blob: 63b8763e9d3572c7d0fb12284351632216c9ea9d [file] [log] [blame]
/*
* STM32L4x5 GPIO (General Purpose Input/Ouput)
*
* Copyright (c) 2024 Arnaud Minier <arnaud.minier@telecom-paris.fr>
* Copyright (c) 2024 Inès Varhol <ines.varhol@telecom-paris.fr>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
/*
* The reference used is the STMicroElectronics RM0351 Reference manual
* for STM32L4x5 and STM32L4x6 advanced Arm ® -based 32-bit MCUs.
* https://www.st.com/en/microcontrollers-microprocessors/stm32l4x5/documentation.html
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "hw/gpio/stm32l4x5_gpio.h"
#include "hw/irq.h"
#include "hw/qdev-clock.h"
#include "hw/qdev-properties.h"
#include "qapi/visitor.h"
#include "qapi/error.h"
#include "migration/vmstate.h"
#include "trace.h"
#define GPIO_MODER 0x00
#define GPIO_OTYPER 0x04
#define GPIO_OSPEEDR 0x08
#define GPIO_PUPDR 0x0C
#define GPIO_IDR 0x10
#define GPIO_ODR 0x14
#define GPIO_BSRR 0x18
#define GPIO_LCKR 0x1C
#define GPIO_AFRL 0x20
#define GPIO_AFRH 0x24
#define GPIO_BRR 0x28
#define GPIO_ASCR 0x2C
/* 0b11111111_11111111_00000000_00000000 */
#define RESERVED_BITS_MASK 0xFFFF0000
static void update_gpio_idr(Stm32l4x5GpioState *s);
static bool is_pull_up(Stm32l4x5GpioState *s, unsigned pin)
{
return extract32(s->pupdr, 2 * pin, 2) == 1;
}
static bool is_pull_down(Stm32l4x5GpioState *s, unsigned pin)
{
return extract32(s->pupdr, 2 * pin, 2) == 2;
}
static bool is_output(Stm32l4x5GpioState *s, unsigned pin)
{
return extract32(s->moder, 2 * pin, 2) == 1;
}
static bool is_open_drain(Stm32l4x5GpioState *s, unsigned pin)
{
return extract32(s->otyper, pin, 1) == 1;
}
static bool is_push_pull(Stm32l4x5GpioState *s, unsigned pin)
{
return extract32(s->otyper, pin, 1) == 0;
}
static void stm32l4x5_gpio_reset_hold(Object *obj)
{
Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj);
s->moder = s->moder_reset;
s->otyper = 0x00000000;
s->ospeedr = s->ospeedr_reset;
s->pupdr = s->pupdr_reset;
s->idr = 0x00000000;
s->odr = 0x00000000;
s->lckr = 0x00000000;
s->afrl = 0x00000000;
s->afrh = 0x00000000;
s->ascr = 0x00000000;
s->disconnected_pins = 0xFFFF;
s->pins_connected_high = 0x0000;
update_gpio_idr(s);
}
static void stm32l4x5_gpio_set(void *opaque, int line, int level)
{
Stm32l4x5GpioState *s = opaque;
/*
* The pin isn't set if line is configured in output mode
* except if level is 0 and the output is open-drain.
* This way there will be no short-circuit prone situations.
