qemu/hw/ssi/allwinner-a10-spi.c
Strahinja Jankovic 8d3dfb6205 hw/ssi: Allwinner A10 SPI emulation
This patch implements Allwinner A10 SPI controller emulation.
Only master-mode functionality is implemented.

Since U-Boot and Linux SPI drivers for Allwinner A10 perform only
byte-wide CPU access (no DMA) to the transmit and receive registers of
the peripheral, the emulated controller does not implement DMA control,
and supports only byte-wide access to transmit and receive registers
(half-word and word accesses will be treated as byte accesses).

Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Message-id: 20241001221349.8319-2-strahinja.p.jankovic@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2024-10-15 15:16:17 +01:00

562 lines
18 KiB
C

/*
* Allwinner SPI Bus Serial Interface Emulation
*
* Copyright (C) 2024 Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "hw/irq.h"
#include "hw/ssi/allwinner-a10-spi.h"
#include "migration/vmstate.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "trace.h"
/* Allwinner SPI memory map */
#define SPI_RXDATA_REG 0x00 /* receive data register */
#define SPI_TXDATA_REG 0x04 /* transmit data register */
#define SPI_CTL_REG 0x08 /* control register */
#define SPI_INTCTL_REG 0x0c /* interrupt control register */
#define SPI_INT_STA_REG 0x10 /* interrupt status register */
#define SPI_DMACTL_REG 0x14 /* DMA control register */
#define SPI_WAIT_REG 0x18 /* wait clock counter register */
#define SPI_CCTL_REG 0x1c /* clock rate control register */
#define SPI_BC_REG 0x20 /* burst control register */
#define SPI_TC_REG 0x24 /* transmit counter register */
#define SPI_FIFO_STA_REG 0x28 /* FIFO status register */
/* Data register */
#define SPI_DATA_RESET 0
/* Control register */
#define SPI_CTL_SDC (1 << 19)
#define SPI_CTL_TP_EN (1 << 18)
#define SPI_CTL_SS_LEVEL (1 << 17)
#define SPI_CTL_SS_CTRL (1 << 16)
#define SPI_CTL_DHB (1 << 15)
#define SPI_CTL_DDB (1 << 14)
#define SPI_CTL_SS (3 << 12)
#define SPI_CTL_SS_SHIFT 12
#define SPI_CTL_RPSM (1 << 11)
#define SPI_CTL_XCH (1 << 10)
#define SPI_CTL_RF_RST (1 << 9)
#define SPI_CTL_TF_RST (1 << 8)
#define SPI_CTL_SSCTL (1 << 7)
#define SPI_CTL_LMTF (1 << 6)
#define SPI_CTL_DMAMC (1 << 5)
#define SPI_CTL_SSPOL (1 << 4)
#define SPI_CTL_POL (1 << 3)
#define SPI_CTL_PHA (1 << 2)
#define SPI_CTL_MODE (1 << 1)
#define SPI_CTL_EN (1 << 0)
#define SPI_CTL_MASK 0xFFFFFu
#define SPI_CTL_RESET 0x0002001Cu
/* Interrupt control register */
#define SPI_INTCTL_SS_INT_EN (1 << 17)
#define SPI_INTCTL_TX_INT_EN (1 << 16)
#define SPI_INTCTL_TF_UR_INT_EN (1 << 14)
#define SPI_INTCTL_TF_OF_INT_EN (1 << 13)
#define SPI_INTCTL_TF_E34_INT_EN (1 << 12)
#define SPI_INTCTL_TF_E14_INT_EN (1 << 11)
#define SPI_INTCTL_TF_FL_INT_EN (1 << 10)
#define SPI_INTCTL_TF_HALF_EMP_INT_EN (1 << 9)
#define SPI_INTCTL_TF_EMP_INT_EN (1 << 8)
#define SPI_INTCTL_RF_UR_INT_EN (1 << 6)
#define SPI_INTCTL_RF_OF_INT_EN (1 << 5)
#define SPI_INTCTL_RF_E34_INT_EN (1 << 4)
#define SPI_INTCTL_RF_E14_INT_EN (1 << 3)
#define SPI_INTCTL_RF_FU_INT_EN (1 << 2)
