bcm2835_aux: add emulation of BCM2835 AUX (aka UART1) block

At present only the core UART functions (data path for tx/rx) are
implemented, which is enough for UEFI to boot. The following
features/registers are unimplemented:
  * Line/modem control
  * Scratch register
  * Extra control
  * Baudrate
  * SPI interfaces

Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1457467526-8840-3-git-send-email-Andrew.Baumann@microsoft.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Andrew Baumann 2016-03-16 17:06:01 +00:00 committed by Peter Maydell
parent a2a8dfa8d8
commit 97398d900c
5 changed files with 384 additions and 0 deletions

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@ -12,6 +12,7 @@
#include "hw/arm/bcm2835_peripherals.h"
#include "hw/misc/bcm2835_mbox_defs.h"
#include "hw/arm/raspi_platform.h"
#include "sysemu/char.h"
/* Peripheral base address on the VC (GPU) system bus */
#define BCM2835_VC_PERI_BASE 0x7e000000
@ -48,6 +49,11 @@ static void bcm2835_peripherals_init(Object *obj)
object_property_add_child(obj, "uart0", OBJECT(s->uart0), NULL);
qdev_set_parent_bus(DEVICE(s->uart0), sysbus_get_default());
/* AUX / UART1 */
object_initialize(&s->aux, sizeof(s->aux), TYPE_BCM2835_AUX);
object_property_add_child(obj, "aux", OBJECT(&s->aux), NULL);
qdev_set_parent_bus(DEVICE(&s->aux), sysbus_get_default());
/* Mailboxes */
object_initialize(&s->mboxes, sizeof(s->mboxes), TYPE_BCM2835_MBOX);
object_property_add_child(obj, "mbox", OBJECT(&s->mboxes), NULL);
@ -79,6 +85,7 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
MemoryRegion *ram;
Error *err = NULL;
uint32_t ram_size;
CharDriverState *chr;
int n;
obj = object_property_get_link(OBJECT(dev), "ram", &err);
@ -131,6 +138,29 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
qdev_get_gpio_in_named(DEVICE(&s->ic), BCM2835_IC_GPU_IRQ,
INTERRUPT_UART));
/* AUX / UART1 */
/* TODO: don't call qemu_char_get_next_serial() here, instead set
* chardev properties for each uart at the board level, once pl011
* (uart0) has been updated to avoid qemu_char_get_next_serial()
*/
chr = qemu_char_get_next_serial();
if (chr == NULL) {
chr = qemu_chr_new("bcm2835.uart1", "null", NULL);
}
qdev_prop_set_chr(DEVICE(&s->aux), "chardev", chr);
object_property_set_bool(OBJECT(&s->aux), true, "realized", &err);
if (err) {
error_propagate(errp, err);
return;
}
memory_region_add_subregion(&s->peri_mr, UART1_OFFSET,
sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->aux), 0));
sysbus_connect_irq(SYS_BUS_DEVICE(&s->aux), 0,
qdev_get_gpio_in_named(DEVICE(&s->ic), BCM2835_IC_GPU_IRQ,
INTERRUPT_AUX));
/* Mailboxes */
object_property_set_bool(OBJECT(&s->mboxes), true, "realized", &err);
if (err) {
@ -203,6 +233,8 @@ static void bcm2835_peripherals_class_init(ObjectClass *oc, void *data)
DeviceClass *dc = DEVICE_CLASS(oc);
dc->realize = bcm2835_peripherals_realize;
/* Reason: realize() method uses qemu_char_get_next_serial() */
dc->cannot_instantiate_with_device_add_yet = true;
}
static const TypeInfo bcm2835_peripherals_type_info = {

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@ -16,6 +16,7 @@ obj-$(CONFIG_SH4) += sh_serial.o
obj-$(CONFIG_PSERIES) += spapr_vty.o
obj-$(CONFIG_DIGIC) += digic-uart.o
obj-$(CONFIG_STM32F2XX_USART) += stm32f2xx_usart.o
obj-$(CONFIG_RASPI) += bcm2835_aux.o
common-obj-$(CONFIG_ETRAXFS) += etraxfs_ser.o
common-obj-$(CONFIG_ISA_DEBUG) += debugcon.o