*/
if (is_output(s, line) && !(is_open_drain(s, line) && (level == 0))) {
qemu_log_mask(LOG_GUEST_ERROR, "Line %d can't be driven externally\n",
line);
return;
}
s->disconnected_pins &= ~(1 << line);
if (level) {
s->pins_connected_high |= (1 << line);
} else {
s->pins_connected_high &= ~(1 << line);
}
trace_stm32l4x5_gpio_pins(s->name, s->disconnected_pins,
s->pins_connected_high);
update_gpio_idr(s);
}
static void update_gpio_idr(Stm32l4x5GpioState *s)
{
uint32_t new_idr_mask = 0;
uint32_t new_idr = s->odr;
uint32_t old_idr = s->idr;
int new_pin_state, old_pin_state;
for (int i = 0; i < GPIO_NUM_PINS; i++) {
if (is_output(s, i)) {
if (is_push_pull(s, i)) {
new_idr_mask |= (1 << i);
} else if (!(s->odr & (1 << i))) {
/* open-drain ODR 0 */
new_idr_mask |= (1 << i);
/* open-drain ODR 1 */
} else if (!(s->disconnected_pins & (1 << i)) &&
!(s->pins_connected_high & (1 << i))) {
/* open-drain ODR 1 with pin connected low */
new_idr_mask |= (1 << i);
new_idr &= ~(1 << i);
/* open-drain ODR 1 with unactive pin */
} else if (is_pull_up(s, i)) {
new_idr_mask |= (1 << i);
} else if (is_pull_down(s, i)) {
new_idr_mask |= (1 << i);
new_idr &= ~(1 << i);
}
/*
* The only case left is for open-drain ODR 1
* with unactive pin without pull-up or pull-down :
* the value is floating.
*/
/* input or analog mode with connected pin */
} else if (!(s->disconnected_pins & (1 << i))) {
if (s->pins_connected_high & (1 << i)) {
/* pin high */
new_idr_mask |= (1 << i);
new_idr |= (1 << i);
} else {
/* pin low */
new_idr_mask |= (1 << i);
new_idr &= ~(1 << i);
}
/* input or analog mode with disconnected pin */
} else {
if (is_pull_up(s, i)) {
/* pull-up */
new_idr_mask |= (1 << i);
new_idr |= (1 << i);
} else if (is_pull_down(s, i)) {
/* pull-down */
new_idr_mask |= (1 << i);
new_idr &= ~(1 << i);
}
/*
* The only case left is for a disconnected pin
* without pull-up or pull-down :
* the value is floating.
*/
}
}
s->idr = (old_idr & ~new_idr_mask) | (new_idr & new_idr_mask);
trace_stm32l4x5_gpio_update_idr(s->name, old_idr, s->idr);
for (int i = 0; i < GPIO_NUM_PINS; i++) {
if (new_idr_mask & (1 << i)) {
new_pin_state = (new_idr & (1 << i)) > 0;
old_pin_state = (old_idr & (1 << i)) > 0;
if (new_pin_state > old_pin_state) {
qemu_irq_raise(s->pin[i]);
} else if (new_pin_state < old_pin_state) {
qemu_irq_lower(s->pin[i]);
}
}
}
}
/*
* Return mask of pins that are both configured in output
* mode and externally driven (except pins in open-drain
* mode externally set to 0).
*/
static uint32_t get_gpio_pinmask_to_disconnect(Stm32l4x5GpioState *s)
{
uint32_t pins_to_disconnect = 0;
for (int i = 0; i < GPIO_NUM_PINS; i++) {
/* for each connected pin in output mode */
if (!(s->disconnected_pins & (1 << i)) && is_output(s, i)) {
/* if either push-pull or high level */
if (is_push_pull(s, i) || s->pins_connected_high & (1 << i)) {
pins_to_disconnect |= (1 << i);
qemu_log_mask(LOG_GUEST_ERROR,
"Line %d can't be driven externally\n",
i);
}
}
}
return pins_to_disconnect;
}
/*
* Set field `disconnected_pins` and call `update_gpio_idr()`
*/
static void disconnect_gpio_pins(Stm32l4x5GpioState *s, uint16_t lines)
