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40b6f91151
Implement the Freescale i.MX UART. This uart is used in a variety of SoCs, including some by Motorola, as well as in the Freescale i.MX series. This patch gives only a `bare-bones' implementation, enough to run Linux or OKL4, but that's about it. Signed-off-by: Philip O'Sullivan <philipo@ok-labs.com> Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
468 lines
13 KiB
C
468 lines
13 KiB
C
/*
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* IMX31 UARTS
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*
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* Copyright (c) 2008 OKL
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* Originally Written by Hans Jiang
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* Copyright (c) 2011 NICTA Pty Ltd.
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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* This is a `bare-bones' implementation of the IMX series serial ports.
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* TODO:
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* -- implement FIFOs. The real hardware has 32 word transmit
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* and receive FIFOs; we currently use a 1-char buffer
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* -- implement DMA
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* -- implement BAUD-rate and modem lines, for when the backend
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* is a real serial device.
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*/
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#include "hw.h"
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#include "sysbus.h"
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#include "sysemu.h"
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#include "qemu-char.h"
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#include "imx.h"
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//#define DEBUG_SERIAL 1
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#ifdef DEBUG_SERIAL
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#define DPRINTF(fmt, args...) \
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do { printf("imx_serial: " fmt , ##args); } while (0)
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#else
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#define DPRINTF(fmt, args...) do {} while (0)
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#endif
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/*
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* Define to 1 for messages about attempts to
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* access unimplemented registers or similar.
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*/
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//#define DEBUG_IMPLEMENTATION 1
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#ifdef DEBUG_IMPLEMENTATION
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# define IPRINTF(fmt, args...) \
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do { fprintf(stderr, "imx_serial: " fmt, ##args); } while (0)
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#else
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# define IPRINTF(fmt, args...) do {} while (0)
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#endif
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typedef struct {
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SysBusDevice busdev;
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MemoryRegion iomem;
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int32_t readbuff;
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uint32_t usr1;
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uint32_t usr2;
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uint32_t ucr1;
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uint32_t ucr2;
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uint32_t uts1;
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/*
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* The registers below are implemented just so that the
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* guest OS sees what it has written
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*/
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uint32_t onems;
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uint32_t ufcr;
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uint32_t ubmr;
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uint32_t ubrc;
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uint32_t ucr3;
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qemu_irq irq;
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CharDriverState *chr;
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} IMXSerialState;
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static const VMStateDescription vmstate_imx_serial = {
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.name = "imx-serial",
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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_INT32(readbuff, IMXSerialState),
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VMSTATE_UINT32(usr1, IMXSerialState),
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VMSTATE_UINT32(usr2, IMXSerialState),
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VMSTATE_UINT32(ucr1, IMXSerialState),
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VMSTATE_UINT32(uts1, IMXSerialState),
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VMSTATE_UINT32(onems, IMXSerialState),
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VMSTATE_UINT32(ufcr, IMXSerialState),
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VMSTATE_UINT32(ubmr, IMXSerialState),
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VMSTATE_UINT32(ubrc, IMXSerialState),
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VMSTATE_UINT32(ucr3, IMXSerialState),
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VMSTATE_END_OF_LIST()
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},
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};
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#define URXD_CHARRDY (1<<15) /* character read is valid */
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#define URXD_ERR (1<<14) /* Character has error */
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#define URXD_BRK (1<<11) /* Break received */
