu_chr_fe_set_handlers(&s->chr, mcf_uart_can_receive, mcf_uart_receive, |
| mcf_uart_event, NULL, s, NULL, true); |
| } |
| |
| static Property mcf_uart_properties[] = { |
| DEFINE_PROP_CHR("chardev", mcf_uart_state, chr), |
| DEFINE_PROP_END_OF_LIST(), |
| }; |
| |
| static void mcf_uart_class_init(ObjectClass *oc, void *data) |
| { |
| DeviceClass *dc = DEVICE_CLASS(oc); |
| |
| dc->realize = mcf_uart_realize; |
| device_class_set_legacy_reset(dc, mcf_uart_reset); |
| device_class_set_props(dc, mcf_uart_properties); |
| set_bit(DEVICE_CATEGORY_INPUT, dc->categories); |
| } |
| |
| static const TypeInfo mcf_uart_info = { |
| .name = TYPE_MCF_UART, |
| .parent = TYPE_SYS_BUS_DEVICE, |
| .instance_size = sizeof(mcf_uart_state), |
| .instance_init = mcf_uart_instance_init, |
| .class_init = mcf_uart_class_init, |
| }; |
| |
| static void mcf_uart_register(void) |
| { |
| type_register_static(&mcf_uart_info); |
| } |
| |
| type_init(mcf_uart_register) |
| |
| DeviceState *mcf_uart_create(qemu_irq irq, Chardev *chrdrv) |
| { |
| DeviceState *dev; |
| |
| dev = qdev_new(TYPE_MCF_UART); |
| if (chrdrv) { |
| qdev_prop_set_chr(dev, "chardev", chrdrv); |
| } |
| sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); |
| sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, irq); |
| |
| return dev; |
| } |
| |
| DeviceState *mcf_uart_create_mmap(hwaddr base, qemu_irq irq, Chardev *chrdrv) |
| { |
| DeviceState *dev; |
| |
| dev = mcf_uart_create(irq, chrdrv); |
| sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, base); |
| |
| return dev; |
| } |