{
s->disconnected_pins |= lines;
trace_stm32l4x5_gpio_pins(s->name, s->disconnected_pins,
s->pins_connected_high);
update_gpio_idr(s);
}
static void disconnected_pins_set(Object *obj, Visitor *v,
const char *name, void *opaque, Error **errp)
{
Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj);
uint16_t value;
if (!visit_type_uint16(v, name, &value, errp)) {
return;
}
disconnect_gpio_pins(s, value);
}
static void disconnected_pins_get(Object *obj, Visitor *v,
const char *name, void *opaque, Error **errp)
{
visit_type_uint16(v, name, (uint16_t *)opaque, errp);
}
static void clock_freq_get(Object *obj, Visitor *v,
const char *name, void *opaque, Error **errp)
{
Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj);
uint32_t clock_freq_hz = clock_get_hz(s->clk);
visit_type_uint32(v, name, &clock_freq_hz, errp);
}
static void stm32l4x5_gpio_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
Stm32l4x5GpioState *s = opaque;
uint32_t value = val64;
trace_stm32l4x5_gpio_write(s->name, addr, val64);
switch (addr) {
case GPIO_MODER:
s->moder = value;
disconnect_gpio_pins(s, get_gpio_pinmask_to_disconnect(s));
qemu_log_mask(LOG_UNIMP,
"%s: Analog and AF modes aren't supported\n\
Analog and AF mode behave like input mode\n",
__func__);
return;
case GPIO_OTYPER:
s->otyper = value & ~RESERVED_BITS_MASK;
disconnect_gpio_pins(s, get_gpio_pinmask_to_disconnect(s));
return;
case GPIO_OSPEEDR:
qemu_log_mask(LOG_UNIMP,
"%s: Changing I/O output speed isn't supported\n\
I/O speed is already maximal\n",
__func__);
s->ospeedr = value;
return;
case GPIO_PUPDR:
s->pupdr = value;
update_gpio_idr(s);
return;
case GPIO_IDR:
qemu_log_mask(LOG_UNIMP,
"%s: GPIO->IDR is read-only\n",
__func__);
return;
case GPIO_ODR:
s->odr = value & ~RESERVED_BITS_MASK;
update_gpio_idr(s);
return;
case GPIO_BSRR: {
uint32_t bits_to_reset = (value & RESERVED_BITS_MASK) >> GPIO_NUM_PINS;
uint32_t bits_to_set = value & ~RESERVED_BITS_MASK;
/* If both BSx and BRx are set, BSx has priority.*/
s->odr &= ~bits_to_reset;
s->odr |= bits_to_set;
update_gpio_idr(s);
return;
}
case GPIO_LCKR:
qemu_log_mask(LOG_UNIMP,
"%s: Locking port bits configuration isn't supported\n",
__func__);
s->lckr = value & ~RESERVED_BITS_MASK;
return;
case GPIO_AFRL:
qemu_log_mask(LOG_UNIMP,
"%s: Alternate functions aren't supported\n",
__func__);
s->afrl = value;
return;
case GPIO_AFRH:
qemu_log_mask(LOG_UNIMP,
"%s: Alternate functions aren't supported\n",
__func__);
s->afrh = value;
return;
case GPIO_BRR: {
uint32_t bits_to_reset = value & ~RESERVED_BITS_MASK;
s->odr &= ~bits_to_reset;
update_gpio_idr(s);
return;
}
case GPIO_ASCR:
qemu_log_mask(LOG_UNIMP,
"%s: ADC function isn't supported\n",
__func__);
s->ascr = value & ~RESERVED_BITS_MASK;
return;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, addr);
}
}
static uint64_t stm32l4x5_gpio_read(void *opaque, hwaddr addr,
unsigned int size)
{
Stm32l4x5GpioState *s = opaque;
trace_stm32l4x5_gpio_read(s->name, addr);
switch (addr) {
case GPIO_MODER:
return s->moder;
case GPIO_OTYPER:
return s->otyper;
case GPIO_OSPEEDR:
return s->ospeedr;
case GPIO_PUPDR:
