blob: 2e0687ac9075fd07aab1f12f2430d2b6220faa55 [file] [log] [blame]
/*
* QEMU model of the Xilinx SPI Controller
*
* Copyright (C) 2010 Edgar E. Iglesias.
* Copyright (C) 2012 Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
* Copyright (C) 2012 PetaLogix
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "qemu/module.h"
#include "qemu/fifo8.h"
#include "hw/irq.h"
#include "hw/qdev-properties.h"
#include "hw/ssi/ssi.h"
#include "qom/object.h"
#ifdef XILINX_SPI_ERR_DEBUG
#define DB_PRINT(...) do { \
fprintf(stderr, ": %s: ", __func__); \
fprintf(stderr, ## __VA_ARGS__); \
} while (0)
#else
#define DB_PRINT(...)
#endif
#define R_DGIER (0x1c / 4)
#define R_DGIER_IE (1 << 31)
#define R_IPISR (0x20 / 4)
#define IRQ_DRR_NOT_EMPTY (1 << (31 - 23))
#define IRQ_DRR_OVERRUN (1 << (31 - 26))
#define IRQ_DRR_FULL (1 << (31 - 27))
#define IRQ_TX_FF_HALF_EMPTY (1 << 6)
#define IRQ_DTR_UNDERRUN (1 << 3)
#define IRQ_DTR_EMPTY (1 << (31 - 29))
#define R_IPIER (0x28 / 4)
#define R_SRR (0x40 / 4)
#define R_SPICR (0x60 / 4)
#define R_SPICR_TXFF_RST (1 << 5)
#define R_SPICR_RXFF_RST (1 << 6)
#define R_SPICR_MTI (1 << 8)
#define R_SPISR (0x64 / 4)
#define SR_TX_FULL (1 << 3)
#define SR_TX_EMPTY (1 << 2)
#define SR_RX_FULL (1 << 1)
#define SR_RX_EMPTY (1 << 0)
#define R_SPIDTR (0x68 / 4)
#define R_SPIDRR (0x6C / 4)
#define R_SPISSR (0x70 / 4)
#define R_TX_FF_OCY (0x74 / 4)
#define R_RX_FF_OCY (0x78 / 4)
#define R_MAX (0x7C / 4)
#define FIFO_CAPACITY 256
#define TYPE_XILINX_SPI "xlnx.xps-spi"
OBJECT_DECLARE_SIMPLE_TYPE(XilinxSPI, XILINX_SPI)
struct XilinxSPI {
SysBusDevice parent_obj;
MemoryRegion mmio;
qemu_irq irq;
int irqline;
uint8_t num_cs;
qemu_irq *cs_lines;
SSIBus *spi;
Fifo8 rx_fifo;
Fifo8 tx_fifo;
uint32_t regs[R_MAX];
};
static void txfifo_reset(XilinxSPI *s)
{
fifo8_reset(&s->tx_fifo);
s->regs[R_SPISR] &= ~SR_TX_FULL;
s->regs[R_SPISR] |= SR_TX_EMPTY;
}
static void rxfifo_reset(XilinxSPI *s)
{
fifo8_reset(&s->rx_fifo);
s->regs[R_SPISR] |= SR_RX_EMPTY;
s->regs[R_SPISR] &= ~SR_RX_FULL;
}
static void xlx_spi_update_cs(XilinxSPI *s)
{
int i;
for (i = 0; i < s->num_cs; ++i) {
qemu_set_irq(s->cs_lines[i], !(~s->regs[R_SPISSR] & 1 << i));
}
}
static void xlx_spi_update_irq(XilinxSPI *s)
{
uint32_t pending;
s->regs[R_IPISR] |=
(!fifo8_is_empty(&s->rx_fifo) ? IRQ_DRR_NOT_EMPTY : 0) |
(fifo8_is_full(&s->rx_fifo) ? IRQ_DRR_FULL : 0);
pending = s->regs[R_IPISR] & s->regs[R_IPIER];
pending = pending && (s->regs[R_DGIER] & R_DGIER_IE);
pending = !!pending;
/* This call lies right in the data paths so don't call the
irq chain unless things really changed. */
if (pending != s->irqline) {
s->irqline = pending;
DB_PRINT("irq_change of state %u ISR:%x IER:%X\n",
pending, s->regs[R_IPISR], s->regs[R_IPIER]);
qemu_set_irq(s->irq, pending);
}
}
static void xlx_spi_do_reset(XilinxSPI *s)
{
memset(s->regs, 0, sizeof s->regs);
rxfifo_reset(s);
txfifo_reset(s);
s->regs[R_SPISSR] = ~0;
s->regs[R_SPICR] = R_SPICR_MTI;
xlx_spi_update_irq(s);
xlx_spi_update_cs(s);
}
static void xlx_spi_reset(DeviceState *d)
{
xlx_spi_do_reset(XILINX_SPI(d));
}
static inline int spi_master_enabled(XilinxSPI *s)
{
return !(s->regs[R_SPICR] & R_SPICR_MTI);
}
static void spi_flush_txfifo(XilinxSPI *s)
{
uint32_t tx;
uint32_t rx;
while (!fifo8_is_empty(&s->tx_fifo)) {
tx = (uint32_t)fifo8_pop(&s->tx_fifo);
DB_PRINT("data tx:%x\n", tx);
rx = ssi_transfer(s->spi, tx);
DB_PRINT("data rx:%x\n", rx);
if (fifo8_is_full(&s->rx_fifo)) {
s->regs[R_IPISR] |= IRQ_DRR_OVERRUN;
} else {
fifo8_push(&s->rx_fifo, (uint8_t)rx);
if (fifo8_is_full(&s->rx_fifo)) {
s->regs[R_SPISR] |= SR_RX_FULL;
s->regs[R_IPISR] |= IRQ_DRR_FULL;
}
}
