qemu-e2k/hw/riscv/sifive_gpio.c
Bin Meng 621c1006d2 hw/riscv: sifive_gpio: Do not blindly trigger output IRQs
At present the GPIO output IRQs are triggered each time any GPIO
register is written. However this is not correct. We should only
trigger the output IRQ when the pin is configured as output enable.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1591625864-31494-9-git-send-email-bmeng.cn@gmail.com
Message-Id: <1591625864-31494-9-git-send-email-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2020-06-19 08:25:27 -07:00

398 lines
9.8 KiB
C

/*
* SiFive System-on-Chip general purpose input/output register definition
*
* Copyright 2019 AdaCore
*
* Base on nrf51_gpio.c:
*
* Copyright 2018 Steffen Görtz <contrib@steffen-goertz.de>
*
* This code is licensed under the GPL version 2 or later. See
* the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "hw/irq.h"
#include "hw/qdev-properties.h"
#include "hw/riscv/sifive_gpio.h"
#include "migration/vmstate.h"
#include "trace.h"
static void update_output_irq(SIFIVEGPIOState *s)
{
uint32_t pending;
uint32_t pin;
pending = s->high_ip & s->high_ie;
pending |= s->low_ip & s->low_ie;
pending |= s->rise_ip & s->rise_ie;
pending |= s->fall_ip & s->fall_ie;
for (int i = 0; i < s->ngpio; i++) {
pin = 1 << i;
qemu_set_irq(s->irq[i], (pending & pin) != 0);
trace_sifive_gpio_update_output_irq(i, (pending & pin) != 0);
}
}
static void update_state(SIFIVEGPIOState *s)
{
size_t i;
bool prev_ival, in, in_mask, port, out_xor, pull, output_en, input_en,
rise_ip, fall_ip, low_ip, high_ip, oval, actual_value, ival;
for (i = 0; i < s->ngpio; i++) {
prev_ival = extract32(s->value, i, 1);
in = extract32(s->in, i, 1);
in_mask = extract32(s->in_mask, i, 1);
port = extract32(s->port, i, 1);
out_xor = extract32(s->out_xor, i, 1);
pull = extract32(s->pue, i, 1);
output_en = extract32(s->output_en, i, 1);
input_en = extract32(s->input_en, i, 1);
rise_ip = extract32(s->rise_ip, i, 1);
fall_ip = extract32(s->fall_ip, i, 1);
low_ip = extract32(s->low_ip, i, 1);
high_ip = extract32(s->high_ip, i, 1);
/* Output value (IOF not supported) */
oval = output_en && (port ^ out_xor);
/* Pin both driven externally and internally */
if (output_en && in_mask) {
qemu_log_mask(LOG_GUEST_ERROR, "GPIO pin %zu short circuited\n", i);
}
if (in_mask) {
/* The pin is driven by external device */
actual_value = in;
} else if (output_en) {
/* The pin is driven by internal circuit */
actual_value = oval;
} else {
/* Floating? Apply pull-up resistor */
actual_value = pull;
}
if (output_en) {
qemu_set_irq(s->output[i], actual_value);
}
/* Input value */
ival = input_en && actual_value;
/* Interrupts */
high_ip = high_ip || ival;
s->high_ip = deposit32(s->high_ip, i, 1, high_ip);
low_ip = low_ip || !ival;
s->low_ip = deposit32(s->low_ip, i, 1, low_ip);
rise_ip = rise_ip || (ival && !prev_ival);
s->rise_ip = deposit32(s->rise_ip, i, 1, rise_ip);
fall_ip = fall_ip || (!ival && prev_ival);
s->fall_ip = deposit32(s->fall_ip, i, 1, fall_ip);
/* Update value */
s->value = deposit32(s->value, i, 1, ival);
}
update_output_irq(s);
}
static uint64_t sifive_gpio_read(void *opaque, hwaddr offset, unsigned int size)
{
SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
uint64_t r = 0;
switch (offset) {
case SIFIVE_GPIO_REG_VALUE:
r = s->value;
break;
case SIFIVE_GPIO_REG_INPUT_EN:
r = s->input_en;
break;
case SIFIVE_GPIO_REG_OUTPUT_EN:
r = s->output_en;
break;
case SIFIVE_GPIO_REG_PORT:
r = s->port;
break;
case SIFIVE_GPIO_REG_PUE:
r = s->pue;
break;
case SIFIVE_GPIO_REG_DS:
r = s->ds;
break;
case SIFIVE_GPIO_REG_RISE_IE:
r = s->rise_ie;
break;
case SIFIVE_GPIO_REG_RISE_IP:
r = s->rise_ip;
break;
case SIFIVE_GPIO_REG_FALL_IE:
r = s->fall_ie;
break;
case SIFIVE_GPIO_REG_FALL_IP:
r = s->fall_ip;
break;
case SIFIVE_GPIO_REG_HIGH_IE:
r = s->high_ie;
break;
case SIFIVE_GPIO_REG_HIGH_IP:
r = s->high_ip;
break;
case SIFIVE_GPIO_REG_LOW_IE:
r = s->low_ie;
break;
case SIFIVE_GPIO_REG_LOW_IP:
r = s->low_ip;
break;
case SIFIVE_GPIO_REG_IOF_EN:
r = s->iof_en;
break;
case SIFIVE_GPIO_REG_IOF_SEL:
r = s->iof_sel;
break;
case SIFIVE_GPIO_REG_OUT_XOR:
r = s->out_xor;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: bad read offset 0x%" HWADDR_PRIx "\n",
__func__, offset);
}
trace_sifive_gpio_read(offset, r);
return r;
}