return s->pupdr;
case GPIO_IDR:
return s->idr;
case GPIO_ODR:
return s->odr;
case GPIO_BSRR:
return 0;
case GPIO_LCKR:
return s->lckr;
case GPIO_AFRL:
return s->afrl;
case GPIO_AFRH:
return s->afrh;
case GPIO_BRR:
return 0;
case GPIO_ASCR:
return s->ascr;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, addr);
return 0;
}
}
static const MemoryRegionOps stm32l4x5_gpio_ops = {
.read = stm32l4x5_gpio_read,
.write = stm32l4x5_gpio_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.impl = {
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
.valid = {
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
};
static void stm32l4x5_gpio_init(Object *obj)
{
Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj);
memory_region_init_io(&s->mmio, obj, &stm32l4x5_gpio_ops, s,
TYPE_STM32L4X5_GPIO, 0x400);
sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
qdev_init_gpio_out(DEVICE(obj), s->pin, GPIO_NUM_PINS);
qdev_init_gpio_in(DEVICE(obj), stm32l4x5_gpio_set, GPIO_NUM_PINS);
s->clk = qdev_init_clock_in(DEVICE(s), "clk", NULL, s, 0);
object_property_add(obj, "disconnected-pins", "uint16",
disconnected_pins_get, disconnected_pins_set,
NULL, &s->disconnected_pins);
object_property_add(obj, "clock-freq-hz", "uint32",
clock_freq_get, NULL, NULL, NULL);
}
static void stm32l4x5_gpio_realize(DeviceState *dev, Error **errp)
{
Stm32l4x5GpioState *s = STM32L4X5_GPIO(dev);
if (!clock_has_source(s->clk)) {
error_setg(errp, "GPIO: clk input must be connected");
return;
}
}
static const VMStateDescription vmstate_stm32l4x5_gpio = {
.name = TYPE_STM32L4X5_GPIO,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]){
VMSTATE_UINT32(moder, Stm32l4x5GpioState),
VMSTATE_UINT32(otyper, Stm32l4x5GpioState),
VMSTATE_UINT32(ospeedr, Stm32l4x5GpioState),
VMSTATE_UINT32(pupdr, Stm32l4x5GpioState),
VMSTATE_UINT32(idr, Stm32l4x5GpioState),
VMSTATE_UINT32(odr, Stm32l4x5GpioState),
VMSTATE_UINT32(lckr, Stm32l4x5GpioState),
VMSTATE_UINT32(afrl, Stm32l4x5GpioState),
VMSTATE_UINT32(afrh, Stm32l4x5GpioState),
VMSTATE_UINT32(ascr, Stm32l4x5GpioState),
VMSTATE_UINT16(disconnected_pins, Stm32l4x5GpioState),
VMSTATE_UINT16(pins_connected_high, Stm32l4x5GpioState),
VMSTATE_END_OF_LIST()
}
};
static Property stm32l4x5_gpio_properties[] = {
DEFINE_PROP_STRING("name", Stm32l4x5GpioState, name),
DEFINE_PROP_UINT32("mode-reset", Stm32l4x5GpioState, moder_reset, 0),
DEFINE_PROP_UINT32("ospeed-reset", Stm32l4x5GpioState, ospeedr_reset, 0),
DEFINE_PROP_UINT32("pupd-reset", Stm32l4x5GpioState, pupdr_reset, 0),
DEFINE_PROP_END_OF_LIST(),
};
static void stm32l4x5_gpio_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
ResettableClass *rc = RESETTABLE_CLASS(klass);
device_class_set_props(dc, stm32l4x5_gpio_properties);
dc->vmsd = &vmstate_stm32l4x5_gpio;
dc->realize = stm32l4x5_gpio_realize;
rc->phases.hold = stm32l4x5_gpio_reset_hold;
}
static const TypeInfo stm32l4x5_gpio_types[] = {
{
.name = TYPE_STM32L4X5_GPIO,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(Stm32l4x5GpioState),
.instance_init = stm32l4x5_gpio_init,
.class_init = stm32l4x5_gpio_class_init,
},
};
DEFINE_TYPES(stm32l4x5_gpio_types)