hw/ssi/xilinx_spi.c - qemu - Git at Google

 /*
  * 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 = (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)
	/*
	* 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 = (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)