#define SPI_INTCTL_RF_HALF_FU_INT_EN (1 << 1)
#define SPI_INTCTL_RF_RDY_INT_EN (1 << 0)
#define SPI_INTCTL_MASK 0x37F7Fu
#define SPI_INTCTL_RESET 0
/* Interrupt status register */
#define SPI_INT_STA_INT_CBF (1 << 31)
#define SPI_INT_STA_SSI (1 << 17)
#define SPI_INT_STA_TC (1 << 16)
#define SPI_INT_STA_TU (1 << 14)
#define SPI_INT_STA_TO (1 << 13)
#define SPI_INT_STA_TE34 (1 << 12)
#define SPI_INT_STA_TE14 (1 << 11)
#define SPI_INT_STA_TF (1 << 10)
#define SPI_INT_STA_THE (1 << 9)
#define SPI_INT_STA_TE (1 << 8)
#define SPI_INT_STA_RU (1 << 6)
#define SPI_INT_STA_RO (1 << 5)
#define SPI_INT_STA_RF34 (1 << 4)
#define SPI_INT_STA_RF14 (1 << 3)
#define SPI_INT_STA_RF (1 << 2)
#define SPI_INT_STA_RHF (1 << 1)
#define SPI_INT_STA_RR (1 << 0)
#define SPI_INT_STA_MASK 0x80037F7Fu
#define SPI_INT_STA_RESET 0x00001B00u
/* DMA control register - not implemented */
#define SPI_DMACTL_RESET 0
/* Wait clock register */
#define SPI_WAIT_REG_WCC_MASK 0xFFFFu
#define SPI_WAIT_RESET 0
/* Clock control register - not implemented */
#define SPI_CCTL_RESET 2
/* Burst count register */
#define SPI_BC_BC_MASK 0xFFFFFFu
#define SPI_BC_RESET 0
/* Transmi counter register */
#define SPI_TC_WTC_MASK 0xFFFFFFu
#define SPI_TC_RESET 0
/* FIFO status register */
#define SPI_FIFO_STA_CNT_MASK 0x7F
#define SPI_FIFO_STA_TF_CNT_SHIFT 16
#define SPI_FIFO_STA_RF_CNT_SHIFT 0
#define SPI_FIFO_STA_RESET 0
#define REG_INDEX(offset) (offset / sizeof(uint32_t))
static const char *allwinner_a10_spi_get_regname(unsigned offset)
{
switch (offset) {
case SPI_RXDATA_REG:
return "RXDATA";
case SPI_TXDATA_REG:
return "TXDATA";
case SPI_CTL_REG:
return "CTL";
case SPI_INTCTL_REG:
return "INTCTL";
case SPI_INT_STA_REG:
return "INT_STA";
case SPI_DMACTL_REG:
return "DMACTL";
case SPI_WAIT_REG:
return "WAIT";
case SPI_CCTL_REG:
return "CCTL";
case SPI_BC_REG:
return "BC";
case SPI_TC_REG:
return "TC";
case SPI_FIFO_STA_REG:
return "FIFO_STA";
default:
return "[?]";
}
}
static bool allwinner_a10_spi_is_enabled(AWA10SPIState *s)
{
return s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_EN;
}
static void allwinner_a10_spi_txfifo_reset(AWA10SPIState *s)
{
fifo8_reset(&s->tx_fifo);
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= (SPI_INT_STA_TE | SPI_INT_STA_TE14 |
SPI_INT_STA_THE | SPI_INT_STA_TE34);
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~(SPI_INT_STA_TU | SPI_INT_STA_TO);
}
static void allwinner_a10_spi_rxfifo_reset(AWA10SPIState *s)
{
fifo8_reset(&s->rx_fifo);
s->regs[REG_INDEX(SPI_INT_STA_REG)] &=
~(SPI_INT_STA_RU | SPI_INT_STA_RO | SPI_INT_STA_RF | SPI_INT_STA_RR |
SPI_INT_STA_RHF | SPI_INT_STA_RF14 | SPI_INT_STA_RF34);
}
static uint8_t allwinner_a10_spi_selected_channel(AWA10SPIState *s)
{
return (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_SS) >> SPI_CTL_SS_SHIFT;
}
static void allwinner_a10_spi_reset_hold(Object *obj, ResetType type)
{
AWA10SPIState *s = AW_A10_SPI(obj);
s->regs[REG_INDEX(SPI_RXDATA_REG)] = SPI_DATA_RESET;
s->regs[REG_INDEX(SPI_TXDATA_REG)] = SPI_DATA_RESET;
