| /* |
| * Copyright (c) 2005 The Regents of The University of Michigan |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @file |
| * Implements a 8250 UART |
| */ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/inifile.hh" |
| #include "base/str.hh" // for to_number |
| #include "base/trace.hh" |
| #include "dev/simconsole.hh" |
| #include "dev/uart8250.hh" |
| #include "dev/platform.hh" |
| #include "mem/bus/bus.hh" |
| #include "mem/bus/pio_interface.hh" |
| #include "mem/bus/pio_interface_impl.hh" |
| #include "mem/functional/memory_control.hh" |
| #include "sim/builder.hh" |
| |
| using namespace std; |
| |
| Uart8250::IntrEvent::IntrEvent(Uart8250 *u, int bit) |
| : Event(&mainEventQueue), uart(u) |
| { |
| DPRINTF(Uart, "UART Interrupt Event Initilizing\n"); |
| intrBit = bit; |
| } |
| |
| const char * |
| Uart8250::IntrEvent::description() |
| { |
| return "uart interrupt delay event"; |
| } |
| |
| void |
| Uart8250::IntrEvent::process() |
| { |
| if (intrBit & uart->IER) { |
| DPRINTF(Uart, "UART InterEvent, interrupting\n"); |
| uart->platform->postConsoleInt(); |
| uart->status |= intrBit; |
| } |
| else |
| DPRINTF(Uart, "UART InterEvent, not interrupting\n"); |
| |
| } |
| |
| /* The linux serial driver (8250.c about line 1182) loops reading from |
| * the device until the device reports it has no more data to |
| * read. After a maximum of 255 iterations the code prints "serial8250 |
| * too much work for irq X," and breaks out of the loop. Since the |
| * simulated system is so much slower than the actual system, if a |
| * user is typing on the keyboard it is very easy for them to provide |
| * input at a fast enough rate to not allow the loop to exit and thus |
| * the error to be printed. This magic number provides a delay between |
| * the time the UART receives a character to send to the simulated |
| * system and the time it actually notifies the system it has a |
| * character to send to alleviate this problem. --Ali |
| */ |
| void |
| Uart8250::IntrEvent::scheduleIntr() |
| { |
| static const Tick interval = (Tick)((Clock::Float::s / 2e9) * 450); |
| DPRINTF(Uart, "Scheduling IER interrupt for %#x, at cycle %lld\n", intrBit, |
| curTick + interval); |
| if (!scheduled()) |
| schedule(curTick + interval); |
| else |
| reschedule(curTick + interval); |
| } |
| |
| |
| Uart8250::Uart8250(const string &name, SimConsole *c, MemoryController *mmu, Addr a, |
| Addr s, HierParams *hier, Bus *bus, Tick pio_latency, Platform *p) |
| : Uart(name, c, mmu, a, s, hier, bus, pio_latency, p), |
| txIntrEvent(this, TX_INT), rxIntrEvent(this, RX_INT) |
| { |
| IER = 0; |
| DLAB = 0; |
| LCR = 0; |
| MCR = 0; |
| |
| } |
| |
| Fault |
| Uart8250::read(MemReqPtr &req, uint8_t *data) |
| { |
| Addr daddr = req->paddr - (addr & EV5::PAddrImplMask); |
| DPRINTF(Uart, " read register %#x\n", daddr); |
| |
| assert(req->size == 1); |
| |
| switch (daddr) { |
| case 0x0: |
| if (!(LCR & 0x80)) { // read byte |
