--- /dev/null
+/*
+ * Arm PrimeCell PL011 UART
+ *
+ * Copyright (c) 2006 CodeSourcery.
+ * Written by Paul Brook
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include "vl.h"
+
+typedef struct {
+ uint32_t base;
+ uint32_t readbuff;
+ uint32_t flags;
+ uint32_t lcr;
+ uint32_t cr;
+ uint32_t dmacr;
+ uint32_t int_enabled;
+ uint32_t int_level;
+ uint32_t read_fifo[16];
+ uint32_t ilpr;
+ uint32_t ibrd;
+ uint32_t fbrd;
+ uint32_t ifl;
+ int read_pos;
+ int read_count;
+ int read_trigger;
+ CharDriverState *chr;
+ void *pic;
+ int irq;
+} pl011_state;
+
+#define PL011_INT_TX 0x20
+#define PL011_INT_RX 0x10
+
+#define PL011_FLAG_TXFE 0x80
+#define PL011_FLAG_RXFF 0x40
+#define PL011_FLAG_TXFF 0x20
+#define PL011_FLAG_RXFE 0x10
+
+static const unsigned char pl011_id[] =
+{ 0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
+
+static void pl011_update(pl011_state *s)
+{
+ uint32_t flags;
+
+ flags = s->int_level & s->int_enabled;
+ pic_set_irq_new(s->pic, s->irq, flags != 0);
+}
+
+static uint32_t pl011_read(void *opaque, target_phys_addr_t offset)
+{
+ pl011_state *s = (pl011_state *)opaque;
+ uint32_t c;
+
+ offset -= s->base;
+ if (offset >= 0xfe0 && offset < 0x1000) {
+ return pl011_id[(offset - 0xfe0) >> 2];
+ }
+ switch (offset >> 2) {
+ case 0: /* UARTDR */
+ s->flags &= ~PL011_FLAG_RXFF;
+ c = s->read_fifo[s->read_pos];
+ if (s->read_count > 0) {
+ s->read_count--;
+ if (++s->read_pos == 16)
+ s->read_pos = 0;
+ }
+ if (s->read_count == 0) {
+ s->flags |= PL011_FLAG_RXFE;
+ }
+ if (s->read_count == s->read_trigger - 1)
+ s->int_level &= ~ PL011_INT_RX;
+ pl011_update(s);
+ return c;
+ case 1: /* UARTCR */
+ return 0;
+ case 6: /* UARTFR */
+ return s->flags;
+ case 8: /* UARTILPR */
+ return s->ilpr;
+ case 9: /* UARTIBRD */
+ return s->ibrd;
+ case 10: /* UARTFBRD */
+ return s->fbrd;
+ case 11: /* UARTLCR_H */
+ return s->lcr;
+ case 12: /* UARTCR */
+ return s->cr;
+ case 13: /* UARTIFLS */
+ return s->ifl;
+ case 14: /* UARTIMSC */
+ return s->int_enabled;
+ case 15: /* UARTRIS */
+ return s->int_level;
+ case 16: /* UARTMIS */
+ return s->int_level & s->int_enabled;
+ case 18: /* UARTDMACR */
+ return s->dmacr;
+ default:
+ cpu_abort (cpu_single_env, "pl011_read: Bad offset %x\n", offset);
+ return 0;
+ }
+}
+
+static void pl011_set_read_trigger(pl011_state *s)
+{
+#if 0
+ /* The docs say the RX interrupt is triggered when the FIFO exceeds
+ the threshold. However linux only reads the FIFO in response to an
+ interrupt. Triggering the interrupt when the FIFO is non-empty seems
+ to make things work. */
+ if (s->lcr & 0x10)
+ s->read_trigger = (s->ifl >> 1) & 0x1c;
+ else
+#endif
+ s->read_trigger = 1;
+}
+
+static void pl011_write(void *opaque, target_phys_addr_t offset,
+ uint32_t value)