s->regs[REG_INDEX(SPI_CTL_REG)] = SPI_CTL_RESET;
s->regs[REG_INDEX(SPI_INTCTL_REG)] = SPI_INTCTL_RESET;
s->regs[REG_INDEX(SPI_INT_STA_REG)] = SPI_INT_STA_RESET;
s->regs[REG_INDEX(SPI_DMACTL_REG)] = SPI_DMACTL_RESET;
s->regs[REG_INDEX(SPI_WAIT_REG)] = SPI_WAIT_RESET;
s->regs[REG_INDEX(SPI_CCTL_REG)] = SPI_CCTL_RESET;
s->regs[REG_INDEX(SPI_BC_REG)] = SPI_BC_RESET;
s->regs[REG_INDEX(SPI_TC_REG)] = SPI_TC_RESET;
s->regs[REG_INDEX(SPI_FIFO_STA_REG)] = SPI_FIFO_STA_RESET;
allwinner_a10_spi_txfifo_reset(s);
allwinner_a10_spi_rxfifo_reset(s);
}
static void allwinner_a10_spi_update_irq(AWA10SPIState *s)
{
bool level;
if (fifo8_is_empty(&s->rx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_RR;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RR;
}
if (fifo8_num_used(&s->rx_fifo) >= (AW_A10_SPI_FIFO_SIZE >> 2)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RF14;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_RF14;
}
if (fifo8_num_used(&s->rx_fifo) >= (AW_A10_SPI_FIFO_SIZE >> 1)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RHF;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_RHF;
}
if (fifo8_num_free(&s->rx_fifo) <= (AW_A10_SPI_FIFO_SIZE >> 2)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RF34;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_RF34;
}
if (fifo8_is_full(&s->rx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RF;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_RF;
}
if (fifo8_is_empty(&s->tx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TE;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_TE;
}
if (fifo8_num_free(&s->tx_fifo) >= (AW_A10_SPI_FIFO_SIZE >> 2)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TE14;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_TE14;
}
if (fifo8_num_free(&s->tx_fifo) >= (AW_A10_SPI_FIFO_SIZE >> 1)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_THE;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_THE;
}
if (fifo8_num_used(&s->tx_fifo) <= (AW_A10_SPI_FIFO_SIZE >> 2)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TE34;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_TE34;
}
if (fifo8_is_full(&s->rx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TF;
} else {
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~SPI_INT_STA_TF;
}
level = (s->regs[REG_INDEX(SPI_INT_STA_REG)] &
s->regs[REG_INDEX(SPI_INTCTL_REG)]) != 0;
qemu_set_irq(s->irq, level);
trace_allwinner_a10_spi_update_irq(level);
}
static void allwinner_a10_spi_flush_txfifo(AWA10SPIState *s)
{
uint32_t burst_count = s->regs[REG_INDEX(SPI_BC_REG)];
uint32_t tx_burst = s->regs[REG_INDEX(SPI_TC_REG)];
trace_allwinner_a10_spi_burst_length(tx_burst);
trace_allwinner_a10_spi_flush_txfifo_begin(fifo8_num_used(&s->tx_fifo),
fifo8_num_used(&s->rx_fifo));
while (!fifo8_is_empty(&s->tx_fifo)) {
uint8_t tx = fifo8_pop(&s->tx_fifo);
uint8_t rx = 0;
bool fill_rx = true;
trace_allwinner_a10_spi_tx(tx);
/* Write one byte at a time */
rx = ssi_transfer(s->bus, tx);
trace_allwinner_a10_spi_rx(rx);
