Re: [Qemu-devel] [PATCH 09/14] xilinx_spi: Initial impl. of Xilinx SPI controller

[Peter Maydell]

On 5 October 2012 01:08, Peter Crosthwaite
<address@hidden> wrote:
> From: Peter A. G. Crosthwaite <address@hidden>
>
> Device model for xilinx XPS SPI controller (v2.0)
>
> Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
> ---
>  hw/microblaze/Makefile.objs |    1 +
>  hw/xilinx_spi.c             |  390 
> +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 391 insertions(+), 0 deletions(-)
>  create mode 100644 hw/xilinx_spi.c
>
> diff --git a/hw/microblaze/Makefile.objs b/hw/microblaze/Makefile.objs
> index 274d2c5..3028e65 100644
> --- a/hw/microblaze/Makefile.objs
> +++ b/hw/microblaze/Makefile.objs
> @@ -1,6 +1,7 @@
>  obj-y = petalogix_s3adsp1800_mmu.o
>  obj-y += petalogix_ml605_mmu.o
>  obj-y += microblaze_boot.o
> +obj-y += xilinx_spi.o
>
>  obj-y += microblaze_pic_cpu.o
>  obj-y += xilinx_ethlite.o
> diff --git a/hw/xilinx_spi.c b/hw/xilinx_spi.c
> new file mode 100644
> index 0000000..0ace004
> --- /dev/null
> +++ b/hw/xilinx_spi.c
> @@ -0,0 +1,390 @@
> +/*
> + * QEMU model of the Xilinx SPI Controller
> + *
> + * Copyright (C) 2010 Edgar E. Iglesias.
> + * Copyright (C) 2012 Peter A. G. Crosthwaite <address@hidden>
> + * 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 int xilinx_spi_post_load(void *opaque, int version_id)
> +{
> +    xlx_spi_update_irq((XilinxSPI *)opaque);

Don't assert outbound IRQs following load: the device on the
other end should handle its own state restoration so after
everybody has loaded both ends should consistently believe
the IRQ has been asserted. If you reassert it in a post_load
hook you'll put the device on the other end into the wrong
state if it was restored before you were.

> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_xilinx_spi = {
> +    .name = "xilinx_spi",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .minimum_version_id_old = 1,
> +    .post_load = xilinx_spi_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_FIFO8(tx_fifo, XilinxSPI),
> +        VMSTATE_FIFO8(rx_fifo, XilinxSPI),
> +        VMSTATE_UINT32_ARRAY(regs, XilinxSPI, R_MAX),

You need also an entry for irqline.

> +        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)
> --
> 1.7.0.4
>
>