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#define USR1_PARTYER (1<<15) /* Parity Error */
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#define USR1_RTSS (1<<14) /* RTS pin status */
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#define USR1_TRDY (1<<13) /* Tx ready */
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#define USR1_RTSD (1<<12) /* RTS delta: pin changed state */
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#define USR1_ESCF (1<<11) /* Escape sequence interrupt */
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#define USR1_FRAMERR (1<<10) /* Framing error */
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#define USR1_RRDY (1<<9) /* receiver ready */
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#define USR1_AGTIM (1<<8) /* Aging timer interrupt */
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#define USR1_DTRD (1<<7) /* DTR changed */
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#define USR1_RXDS (1<<6) /* Receiver is idle */
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#define USR1_AIRINT (1<<5) /* Aysnch IR interrupt */
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#define USR1_AWAKE (1<<4) /* Falling edge detected on RXd pin */
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#define USR2_ADET (1<<15) /* Autobaud complete */
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#define USR2_TXFE (1<<14) /* Transmit FIFO empty */
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#define USR2_DTRF (1<<13) /* DTR/DSR transition */
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#define USR2_IDLE (1<<12) /* UART has been idle for too long */
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#define USR2_ACST (1<<11) /* Autobaud counter stopped */
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#define USR2_RIDELT (1<<10) /* Ring Indicator delta */
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#define USR2_RIIN (1<<9) /* Ring Indicator Input */
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#define USR2_IRINT (1<<8) /* Serial Infrared Interrupt */
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#define USR2_WAKE (1<<7) /* Start bit detected */
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#define USR2_DCDDELT (1<<6) /* Data Carrier Detect delta */
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#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
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#define USR2_RTSF (1<<4) /* RTS transition */
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#define USR2_TXDC (1<<3) /* Transmission complete */
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#define USR2_BRCD (1<<2) /* Break condition detected */
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#define USR2_ORE (1<<1) /* Overrun error */
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#define USR2_RDR (1<<0) /* Receive data ready */
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#define UCR1_TRDYEN (1<<13) /* Tx Ready Interrupt Enable */
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#define UCR1_RRDYEN (1<<9) /* Rx Ready Interrupt Enable */
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#define UCR1_TXMPTYEN (1<<6) /* Tx Empty Interrupt Enable */
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#define UCR1_UARTEN (1<<0) /* UART Enable */
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#define UCR2_TXEN (1<<2) /* Transmitter enable */
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#define UCR2_RXEN (1<<1) /* Receiver enable */
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#define UCR2_SRST (1<<0) /* Reset complete */
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#define UTS1_TXEMPTY (1<<6)
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#define UTS1_RXEMPTY (1<<5)
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#define UTS1_TXFULL (1<<4)
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#define UTS1_RXFULL (1<<3)
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static void imx_update(IMXSerialState *s)
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{
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uint32_t flags;
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flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
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if (!(s->ucr1 & UCR1_TXMPTYEN)) {
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flags &= ~USR1_TRDY;
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}
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qemu_set_irq(s->irq, !!flags);
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}
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static void imx_serial_reset(IMXSerialState *s)
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{
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s->usr1 = USR1_TRDY | USR1_RXDS;
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/*
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* Fake attachment of a terminal: assert RTS.
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*/
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s->usr1 |= USR1_RTSS;
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s->usr2 = USR2_TXFE | USR2_TXDC | USR2_DCDIN;
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s->uts1 = UTS1_RXEMPTY | UTS1_TXEMPTY;
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s->ucr1 = 0;
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s->ucr2 = UCR2_SRST;
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s->ucr3 = 0x700;
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s->ubmr = 0;
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s->ubrc = 4;
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s->readbuff = URXD_ERR;
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}
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static void imx_serial_reset_at_boot(DeviceState *dev)
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{
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IMXSerialState *s = container_of(dev, IMXSerialState, busdev.qdev);
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imx_serial_reset(s);
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/*
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* enable the uart on boot, so messages from the linux decompresser
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* are visible. On real hardware this is done by the boot rom
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* before anything else is loaded.
