300 lines
7.6 KiB
C
300 lines
7.6 KiB
C
/*
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* Arm PrimeCell PL011 UART
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*
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* Copyright (c) 2006 CodeSourcery.
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* Written by Paul Brook
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*
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* This code is licensed under the GPL.
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*/
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#include "sysbus.h"
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#include "qemu-char.h"
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typedef struct {
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SysBusDevice busdev;
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MemoryRegion iomem;
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uint32_t readbuff;
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uint32_t flags;
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uint32_t lcr;
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uint32_t cr;
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uint32_t dmacr;
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uint32_t int_enabled;
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uint32_t int_level;
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uint32_t read_fifo[16];
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uint32_t ilpr;
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uint32_t ibrd;
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uint32_t fbrd;
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uint32_t ifl;
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int read_pos;
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int read_count;
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int read_trigger;
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CharDriverState *chr;
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qemu_irq irq;
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const unsigned char *id;
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} pl011_state;
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#define PL011_INT_TX 0x20
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#define PL011_INT_RX 0x10
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#define PL011_FLAG_TXFE 0x80
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#define PL011_FLAG_RXFF 0x40
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#define PL011_FLAG_TXFF 0x20
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#define PL011_FLAG_RXFE 0x10
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static const unsigned char pl011_id_arm[8] =
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{ 0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
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static const unsigned char pl011_id_luminary[8] =
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{ 0x11, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1 };
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static void pl011_update(pl011_state *s)
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{
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uint32_t flags;
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flags = s->int_level & s->int_enabled;
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qemu_set_irq(s->irq, flags != 0);
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}
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static uint64_t pl011_read(void *opaque, target_phys_addr_t offset,
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unsigned size)
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{
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pl011_state *s = (pl011_state *)opaque;
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uint32_t c;
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if (offset >= 0xfe0 && offset < 0x1000) {
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return s->id[(offset - 0xfe0) >> 2];
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}
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switch (offset >> 2) {
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case 0: /* UARTDR */
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s->flags &= ~PL011_FLAG_RXFF;
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c = s->read_fifo[s->read_pos];
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if (s->read_count > 0) {
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s->read_count--;
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if (++s->read_pos == 16)
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s->read_pos = 0;
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}
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if (s->read_count == 0) {
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s->flags |= PL011_FLAG_RXFE;
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}
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if (s->read_count == s->read_trigger - 1)
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s->int_level &= ~ PL011_INT_RX;
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pl011_update(s);
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qemu_chr_accept_input(s->chr);
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return c;
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case 1: /* UARTCR */
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return 0;
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case 6: /* UARTFR */
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return s->flags;
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case 8: /* UARTILPR */
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return s->ilpr;
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case 9: /* UARTIBRD */
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return s->ibrd;
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case 10: /* UARTFBRD */
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return s->fbrd;
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case 11: /* UARTLCR_H */
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return s->lcr;
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case 12: /* UARTCR */
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return s->cr;
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case 13: /* UARTIFLS */
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return s->ifl;
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case 14: /* UARTIMSC */
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return s->int_enabled;
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case 15: /* UARTRIS */
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return s->int_level;
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case 16: /* UARTMIS */
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return s->int_level & s->int_enabled;
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case 18: /* UARTDMACR */
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return s->dmacr;
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default:
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hw_error("pl011_read: Bad offset %x\n", (int)offset);
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return 0;
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}
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}
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static void pl011_set_read_trigger(pl011_state *s)
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{
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#if 0
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/* The docs say the RX interrupt is triggered when the FIFO exceeds
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the threshold. However linux only reads the FIFO in response to an
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interrupt. Triggering the interrupt when the FIFO is non-empty seems
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to make things work. */
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if (s->lcr & 0x10)
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s->read_trigger = (s->ifl >> 1) & 0x1c;
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else
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#endif
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s->read_trigger = 1;
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}
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static void pl011_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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pl011_state *s = (pl011_state *)opaque;
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unsigned char ch;
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switch (offset >> 2) {
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case 0: /* UARTDR */
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/* ??? Check if transmitter is enabled. */
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ch = value;
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if (s->chr)
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qemu_chr_fe_write(s->chr, &ch, 1);
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s->int_level |= PL011_INT_TX;
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pl011_update(s);
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break;
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case 1: /* UARTCR */
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s->cr = value;
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break;
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case 6: /* UARTFR */
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/* Writes to Flag register are ignored. */
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break;
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case 8: /* UARTUARTILPR */
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s->ilpr = value;