316
hw/char/bcm2835_aux.c Normal file
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@ -0,0 +1,316 @@
/*
* BCM2835 (Raspberry Pi / Pi 2) Aux block (mini UART and SPI).
* Copyright (c) 2015, Microsoft
* Written by Andrew Baumann
* Based on pl011.c, copyright terms below:
*
* Arm PrimeCell PL011 UART
*
* Copyright (c) 2006 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the GPL.
*
* At present only the core UART functions (data path for tx/rx) are
* implemented. The following features/registers are unimplemented:
* - Line/modem control
* - Scratch register
* - Extra control
* - Baudrate
* - SPI interfaces
*/
#include "qemu/osdep.h"
#include "hw/char/bcm2835_aux.h"
#define AUX_IRQ 0x0
#define AUX_ENABLES 0x4
#define AUX_MU_IO_REG 0x40
#define AUX_MU_IER_REG 0x44
#define AUX_MU_IIR_REG 0x48
#define AUX_MU_LCR_REG 0x4c
#define AUX_MU_MCR_REG 0x50
#define AUX_MU_LSR_REG 0x54
#define AUX_MU_MSR_REG 0x58
#define AUX_MU_SCRATCH 0x5c
#define AUX_MU_CNTL_REG 0x60
#define AUX_MU_STAT_REG 0x64
#define AUX_MU_BAUD_REG 0x68
/* bits in IER/IIR registers */
#define TX_INT 0x1
#define RX_INT 0x2
static void bcm2835_aux_update(BCM2835AuxState *s)
{
/* signal an interrupt if either:
* 1. rx interrupt is enabled and we have a non-empty rx fifo, or
* 2. the tx interrupt is enabled (since we instantly drain the tx fifo)
*/
s->iir = 0;
if ((s->ier & RX_INT) && s->read_count != 0) {
s->iir |= RX_INT;
}
if (s->ier & TX_INT) {
s->iir |= TX_INT;
}
qemu_set_irq(s->irq, s->iir != 0);
}
static uint64_t bcm2835_aux_read(void *opaque, hwaddr offset, unsigned size)
{
BCM2835AuxState *s = opaque;
uint32_t c, res;
switch (offset) {
case AUX_IRQ:
return s->iir != 0;
case AUX_ENABLES:
return 1; /* mini UART permanently enabled */
case AUX_MU_IO_REG:
/* "DLAB bit set means access baudrate register" is NYI */
c = s->read_fifo[s->read_pos];
if (s->read_count > 0) {
s->read_count--;
if (++s->read_pos == BCM2835_AUX_RX_FIFO_LEN) {
s->read_pos = 0;
}
}
if (s->chr) {
qemu_chr_accept_input(s->chr);
}
bcm2835_aux_update(s);
return c;
case AUX_MU_IER_REG:
/* "DLAB bit set means access baudrate register" is NYI */
return 0xc0 | s->ier; /* FIFO enables always read 1 */
case AUX_MU_IIR_REG:
res = 0xc0; /* FIFO enables */
/* The spec is unclear on what happens when both tx and rx
* interrupts are active, besides that this cannot occur. At
* present, we choose to prioritise the rx interrupt, since
* the tx fifo is always empty. */
if (s->read_count != 0) {
res |= 0x4;
} else {
res |= 0x2;
}
if (s->iir == 0) {
res |= 0x1;
}
return res;
case AUX_MU_LCR_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_LCR_REG unsupported\n", __func__);
return 0;
case AUX_MU_MCR_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_MCR_REG unsupported\n", __func__);
return 0;
case AUX_MU_LSR_REG:
res = 0x60; /* tx idle, empty */
if (s->read_count != 0) {
res |= 0x1;
}
return res;
case AUX_MU_MSR_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_MSR_REG unsupported\n", __func__);
return 0;
case AUX_MU_SCRATCH:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_SCRATCH unsupported\n", __func__);
return 0;
case AUX_MU_CNTL_REG:
return 0x3; /* tx, rx enabled */
case AUX_MU_STAT_REG:
res = 0x30e; /* space in the output buffer, empty tx fifo, idle tx/rx */
if (s->read_count > 0) {
res |= 0x1; /* data in input buffer */
assert(s->read_count < BCM2835_AUX_RX_FIFO_LEN);
res |= ((uint32_t)s->read_count) << 16; /* rx fifo fill level */
}
return res;
case AUX_MU_BAUD_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_BAUD_REG unsupported\n", __func__);
return 0;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
return 0;
}
}
static void bcm2835_aux_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
BCM2835AuxState *s = opaque;
unsigned char ch;
switch (offset) {
case AUX_ENABLES:
if (value != 1) {
qemu_log_mask(LOG_UNIMP, "%s: unsupported attempt to enable SPI "
"or disable UART\n", __func__);
}
break;
case AUX_MU_IO_REG:
/* "DLAB bit set means access baudrate register" is NYI */
ch = value;
if (s->chr) {
qemu_chr_fe_write(s->chr, &ch, 1);
}
break;
case AUX_MU_IER_REG:
/* "DLAB bit set means access baudrate register" is NYI */
s->ier = value & (TX_INT | RX_INT);
bcm2835_aux_update(s);
break;
case AUX_MU_IIR_REG:
if (value & 0x2) {
s->read_count = 0;
}
break;
case AUX_MU_LCR_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_LCR_REG unsupported\n", __func__);
break;
case AUX_MU_MCR_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_MCR_REG unsupported\n", __func__);
break;
case AUX_MU_SCRATCH:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_SCRATCH unsupported\n", __func__);
break;
case AUX_MU_CNTL_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_CNTL_REG unsupported\n", __func__);
break;
case AUX_MU_BAUD_REG:
qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_BAUD_REG unsupported\n", __func__);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
__func__, offset);
}
bcm2835_aux_update(s);
}
static int bcm2835_aux_can_receive(void *opaque)
{
BCM2835AuxState *s = opaque;
return s->read_count < BCM2835_AUX_RX_FIFO_LEN;
}
static void bcm2835_aux_put_fifo(void *opaque, uint8_t value)
{
BCM2835AuxState *s = opaque;
int slot;
slot = s->read_pos + s->read_count;
if (slot >= BCM2835_AUX_RX_FIFO_LEN) {
slot -= BCM2835_AUX_RX_FIFO_LEN;
}
s->read_fifo[slot] = value;
s->read_count++;
if (s->read_count == BCM2835_AUX_RX_FIFO_LEN) {
/* buffer full */
}
bcm2835_aux_update(s);
}
static void bcm2835_aux_receive(void *opaque, const uint8_t *buf, int size)
{
bcm2835_aux_put_fifo(opaque, *buf);
}
static const MemoryRegionOps bcm2835_aux_ops = {
.read = bcm2835_aux_read,
.write = bcm2835_aux_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
};
static const VMStateDescription vmstate_bcm2835_aux = {
.name = TYPE_BCM2835_AUX,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8_ARRAY(read_fifo, BCM2835AuxState,
BCM2835_AUX_RX_FIFO_LEN),
VMSTATE_UINT8(read_pos, BCM2835AuxState),
VMSTATE_UINT8(read_count, BCM2835AuxState),
VMSTATE_UINT8(ier, BCM2835AuxState),
VMSTATE_UINT8(iir, BCM2835AuxState),
VMSTATE_END_OF_LIST()
}
};
static void bcm2835_aux_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
BCM2835AuxState *s = BCM2835_AUX(obj);
memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_aux_ops, s,
TYPE_BCM2835_AUX, 0x100);
sysbus_init_mmio(sbd, &s->iomem);
sysbus_init_irq(sbd, &s->irq);
}
static void bcm2835_aux_realize(DeviceState *dev, Error **errp)
{
BCM2835AuxState *s = BCM2835_AUX(dev);
if (s->chr) {
qemu_chr_add_handlers(s->chr, bcm2835_aux_can_receive,
bcm2835_aux_receive, NULL, s);
}
}
static Property bcm2835_aux_props[] = {
DEFINE_PROP_CHR("chardev", BCM2835AuxState, chr),
DEFINE_PROP_END_OF_LIST(),
};
static void bcm2835_aux_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
dc->realize = bcm2835_aux_realize;
dc->vmsd = &vmstate_bcm2835_aux;
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
dc->props = bcm2835_aux_props;
}
static const TypeInfo bcm2835_aux_info = {
.name = TYPE_BCM2835_AUX,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(BCM2835AuxState),
.instance_init = bcm2835_aux_init,
.class_init = bcm2835_aux_class_init,
};
static void bcm2835_aux_register_types(void)
{
type_register_static(&bcm2835_aux_info);
}
type_init(bcm2835_aux_register_types)

