root / hw / etraxfs_ser.c @ a8a358bf
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/*
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* QEMU ETRAX System Emulator
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*
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* Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "sysbus.h" |
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#include "qemu-char.h" |
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#define D(x)
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#define RW_TR_CTRL (0x00 / 4) |
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#define RW_TR_DMA_EN (0x04 / 4) |
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#define RW_REC_CTRL (0x08 / 4) |
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#define RW_DOUT (0x1c / 4) |
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#define RS_STAT_DIN (0x20 / 4) |
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#define R_STAT_DIN (0x24 / 4) |
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#define RW_INTR_MASK (0x2c / 4) |
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#define RW_ACK_INTR (0x30 / 4) |
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#define R_INTR (0x34 / 4) |
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#define R_MASKED_INTR (0x38 / 4) |
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#define R_MAX (0x3c / 4) |
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#define STAT_DAV 16 |
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#define STAT_TR_IDLE 22 |
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#define STAT_TR_RDY 24 |
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struct etrax_serial
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{ |
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SysBusDevice busdev; |
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CharDriverState *chr; |
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qemu_irq irq; |
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/* This pending thing is a hack. */
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int pending_tx;
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/* Control registers. */
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uint32_t regs[R_MAX]; |
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}; |
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static void ser_update_irq(struct etrax_serial *s) |
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{ |
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s->regs[R_INTR] &= ~(s->regs[RW_ACK_INTR]); |
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s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK]; |
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qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]); |
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s->regs[RW_ACK_INTR] = 0;
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} |
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static uint32_t ser_readl (void *opaque, target_phys_addr_t addr) |
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{ |
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struct etrax_serial *s = opaque;
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D(CPUState *env = s->env); |
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uint32_t r = 0;
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addr >>= 2;
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switch (addr)
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{ |
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case R_STAT_DIN:
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r = s->regs[RS_STAT_DIN]; |
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break;
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case RS_STAT_DIN:
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r = s->regs[addr]; |
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/* Read side-effect: clear dav. */
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s->regs[addr] &= ~(1 << STAT_DAV);
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break;
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default:
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r = s->regs[addr]; |
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D(printf ("%s %x=%x\n", __func__, addr, r));
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break;
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} |
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return r;
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} |
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static void |
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ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
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{ |
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struct etrax_serial *s = opaque;
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unsigned char ch = value; |
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D(CPUState *env = s->env); |
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D(printf ("%s %x %x\n", __func__, addr, value));
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addr >>= 2;
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switch (addr)
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{ |
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case RW_DOUT:
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qemu_chr_write(s->chr, &ch, 1);
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s->regs[R_INTR] |= 1;
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s->pending_tx = 1;
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s->regs[addr] = value; |
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break;
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case RW_ACK_INTR:
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s->regs[addr] = value; |
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if (s->pending_tx && (s->regs[addr] & 1)) { |
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s->regs[R_INTR] |= 1;
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s->pending_tx = 0;
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s->regs[addr] &= ~1;
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} |
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break;
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default:
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s->regs[addr] = value; |
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break;
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} |
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ser_update_irq(s); |
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} |
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static CPUReadMemoryFunc * const ser_read[] = { |
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NULL, NULL, |
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&ser_readl, |
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}; |
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static CPUWriteMemoryFunc * const ser_write[] = { |
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NULL, NULL, |
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&ser_writel, |
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}; |
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static void serial_receive(void *opaque, const uint8_t *buf, int size) |
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{ |
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struct etrax_serial *s = opaque;
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s->regs[R_INTR] |= 8;
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s->regs[RS_STAT_DIN] &= ~0xff;
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s->regs[RS_STAT_DIN] |= (buf[0] & 0xff); |
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s->regs[RS_STAT_DIN] |= (1 << STAT_DAV); /* dav. */ |
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ser_update_irq(s); |
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} |
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static int serial_can_receive(void *opaque) |
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{ |
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struct etrax_serial *s = opaque;
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int r;
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/* Is the receiver enabled? */
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r = s->regs[RW_REC_CTRL] & 1;
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/* Pending rx data? */
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r |= !(s->regs[R_INTR] & 8);
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return r;
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} |
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static void serial_event(void *opaque, int event) |
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{ |
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} |
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static void etraxfs_ser_init(SysBusDevice *dev) |
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{ |
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struct etrax_serial *s = FROM_SYSBUS(typeof (*s), dev);
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int ser_regs;
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/* transmitter begins ready and idle. */
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s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY);
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s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE);
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sysbus_init_irq(dev, &s->irq); |
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ser_regs = cpu_register_io_memory(ser_read, ser_write, s); |
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sysbus_init_mmio(dev, R_MAX * 4, ser_regs);
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s->chr = qdev_init_chardev(&dev->qdev); |
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if (s->chr)
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qemu_chr_add_handlers(s->chr, |
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serial_can_receive, serial_receive, |
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serial_event, s); |
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} |
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static void etraxfs_serial_register(void) |
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{ |
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sysbus_register_dev("etraxfs,serial", sizeof (struct etrax_serial), |
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etraxfs_ser_init); |
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} |
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device_init(etraxfs_serial_register) |