Re: [Qemu-devel] [PATCH v3 3/4] xilinx_spi: initial version

[Peter Maydell]

On 20 April 2012 03:12, Peter A. G. Crosthwaite
<address@hidden> wrote:
> device model for xilinx XPS SPI controller (v2.0)
>
> Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
> ---
> changed from v2:
> converted spi api to ssi api
> changed from v1:
> converted spi api to modified txrx style
>
>  Makefile.target |    1 +
>  hw/xilinx_spi.c |  453 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 454 insertions(+), 0 deletions(-)
>  create mode 100644 hw/xilinx_spi.c
>
> diff --git a/Makefile.target b/Makefile.target
> index 3f7c38e..e163c64 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -327,6 +327,7 @@ obj-microblaze-y = petalogix_s3adsp1800_mmu.o
>  obj-microblaze-y += petalogix_ml605_mmu.o
>  obj-microblaze-y += microblaze_boot.o
>  obj-microblaze-y += m25p80.o
> +obj-microblaze-y += xilinx_spi.o
>
>  obj-microblaze-y += microblaze_pic_cpu.o
>  obj-microblaze-y += xilinx_intc.o
> diff --git a/hw/xilinx_spi.c b/hw/xilinx_spi.c
> new file mode 100644
> index 0000000..82a6b32
> --- /dev/null
> +++ b/hw/xilinx_spi.c
> @@ -0,0 +1,453 @@
> +/*
> + * 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 "ptimer.h"
> +#include "qemu-log.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)
> +
> +struct XilinxSPI {
> +    SysBusDevice busdev;
> +    MemoryRegion mmio;
> +    qemu_irq irq;
> +    int irqline;
> +
> +    QEMUBH *bh;
> +    ptimer_state *ptimer;
> +
> +    SSIBus *spi;
> +
> +    uint32_t c_fifo_exist;
> +
> +    uint8_t rx_fifo[256];
> +    unsigned int rx_fifo_pos;
> +    unsigned int rx_fifo_len;
> +
> +    uint8_t tx_fifo[256];
> +    unsigned int tx_fifo_pos;
> +    unsigned int tx_fifo_len;
> +
> +    /* Slave select.  */
> +    uint8_t num_cs;
> +    int cmd_ongoing;
> +
> +    uint32_t regs[R_MAX];
> +};

Needs save/load support.

> +
> +static void txfifo_reset(struct XilinxSPI *s)
> +{
> +    s->tx_fifo_pos = 0;
> +    s->tx_fifo_len = 0;
> +
> +    s->regs[R_SPISR] &= ~SR_TX_FULL;
> +    s->regs[R_SPISR] |= SR_TX_EMPTY;
> +    s->regs[R_SPISR] &= ~SR_TX_FULL;

Duplicate of the first line, some typo here??

> +    s->regs[R_IPISR] |= IRQ_DTR_EMPTY;

> +}
> +
> +static void rxfifo_reset(struct XilinxSPI *s)
> +{
> +    s->rx_fifo_pos = 0;
> +    s->rx_fifo_len = 0;
> +
> +    s->regs[R_SPISR] |= SR_RX_EMPTY;
> +    s->regs[R_SPISR] &= ~SR_RX_FULL;
> +    s->regs[R_IPISR] &= ~IRQ_DRR_NOT_EMPTY;
> +    s->regs[R_IPISR] &= ~IRQ_DRR_OVERRUN;
> +}
> +
> +static void xlx_spi_reset(struct XilinxSPI *s)
> +{
> +    memset(s->regs, 0, sizeof s->regs);
> +
> +    rxfifo_reset(s);
> +    txfifo_reset(s);
> +
> +    s->regs[R_SPISSR] = 1;
> +    ssi_select_slave(s->spi, 0);
> +}
> +
> +static void xlx_spi_update_irq(struct XilinxSPI *s)
> +{
> +    uint32_t pending;
> +    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 dont call the
> +       irq chain unless things really changed.  */

"don't".

