[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [RFC PATCH 2/2] hw/char/bcm2835_aux: Provide full 16550 UAR
|
From: |
Philippe Mathieu-Daudé |
|
Subject: |
[Qemu-devel] [RFC PATCH 2/2] hw/char/bcm2835_aux: Provide full 16550 UART support |
|
Date: |
Tue, 20 Aug 2019 14:34:17 +0200 |
From: Philippe Mathieu-Daudé <address@hidden>
The BCM2835 AUX UART is compatible with the 16650 model.
Since a such model is already available and tested, reuse
it.
TODO:
- The serial model hardcodes a 16B FIFO (16550A) while
this model is a 8B FIFO
- Various 16550A register bits are not implemented, thus
require to be properly masked
- How to keep migration working?
- How to use a chardev property?
Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
hw/arm/bcm2835_peripherals.c | 2 -
hw/char/bcm2835_aux.c | 211 +++-------------------------------
include/hw/char/bcm2835_aux.h | 7 +-
3 files changed, 20 insertions(+), 200 deletions(-)
diff --git a/hw/arm/bcm2835_peripherals.c b/hw/arm/bcm2835_peripherals.c
index 8984e2e91f..dbe396fd40 100644
--- a/hw/arm/bcm2835_peripherals.c
+++ b/hw/arm/bcm2835_peripherals.c
@@ -167,8 +167,6 @@ 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 */
- qdev_prop_set_chr(DEVICE(&s->aux), "chardev", serial_hd(1));
-
object_property_set_bool(OBJECT(&s->aux), true, "realized", &err);
if (err) {
error_propagate(errp, err);
diff --git a/hw/char/bcm2835_aux.c b/hw/char/bcm2835_aux.c
index 3f855196e3..10154b9530 100644
--- a/hw/char/bcm2835_aux.c
+++ b/hw/char/bcm2835_aux.c
@@ -2,149 +2,56 @@
* 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"
-#include "hw/irq.h"
-#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "qemu/log.h"
-#include "qemu/module.h"
+#include "sysemu/sysemu.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_REGS 0x40
#define AUX_MU_CNTL_REG 0x60
#define AUX_MU_STAT_REG 0x64
#define AUX_MU_BAUD_REG 0x68
-/* bits in IER/IIR registers */
-#define RX_INT 0x1
-#define TX_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;
+ uint32_t res;
switch (offset) {
case AUX_IRQ:
- return s->iir != 0;
+ return s->serial->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;
- }
- }
- qemu_chr_fe_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 */
- }
+ res |= fifo8_num_used(&s->serial->xmit_fifo) << 24;
+ res |= fifo8_num_used(&s->serial->recv_fifo) << 16;
+ res |= fifo8_is_empty(&s->serial->xmit_fifo) << 8;
+ res |= fifo8_is_full(&s->serial->xmit_fifo) << 5;
+ res |= fifo8_is_full(&s->serial->recv_fifo) << 4;
+ res |= !fifo8_is_full(&s->serial->xmit_fifo) << 1;
+ res |= !fifo8_is_empty(&s->serial->recv_fifo) << 0;
return res;
case AUX_MU_BAUD_REG:
- qemu_log_mask(LOG_UNIMP, "%s: AUX_MU_BAUD_REG unsupported\n",
__func__);
- return 0;
+ return s->serial->divider;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
@@ -157,7 +64,6 @@ 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:
@@ -167,81 +73,18 @@ static void bcm2835_aux_write(void *opaque, hwaddr offset,
uint64_t value,
}
break;
- case AUX_MU_IO_REG:
- /* "DLAB bit set means access baudrate register" is NYI */
- ch = value;
- /* XXX this blocks entire thread. Rewrite to use
- * qemu_chr_fe_write and background I/O callbacks */
- qemu_chr_fe_write_all(&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__);
+ serial_set_divider(s->serial, value);
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 = {
@@ -254,15 +97,9 @@ static const MemoryRegionOps bcm2835_aux_ops = {
static const VMStateDescription vmstate_bcm2835_aux = {
.name = TYPE_BCM2835_AUX,
- .version_id = 1,
- .minimum_version_id = 1,
+ .version_id = 2,
+ .minimum_version_id = 2,
.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()
}
};
@@ -276,29 +113,17 @@ static void bcm2835_aux_init(Object *obj)
TYPE_BCM2835_AUX, 0x100);
sysbus_init_mmio(sbd, &s->iomem);
sysbus_init_irq(sbd, &s->irq);
+
+ s->serial = serial_mm_init(&s->iomem, AUX_MU_REGS, 2, s->irq, 2419200,
+ serial_hd(1), DEVICE_LITTLE_ENDIAN);
}
-static void bcm2835_aux_realize(DeviceState *dev, Error **errp)
-{
- BCM2835AuxState *s = BCM2835_AUX(dev);
-
- qemu_chr_fe_set_handlers(&s->chr, bcm2835_aux_can_receive,
- bcm2835_aux_receive, NULL, NULL, s, NULL, true);
-}
-
-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 = {
diff --git a/include/hw/char/bcm2835_aux.h b/include/hw/char/bcm2835_aux.h
index cdbf7e3e37..f534bccf5d 100644
--- a/include/hw/char/bcm2835_aux.h
+++ b/include/hw/char/bcm2835_aux.h
@@ -9,6 +9,7 @@
#define BCM2835_AUX_H
#include "hw/sysbus.h"
+#include "hw/char/serial.h"
#include "chardev/char-fe.h"
#define TYPE_BCM2835_AUX "bcm2835-aux"
@@ -22,12 +23,8 @@ typedef struct {
/*< public >*/
MemoryRegion iomem;
- CharBackend chr;
qemu_irq irq;
-
- uint8_t read_fifo[BCM2835_AUX_RX_FIFO_LEN];
- uint8_t read_pos, read_count;
- uint8_t ier, iir;
+ SerialState *serial;
} BCM2835AuxState;
#endif
--
2.20.1