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-rw-r--r--src/hw/char/imx_serial.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/src/hw/char/imx_serial.c b/src/hw/char/imx_serial.c
new file mode 100644
index 0000000..f30f9c2
--- /dev/null
+++ b/src/hw/char/imx_serial.c
@@ -0,0 +1,366 @@
+/*
+ * IMX31 UARTS
+ *
+ * Copyright (c) 2008 OKL
+ * Originally Written by Hans Jiang
+ * Copyright (c) 2011 NICTA Pty Ltd.
+ * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * This is a `bare-bones' implementation of the IMX series serial ports.
+ * TODO:
+ * -- implement FIFOs. The real hardware has 32 word transmit
+ * and receive FIFOs; we currently use a 1-char buffer
+ * -- implement DMA
+ * -- implement BAUD-rate and modem lines, for when the backend
+ * is a real serial device.
+ */
+
+#include "hw/char/imx_serial.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/char.h"
+
+#ifndef DEBUG_IMX_UART
+#define DEBUG_IMX_UART 0
+#endif
+
+#define DPRINTF(fmt, args...) \
+ do { \
+ if (DEBUG_IMX_UART) { \
+ fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_SERIAL, \
+ __func__, ##args); \
+ } \
+ } while (0)
+
+static const VMStateDescription vmstate_imx_serial = {
+ .name = TYPE_IMX_SERIAL,
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT32(readbuff, IMXSerialState),
+ VMSTATE_UINT32(usr1, IMXSerialState),
+ VMSTATE_UINT32(usr2, IMXSerialState),
+ VMSTATE_UINT32(ucr1, IMXSerialState),
+ VMSTATE_UINT32(uts1, IMXSerialState),
+ VMSTATE_UINT32(onems, IMXSerialState),
+ VMSTATE_UINT32(ufcr, IMXSerialState),
+ VMSTATE_UINT32(ubmr, IMXSerialState),
+ VMSTATE_UINT32(ubrc, IMXSerialState),
+ VMSTATE_UINT32(ucr3, IMXSerialState),
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static void imx_update(IMXSerialState *s)
+{
+ uint32_t flags;
+
+ flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
+ if (s->ucr1 & UCR1_TXMPTYEN) {
+ flags |= (s->uts1 & UTS1_TXEMPTY);
+ } else {
+ flags &= ~USR1_TRDY;
+ }
+
+ qemu_set_irq(s->irq, !!flags);
+}
+
+static void imx_serial_reset(IMXSerialState *s)
+{
+
+ s->usr1 = USR1_TRDY | USR1_RXDS;
+ /*
+ * Fake attachment of a terminal: assert RTS.
+ */
+ s->usr1 |= USR1_RTSS;
+ s->usr2 = USR2_TXFE | USR2_TXDC | USR2_DCDIN;
+ s->uts1 = UTS1_RXEMPTY | UTS1_TXEMPTY;
+ s->ucr1 = 0;
+ s->ucr2 = UCR2_SRST;
+ s->ucr3 = 0x700;
+ s->ubmr = 0;
+ s->ubrc = 4;
+ s->readbuff = URXD_ERR;
+}
+
+static void imx_serial_reset_at_boot(DeviceState *dev)
+{
+ IMXSerialState *s = IMX_SERIAL(dev);
+
+ imx_serial_reset(s);
+
+ /*
+ * enable the uart on boot, so messages from the linux decompresser
+ * are visible. On real hardware this is done by the boot rom
+ * before anything else is loaded.
+ */
+ s->ucr1 = UCR1_UARTEN;
+ s->ucr2 = UCR2_TXEN;
+
+}
+
+static uint64_t imx_serial_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+ uint32_t c;
+
+ DPRINTF("read(offset=0x%" HWADDR_PRIx ")\n", offset);
+
+ switch (offset >> 2) {
+ case 0x0: /* URXD */
+ c = s->readbuff;
+ if (!(s->uts1 & UTS1_RXEMPTY)) {
+ /* Character is valid */
+ c |= URXD_CHARRDY;
+ s->usr1 &= ~USR1_RRDY;
+ s->usr2 &= ~USR2_RDR;
+ s->uts1 |= UTS1_RXEMPTY;
+ imx_update(s);
+ if (s->chr) {
+ qemu_chr_accept_input(s->chr);
+ }
+ }
+ return c;
+
+ case 0x20: /* UCR1 */
+ return s->ucr1;
+
+ case 0x21: /* UCR2 */
+ return s->ucr2;
+
+ case 0x25: /* USR1 */
+ return s->usr1;
+
+ case 0x26: /* USR2 */
+ return s->usr2;
+
+ case 0x2A: /* BRM Modulator */
+ return s->ubmr;
+
+ case 0x2B: /* Baud Rate Count */
+ return s->ubrc;
+
+ case 0x2d: /* Test register */
+ return s->uts1;
+
+ case 0x24: /* UFCR */
+ return s->ufcr;
+
+ case 0x2c:
+ return s->onems;
+
+ case 0x22: /* UCR3 */
+ return s->ucr3;
+
+ case 0x23: /* UCR4 */
+ case 0x29: /* BRM Incremental */
+ return 0x0; /* TODO */
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+ HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset);
+ return 0;
+ }
+}
+
+static void imx_serial_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+ unsigned char ch;
+
+ DPRINTF("write(offset=0x%" HWADDR_PRIx ", value = 0x%x) to %s\n",
+ offset, (unsigned int)value, s->chr ? s->chr->label : "NODEV");
+
+ switch (offset >> 2) {
+ case 0x10: /* UTXD */
+ ch = value;
+ if (s->ucr2 & UCR2_TXEN) {
+ if (s->chr) {
+ qemu_chr_fe_write(s->chr, &ch, 1);
+ }
+ s->usr1 &= ~USR1_TRDY;
+ imx_update(s);
+ s->usr1 |= USR1_TRDY;
+ imx_update(s);
+ }
+ break;
+
+ case 0x20: /* UCR1 */
+ s->ucr1 = value & 0xffff;
+
+ DPRINTF("write(ucr1=%x)\n", (unsigned int)value);
+
+ imx_update(s);
+ break;
+
+ case 0x21: /* UCR2 */
+ /*
+ * Only a few bits in control register 2 are implemented as yet.