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@ -14,6 +14,7 @@
#include "qemu-common.h"
#include "exec/address-spaces.h"
#include "hw/sysbus.h"
#include "hw/char/bcm2835_aux.h"
#include "hw/intc/bcm2835_ic.h"
#include "hw/misc/bcm2835_property.h"
#include "hw/misc/bcm2835_mbox.h"
@ -33,6 +34,7 @@ typedef struct BCM2835PeripheralState {
qemu_irq irq, fiq;
SysBusDevice *uart0;
BCM2835AuxState aux;
BCM2835ICState ic;
BCM2835PropertyState property;
BCM2835MboxState mboxes;

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@ -0,0 +1,33 @@
/*
* Rasperry Pi 2 emulation and refactoring Copyright (c) 2015, Microsoft
* Written by Andrew Baumann
*
* This code is licensed under the GNU GPLv2 and later.
*/
#ifndef BCM2835_AUX_H
#define BCM2835_AUX_H
#include "hw/sysbus.h"
#include "sysemu/char.h"
#define TYPE_BCM2835_AUX "bcm2835-aux"
#define BCM2835_AUX(obj) OBJECT_CHECK(BCM2835AuxState, (obj), TYPE_BCM2835_AUX)
#define BCM2835_AUX_RX_FIFO_LEN 8
typedef struct {
/*< private >*/
SysBusDevice parent_obj;
/*< public >*/
MemoryRegion iomem;
CharDriverState *chr;
qemu_irq irq;
uint8_t read_fifo[BCM2835_AUX_RX_FIFO_LEN];
uint8_t read_pos, read_count;
uint8_t ier, iir;
} BCM2835AuxState;
#endif