--- /dev/null
+/*
+ * 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 "sysbus.h"
+#include "sysemu.h"
+#include "qemu-log.h"
+#include "fifo.h"
+
+#include "ssi.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
+
+typedef struct XilinxSPI {
+ SysBusDevice busdev;
+ 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];
+} XilinxSPI;
+
+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 %d 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;
+ xlx_spi_update_irq(s);
+ xlx_spi_update_cs(s);
+}
+
+static void xlx_spi_reset(DeviceState *d)
+{
+ xlx_spi_do_reset(DO_UPCAST(XilinxSPI, busdev.qdev, 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, target_phys_addr_t 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=" TARGET_FMT_plx " = %x\n", addr * 4, r);
+ xlx_spi_update_irq(s);
+ return r;
+}
+
+static void
+spi_write(void *opaque, target_phys_addr_t addr,
+ uint64_t val64, unsigned int size)
+{
+ XilinxSPI *s = opaque;
+ uint32_t value = val64;
+
+ DB_PRINT("addr=" TARGET_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 int xilinx_spi_init(SysBusDevice *dev)
+{
+ int i;
+ XilinxSPI *s = FROM_SYSBUS(typeof(*s), dev);
+
+ DB_PRINT("\n");
+ sysbus_init_irq(dev, &s->irq);
+ s->cs_lines = g_new(qemu_irq, s->num_cs);
+ for (i = 0; i < s->num_cs; ++i) {
+ sysbus_init_irq(dev, &s->cs_lines[i]);
+ }
+
+ memory_region_init_io(&s->mmio, &spi_ops, s, "xilinx-spi", R_MAX * 4);
+ sysbus_init_mmio(dev, &s->mmio);
+
+ s->irqline = -1;
+
+ s->spi = ssi_create_bus(&dev->qdev, "spi");
+
+ fifo8_create(&s->tx_fifo, FIFO_CAPACITY);
+ fifo8_create(&s->rx_fifo, FIFO_CAPACITY);
+
+ return 0;
+}
+
+static const VMStateDescription vmstate_xilinx_spi = {
+ .name = "xilinx_spi",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .fields = (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);
+ SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+ k->init = xilinx_spi_init;
+ dc->reset = xlx_spi_reset;
+ dc->props = xilinx_spi_properties;
+ dc->vmsd = &vmstate_xilinx_spi;
+}
+
+static TypeInfo xilinx_spi_info = {
+ .name = "xlnx.xps-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)