/*
* Nuvoton NPCM7xx General Purpose Input / Output (GPIO)
*
* Copyright 2020 Google LLC
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "qemu/osdep.h"
#include "hw/gpio/npcm7xx_gpio.h"
#include "hw/irq.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "qapi/error.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/units.h"
#include "trace.h"
/* 32-bit register indices. */
enum NPCM7xxGPIORegister {
NPCM7XX_GPIO_TLOCK1,
NPCM7XX_GPIO_DIN,
NPCM7XX_GPIO_POL,
NPCM7XX_GPIO_DOUT,
NPCM7XX_GPIO_OE,
NPCM7XX_GPIO_OTYP,
NPCM7XX_GPIO_MP,
NPCM7XX_GPIO_PU,
NPCM7XX_GPIO_PD,
NPCM7XX_GPIO_DBNC,
NPCM7XX_GPIO_EVTYP,
NPCM7XX_GPIO_EVBE,
NPCM7XX_GPIO_OBL0,
NPCM7XX_GPIO_OBL1,
NPCM7XX_GPIO_OBL2,
NPCM7XX_GPIO_OBL3,
NPCM7XX_GPIO_EVEN,
NPCM7XX_GPIO_EVENS,
NPCM7XX_GPIO_EVENC,
NPCM7XX_GPIO_EVST,
NPCM7XX_GPIO_SPLCK,
NPCM7XX_GPIO_MPLCK,
NPCM7XX_GPIO_IEM,
NPCM7XX_GPIO_OSRC,
NPCM7XX_GPIO_ODSC,
NPCM7XX_GPIO_DOS = 0x68 / sizeof(uint32_t),
NPCM7XX_GPIO_DOC,
NPCM7XX_GPIO_OES,
NPCM7XX_GPIO_OEC,
NPCM7XX_GPIO_TLOCK2 = 0x7c / sizeof(uint32_t),
NPCM7XX_GPIO_REGS_END,
};
#define NPCM7XX_GPIO_REGS_SIZE (4 * KiB)
#define NPCM7XX_GPIO_LOCK_MAGIC1 (0xc0defa73)
#define NPCM7XX_GPIO_LOCK_MAGIC2 (0xc0de1248)
static void npcm7xx_gpio_update_events(NPCM7xxGPIOState *s, uint32_t din_diff)
{
uint32_t din_new = s->regs[NPCM7XX_GPIO_DIN];
/* Trigger on high level */
s->regs[NPCM7XX_GPIO_EVST] |= din_new & ~s->regs[NPCM7XX_GPIO_EVTYP];
/* Trigger on both edges */
s->regs[NPCM7XX_GPIO_EVST] |= (din_diff & s->regs[NPCM7XX_GPIO_EVTYP]
& s->regs[NPCM7XX_GPIO_EVBE]);
/* Trigger on rising edge */
s->regs[NPCM7XX_GPIO_EVST] |= (din_diff & din_new
& s->regs[NPCM7XX_GPIO_EVTYP]);
trace_npcm7xx_gpio_update_events(DEVICE(s)->canonical_path,
s->regs[NPCM7XX_GPIO_EVST],
s->regs[NPCM7XX_GPIO_EVEN]);
qemu_set_irq(s->irq, !!(s->regs[NPCM7XX_GPIO_EVST]
& s->regs[NPCM7XX_GPIO_EVEN]));
}
static void npcm7xx_gpio_update_pins(NPCM7xxGPIOState *s, uint32_t diff)
{
uint32_t drive_en;
uint32_t drive_lvl;
uint32_t not_driven;
uint32_t undefined;
uint32_t pin_diff;
uint32_t din_old;
/* Calculate level of each pin driven by GPIO controller. */
drive_lvl = s->regs[NPCM7XX_GPIO_DOUT] ^ s->regs[NPCM7XX_GPIO_POL];
/* If OTYP=1, only drive low (open drain) */
drive_en = s->regs[NPCM7XX_GPIO_OE] & ~(s->regs[NPCM7XX_GPIO_OTYP]
& drive_lvl);
/*
* If a pin is driven to opposite levels by the GPIO controller and the
* external driver, the result is undefined.