/* Check DHB here to determine if RX bytes should be stored */
if (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_DHB) {
/* Store rx bytes only after WTC transfers */
if (tx_burst > 0u) {
fill_rx = false;
tx_burst--;
}
}
if (fill_rx) {
if (fifo8_is_full(&s->rx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_RF;
} else {
fifo8_push(&s->rx_fifo, rx);
}
}
allwinner_a10_spi_update_irq(s);
burst_count--;
if (burst_count == 0) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TC;
s->regs[REG_INDEX(SPI_CTL_REG)] &= ~SPI_CTL_XCH;
break;
}
}
if (fifo8_is_empty(&s->tx_fifo)) {
s->regs[REG_INDEX(SPI_INT_STA_REG)] |= SPI_INT_STA_TC;
s->regs[REG_INDEX(SPI_CTL_REG)] &= ~SPI_CTL_XCH;
}
trace_allwinner_a10_spi_flush_txfifo_end(fifo8_num_used(&s->tx_fifo),
fifo8_num_used(&s->rx_fifo));
}
static uint64_t allwinner_a10_spi_read(void *opaque, hwaddr offset,
unsigned size)
{
uint32_t value = 0;
AWA10SPIState *s = opaque;
uint32_t index = offset >> 2;
if (offset > SPI_FIFO_STA_REG) {
qemu_log_mask(LOG_GUEST_ERROR,
"[%s]%s: Bad register at offset 0x%" HWADDR_PRIx "\n",
TYPE_AW_A10_SPI, __func__, offset);
return 0;
}
value = s->regs[index];
if (allwinner_a10_spi_is_enabled(s)) {
switch (offset) {
case SPI_RXDATA_REG:
if (fifo8_is_empty(&s->rx_fifo)) {
/* value is undefined */
value = 0xdeadbeef;
} else {
/* read from the RX FIFO */
value = fifo8_pop(&s->rx_fifo);
}
break;
case SPI_TXDATA_REG:
qemu_log_mask(LOG_GUEST_ERROR,
"[%s]%s: Trying to read from TX FIFO\n",
TYPE_AW_A10_SPI, __func__);
/* Reading from TXDATA gives 0 */
break;
case SPI_FIFO_STA_REG:
/* Read current tx/rx fifo data count */
value = fifo8_num_used(&s->tx_fifo) << SPI_FIFO_STA_TF_CNT_SHIFT |
fifo8_num_used(&s->rx_fifo) << SPI_FIFO_STA_RF_CNT_SHIFT;
break;
case SPI_CTL_REG:
case SPI_INTCTL_REG:
case SPI_INT_STA_REG:
case SPI_DMACTL_REG:
case SPI_WAIT_REG:
case SPI_CCTL_REG:
case SPI_BC_REG:
case SPI_TC_REG:
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: bad offset 0x%x\n", __func__,
(uint32_t)offset);
break;
}
allwinner_a10_spi_update_irq(s);
}
trace_allwinner_a10_spi_read(allwinner_a10_spi_get_regname(offset), value);
return value;
}
static bool allwinner_a10_spi_update_cs_level(AWA10SPIState *s, int cs_line_nr)
{
if (cs_line_nr == allwinner_a10_spi_selected_channel(s)) {
return (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_SS_LEVEL) != 0;
} else {
return (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_SSPOL) != 0;
}
}
static void allwinner_a10_spi_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
AWA10SPIState *s = opaque;
uint32_t index = offset >> 2;
int i = 0;
if (offset > SPI_FIFO_STA_REG) {
qemu_log_mask(LOG_GUEST_ERROR,
"[%s]%s: Bad register at offset 0x%" HWADDR_PRIx "\n",
TYPE_AW_A10_SPI, __func__, offset);
return;
}
trace_allwinner_a10_spi_write(allwinner_a10_spi_get_regname(offset),
(uint32_t)value);
if (!allwinner_a10_spi_is_enabled(s)) {
/* Block is disabled */
if (offset != SPI_CTL_REG) {
/* Ignore access */
return;
}
}
switch (offset) {
case SPI_RXDATA_REG:
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Trying to write to RX FIFO\n",
