/* * 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 "sysbus.h" #include "qemu-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, target_phys_addr_t addr, unsigned int size) { struct etrax_serial *s = opaque; D(CPUState *env = s->env); 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, target_phys_addr_t addr, uint64_t val64, unsigned int size) { struct etrax_serial *s = opaque; uint32_t value = val64; unsigned char ch = val64; D(CPUState *env = s->env); 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 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)