*/
undefined = drive_en & s->ext_driven & (drive_lvl ^ s->ext_level);
if (undefined) {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: pins have multiple drivers: 0x%" PRIx32 "\n",
DEVICE(s)->canonical_path, undefined);
}
not_driven = ~(drive_en | s->ext_driven);
pin_diff = s->pin_level;
/* Set pins to externally driven level. */
s->pin_level = s->ext_level & s->ext_driven;
/* Set internally driven pins, ignoring any conflicts. */
s->pin_level |= drive_lvl & drive_en;
/* Pull up undriven pins with internal pull-up enabled. */
s->pin_level |= not_driven & s->regs[NPCM7XX_GPIO_PU];
/* Pins not driven, pulled up or pulled down are undefined */
undefined |= not_driven & ~(s->regs[NPCM7XX_GPIO_PU]
| s->regs[NPCM7XX_GPIO_PD]);
/* If any pins changed state, update the outgoing GPIOs. */
pin_diff ^= s->pin_level;
pin_diff |= undefined & diff;
if (pin_diff) {
int i;
for (i = 0; i < NPCM7XX_GPIO_NR_PINS; i++) {
uint32_t mask = BIT(i);
if (pin_diff & mask) {
int level = (undefined & mask) ? -1 : !!(s->pin_level & mask);
trace_npcm7xx_gpio_set_output(DEVICE(s)->canonical_path,
i, level);
qemu_set_irq(s->output[i], level);
}
}
}
/* Calculate new value of DIN after masking and polarity setting. */
din_old = s->regs[NPCM7XX_GPIO_DIN];
s->regs[NPCM7XX_GPIO_DIN] = ((s->pin_level & s->regs[NPCM7XX_GPIO_IEM])
^ s->regs[NPCM7XX_GPIO_POL]);
/* See if any new events triggered because of all this. */
npcm7xx_gpio_update_events(s, din_old ^ s->regs[NPCM7XX_GPIO_DIN]);
}
static bool npcm7xx_gpio_is_locked(NPCM7xxGPIOState *s)
{
return s->regs[NPCM7XX_GPIO_TLOCK1] == 1;
}
static uint64_t npcm7xx_gpio_regs_read(void *opaque, hwaddr addr,
unsigned int size)
{
hwaddr reg = addr / sizeof(uint32_t);
NPCM7xxGPIOState *s = opaque;
uint64_t value = 0;
switch (reg) {
case NPCM7XX_GPIO_TLOCK1 ... NPCM7XX_GPIO_EVEN:
case NPCM7XX_GPIO_EVST ... NPCM7XX_GPIO_ODSC:
value = s->regs[reg];
break;
case NPCM7XX_GPIO_EVENS ... NPCM7XX_GPIO_EVENC:
case NPCM7XX_GPIO_DOS ... NPCM7XX_GPIO_TLOCK2:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: read from write-only register 0x%" HWADDR_PRIx "\n",
DEVICE(s)->canonical_path, addr);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: read from invalid offset 0x%" HWADDR_PRIx "\n",
DEVICE(s)->canonical_path, addr);
break;
}
trace_npcm7xx_gpio_read(DEVICE(s)->canonical_path, addr, value);
return value;
}
static void npcm7xx_gpio_regs_write(void *opaque, hwaddr addr, uint64_t v,
unsigned int size)
{
hwaddr reg = addr / sizeof(uint32_t);
NPCM7xxGPIOState *s = opaque;
uint32_t value = v;
uint32_t diff;
trace_npcm7xx_gpio_write(DEVICE(s)->canonical_path, addr, v);
if (npcm7xx_gpio_is_locked(s)) {
switch (reg) {
case NPCM7XX_GPIO_TLOCK1:
if (s->regs[NPCM7XX_GPIO_TLOCK2] == NPCM7XX_GPIO_LOCK_MAGIC2 &&
value == NPCM7XX_GPIO_LOCK_MAGIC1) {
s->regs[NPCM7XX_GPIO_TLOCK1] = 0;
s->regs[NPCM7XX_GPIO_TLOCK2] = 0;
}
break;
case NPCM7XX_GPIO_TLOCK2:
s->regs[reg] = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to locked register @ 0x%" HWADDR_PRIx "\n",
DEVICE(s)->canonical_path, addr);
break;
}
return;
}
diff = s->regs[reg] ^ value;
switch (reg) {
case NPCM7XX_GPIO_TLOCK1:
case NPCM7XX_GPIO_TLOCK2:
s->regs[NPCM7XX_GPIO_TLOCK1] = 1;
s->regs[NPCM7XX_GPIO_TLOCK2] = 0;
break;
case NPCM7XX_GPIO_DIN:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to read-only register @ 0x%" HWADDR_PRIx "\n",
DEVICE(s)->canonical_path, addr);
break;
case NPCM7XX_GPIO_POL:
case NPCM7XX_GPIO_DOUT:
case NPCM7XX_GPIO_OE:
case NPCM7XX_GPIO_OTYP:
case NPCM7XX_GPIO_PU:
case NPCM7XX_GPIO_PD:
case NPCM7XX_GPIO_IEM:
s->regs[reg] = value;
npcm7xx_gpio_update_pins(s, diff);
break;
case NPCM7XX_GPIO_DOS:
s->regs[NPCM7XX_GPIO_DOUT] |= value;
npcm7xx_gpio_update_pins(s, value);
break;
case NPCM7XX_GPIO_DOC:
s->regs[NPCM7XX_GPIO_DOUT] &= ~value;
npcm7xx_gpio_update_pins(s, value);
break;
case NPCM7XX_GPIO_OES:
s->regs[NPCM7XX_GPIO_OE] |= value;
npcm7xx_gpio_update_pins(s, value);
break;
case NPCM7XX_GPIO_OEC:
s->regs[NPCM7XX_GPIO_OE] &= ~value;
npcm7xx_gpio_update_pins(s, value);
break;
case NPCM7XX_GPIO_EVTYP:
case NPCM7XX_GPIO_EVBE:
case NPCM7XX_GPIO_EVEN:
s->regs[reg] = value;
npcm7xx_gpio_update_events(s, 0);
break;
case NPCM7XX_GPIO_EVENS:
s->regs[NPCM7XX_GPIO_EVEN] |= value;
npcm7xx_gpio_update_events(s, 0);
break;
case NPCM7XX_GPIO_EVENC:
s->regs[NPCM7XX_GPIO_EVEN] &= ~value;
npcm7xx_gpio_update_events(s, 0);
break;
case NPCM7XX_GPIO_EVST:
s->regs[reg] &= ~value;
npcm7xx_gpio_update_events(s, 0);
break;
case NPCM7XX_GPIO_MP:
case NPCM7XX_GPIO_DBNC:
case NPCM7XX_GPIO_OSRC:
case NPCM7XX_GPIO_ODSC:
/* Nothing to do; just store the value. */
s->regs[reg] = value;
break;
case NPCM7XX_GPIO_OBL0:
case NPCM7XX_GPIO_OBL1:
case NPCM7XX_GPIO_OBL2:
case NPCM7XX_GPIO_OBL3:
s->regs[reg] = value;
qemu_log_mask(LOG_UNIMP, "%s: Blinking is not implemented\n",
__func__);
break;
case NPCM7XX_GPIO_SPLCK:
case NPCM7XX_GPIO_MPLCK:
qemu_log_mask(LOG_UNIMP, "%s: Per-pin lock is not implemented\n",
__func__);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to invalid offset 0x%" HWADDR_PRIx "\n",
DEVICE(s)->canonical_path, addr);
break;
}
}
static const MemoryRegionOps npcm7xx_gpio_regs_ops = {
.read = npcm7xx_gpio_regs_read,
.write = npcm7xx_gpio_regs_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
};
static void npcm7xx_gpio_set_input(void *opaque, int line, int level)
{
NPCM7xxGPIOState *s = opaque;
trace_npcm7xx_gpio_set_input(DEVICE(s)->canonical_path, line, level);