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*/
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s->ucr1 = UCR1_UARTEN;
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s->ucr2 = UCR2_TXEN;
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}
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static uint64_t imx_serial_read(void *opaque, target_phys_addr_t offset,
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unsigned size)
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{
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IMXSerialState *s = (IMXSerialState *)opaque;
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uint32_t c;
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DPRINTF("read(offset=%x)\n", offset >> 2);
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switch (offset >> 2) {
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case 0x0: /* URXD */
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c = s->readbuff;
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if (!(s->uts1 & UTS1_RXEMPTY)) {
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/* Character is valid */
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c |= URXD_CHARRDY;
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s->usr1 &= ~USR1_RRDY;
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s->usr2 &= ~USR2_RDR;
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s->uts1 |= UTS1_RXEMPTY;
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imx_update(s);
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qemu_chr_accept_input(s->chr);
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}
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return c;
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case 0x20: /* UCR1 */
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return s->ucr1;
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case 0x21: /* UCR2 */
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return s->ucr2;
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case 0x25: /* USR1 */
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return s->usr1;
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case 0x26: /* USR2 */
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return s->usr2;
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case 0x2A: /* BRM Modulator */
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return s->ubmr;
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case 0x2B: /* Baud Rate Count */
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return s->ubrc;
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case 0x2d: /* Test register */
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return s->uts1;
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case 0x24: /* UFCR */
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return s->ufcr;
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case 0x2c:
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return s->onems;
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case 0x22: /* UCR3 */
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return s->ucr3;
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case 0x23: /* UCR4 */
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case 0x29: /* BRM Incremental */
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return 0x0; /* TODO */
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default:
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IPRINTF("imx_serial_read: bad offset: 0x%x\n", (int)offset);
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return 0;
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}
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}
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static void imx_serial_write(void *opaque, target_phys_addr_t offset,
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uint64_t value, unsigned size)
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{
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IMXSerialState *s = (IMXSerialState *)opaque;
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unsigned char ch;
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DPRINTF("write(offset=%x, value = %x) to %s\n",
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offset >> 2,
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(unsigned int)value, s->chr ? s->chr->label : "NODEV");
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switch (offset >> 2) {
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case 0x10: /* UTXD */
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ch = value;
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if (s->ucr2 & UCR2_TXEN) {
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if (s->chr) {
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qemu_chr_fe_write(s->chr, &ch, 1);
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}
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s->usr1 &= ~USR1_TRDY;
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imx_update(s);
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s->usr1 |= USR1_TRDY;
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imx_update(s);
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}
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break;
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case 0x20: /* UCR1 */
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s->ucr1 = value & 0xffff;
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DPRINTF("write(ucr1=%x)\n", (unsigned int)value);
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imx_update(s);
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break;
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case 0x21: /* UCR2 */
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/*
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* Only a few bits in control register 2 are implemented as yet.
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* If it's intended to use a real serial device as a back-end, this
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* register will have to be implemented more fully.
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*/
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if (!(value & UCR2_SRST)) {
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imx_serial_reset(s);
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imx_update(s);
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value |= UCR2_SRST;
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}
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if (value & UCR2_RXEN) {
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if (!(s->ucr2 & UCR2_RXEN)) {
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qemu_chr_accept_input(s->chr);
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}
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}
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s->ucr2 = value & 0xffff;
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break;
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case 0x25: /* USR1 */
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value &= USR1_AWAKE | USR1_AIRINT | USR1_DTRD | USR1_AGTIM |
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USR1_FRAMERR | USR1_ESCF | USR1_RTSD | USR1_PARTYER;
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s->usr1 &= ~value;
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break;
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case 0x26: /* USR2 */
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/*
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* Writing 1 to some bits clears them; all other
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* values are ignored
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*/
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value &= USR2_ADET | USR2_DTRF | USR2_IDLE | USR2_ACST |
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USR2_RIDELT | USR2_IRINT | USR2_WAKE |
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USR2_DCDDELT | USR2_RTSF | USR2_BRCD | USR2_ORE;
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s->usr2 &= ~value;
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break;
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/*
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* Linux expects to see what it writes to these registers
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* We don't currently alter the baud rate
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*/
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case 0x29: /* UBIR */
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s->ubrc = value & 0xffff;
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break;
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case 0x2a: /* UBMR */
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s->ubmr = value & 0xffff;
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break;
