/* * QEMU model of Xilinx uartlite. * * Copyright (c) 2009 Edgar E. Iglesias. * * 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 "qemu/osdep.h" #include "hw/irq.h" #include "hw/sysbus.h" #include "qemu/module.h" #include "chardev/char-fe.h" #define DUART(x) #define R_RX 0 #define R_TX 1 #define R_STATUS 2 #define R_CTRL 3 #define R_MAX 4 #define STATUS_RXVALID 0x01 #define STATUS_RXFULL 0x02 #define STATUS_TXEMPTY 0x04 #define STATUS_TXFULL 0x08 #define STATUS_IE 0x10 #define STATUS_OVERRUN 0x20 #define STATUS_FRAME 0x40 #define STATUS_PARITY 0x80 #define CONTROL_RST_TX 0x01 #define CONTROL_RST_RX 0x02 #define CONTROL_IE 0x10 #define TYPE_XILINX_UARTLITE "xlnx.xps-uartlite" #define XILINX_UARTLITE(obj) \ OBJECT_CHECK(XilinxUARTLite, (obj), TYPE_XILINX_UARTLITE) typedef struct XilinxUARTLite { SysBusDevice parent_obj; MemoryRegion mmio; CharBackend chr; qemu_irq irq; uint8_t rx_fifo[8]; unsigned int rx_fifo_pos; unsigned int rx_fifo_len; uint32_t regs[R_MAX]; } XilinxUARTLite; static void uart_update_irq(XilinxUARTLite *s) { unsigned int irq; if (s->rx_fifo_len) s->regs[R_STATUS] |= STATUS_IE; irq = (s->regs[R_STATUS] & STATUS_IE) && (s->regs[R_CTRL] & CONTROL_IE); qemu_set_irq(s->irq, irq); } static void uart_update_status(XilinxUARTLite *s) { uint32_t r; r = s->regs[R_STATUS]; r &= ~7; r |= 1 << 2; /* Tx fifo is always empty. We are fast :) */ r |= (s->rx_fifo_len == sizeof (s->rx_fifo)) << 1; r |= (!!s->rx_fifo_len); s->regs[R_STATUS] = r; } static void xilinx_uartlite_reset(DeviceState *dev) { uart_update_status(XILINX_UARTLITE(dev)); } static uint64_t uart_read(void *opaque, hwaddr addr, unsigned int size) { XilinxUARTLite *s = opaque; uint32_t r = 0; addr >>= 2; switch (addr) { case R_RX: r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 7]; if (s->rx_fifo_len) s->rx_fifo_len--; uart_update_status(s); uart_update_irq(s); qemu_chr_fe_accept_input(&s->chr); break; default: if (addr < ARRAY_SIZE(s->regs)) r = s->regs[addr]; DUART(qemu_log("%s addr=%x v=%x\n", __func__, addr, r)); break; } return r; } static void uart_write(void *opaque, hwaddr addr, uint64_t val64, unsigned int size) { XilinxUARTLite *s = opaque; uint32_t value = val64; unsigned char ch = value; addr >>= 2; switch (addr) { case R_STATUS: hw_error("write to UART STATUS?\n"); break; case R_CTRL: if (value & CONTROL_RST_RX) { s->rx_fifo_pos = 0; s->rx_fifo_len = 0; } s->regs[addr] = value; break; case R_TX: /* XXX this blocks entire thread. Rewrite to use * qemu_chr_fe_write and background I/O callbacks */ qemu_chr_fe_write_all(&s->chr, &ch, 1); s->regs[addr] = value; /* hax. */ s->regs[R_STATUS] |= STATUS_IE; break; default: DUART(printf("%s addr=%x v=%x\n", __func__, addr, value)); if (addr < ARRAY_SIZE(s->regs)) s->regs[addr] = value; break; } uart_update_status(s); uart_update_irq(s); } static const MemoryRegionOps uart_ops = { .read = uart_read, .write = uart_write, .endianness = DEVICE_NATIVE_ENDIAN, .valid = { .min_access_size = 1, .max_access_size = 4 } }; static Property xilinx_uartlite_properties[] = { DEFINE_PROP_CHR("chardev", XilinxUARTLite, chr), DEFINE_PROP_END_OF_LIST(), }; static void uart_rx(void *opaque, const uint8_t *buf, int size) { XilinxUARTLite *s = opaque; /* Got a byte. */ if (s->rx_fifo_len >= 8) { printf("WARNING: UART dropped char.\n"); return; } s->rx_fifo[s->rx_fifo_pos] = *buf; s->rx_fifo_pos++; s->rx_fifo_pos &= 0x7; s->rx_fifo_len++; uart_update_status(s); uart_update_irq(s); } static int uart_can_rx(void *opaque) { XilinxUARTLite *s = opaque; return s->rx_fifo_len < sizeof(s->rx_fifo); } static void uart_event(void *opaque, int event) { } static void xilinx_uartlite_realize(DeviceState *dev, Error **errp) { XilinxUARTLite *s = XILINX_UARTLITE(dev); qemu_chr_fe_set_handlers(&s->chr, uart_can_rx, uart_rx, uart_event, NULL, s, NULL, true); } static void xilinx_uartlite_init(Object *obj) { XilinxUARTLite *s = XILINX_UARTLITE(obj); sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq); memory_region_init_io(&s->mmio, obj, &uart_ops, s, "xlnx.xps-uartlite", R_MAX * 4); sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio); } static void xilinx_uartlite_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->reset = xilinx_uartlite_reset; dc->realize = xilinx_uartlite_realize; dc->props = xilinx_uartlite_properties; } static const TypeInfo xilinx_uartlite_info = { .name = TYPE_XILINX_UARTLITE, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(XilinxUARTLite), .instance_init = xilinx_uartlite_init, .class_init = xilinx_uartlite_class_init, }; static void xilinx_uart_register_types(void) { type_register_static(&xilinx_uartlite_info); } type_init(xilinx_uart_register_types)