g_assert(line >= 0 && line < NPCM7XX_GPIO_NR_PINS);
s->ext_driven = deposit32(s->ext_driven, line, 1, level >= 0);
s->ext_level = deposit32(s->ext_level, line, 1, level > 0);
npcm7xx_gpio_update_pins(s, BIT(line));
}
static void npcm7xx_gpio_enter_reset(Object *obj, ResetType type)
{
NPCM7xxGPIOState *s = NPCM7XX_GPIO(obj);
memset(s->regs, 0, sizeof(s->regs));
s->regs[NPCM7XX_GPIO_PU] = s->reset_pu;
s->regs[NPCM7XX_GPIO_PD] = s->reset_pd;
s->regs[NPCM7XX_GPIO_OSRC] = s->reset_osrc;
s->regs[NPCM7XX_GPIO_ODSC] = s->reset_odsc;
}
static void npcm7xx_gpio_hold_reset(Object *obj)
{
NPCM7xxGPIOState *s = NPCM7XX_GPIO(obj);
npcm7xx_gpio_update_pins(s, -1);
}
static void npcm7xx_gpio_init(Object *obj)
{
NPCM7xxGPIOState *s = NPCM7XX_GPIO(obj);
DeviceState *dev = DEVICE(obj);
memory_region_init_io(&s->mmio, obj, &npcm7xx_gpio_regs_ops, s,
"regs", NPCM7XX_GPIO_REGS_SIZE);
sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
qdev_init_gpio_in(dev, npcm7xx_gpio_set_input, NPCM7XX_GPIO_NR_PINS);
qdev_init_gpio_out(dev, s->output, NPCM7XX_GPIO_NR_PINS);
}
static const VMStateDescription vmstate_npcm7xx_gpio = {
.name = "npcm7xx-gpio",
.version_id = 0,
.minimum_version_id = 0,
.fields = (VMStateField[]) {
VMSTATE_UINT32(pin_level, NPCM7xxGPIOState),
VMSTATE_UINT32(ext_level, NPCM7xxGPIOState),
VMSTATE_UINT32(ext_driven, NPCM7xxGPIOState),
VMSTATE_UINT32_ARRAY(regs, NPCM7xxGPIOState, NPCM7XX_GPIO_NR_REGS),
VMSTATE_END_OF_LIST(),
},
};
static Property npcm7xx_gpio_properties[] = {
/* Bit n set => pin n has pullup enabled by default. */
DEFINE_PROP_UINT32("reset-pullup", NPCM7xxGPIOState, reset_pu, 0),
/* Bit n set => pin n has pulldown enabled by default. */
DEFINE_PROP_UINT32("reset-pulldown", NPCM7xxGPIOState, reset_pd, 0),
/* Bit n set => pin n has high slew rate by default. */
DEFINE_PROP_UINT32("reset-osrc", NPCM7xxGPIOState, reset_osrc, 0),
/* Bit n set => pin n has high drive strength by default. */
DEFINE_PROP_UINT32("reset-odsc", NPCM7xxGPIOState, reset_odsc, 0),
DEFINE_PROP_END_OF_LIST(),
};
static void npcm7xx_gpio_class_init(ObjectClass *klass, void *data)
{
ResettableClass *reset = RESETTABLE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
QEMU_BUILD_BUG_ON(NPCM7XX_GPIO_REGS_END > NPCM7XX_GPIO_NR_REGS);
dc->desc = "NPCM7xx GPIO Controller";
dc->vmsd = &vmstate_npcm7xx_gpio;
reset->phases.enter = npcm7xx_gpio_enter_reset;
reset->phases.hold = npcm7xx_gpio_hold_reset;
device_class_set_props(dc, npcm7xx_gpio_properties);
}
static const TypeInfo npcm7xx_gpio_types[] = {
{
.name = TYPE_NPCM7XX_GPIO,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(NPCM7xxGPIOState),
.class_init = npcm7xx_gpio_class_init,
.instance_init = npcm7xx_gpio_init,
},
};
DEFINE_TYPES(npcm7xx_gpio_types);