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case 0x2c: /* One ms reg */
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s->onems = value & 0xffff;
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break;
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case 0x24: /* FIFO control register */
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s->ufcr = value & 0xffff;
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break;
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case 0x22: /* UCR3 */
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s->ucr3 = value & 0xffff;
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break;
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case 0x2d: /* UTS1 */
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case 0x23: /* UCR4 */
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IPRINTF("Unimplemented Register %x written to\n", offset >> 2);
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/* TODO */
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break;
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default:
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IPRINTF("imx_serial_write: Bad offset 0x%x\n", (int)offset);
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}
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}
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static int imx_can_receive(void *opaque)
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{
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IMXSerialState *s = (IMXSerialState *)opaque;
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return !(s->usr1 & USR1_RRDY);
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}
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static void imx_put_data(void *opaque, uint32_t value)
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{
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IMXSerialState *s = (IMXSerialState *)opaque;
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DPRINTF("received char\n");
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s->usr1 |= USR1_RRDY;
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s->usr2 |= USR2_RDR;
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s->uts1 &= ~UTS1_RXEMPTY;
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s->readbuff = value;
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imx_update(s);
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}
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static void imx_receive(void *opaque, const uint8_t *buf, int size)
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{
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imx_put_data(opaque, *buf);
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}
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static void imx_event(void *opaque, int event)
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{
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if (event == CHR_EVENT_BREAK) {
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imx_put_data(opaque, URXD_BRK);
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}
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}
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static const struct MemoryRegionOps imx_serial_ops = {
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.read = imx_serial_read,
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.write = imx_serial_write,
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.endianness = DEVICE_NATIVE_ENDIAN,
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};
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static int imx_serial_init(SysBusDevice *dev)
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{
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IMXSerialState *s = FROM_SYSBUS(IMXSerialState, dev);
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memory_region_init_io(&s->iomem, &imx_serial_ops, s, "imx-serial", 0x1000);
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sysbus_init_mmio(dev, &s->iomem);
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sysbus_init_irq(dev, &s->irq);
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if (s->chr) {
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qemu_chr_add_handlers(s->chr, imx_can_receive, imx_receive,
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imx_event, s);
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} else {
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DPRINTF("No char dev for uart at 0x%lx\n",
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(unsigned long)s->iomem.ram_addr);
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}
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return 0;
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}
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void imx_serial_create(int uart, const target_phys_addr_t addr, qemu_irq irq)
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{
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DeviceState *dev;
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SysBusDevice *bus;
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CharDriverState *chr;
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const char chr_name[] = "serial";
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char label[ARRAY_SIZE(chr_name) + 1];
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dev = qdev_create(NULL, "imx-serial");
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if (uart >= MAX_SERIAL_PORTS) {
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hw_error("Cannot assign uart %d: QEMU supports only %d ports\n",
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uart, MAX_SERIAL_PORTS);
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}
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chr = serial_hds[uart];
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if (!chr) {
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snprintf(label, ARRAY_SIZE(label), "%s%d", chr_name, uart);
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chr = qemu_chr_new(label, "null", NULL);
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if (!(chr)) {
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hw_error("Can't assign serial port to imx-uart%d.\n", uart);
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}
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}
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qdev_prop_set_chr(dev, "chardev", chr);
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bus = sysbus_from_qdev(dev);
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qdev_init_nofail(dev);
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if (addr != (target_phys_addr_t)-1) {
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sysbus_mmio_map(bus, 0, addr);
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}
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sysbus_connect_irq(bus, 0, irq);
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}
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static Property imx32_serial_properties[] = {
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DEFINE_PROP_CHR("chardev", IMXSerialState, chr),
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DEFINE_PROP_END_OF_LIST(),
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};
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static void imx_serial_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(klass);
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SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
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k->init = imx_serial_init;
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dc->vmsd = &vmstate_imx_serial;
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dc->reset = imx_serial_reset_at_boot;
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dc->desc = "i.MX series UART";
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dc->props = imx32_serial_properties;
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}
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static TypeInfo imx_serial_info = {
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.name = "imx-serial",
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.parent = TYPE_SYS_BUS_DEVICE,
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.instance_size = sizeof(IMXSerialState),
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.class_init = imx_serial_class_init,
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};
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static void imx_serial_register_types(void)
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{
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type_register_static(&imx_serial_info);
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}
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type_init(imx_serial_register_types)
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