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 <phil...@ok-labs.com>
Signed-off-by: Peter Chubb <peter.ch...@nicta.com.au>
Reviewed-by: Peter Maydell <peter.mayd...@linaro.org>
---
Makefile.target | 1
hw/imx.h | 16 +
hw/imx_serial.c | 467 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 484 insertions(+)
create mode 100644 hw/imx_serial.c
Index: qemu-working/hw/imx_serial.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ qemu-working/hw/imx_serial.c 2012-04-03 11:48:47.732705764 +1000
@@ -0,0 +1,467 @@
+/*
+ * IMX31 UARTS
+ *
+ * Copyright (c) 2008 OKL
+ * Originally Written by Hans Jiang
+ * Copyright (c) 2011 NICTA Pty Ltd.
+ *
+ * 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.h"
+#include "sysbus.h"
+#include "sysemu.h"
+#include "qemu-char.h"
+#include "imx.h"
+
+//#define DEBUG_SERIAL 1
+#ifdef DEBUG_SERIAL
+#define DPRINTF(fmt, args...) \
+do { printf("imx_serial: " fmt , ##args); } while (0)
+#else
+#define DPRINTF(fmt, args...) do {} while (0)
+#endif
+
+/*
+ * Define to 1 for messages about attempts to
+ * access unimplemented registers or similar.
+ */
+//#define DEBUG_IMPLEMENTATION 1
+#ifdef DEBUG_IMPLEMENTATION
+# define IPRINTF(fmt, args...) \
+ do { fprintf(stderr, "imx_serial: " fmt, ##args); } while (0)
+#else
+# define IPRINTF(fmt, args...) do {} while (0)
+#endif
+
+typedef struct {
+ SysBusDevice busdev;
+ MemoryRegion iomem;
+ int32_t readbuff;
+
+ uint32_t usr1;
+ uint32_t usr2;
+ uint32_t ucr1;
+ uint32_t ucr2;
+ uint32_t uts1;
+
+ /*
+ * The registers below are implemented just so that the
+ * guest OS sees what it has written
+ */
+ uint32_t onems;
+ uint32_t ufcr;
+ uint32_t ubmr;
+ uint32_t ubrc;
+ uint32_t ucr3;
+
+ qemu_irq irq;
+ CharDriverState *chr;
+} IMXSerialState;
+
+static const VMStateDescription vmstate_imx_serial = {
+ .name = "imx-serial",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 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()
+ },
+};
+
+
+#define URXD_CHARRDY (1<<15) /* character read is valid */
+#define URXD_ERR (1<<14) /* Character has error */
+#define URXD_BRK (1<<11) /* Break received */
+
+#define USR1_PARTYER (1<<15) /* Parity Error */
+#define USR1_RTSS (1<<14) /* RTS pin status */
+#define USR1_TRDY (1<<13) /* Tx ready */
+#define USR1_RTSD (1<<12) /* RTS delta: pin changed state */
+#define USR1_ESCF (1<<11) /* Escape sequence interrupt */
+#define USR1_FRAMERR (1<<10) /* Framing error */
+#define USR1_RRDY (1<<9) /* receiver ready */
+#define USR1_AGTIM (1<<8) /* Aging timer interrupt */
+#define USR1_DTRD (1<<7) /* DTR changed */
+#define USR1_RXDS (1<<6) /* Receiver is idle */
+#define USR1_AIRINT (1<<5) /* Aysnch IR interrupt */
+#define USR1_AWAKE (1<<4) /* Falling edge detected on RXd pin */
+
+#define USR2_ADET (1<<15) /* Autobaud complete */
+#define USR2_TXFE (1<<14) /* Transmit FIFO empty */
+#define USR2_DTRF (1<<13) /* DTR/DSR transition */
+#define USR2_IDLE (1<<12) /* UART has been idle for too long */
+#define USR2_ACST (1<<11) /* Autobaud counter stopped */
+#define USR2_RIDELT (1<<10) /* Ring Indicator delta */
+#define USR2_RIIN (1<<9) /* Ring Indicator Input */
+#define USR2_IRINT (1<<8) /* Serial Infrared Interrupt */
+#define USR2_WAKE (1<<7) /* Start bit detected */
+#define USR2_DCDDELT (1<<6) /* Data Carrier Detect delta */
+#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
+#define USR2_RTSF (1<<4) /* RTS transition */
+#define USR2_TXDC (1<<3) /* Transmission complete */
+#define USR2_BRCD (1<<2) /* Break condition detected */
+#define USR2_ORE (1<<1) /* Overrun error */
+#define USR2_RDR (1<<0) /* Receive data ready */
+
+#define UCR1_TRDYEN (1<<13) /* Tx Ready Interrupt Enable */
+#define UCR1_RRDYEN (1<<9) /* Rx Ready Interrupt Enable */
+#define UCR1_TXMPTYEN (1<<6) /* Tx Empty Interrupt Enable */
+#define UCR1_UARTEN (1<<0) /* UART Enable */
+
+#define UCR2_TXEN (1<<2) /* Transmitter enable */
+#define UCR2_RXEN (1<<1) /* Receiver enable */
+#define UCR2_SRST (1<<0) /* Reset complete */
+
+#define UTS1_TXEMPTY (1<<6)
+#define UTS1_RXEMPTY (1<<5)
+#define UTS1_TXFULL (1<<4)