static void sifive_gpio_write(void *opaque, hwaddr offset,
uint64_t value, unsigned int size)
{
SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
trace_sifive_gpio_write(offset, value);
switch (offset) {
case SIFIVE_GPIO_REG_INPUT_EN:
s->input_en = value;
break;
case SIFIVE_GPIO_REG_OUTPUT_EN:
s->output_en = value;
break;
case SIFIVE_GPIO_REG_PORT:
s->port = value;
break;
case SIFIVE_GPIO_REG_PUE:
s->pue = value;
break;
case SIFIVE_GPIO_REG_DS:
s->ds = value;
break;
case SIFIVE_GPIO_REG_RISE_IE:
s->rise_ie = value;
break;
case SIFIVE_GPIO_REG_RISE_IP:
/* Write 1 to clear */
s->rise_ip &= ~value;
break;
case SIFIVE_GPIO_REG_FALL_IE:
s->fall_ie = value;
break;
case SIFIVE_GPIO_REG_FALL_IP:
/* Write 1 to clear */
s->fall_ip &= ~value;
break;
case SIFIVE_GPIO_REG_HIGH_IE:
s->high_ie = value;
break;
case SIFIVE_GPIO_REG_HIGH_IP:
/* Write 1 to clear */
s->high_ip &= ~value;
break;
case SIFIVE_GPIO_REG_LOW_IE:
s->low_ie = value;
break;
case SIFIVE_GPIO_REG_LOW_IP:
/* Write 1 to clear */
s->low_ip &= ~value;
break;
case SIFIVE_GPIO_REG_IOF_EN:
s->iof_en = value;
break;
case SIFIVE_GPIO_REG_IOF_SEL:
s->iof_sel = value;
break;
case SIFIVE_GPIO_REG_OUT_XOR:
s->out_xor = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: bad write offset 0x%" HWADDR_PRIx "\n",
__func__, offset);
}
update_state(s);
}
static const MemoryRegionOps gpio_ops = {
.read = sifive_gpio_read,
.write = sifive_gpio_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.impl.min_access_size = 4,
.impl.max_access_size = 4,
};
static void sifive_gpio_set(void *opaque, int line, int value)
{
SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
trace_sifive_gpio_set(line, value);
assert(line >= 0 && line < SIFIVE_GPIO_PINS);
s->in_mask = deposit32(s->in_mask, line, 1, value >= 0);
if (value >= 0) {
s->in = deposit32(s->in, line, 1, value != 0);
}
update_state(s);
}
static void sifive_gpio_reset(DeviceState *dev)
{
SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
s->value = 0;
s->input_en = 0;
s->output_en = 0;
s->port = 0;
s->pue = 0;
s->ds = 0;
s->rise_ie = 0;
s->rise_ip = 0;
s->fall_ie = 0;
s->fall_ip = 0;
s->high_ie = 0;
s->high_ip = 0;
s->low_ie = 0;
s->low_ip = 0;
s->iof_en = 0;
s->iof_sel = 0;
s->out_xor = 0;
s->in = 0;
s->in_mask = 0;
}
static const VMStateDescription vmstate_sifive_gpio = {
.name = TYPE_SIFIVE_GPIO,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(value, SIFIVEGPIOState),
VMSTATE_UINT32(input_en, SIFIVEGPIOState),
VMSTATE_UINT32(output_en, SIFIVEGPIOState),
VMSTATE_UINT32(port, SIFIVEGPIOState),
VMSTATE_UINT32(pue, SIFIVEGPIOState),
VMSTATE_UINT32(rise_ie, SIFIVEGPIOState),
VMSTATE_UINT32(rise_ip, SIFIVEGPIOState),
VMSTATE_UINT32(fall_ie, SIFIVEGPIOState),
VMSTATE_UINT32(fall_ip, SIFIVEGPIOState),
VMSTATE_UINT32(high_ie, SIFIVEGPIOState),
VMSTATE_UINT32(high_ip, SIFIVEGPIOState),
VMSTATE_UINT32(low_ie, SIFIVEGPIOState),
VMSTATE_UINT32(low_ip, SIFIVEGPIOState),
VMSTATE_UINT32(iof_en, SIFIVEGPIOState),
VMSTATE_UINT32(iof_sel, SIFIVEGPIOState),
VMSTATE_UINT32(out_xor, SIFIVEGPIOState),
VMSTATE_UINT32(in, SIFIVEGPIOState),
VMSTATE_UINT32(in_mask, SIFIVEGPIOState),
VMSTATE_END_OF_LIST()
}
};
static Property sifive_gpio_properties[] = {
DEFINE_PROP_UINT32("ngpio", SIFIVEGPIOState, ngpio, SIFIVE_GPIO_PINS),
DEFINE_PROP_END_OF_LIST(),
};
static void sifive_gpio_realize(DeviceState *dev, Error **errp)
{
SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
memory_region_init_io(&s->mmio, OBJECT(dev), &gpio_ops, s,
TYPE_SIFIVE_GPIO, SIFIVE_GPIO_SIZE);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
for (int i = 0; i < s->ngpio; i++) {
sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[i]);
}
qdev_init_gpio_in(DEVICE(s), sifive_gpio_set, s->ngpio);
qdev_init_gpio_out(DEVICE(s), s->output, s->ngpio);
}
static void sifive_gpio_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
device_class_set_props(dc, sifive_gpio_properties);
dc->vmsd = &vmstate_sifive_gpio;
dc->realize = sifive_gpio_realize;
dc->reset = sifive_gpio_reset;
dc->desc = "SiFive GPIO";
}
static const TypeInfo sifive_gpio_info = {
.name = TYPE_SIFIVE_GPIO,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SIFIVEGPIOState),
.class_init = sifive_gpio_class_init
};
static void sifive_gpio_register_types(void)
{
type_register_static(&sifive_gpio_info);
}
type_init(sifive_gpio_register_types)