> +    if (pending != s->irqline) {
> +        s->irqline = pending;
> +        DB_PRINT("irq_change_of of state %d\n", pending);
> +        qemu_set_irq(s->irq, pending);
> +    }
> +}
> +
> +static inline int spi_master_enabled(struct XilinxSPI *s)
> +{
> +    return !(s->regs[R_SPICR] & R_SPICR_MTI);
> +}
> +
> +static int spi_slave_select(struct XilinxSPI *s, uint32_t v)
> +{
> +    unsigned int ss;
> +
> +    ss = ffs(v) - 1;
> +    return ss < s->num_cs ? ss : SSI_SLAVE_SELECT_NONE;
> +}
> +
> +static inline int txfifo_empty(struct XilinxSPI *s)
> +{
> +    return s->tx_fifo_len == 0;
> +}
> +
> +static inline int txfifo_full(struct XilinxSPI *s)
> +{
> +    return s->tx_fifo_len >= ARRAY_SIZE(s->tx_fifo);
> +}
> +
> +static inline int rxfifo_empty(struct XilinxSPI *s)
> +{
> +    return s->rx_fifo_len == 0;
> +}
> +
> +static inline int rxfifo_full(struct XilinxSPI *s)
> +{
> +    return s->rx_fifo_len >= ARRAY_SIZE(s->rx_fifo);
> +}
> +
> +static inline void txfifo_put(struct XilinxSPI *s, uint8_t v)
> +{
> +    s->regs[R_SPISR] &= ~SR_TX_EMPTY;
> +    s->regs[R_IPISR] &= ~IRQ_DTR_EMPTY;
> +
> +    s->tx_fifo[s->tx_fifo_pos] = v;
> +    s->tx_fifo_pos++;
> +    s->tx_fifo_pos &= ARRAY_SIZE(s->tx_fifo) - 1;
> +    s->tx_fifo_len++;
> +
> +    s->regs[R_SPISR] &= ~SR_TX_FULL;
> +    if (txfifo_full(s)) {
> +        s->regs[R_SPISR] |= SR_TX_FULL;
> +    }
> +}
> +
> +static inline uint8_t txfifo_get(struct XilinxSPI *s)
> +{
> +    uint8_t r = 0;
> +    assert(s->tx_fifo_len);
> +
> +    r = s->tx_fifo[(s->tx_fifo_pos - s->tx_fifo_len) &
> +                                (ARRAY_SIZE(s->tx_fifo) - 1)];
> +    s->tx_fifo_len--;
> +
> +    s->regs[R_SPISR] &= ~SR_TX_FULL;
> +    if (txfifo_empty(s)) {
> +        s->regs[R_SPISR] |= SR_TX_EMPTY;
> +        s->regs[R_IPISR] |= IRQ_DTR_EMPTY;
> +    }
> +
> +    return r;
> +}
> +
> +static inline void rxfifo_put(struct XilinxSPI *s, uint8_t v)
> +{
> +    DB_PRINT("%x\n", v);
> +    s->regs[R_SPISR] &= ~SR_RX_EMPTY;
> +    s->regs[R_IPISR] |= IRQ_DRR_NOT_EMPTY;
> +
> +    s->rx_fifo[s->rx_fifo_pos] = v;
> +    s->rx_fifo_pos++;
> +    s->rx_fifo_pos &= ARRAY_SIZE(s->rx_fifo) - 1;
> +    s->rx_fifo_len++;
> +
> +    s->regs[R_SPISR] &= ~SR_RX_FULL;
> +    if (s->rx_fifo_len >= ARRAY_SIZE(s->rx_fifo)) {
> +        s->regs[R_SPISR] |= SR_RX_FULL;
> +        s->regs[R_IPISR] |= IRQ_DRR_OVERRUN;
> +    }
> +}
> +
> +static inline uint32_t rxfifo_get(struct XilinxSPI *s)
> +{
> +    uint32_t r = 0;
> +    assert(s->rx_fifo_len);
> +
> +    r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) &
> +                            (ARRAY_SIZE(s->rx_fifo) - 1)];
> +    s->rx_fifo_len--;
> +
> +    s->regs[R_SPISR] &= ~SR_RX_FULL;
> +    if (rxfifo_empty(s)) {
> +        s->regs[R_SPISR] |= SR_RX_EMPTY;
> +        s->regs[R_IPISR] &= ~IRQ_DRR_NOT_EMPTY;
> +    }
> +
> +    return r;
> +}
> +
> +static void spi_timer_run(struct XilinxSPI *s, int delay)
> +{
> +    ptimer_set_count(s->ptimer, delay);
> +    ptimer_run(s->ptimer, 1);
> +}