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break;
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case 9: /* UARTIBRD */
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s->ibrd = value;
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break;
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case 10: /* UARTFBRD */
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s->fbrd = value;
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break;
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case 11: /* UARTLCR_H */
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s->lcr = value;
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pl011_set_read_trigger(s);
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break;
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case 12: /* UARTCR */
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/* ??? Need to implement the enable and loopback bits. */
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s->cr = value;
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break;
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case 13: /* UARTIFS */
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s->ifl = value;
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pl011_set_read_trigger(s);
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break;
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case 14: /* UARTIMSC */
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s->int_enabled = value;
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pl011_update(s);
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break;
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case 17: /* UARTICR */
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s->int_level &= ~value;
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pl011_update(s);
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break;
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case 18: /* UARTDMACR */
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s->dmacr = value;
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if (value & 3)
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hw_error("PL011: DMA not implemented\n");
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break;
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default:
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hw_error("pl011_write: Bad offset %x\n", (int)offset);
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}
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}
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static int pl011_can_receive(void *opaque)
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{
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pl011_state *s = (pl011_state *)opaque;
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if (s->lcr & 0x10)
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return s->read_count < 16;
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else
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return s->read_count < 1;
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}
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static void pl011_put_fifo(void *opaque, uint32_t value)
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{
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pl011_state *s = (pl011_state *)opaque;
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int slot;
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slot = s->read_pos + s->read_count;
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if (slot >= 16)
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slot -= 16;
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s->read_fifo[slot] = value;
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s->read_count++;
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s->flags &= ~PL011_FLAG_RXFE;
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if (s->cr & 0x10 || s->read_count == 16) {
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s->flags |= PL011_FLAG_RXFF;
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}
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if (s->read_count == s->read_trigger) {
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s->int_level |= PL011_INT_RX;
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pl011_update(s);
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}
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}
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static void pl011_receive(void *opaque, const uint8_t *buf, int size)
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{
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pl011_put_fifo(opaque, *buf);
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}
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static void pl011_event(void *opaque, int event)
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{
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if (event == CHR_EVENT_BREAK)
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pl011_put_fifo(opaque, 0x400);
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}
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static const MemoryRegionOps pl011_ops = {
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.read = pl011_read,
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.write = pl011_write,
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.endianness = DEVICE_NATIVE_ENDIAN,
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};
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static const VMStateDescription vmstate_pl011 = {
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.name = "pl011",
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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(readbuff, pl011_state),
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VMSTATE_UINT32(flags, pl011_state),
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VMSTATE_UINT32(lcr, pl011_state),
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VMSTATE_UINT32(cr, pl011_state),
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VMSTATE_UINT32(dmacr, pl011_state),
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VMSTATE_UINT32(int_enabled, pl011_state),
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VMSTATE_UINT32(int_level, pl011_state),
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VMSTATE_UINT32_ARRAY(read_fifo, pl011_state, 16),
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VMSTATE_UINT32(ilpr, pl011_state),
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VMSTATE_UINT32(ibrd, pl011_state),
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VMSTATE_UINT32(fbrd, pl011_state),
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VMSTATE_UINT32(ifl, pl011_state),
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VMSTATE_INT32(read_pos, pl011_state),
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VMSTATE_INT32(read_count, pl011_state),
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VMSTATE_INT32(read_trigger, pl011_state),
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VMSTATE_END_OF_LIST()
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}
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};
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static int pl011_init(SysBusDevice *dev, const unsigned char *id)
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{
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pl011_state *s = FROM_SYSBUS(pl011_state, dev);
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memory_region_init_io(&s->iomem, &pl011_ops, s, "pl011", 0x1000);
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sysbus_init_mmio_region(dev, &s->iomem);
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sysbus_init_irq(dev, &s->irq);
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s->id = id;
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s->chr = qdev_init_chardev(&dev->qdev);
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s->read_trigger = 1;
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s->ifl = 0x12;
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s->cr = 0x300;
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s->flags = 0x90;
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if (s->chr) {
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qemu_chr_add_handlers(s->chr, pl011_can_receive, pl011_receive,
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pl011_event, s);
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}
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vmstate_register(&dev->qdev, -1, &vmstate_pl011, s);
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return 0;
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}
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static int pl011_init_arm(SysBusDevice *dev)
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{
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return pl011_init(dev, pl011_id_arm);
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}
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static int pl011_init_luminary(SysBusDevice *dev)
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{
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return pl011_init(dev, pl011_id_luminary);
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}
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static void pl011_register_devices(void)
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{
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sysbus_register_dev("pl011", sizeof(pl011_state),
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pl011_init_arm);
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sysbus_register_dev("pl011_luminary", sizeof(pl011_state),
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pl011_init_luminary);
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}
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device_init(pl011_register_devices)
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