| if (cons->dataAvailable()) |
| cons->in(*data); |
| else { |
| *(uint8_t*)data = 0; |
| // A limited amount of these are ok. |
| DPRINTF(Uart, "empty read of RX register\n"); |
| } |
| status &= ~RX_INT; |
| platform->clearConsoleInt(); |
| |
| if (cons->dataAvailable() && (IER & UART_IER_RDI)) |
| rxIntrEvent.scheduleIntr(); |
| } else { // dll divisor latch |
| ; |
| } |
| break; |
| case 0x1: |
| if (!(LCR & 0x80)) { // Intr Enable Register(IER) |
| *(uint8_t*)data = IER; |
| } else { // DLM divisor latch MSB |
| ; |
| } |
| break; |
| case 0x2: // Intr Identification Register (IIR) |
| DPRINTF(Uart, "IIR Read, status = %#x\n", (uint32_t)status); |
| |
| if (status & RX_INT) /* Rx data interrupt has a higher priority */ |
| *(uint8_t*)data = IIR_RXID; |
| else if (status & TX_INT) |
| *(uint8_t*)data = IIR_TXID; |
| else |
| *(uint8_t*)data = IIR_NOPEND; |
| |
| //Tx interrupts are cleared on IIR reads |
| status &= ~TX_INT; |
| break; |
| case 0x3: // Line Control Register (LCR) |
| *(uint8_t*)data = LCR; |
| break; |
| case 0x4: // Modem Control Register (MCR) |
| break; |
| case 0x5: // Line Status Register (LSR) |
| uint8_t lsr; |
| lsr = 0; |
| // check if there are any bytes to be read |
| if (cons->dataAvailable()) |
| lsr = UART_LSR_DR; |
| lsr |= UART_LSR_TEMT | UART_LSR_THRE; |
| *(uint8_t*)data = lsr; |
| break; |
| case 0x6: // Modem Status Register (MSR) |
| *(uint8_t*)data = 0; |
| break; |
| case 0x7: // Scratch Register (SCR) |
| *(uint8_t*)data = 0; // doesn't exist with at 8250. |
| break; |
| default: |
| panic("Tried to access a UART port that doesn't exist\n"); |
| break; |
| } |
| |
| return No_Fault; |
| |
| } |
| |
| Fault |
| Uart8250::write(MemReqPtr &req, const uint8_t *data) |
| { |
| Addr daddr = req->paddr - (addr & EV5::PAddrImplMask); |
| |
| DPRINTF(Uart, " write register %#x value %#x\n", daddr, *(uint8_t*)data); |
| |
| switch (daddr) { |
| case 0x0: |
| if (!(LCR & 0x80)) { // write byte |
| cons->out(*(uint8_t *)data); |
| platform->clearConsoleInt(); |
| status &= ~TX_INT; |
| if (UART_IER_THRI & IER) |
| txIntrEvent.scheduleIntr(); |
| } else { // dll divisor latch |
| ; |
| } |
| break; |
| case 0x1: |
| if (!(LCR & 0x80)) { // Intr Enable Register(IER) |
| IER = *(uint8_t*)data; |
| if (UART_IER_THRI & IER) |
| { |
| DPRINTF(Uart, "IER: IER_THRI set, scheduling TX intrrupt\n"); |
| txIntrEvent.scheduleIntr(); |
| } |
| else |
| { |
| DPRINTF(Uart, "IER: IER_THRI cleared, descheduling TX intrrupt\n"); |
| if (txIntrEvent.scheduled()) |
| txIntrEvent.deschedule(); |
| if (status & TX_INT) |
| platform->clearConsoleInt(); |
| status &= ~TX_INT; |
| } |
| |
| if ((UART_IER_RDI & IER) && cons->dataAvailable()) { |
| DPRINTF(Uart, "IER: IER_RDI set, scheduling RX intrrupt\n"); |
| rxIntrEvent.scheduleIntr(); |
| } else { |
| DPRINTF(Uart, "IER: IER_RDI cleared, descheduling RX intrrupt\n"); |
| if (rxIntrEvent.scheduled()) |
| rxIntrEvent.deschedule(); |