s->regs[R_SPISR] &= ~SR_RX_EMPTY;
s->regs[R_SPISR] &= ~SR_TX_FULL;
s->regs[R_SPISR] |= SR_TX_EMPTY;
s->regs[R_IPISR] |= IRQ_DTR_EMPTY;
s->regs[R_IPISR] |= IRQ_DRR_NOT_EMPTY;
}
}
static uint64_t
spi_read(void *opaque, hwaddr addr, unsigned int size)
{
XilinxSPI *s = opaque;
uint32_t r = 0;
addr >>= 2;
switch (addr) {
case R_SPIDRR:
if (fifo8_is_empty(&s->rx_fifo)) {
DB_PRINT("Read from empty FIFO!\n");
return 0xdeadbeef;
}
s->regs[R_SPISR] &= ~SR_RX_FULL;
r = fifo8_pop(&s->rx_fifo);
if (fifo8_is_empty(&s->rx_fifo)) {
s->regs[R_SPISR] |= SR_RX_EMPTY;
}
break;
case R_SPISR:
r = s->regs[addr];
break;
default:
if (addr < ARRAY_SIZE(s->regs)) {
r = s->regs[addr];
}
break;
}
DB_PRINT("addr=" HWADDR_FMT_plx " = %x\n", addr * 4, r);
xlx_spi_update_irq(s);
return r;
}
static void
spi_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
XilinxSPI *s = opaque;
uint32_t value = val64;
DB_PRINT("addr=" HWADDR_FMT_plx " = %x\n", addr, value);
addr >>= 2;
switch (addr) {
case R_SRR:
if (value != 0xa) {
DB_PRINT("Invalid write to SRR %x\n", value);
} else {
xlx_spi_do_reset(s);
}
break;
case R_SPIDTR:
s->regs[R_SPISR] &= ~SR_TX_EMPTY;
fifo8_push(&s->tx_fifo, (uint8_t)value);
if (fifo8_is_full(&s->tx_fifo)) {
s->regs[R_SPISR] |= SR_TX_FULL;
}
if (!spi_master_enabled(s)) {
goto done;
} else {
DB_PRINT("DTR and master enabled\n");
}
spi_flush_txfifo(s);
break;
case R_SPISR:
DB_PRINT("Invalid write to SPISR %x\n", value);
break;
case R_IPISR:
/* Toggle the bits. */
s->regs[addr] ^= value;
break;
/* Slave Select Register. */
case R_SPISSR:
s->regs[addr] = value;
xlx_spi_update_cs(s);
break;
case R_SPICR:
/* FIXME: reset irq and sr state to empty queues. */
if (value & R_SPICR_RXFF_RST) {
rxfifo_reset(s);
}
if (value & R_SPICR_TXFF_RST) {
txfifo_reset(s);
}
value &= ~(R_SPICR_RXFF_RST | R_SPICR_TXFF_RST);
s->regs[addr] = value;
if (!(value & R_SPICR_MTI)) {
spi_flush_txfifo(s);
}
break;
default:
if (addr < ARRAY_SIZE(s->regs)) {
s->regs[addr] = value;
}
break;
}
done:
xlx_spi_update_irq(s);
}
static const MemoryRegionOps spi_ops = {
.read = spi_read,
.write = spi_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4
}
};
static void xilinx_spi_realize(DeviceState *dev, Error **errp)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
XilinxSPI *s = XILINX_SPI(dev);
int i;
DB_PRINT("\n");
s->spi = ssi_create_bus(dev, "spi");
sysbus_init_irq(sbd, &s->irq);
s->cs_lines = g_new0(qemu_irq, s->num_cs);
for (i = 0; i < s->num_cs; ++i) {
sysbus_init_irq(sbd, &s->cs_lines[i]);
}
memory_region_init_io(&s->mmio, OBJECT(s), &spi_ops, s,
"xilinx-spi", R_MAX * 4);
sysbus_init_mmio(sbd, &s->mmio);
s->irqline = -1;
fifo8_create(&s->tx_fifo, FIFO_CAPACITY);
fifo8_create(&s->rx_fifo, FIFO_CAPACITY);
}
static const VMStateDescription vmstate_xilinx_spi = {
.name = "xilinx_spi",
.version_id = 1,
.minimum_version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_FIFO8(tx_fifo, XilinxSPI),
VMSTATE_FIFO8(rx_fifo, XilinxSPI),
VMSTATE_UINT32_ARRAY(regs, XilinxSPI, R_MAX),
VMSTATE_END_OF_LIST()
}
};
static Property xilinx_spi_properties[] = {
DEFINE_PROP_UINT8("num-ss-bits", XilinxSPI, num_cs, 1),
DEFINE_PROP_END_OF_LIST(),
};
static void xilinx_spi_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = xilinx_spi_realize;
dc->reset = xlx_spi_reset;
device_class_set_props(dc, xilinx_spi_properties);
dc->vmsd = &vmstate_xilinx_spi;
}
static const TypeInfo xilinx_spi_info = {
.name = TYPE_XILINX_SPI,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(XilinxSPI),
.class_init = xilinx_spi_class_init,
};
static void xilinx_spi_register_types(void)
{
type_register_static(&xilinx_spi_info);
}
type_init(xilinx_spi_register_types)