root / hw / lm32_uart.c @ 770ae571
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/*
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* QEMU model of the LatticeMico32 UART block.
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*
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* Copyright (c) 2010 Michael Walle <michael@walle.cc>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*
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* Specification available at:
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* http://www.latticesemi.com/documents/mico32uart.pdf
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*/
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#include "hw.h" |
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#include "sysbus.h" |
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#include "trace.h" |
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#include "qemu-char.h" |
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#include "qemu-error.h" |
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enum {
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R_RXTX = 0,
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R_IER, |
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R_IIR, |
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R_LCR, |
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R_MCR, |
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R_LSR, |
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R_MSR, |
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R_DIV, |
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R_MAX |
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}; |
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enum {
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IER_RBRI = (1<<0), |
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IER_THRI = (1<<1), |
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IER_RLSI = (1<<2), |
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IER_MSI = (1<<3), |
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}; |
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enum {
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IIR_STAT = (1<<0), |
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IIR_ID0 = (1<<1), |
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IIR_ID1 = (1<<2), |
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}; |
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enum {
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LCR_WLS0 = (1<<0), |
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LCR_WLS1 = (1<<1), |
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LCR_STB = (1<<2), |
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LCR_PEN = (1<<3), |
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LCR_EPS = (1<<4), |
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LCR_SP = (1<<5), |
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LCR_SB = (1<<6), |
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}; |
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enum {
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MCR_DTR = (1<<0), |
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MCR_RTS = (1<<1), |
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}; |
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enum {
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LSR_DR = (1<<0), |
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LSR_OE = (1<<1), |
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LSR_PE = (1<<2), |
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LSR_FE = (1<<3), |
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LSR_BI = (1<<4), |
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LSR_THRE = (1<<5), |
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LSR_TEMT = (1<<6), |
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}; |
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enum {
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MSR_DCTS = (1<<0), |
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MSR_DDSR = (1<<1), |
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MSR_TERI = (1<<2), |
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MSR_DDCD = (1<<3), |
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MSR_CTS = (1<<4), |
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MSR_DSR = (1<<5), |
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MSR_RI = (1<<6), |
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MSR_DCD = (1<<7), |
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}; |
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struct LM32UartState {
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SysBusDevice busdev; |
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CharDriverState *chr; |
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qemu_irq irq; |
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uint32_t regs[R_MAX]; |
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}; |
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typedef struct LM32UartState LM32UartState; |
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static void uart_update_irq(LM32UartState *s) |
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{ |
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unsigned int irq; |
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if ((s->regs[R_LSR] & (LSR_OE | LSR_PE | LSR_FE | LSR_BI))
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&& (s->regs[R_IER] & IER_RLSI)) { |
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irq = 1;
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s->regs[R_IIR] = IIR_ID1 | IIR_ID0; |
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} else if ((s->regs[R_LSR] & LSR_DR) && (s->regs[R_IER] & IER_RBRI)) { |
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irq = 1;
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s->regs[R_IIR] = IIR_ID1; |
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} else if ((s->regs[R_LSR] & LSR_THRE) && (s->regs[R_IER] & IER_THRI)) { |
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irq = 1;
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s->regs[R_IIR] = IIR_ID0; |
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} else if ((s->regs[R_MSR] & 0x0f) && (s->regs[R_IER] & IER_MSI)) { |
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irq = 1;
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s->regs[R_IIR] = 0;
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} else {
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irq = 0;
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s->regs[R_IIR] = IIR_STAT; |
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} |
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trace_lm32_uart_irq_state(irq); |
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qemu_set_irq(s->irq, irq); |
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} |
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static uint32_t uart_read(void *opaque, target_phys_addr_t addr) |
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{ |
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LM32UartState *s = opaque; |
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uint32_t r = 0;
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addr >>= 2;
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switch (addr) {
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case R_RXTX:
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r = s->regs[R_RXTX]; |
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s->regs[R_LSR] &= ~LSR_DR; |
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uart_update_irq(s); |
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break;
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case R_IIR:
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case R_LSR:
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case R_MSR:
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r = s->regs[addr]; |
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break;
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case R_IER:
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case R_LCR:
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case R_MCR:
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case R_DIV:
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error_report("lm32_uart: read access to write only register 0x"