+ * If it's intended to use a real serial device as a back-end, this
+ * register will have to be implemented more fully.
+ */
+ if (!(value & UCR2_SRST)) {
+ imx_serial_reset(s);
+ imx_update(s);
+ value |= UCR2_SRST;
+ }
+ if (value & UCR2_RXEN) {
+ if (!(s->ucr2 & UCR2_RXEN)) {
+ if (s->chr) {
+ qemu_chr_accept_input(s->chr);
+ }
+ }
+ }
+ s->ucr2 = value & 0xffff;
+ break;
+
+ case 0x25: /* USR1 */
+ value &= USR1_AWAKE | USR1_AIRINT | USR1_DTRD | USR1_AGTIM |
+ USR1_FRAMERR | USR1_ESCF | USR1_RTSD | USR1_PARTYER;
+ s->usr1 &= ~value;
+ break;
+
+ case 0x26: /* USR2 */
+ /*
+ * Writing 1 to some bits clears them; all other
+ * values are ignored
+ */
+ value &= USR2_ADET | USR2_DTRF | USR2_IDLE | USR2_ACST |
+ USR2_RIDELT | USR2_IRINT | USR2_WAKE |
+ USR2_DCDDELT | USR2_RTSF | USR2_BRCD | USR2_ORE;
+ s->usr2 &= ~value;
+ break;
+
+ /*
+ * Linux expects to see what it writes to these registers
+ * We don't currently alter the baud rate
+ */
+ case 0x29: /* UBIR */
+ s->ubrc = value & 0xffff;
+ break;
+
+ case 0x2a: /* UBMR */
+ s->ubmr = value & 0xffff;
+ break;
+
+ case 0x2c: /* One ms reg */
+ s->onems = value & 0xffff;
+ break;
+
+ case 0x24: /* FIFO control register */
+ s->ufcr = value & 0xffff;
+ break;
+
+ case 0x22: /* UCR3 */
+ s->ucr3 = value & 0xffff;
+ break;
+
+ case 0x2d: /* UTS1 */
+ case 0x23: /* UCR4 */
+ qemu_log_mask(LOG_UNIMP, "[%s]%s: Unimplemented reg 0x%"
+ HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset);
+ /* TODO */
+ break;
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+ HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, offset);
+ }
+}
+
+static int imx_can_receive(void *opaque)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+ return !(s->usr1 & USR1_RRDY);
+}
+
+static void imx_put_data(void *opaque, uint32_t value)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+
+ DPRINTF("received char\n");
+
+ s->usr1 |= USR1_RRDY;
+ s->usr2 |= USR2_RDR;
+ s->uts1 &= ~UTS1_RXEMPTY;
+ s->readbuff = value;
+ imx_update(s);
+}
+
+static void imx_receive(void *opaque, const uint8_t *buf, int size)
+{
+ imx_put_data(opaque, *buf);
+}
+
+static void imx_event(void *opaque, int event)
+{
+ if (event == CHR_EVENT_BREAK) {
+ imx_put_data(opaque, URXD_BRK);
+ }
+}
+
+
+static const struct MemoryRegionOps imx_serial_ops = {
+ .read = imx_serial_read,
+ .write = imx_serial_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void imx_serial_realize(DeviceState *dev, Error **errp)
+{
+ IMXSerialState *s = IMX_SERIAL(dev);
+
+ if (s->chr) {
+ qemu_chr_add_handlers(s->chr, imx_can_receive, imx_receive,
+ imx_event, s);
+ } else {
+ DPRINTF("No char dev for uart\n");
+ }
+}
+
+static void imx_serial_init(Object *obj)
+{
+ SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+ IMXSerialState *s = IMX_SERIAL(obj);
+
+ memory_region_init_io(&s->iomem, obj, &imx_serial_ops, s,
+ TYPE_IMX_SERIAL, 0x1000);
+ sysbus_init_mmio(sbd, &s->iomem);
+ sysbus_init_irq(sbd, &s->irq);
+}
+
+static Property imx_serial_properties[] = {
+ DEFINE_PROP_CHR("chardev", IMXSerialState, chr),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void imx_serial_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->realize = imx_serial_realize;
+ dc->vmsd = &vmstate_imx_serial;
+ dc->reset = imx_serial_reset_at_boot;
+ set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+ dc->desc = "i.MX series UART";
+ dc->props = imx_serial_properties;
+}
+
+static const TypeInfo imx_serial_info = {
+ .name = TYPE_IMX_SERIAL,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(IMXSerialState),
+ .instance_init = imx_serial_init,
+ .class_init = imx_serial_class_init,
+};
+
+static void imx_serial_register_types(void)
+{
+ type_register_static(&imx_serial_info);
+}
+
+type_init(imx_serial_register_types)
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