TYPE_AW_A10_SPI, __func__);
break;
case SPI_TXDATA_REG:
if (fifo8_is_full(&s->tx_fifo)) {
/* Ignore writes if queue is full */
break;
}
fifo8_push(&s->tx_fifo, (uint8_t)value);
break;
case SPI_INT_STA_REG:
/* Handle W1C bits - everything except SPI_INT_STA_INT_CBF. */
value &= ~SPI_INT_STA_INT_CBF;
s->regs[REG_INDEX(SPI_INT_STA_REG)] &= ~(value & SPI_INT_STA_MASK);
break;
case SPI_CTL_REG:
s->regs[REG_INDEX(SPI_CTL_REG)] = value;
for (i = 0; i < AW_A10_SPI_CS_LINES_NR; i++) {
qemu_set_irq(
s->cs_lines[i],
allwinner_a10_spi_update_cs_level(s, i));
}
if (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_XCH) {
/* Request to start emitting */
allwinner_a10_spi_flush_txfifo(s);
}
if (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_TF_RST) {
allwinner_a10_spi_txfifo_reset(s);
s->regs[REG_INDEX(SPI_CTL_REG)] &= ~SPI_CTL_TF_RST;
}
if (s->regs[REG_INDEX(SPI_CTL_REG)] & SPI_CTL_RF_RST) {
allwinner_a10_spi_rxfifo_reset(s);
s->regs[REG_INDEX(SPI_CTL_REG)] &= ~SPI_CTL_RF_RST;
}
break;
case SPI_INTCTL_REG:
case SPI_DMACTL_REG:
case SPI_WAIT_REG:
case SPI_CCTL_REG:
case SPI_BC_REG:
case SPI_TC_REG:
case SPI_FIFO_STA_REG:
s->regs[index] = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: bad offset 0x%x\n", __func__,
(uint32_t)offset);
break;
}
allwinner_a10_spi_update_irq(s);
}
static const MemoryRegionOps allwinner_a10_spi_ops = {
.read = allwinner_a10_spi_read,
.write = allwinner_a10_spi_write,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static const VMStateDescription allwinner_a10_spi_vmstate = {
.name = TYPE_AW_A10_SPI,
.version_id = 1,
.minimum_version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_FIFO8(tx_fifo, AWA10SPIState),
VMSTATE_FIFO8(rx_fifo, AWA10SPIState),
VMSTATE_UINT32_ARRAY(regs, AWA10SPIState, AW_A10_SPI_REGS_NUM),
VMSTATE_END_OF_LIST()
}
};
static void allwinner_a10_spi_realize(DeviceState *dev, Error **errp)
{
AWA10SPIState *s = AW_A10_SPI(dev);
int i = 0;
memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_a10_spi_ops, s,
TYPE_AW_A10_SPI, AW_A10_SPI_IOSIZE);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
s->bus = ssi_create_bus(dev, "spi");
for (i = 0; i < AW_A10_SPI_CS_LINES_NR; i++) {
sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->cs_lines[i]);
}
fifo8_create(&s->tx_fifo, AW_A10_SPI_FIFO_SIZE);
fifo8_create(&s->rx_fifo, AW_A10_SPI_FIFO_SIZE);
}
static void allwinner_a10_spi_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
ResettableClass *rc = RESETTABLE_CLASS(klass);
rc->phases.hold = allwinner_a10_spi_reset_hold;
dc->vmsd = &allwinner_a10_spi_vmstate;
dc->realize = allwinner_a10_spi_realize;
dc->desc = "Allwinner A10 SPI Controller";
}
static const TypeInfo allwinner_a10_spi_type_info = {
.name = TYPE_AW_A10_SPI,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(AWA10SPIState),
.class_init = allwinner_a10_spi_class_init,
};
static void allwinner_a10_spi_register_types(void)
{
type_register_static(&allwinner_a10_spi_type_info);
}
type_init(allwinner_a10_spi_register_types)