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TARGET_FMT_plx, addr << 2);
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break;
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default:
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error_report("lm32_uart: read access to unkown register 0x"
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TARGET_FMT_plx, addr << 2);
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break;
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} |
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trace_lm32_uart_memory_read(addr << 2, r);
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return r;
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} |
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static void uart_write(void *opaque, target_phys_addr_t addr, uint32_t value) |
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{ |
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LM32UartState *s = opaque; |
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unsigned char ch = value; |
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trace_lm32_uart_memory_write(addr, value); |
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addr >>= 2;
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switch (addr) {
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case R_RXTX:
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if (s->chr) {
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qemu_chr_write(s->chr, &ch, 1);
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} |
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break;
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case R_IER:
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case R_LCR:
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case R_MCR:
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case R_DIV:
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s->regs[addr] = value; |
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break;
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case R_IIR:
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case R_LSR:
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case R_MSR:
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error_report("lm32_uart: write access to read only register 0x"
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TARGET_FMT_plx, addr << 2);
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break;
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default:
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error_report("lm32_uart: write access to unkown register 0x"
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TARGET_FMT_plx, addr << 2);
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break;
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} |
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uart_update_irq(s); |
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} |
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static CPUReadMemoryFunc * const uart_read_fn[] = { |
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NULL,
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NULL,
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&uart_read, |
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}; |
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static CPUWriteMemoryFunc * const uart_write_fn[] = { |
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NULL,
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NULL,
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&uart_write, |
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}; |
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static void uart_rx(void *opaque, const uint8_t *buf, int size) |
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{ |
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LM32UartState *s = opaque; |
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if (s->regs[R_LSR] & LSR_DR) {
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s->regs[R_LSR] |= LSR_OE; |
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} |
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s->regs[R_LSR] |= LSR_DR; |
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s->regs[R_RXTX] = *buf; |
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uart_update_irq(s); |
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} |
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static int uart_can_rx(void *opaque) |
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{ |
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LM32UartState *s = opaque; |
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return !(s->regs[R_LSR] & LSR_DR);
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} |
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static void uart_event(void *opaque, int event) |
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{ |
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} |
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static void uart_reset(DeviceState *d) |
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{ |
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LM32UartState *s = container_of(d, LM32UartState, busdev.qdev); |
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int i;
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for (i = 0; i < R_MAX; i++) { |
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s->regs[i] = 0;
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} |
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/* defaults */
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s->regs[R_LSR] = LSR_THRE | LSR_TEMT; |
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} |
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static int lm32_uart_init(SysBusDevice *dev) |
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{ |
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LM32UartState *s = FROM_SYSBUS(typeof(*s), dev); |
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int uart_regs;
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sysbus_init_irq(dev, &s->irq); |
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uart_regs = cpu_register_io_memory(uart_read_fn, uart_write_fn, s, |
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DEVICE_NATIVE_ENDIAN); |
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sysbus_init_mmio(dev, R_MAX * 4, uart_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, uart_can_rx, uart_rx, uart_event, s); |
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} |
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return 0; |
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} |
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static const VMStateDescription vmstate_lm32_uart = { |
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.name = "lm32-uart",
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.version_id = 1,
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.minimum_version_id = 1,
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.minimum_version_id_old = 1,
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.fields = (VMStateField[]) { |
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VMSTATE_UINT32_ARRAY(regs, LM32UartState, R_MAX), |
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VMSTATE_END_OF_LIST() |
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} |
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}; |
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static SysBusDeviceInfo lm32_uart_info = {
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.init = lm32_uart_init, |
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.qdev.name = "lm32-uart",
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.qdev.size = sizeof(LM32UartState),
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.qdev.vmsd = &vmstate_lm32_uart, |
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.qdev.reset = uart_reset, |
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}; |
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static void lm32_uart_register(void) |
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{ |
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sysbus_register_withprop(&lm32_uart_info); |
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} |
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device_init(lm32_uart_register) |