| if (status & RX_INT) |
| platform->clearConsoleInt(); |
| status &= ~RX_INT; |
| } |
| } else { // DLM divisor latch MSB |
| ; |
| } |
| break; |
| case 0x2: // FIFO Control Register (FCR) |
| break; |
| case 0x3: // Line Control Register (LCR) |
| LCR = *(uint8_t*)data; |
| break; |
| case 0x4: // Modem Control Register (MCR) |
| if (*(uint8_t*)data == (UART_MCR_LOOP | 0x0A)) |
| MCR = 0x9A; |
| break; |
| case 0x7: // Scratch Register (SCR) |
| // We are emulating a 8250 so we don't have a scratch reg |
| break; |
| default: |
| panic("Tried to access a UART port that doesn't exist\n"); |
| break; |
| } |
| return No_Fault; |
| } |
| |
| void |
| Uart8250::dataAvailable() |
| { |
| // if the kernel wants an interrupt when we have data |
| if (IER & UART_IER_RDI) |
| { |
| platform->postConsoleInt(); |
| status |= RX_INT; |
| } |
| |
| } |
| |
| |
| |
| void |
| Uart8250::serialize(ostream &os) |
| { |
| SERIALIZE_SCALAR(status); |
| SERIALIZE_SCALAR(IER); |
| SERIALIZE_SCALAR(DLAB); |
| SERIALIZE_SCALAR(LCR); |
| SERIALIZE_SCALAR(MCR); |
| Tick rxintrwhen; |
| if (rxIntrEvent.scheduled()) |
| rxintrwhen = rxIntrEvent.when(); |
| else |
| rxintrwhen = 0; |
| Tick txintrwhen; |
| if (txIntrEvent.scheduled()) |
| txintrwhen = txIntrEvent.when(); |
| else |
| txintrwhen = 0; |
| SERIALIZE_SCALAR(rxintrwhen); |
| SERIALIZE_SCALAR(txintrwhen); |
| } |
| |
| void |
| Uart8250::unserialize(Checkpoint *cp, const std::string §ion) |
| { |
| UNSERIALIZE_SCALAR(status); |
| UNSERIALIZE_SCALAR(IER); |
| UNSERIALIZE_SCALAR(DLAB); |
| UNSERIALIZE_SCALAR(LCR); |
| UNSERIALIZE_SCALAR(MCR); |
| Tick rxintrwhen; |
| Tick txintrwhen; |
| UNSERIALIZE_SCALAR(rxintrwhen); |
| UNSERIALIZE_SCALAR(txintrwhen); |
| if (rxintrwhen != 0) |
| rxIntrEvent.schedule(rxintrwhen); |
| if (txintrwhen != 0) |
| txIntrEvent.schedule(txintrwhen); |
| } |
| |
| BEGIN_DECLARE_SIM_OBJECT_PARAMS(Uart8250) |
| |
| SimObjectParam<SimConsole *> console; |
| SimObjectParam<MemoryController *> mmu; |
| SimObjectParam<Platform *> platform; |
| Param<Addr> addr; |
| Param<Addr> size; |
| SimObjectParam<Bus*> io_bus; |
| Param<Tick> pio_latency; |
| SimObjectParam<HierParams *> hier; |
| |
| |
| END_DECLARE_SIM_OBJECT_PARAMS(Uart8250) |
| |
| BEGIN_INIT_SIM_OBJECT_PARAMS(Uart8250) |
| |
| INIT_PARAM(console, "The console"), |
| INIT_PARAM(mmu, "Memory Controller"), |
| INIT_PARAM(platform, "Pointer to platfrom"), |
| INIT_PARAM(addr, "Device Address"), |
| INIT_PARAM_DFLT(size, "Device size", 0x8), |
| INIT_PARAM_DFLT(io_bus, "The IO Bus to attach to", NULL), |
| INIT_PARAM_DFLT(pio_latency, "Programmed IO latency in bus cycles", 1), |
| INIT_PARAM_DFLT(hier, "Hierarchy global variables", &defaultHierParams) |
| |
| END_INIT_SIM_OBJECT_PARAMS(Uart8250) |
| |
| CREATE_SIM_OBJECT(Uart8250) |
| { |
| return new Uart8250(getInstanceName(), console, mmu, addr, size, hier, io_bus, |
| pio_latency, platform); |
| } |
| |
| REGISTER_SIM_OBJECT("Uart8250", Uart8250) |