You should ptimer_stop() this timer in some reset function
somewhere, otherwise it might erroneously fire if it happened
to be running when we do a reset.


> +
> +static void
> +spi_flush_txfifo(struct XilinxSPI *s)
> +{
> +    uint32_t tx;
> +    uint32_t rx;
> +
> +    while (!txfifo_empty(s)) {
> +        tx = (uint32_t)txfifo_get(s);
> +        DB_PRINT("data transfer:%x\n", tx);
> +        rx = ssi_transfer(s->spi, (uint32_t)tx);
> +        rxfifo_put(s, rx);
> +    }
> +}
> +
> +static uint64_t
> +spi_read(void *opaque, target_phys_addr_t addr, unsigned int size)
> +{
> +    struct XilinxSPI *s = opaque;
> +    uint32_t r = 0;
> +
> +    addr >>= 2;
> +    switch (addr) {
> +    case R_SPIDRR:
> +        if (rxfifo_empty(s)) {
> +            DB_PRINT("Read from empty FIFO!\n");
> +            return 0xdeadbeef;
> +        }
> +
> +        r = rxfifo_get(s);
> +        break;
> +
> +    case R_SPISR:
> +        r = s->regs[addr];
> +        if (rxfifo_empty(s)) {
> +            spi_timer_run(s, 1);
> +        }
> +        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)
> +{
> +    struct 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_reset(s);
> +        }
> +        break;
> +
> +    case R_SPIDTR:
> +        txfifo_put(s, value);
> +
> +        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:
> +        ssi_select_slave(s->spi, spi_slave_select(s, ~value));
> +        s->regs[addr] = value;
> +        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)) {
> +            /* When releasing the master disable, initiate a timer
> +               that eventually will flush the txfifo.  */
> +            spi_timer_run(s, 1);
> +        }
> +        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 timer_hit(void *opaque)
> +{
> +    struct XilinxSPI *s = opaque;
> +
> +    if (!txfifo_empty(s)) {
> +        spi_flush_txfifo(s);
> +        s->cmd_ongoing = 1;
> +    }
> +    xlx_spi_update_irq(s);
> +}
> +
> +static int xilinx_spi_init(SysBusDevice *dev)
> +{
> +    struct XilinxSPI *s = FROM_SYSBUS(typeof(*s), dev);
> +
> +    DB_PRINT("\n");
> +    sysbus_init_irq(dev, &s->irq);
> +
> +    memory_region_init_io(&s->mmio, &spi_ops, s, "xilinx-spi", R_MAX * 4);
> +    sysbus_init_mmio(dev, &s->mmio);
> +
> +    s->bh = qemu_bh_new(timer_hit, s);
> +    s->ptimer = ptimer_init(s->bh);
> +    ptimer_set_freq(s->ptimer, 10 * 1000 * 1000);
> +
> +    s->spi = ssi_create_bus(&dev->qdev, "spi");
> +
> +    xlx_spi_reset(s);
> +    return 0;
> +}
> +
> +static Property xilinx_spi_properties[] = {
> +    DEFINE_PROP_UINT8("num-cs", struct 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->props = xilinx_spi_properties;
> +}
> +
> +static TypeInfo xilinx_spi_info = {
> +    .name           = "xilinx,spi",
> +    .parent         = TYPE_SYS_BUS_DEVICE,
> +    .instance_size  = sizeof(struct 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)

-- PMM