+{
+ pl011_state *s = (pl011_state *)opaque;
+ unsigned char ch;
+
+ offset -= s->base;
+ switch (offset >> 2) {
+ case 0: /* UARTDR */
+ /* ??? Check if transmitter is enabled. */
+ ch = value;
+ if (s->chr)
+ qemu_chr_write(s->chr, &ch, 1);
+ s->int_level |= PL011_INT_TX;
+ pl011_update(s);
+ break;
+ case 1: /* UARTCR */
+ s->cr = value;
+ break;
+ case 8: /* UARTUARTILPR */
+ s->ilpr = value;
+ break;
+ case 9: /* UARTIBRD */
+ s->ibrd = value;
+ break;
+ case 10: /* UARTFBRD */
+ s->fbrd = value;
+ break;
+ case 11: /* UARTLCR_H */
+ s->lcr = value;
+ pl011_set_read_trigger(s);
+ break;
+ case 12: /* UARTCR */
+ /* ??? Need to implement the enable and loopback bits. */
+ s->cr = value;
+ break;
+ case 13: /* UARTIFS */
+ s->ifl = value;
+ pl011_set_read_trigger(s);
+ break;
+ case 14: /* UARTIMSC */
+ s->int_enabled = value;
+ pl011_update(s);
+ break;
+ case 17: /* UARTICR */
+ s->int_level &= ~value;
+ pl011_update(s);
+ break;
+ case 18: /* UARTDMACR */
+ s->dmacr = value;
+ if (value & 3)
+ cpu_abort(cpu_single_env, "PL011: DMA not implemented\n");
+ break;
+ default:
+ cpu_abort (cpu_single_env, "pl011_write: Bad offset %x\n", offset);
+ }
+}
+
+static int pl011_can_recieve(void *opaque)
+{
+ pl011_state *s = (pl011_state *)opaque;
+
+ if (s->lcr & 0x10)
+ return s->read_count < 16;
+ else
+ return s->read_count < 1;
+}
+
+static void pl011_recieve(void *opaque, const uint8_t *buf, int size)
+{
+ pl011_state *s = (pl011_state *)opaque;
+ int slot;
+
+ slot = s->read_pos + s->read_count;
+ if (slot >= 16)
+ slot -= 16;
+ s->read_fifo[slot] = *buf;
+ s->read_count++;
+ s->flags &= ~PL011_FLAG_RXFE;
+ if (s->cr & 0x10 || s->read_count == 16) {
+ s->flags |= PL011_FLAG_RXFF;
+ }
+ if (s->read_count == s->read_trigger) {
+ s->int_level |= PL011_INT_RX;
+ pl011_update(s);
+ }
+}
+
+static void pl011_event(void *opaque, int event)
+{
+ /* ??? Should probably implement break. */
+}
+
+static CPUReadMemoryFunc *pl011_readfn[] = {
+ pl011_read,
+ pl011_read,
+ pl011_read
+};
+
+static CPUWriteMemoryFunc *pl011_writefn[] = {
+ pl011_write,
+ pl011_write,
+ pl011_write
+};
+
+void pl011_init(uint32_t base, void *pic, int irq,
+ CharDriverState *chr)
+{
+ int iomemtype;
+ pl011_state *s;
+
+ s = (pl011_state *)qemu_mallocz(sizeof(pl011_state));
+ iomemtype = cpu_register_io_memory(0, pl011_readfn,
+ pl011_writefn, s);
+ cpu_register_physical_memory(base, 0x00000fff, iomemtype);
+ s->base = base;
+ s->pic = pic;
+ s->irq = irq;
+ s->chr = chr;
+ s->read_trigger = 1;
+ s->ifl = 0x12;
+ s->cr = 0x300;
+ s->flags = 0x90;
+ if (chr){
+ qemu_chr_add_read_handler(chr, pl011_can_recieve, pl011_recieve, s);
+ qemu_chr_add_event_handler(chr, pl011_event);
+ }
+ /* ??? Save/restore. */
+}
+
projects / qemu / blobdiff