+#define UTS1_RXFULL (1<<3)
+
+static void imx_update(IMXSerialState *s)
+{
+ uint32_t flags;
+
+ flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
+ if (!(s->ucr1 & UCR1_TXMPTYEN)) {
+ 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 = container_of(dev, IMXSerialState, busdev.qdev);
+
+ 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, target_phys_addr_t offset,
+ unsigned size)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+ uint32_t c;
+
+ DPRINTF("read(offset=%x)\n", offset >> 2);
+ 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);
+ 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:
+ IPRINTF("imx_serial_read: bad offset: 0x%x\n", (int)offset);
+ return 0;
+ }
+}
+
+static void imx_serial_write(void *opaque, target_phys_addr_t offset,
+ uint64_t value, unsigned size)
+{
+ IMXSerialState *s = (IMXSerialState *)opaque;
+ unsigned char ch;
+
+ DPRINTF("write(offset=%x, value = %x) to %s\n",
+ offset >> 2,
+ (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)) {
+ 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 */
+ IPRINTF("Unimplemented Register %x written to\n", offset >> 2);
+ /* TODO */
+ break;
+
+ default:
+ IPRINTF("imx_serial_write: Bad offset 0x%x\n", (int)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 int imx_serial_init(SysBusDevice *dev)
+{
+ IMXSerialState *s = FROM_SYSBUS(IMXSerialState, dev);
+
+
+ memory_region_init_io(&s->iomem, &imx_serial_ops, s, "imx-serial", 0x1000);
+ sysbus_init_mmio(dev, &s->iomem);
+ sysbus_init_irq(dev, &s->irq);
+
+ if (s->chr) {
+ qemu_chr_add_handlers(s->chr, imx_can_receive, imx_receive,
+ imx_event, s);
+ } else {
+ DPRINTF("No char dev for uart at 0x%lx\n",
+ (unsigned long)s->iomem.ram_addr);
+ }
+
+ return 0;
+}
+
+void imx_serial_create(int uart, const target_phys_addr_t addr, qemu_irq irq)
+{
+ DeviceState *dev;
+ SysBusDevice *bus;
+ CharDriverState *chr;
+ const char chr_name[] = "serial";
+ char label[ARRAY_SIZE(chr_name) + 1];
+
+ dev = qdev_create(NULL, "imx-serial");
+
+ if (uart >= MAX_SERIAL_PORTS) {
+ hw_error("Cannot assign uart %d: QEMU supports only %d ports\n",
+ uart, MAX_SERIAL_PORTS);
+ }
+ chr = serial_hds[uart];
+ if (!chr) {
+ snprintf(label, ARRAY_SIZE(label), "%s%d", chr_name, uart);
+ chr = qemu_chr_new(label, "null", NULL);
+ if (!(chr)) {
+ hw_error("Can't assign serial port to imx-uart%d.\n", uart);
+ }
+ }
+
+ qdev_prop_set_chr(dev, "chardev", chr);
+ bus = sysbus_from_qdev(dev);
+ qdev_init_nofail(dev);
+ if (addr != (target_phys_addr_t)-1) {
+ sysbus_mmio_map(bus, 0, addr);
+ }
+ sysbus_connect_irq(bus, 0, irq);
+
+}
+
+
+static Property imx32_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);
+ SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+ k->init = imx_serial_init;
+ dc->vmsd = &vmstate_imx_serial;
+ dc->reset = imx_serial_reset_at_boot;
+ dc->desc = "i.MX series UART";
+ dc->props = imx32_serial_properties;
+}
+
+static TypeInfo imx_serial_info = {
+ .name = "imx-serial",
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(IMXSerialState),
+ .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)
Index: qemu-working/Makefile.target
===================================================================
--- qemu-working.orig/Makefile.target 2012-04-03 11:48:46.012701561 +1000
+++ qemu-working/Makefile.target 2012-04-03 11:48:47.732705764 +1000
@@ -393,6 +393,7 @@ obj-arm-y += vexpress.o
obj-arm-y += strongarm.o
obj-arm-y += collie.o
obj-arm-y += pl041.o lm4549.o
+obj-arm-y += imx_serial.o
obj-arm-$(CONFIG_FDT) += device_tree.o
obj-sh4-y = shix.o r2d.o sh7750.o sh7750_regnames.o tc58128.o
Index: qemu-working/hw/imx.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ qemu-working/hw/imx.h 2012-04-03 11:48:47.732705764 +1000
@@ -0,0 +1,16 @@
+/*
+ * i.MX31 emulation
+ *
+ * Copyright (C) 2012 Peter Chubb
+ * NICTA
+ *
+ * This code is released under the GPL, version 2.0 or later
+ * See the file `../COPYING' for details.
+ */
+
+#ifndef IMX_H
+#define IMX_H
+
+void imx_serial_create(int uart, const target_phys_addr_t addr, qemu_irq irq);
+
+#endif /* IMX_H */
