blob: 41a53235303beac8c5731d1f4c0bbe5f173cb604 [file] [log] [blame]
/*
* Nuvoton NPCM Peripheral SPI Module (PSPI)
*
* Copyright 2023 Google LLC
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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/irq.h"
#include "hw/registerfields.h"
#include "hw/ssi/npcm_pspi.h"
#include "migration/vmstate.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/units.h"
#include "trace.h"
REG16(PSPI_DATA, 0x0)
REG16(PSPI_CTL1, 0x2)
FIELD(PSPI_CTL1, SPIEN, 0, 1)
FIELD(PSPI_CTL1, MOD, 2, 1)
FIELD(PSPI_CTL1, EIR, 5, 1)
FIELD(PSPI_CTL1, EIW, 6, 1)
FIELD(PSPI_CTL1, SCM, 7, 1)
FIELD(PSPI_CTL1, SCIDL, 8, 1)
FIELD(PSPI_CTL1, SCDV, 9, 7)
REG16(PSPI_STAT, 0x4)
FIELD(PSPI_STAT, BSY, 0, 1)
FIELD(PSPI_STAT, RBF, 1, 1)
static void npcm_pspi_update_irq(NPCMPSPIState *s)
{
int level = 0;
/* Only fire IRQ when the module is enabled. */
if (FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, SPIEN)) {
/* Update interrupt as BSY is cleared. */
if ((!FIELD_EX16(s->regs[R_PSPI_STAT], PSPI_STAT, BSY)) &&
FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, EIW)) {
level = 1;
}
/* Update interrupt as RBF is set. */
if (FIELD_EX16(s->regs[R_PSPI_STAT], PSPI_STAT, RBF) &&
FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, EIR)) {
level = 1;
}
}
qemu_set_irq(s->irq, level);
}
static uint16_t npcm_pspi_read_data(NPCMPSPIState *s)
{
uint16_t value = s->regs[R_PSPI_DATA];
/* Clear stat bits as the value are read out. */
s->regs[R_PSPI_STAT] = 0;
return value;
}
static void npcm_pspi_write_data(NPCMPSPIState *s, uint16_t data)
{
uint16_t value = 0;
if (FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, MOD)) {
value = ssi_transfer(s->spi, extract16(data, 8, 8)) << 8;
}
value |= ssi_transfer(s->spi, extract16(data, 0, 8));
s->regs[R_PSPI_DATA] = value;
/* Mark data as available */
s->regs[R_PSPI_STAT] = R_PSPI_STAT_BSY_MASK | R_PSPI_STAT_RBF_MASK;
}
/* Control register read handler. */
static uint64_t npcm_pspi_ctrl_read(void *opaque, hwaddr addr,
unsigned int size)
{
NPCMPSPIState *s = opaque;
uint16_t value;
switch (addr) {
case A_PSPI_DATA:
value = npcm_pspi_read_data(s);
break;
case A_PSPI_CTL1:
value = s->regs[R_PSPI_CTL1];
break;
case A_PSPI_STAT:
value = s->regs[R_PSPI_STAT];
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to invalid offset 0x%" PRIx64 "\n",
DEVICE(s)->canonical_path, addr);
return 0;
}
trace_npcm_pspi_ctrl_read(DEVICE(s)->canonical_path, addr, value);
npcm_pspi_update_irq(s);
return value;
}
/* Control register write handler. */
static void npcm_pspi_ctrl_write(void *opaque, hwaddr addr, uint64_t v,
unsigned int size)
{
NPCMPSPIState *s = opaque;
uint16_t value = v;
trace_npcm_pspi_ctrl_write(DEVICE(s)->canonical_path, addr, value);
switch (addr) {
case A_PSPI_DATA:
npcm_pspi_write_data(s, value);
break;
case A_PSPI_CTL1:
s->regs[R_PSPI_CTL1] = value;
break;
case A_PSPI_STAT:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to read-only register PSPI_STAT: 0x%08"
PRIx64 "\n", DEVICE(s)->canonical_path, v);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: write to invalid offset 0x%" PRIx64 "\n",
DEVICE(s)->canonical_path, addr);
return;
}
npcm_pspi_update_irq(s);
}
static const MemoryRegionOps npcm_pspi_ctrl_ops = {
.read = npcm_pspi_ctrl_read,
.write = npcm_pspi_ctrl_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 2,
.unaligned = false,
},
.impl = {
.min_access_size = 2,
.max_access_size = 2,
.unaligned = false,
},
};
static void npcm_pspi_enter_reset(Object *obj, ResetType type)
{
NPCMPSPIState *s = NPCM_PSPI(obj);
trace_npcm_pspi_enter_reset(DEVICE(obj)->canonical_path, type);
memset(s->regs, 0, sizeof(s->regs));
}
static void npcm_pspi_realize(DeviceState *dev, Error **errp)
{
NPCMPSPIState *s = NPCM_PSPI(dev);
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
Object *obj = OBJECT(dev);
s->spi = ssi_create_bus(dev, "pspi");
memory_region_init_io(&s->mmio, obj, &npcm_pspi_ctrl_ops, s,
"mmio", 4 * KiB);
sysbus_init_mmio(sbd, &s->mmio);
sysbus_init_irq(sbd, &s->irq);
}
static const VMStateDescription vmstate_npcm_pspi = {
.name = "npcm-pspi",
.version_id = 0,
.minimum_version_id = 0,
.fields = (const VMStateField[]) {
VMSTATE_UINT16_ARRAY(regs, NPCMPSPIState, NPCM_PSPI_NR_REGS),
VMSTATE_END_OF_LIST(),
},
};
static void npcm_pspi_class_init(ObjectClass *klass, void *data)
{
ResettableClass *rc = RESETTABLE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
dc->desc = "NPCM Peripheral SPI Module";
dc->realize = npcm_pspi_realize;
dc->vmsd = &vmstate_npcm_pspi;
rc->phases.enter = npcm_pspi_enter_reset;
}
static const TypeInfo npcm_pspi_types[] = {
{
.name = TYPE_NPCM_PSPI,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(NPCMPSPIState),
.class_init = npcm_pspi_class_init,
},
};
DEFINE_TYPES(npcm_pspi_types);