Re: [Qemu-devel] [Qemu devel v6 PATCH 3/5] msf2: Add Smartfusion2 SPI controller

[Alistair Francis <alistair23@gmail.com>]

On Sun, Jul 2, 2017 at 9:45 PM, Subbaraya Sundeep
<sundeep.lkml@gmail.com> wrote:
> Modelled Microsemi's Smartfusion2 SPI controller.
>
> Signed-off-by: Subbaraya Sundeep <sundeep.lkml@gmail.com>
> ---
>  hw/ssi/Makefile.objs     |   1 +
>  hw/ssi/mss-spi.c         | 414 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/ssi/mss-spi.h |  62 +++++++
>  3 files changed, 477 insertions(+)
>  create mode 100644 hw/ssi/mss-spi.c
>  create mode 100644 include/hw/ssi/mss-spi.h
>
> diff --git a/hw/ssi/Makefile.objs b/hw/ssi/Makefile.objs
> index 487add2..f5bcc65 100644
> --- a/hw/ssi/Makefile.objs
> +++ b/hw/ssi/Makefile.objs
> @@ -4,6 +4,7 @@ common-obj-$(CONFIG_XILINX_SPI) += xilinx_spi.o
>  common-obj-$(CONFIG_XILINX_SPIPS) += xilinx_spips.o
>  common-obj-$(CONFIG_ASPEED_SOC) += aspeed_smc.o
>  common-obj-$(CONFIG_STM32F2XX_SPI) += stm32f2xx_spi.o
> +common-obj-$(CONFIG_MSF2) += mss-spi.o
>
>  obj-$(CONFIG_OMAP) += omap_spi.o
>  obj-$(CONFIG_IMX) += imx_spi.o
> diff --git a/hw/ssi/mss-spi.c b/hw/ssi/mss-spi.c
> new file mode 100644
> index 0000000..a572abc
> --- /dev/null
> +++ b/hw/ssi/mss-spi.c
> @@ -0,0 +1,414 @@
> +/*
> + * Block model of SPI controller present in
> + * Microsemi's SmartFusion2 and SmartFusion SoCs.
> + *
> + * Copyright (C) 2017 Subbaraya Sundeep <sundeep.lkml@gmail.com>
> + *
> + * 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 "hw/ssi/mss-spi.h"

Same comment as earlier patches.

> +
> +#ifndef MSS_SPI_ERR_DEBUG
> +#define MSS_SPI_ERR_DEBUG   0
> +#endif
> +
> +#define DB_PRINT_L(lvl, fmt, args...) do { \
> +    if (MSS_SPI_ERR_DEBUG >= lvl) { \
> +        qemu_log("%s: " fmt "\n", __func__, ## args); \
> +    } \
> +} while (0);
> +
> +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
> +
> +#define FIFO_CAPACITY         32
> +#define FIFO_CAPACITY         32
> +
> +#define R_SPI_CONTROL         0
> +#define R_SPI_DFSIZE          1
> +#define R_SPI_STATUS          2
> +#define R_SPI_INTCLR          3
> +#define R_SPI_RX              4
> +#define R_SPI_TX              5
> +#define R_SPI_CLKGEN          6
> +#define R_SPI_SS              7
> +#define R_SPI_MIS             8
> +#define R_SPI_RIS             9
> +
> +#define S_TXDONE             (1 << 0)
> +#define S_RXRDY              (1 << 1)
> +#define S_RXCHOVRF           (1 << 2)
> +#define S_RXFIFOFUL          (1 << 4)
> +#define S_RXFIFOFULNXT       (1 << 5)
> +#define S_RXFIFOEMP          (1 << 6)
> +#define S_RXFIFOEMPNXT       (1 << 7)
> +#define S_TXFIFOFUL          (1 << 8)
> +#define S_TXFIFOFULNXT       (1 << 9)
> +#define S_TXFIFOEMP          (1 << 10)
> +#define S_TXFIFOEMPNXT       (1 << 11)
> +#define S_FRAMESTART         (1 << 12)
> +#define S_SSEL               (1 << 13)
> +#define S_ACTIVE             (1 << 14)
> +
> +#define C_ENABLE             (1 << 0)
> +#define C_MODE               (1 << 1)
> +#define C_INTRXDATA          (1 << 4)
> +#define C_INTTXDATA          (1 << 5)
> +#define C_INTRXOVRFLO        (1 << 6)
> +#define C_SPS                (1 << 26)
> +#define C_BIGFIFO            (1 << 29)
> +#define C_RESET              (1 << 31)
> +
> +#define FRAMESZ_MASK         0x1F
> +#define FMCOUNT_MASK         0x00FFFF00
> +#define FMCOUNT_SHIFT        8
> +
> +static void txfifo_reset(MSSSpiState *s)
> +{
> +    fifo32_reset(&s->tx_fifo);
> +
> +    s->regs[R_SPI_STATUS] &= ~S_TXFIFOFUL;
> +    s->regs[R_SPI_STATUS] |= S_TXFIFOEMP;
> +}
> +
> +static void rxfifo_reset(MSSSpiState *s)
> +{
> +    fifo32_reset(&s->rx_fifo);
> +
> +    s->regs[R_SPI_STATUS] &= ~S_RXFIFOFUL;
> +    s->regs[R_SPI_STATUS] |= S_RXFIFOEMP;
> +}
> +
> +static void set_fifodepth(MSSSpiState *s)
> +{
> +    unsigned int size = s->regs[R_SPI_DFSIZE] & FRAMESZ_MASK;
> +
> +    if (size <= 8) {
> +        s->fifo_depth = 32;
> +    } else if (size <= 16) {
> +        s->fifo_depth = 16;
> +    } else if (size <= 32) {
> +        s->fifo_depth = 8;
> +    } else {
> +        s->fifo_depth = 4;
> +    }
> +}
> +
> +static void mss_spi_do_reset(MSSSpiState *s)
> +{
> +    memset(s->regs, 0, sizeof s->regs);
> +    s->regs[R_SPI_CONTROL] = 0x80000102;
> +    s->regs[R_SPI_DFSIZE] = 0x4;
> +    s->regs[R_SPI_STATUS] = S_SSEL | S_TXFIFOEMP | S_RXFIFOEMP;
> +    s->regs[R_SPI_CLKGEN] = 0x7;
> +    s->regs[R_SPI_RIS] = 0x0;
> +
> +    s->fifo_depth = 4;
> +    s->frame_count = 1;
> +    s->enabled = false;
> +
> +    rxfifo_reset(s);
> +    txfifo_reset(s);
> +}
> +
> +static void update_mis(MSSSpiState *s)
> +{
> +    uint32_t reg = s->regs[R_SPI_CONTROL];
> +    uint32_t tmp;
> +
> +    /*
> +     * form the Control register interrupt enable bits
> +     * same as RIS, MIS and Interrupt clear registers for simplicity
> +     */
> +    tmp = ((reg & C_INTRXOVRFLO) >> 4) | ((reg & C_INTRXDATA) >> 3) |
> +           ((reg & C_INTTXDATA) >> 5);
> +    s->regs[R_SPI_MIS] |= tmp & s->regs[R_SPI_RIS];
> +}
> +
> +static void spi_update_irq(MSSSpiState *s)
> +{
> +    int irq;
> +
> +    update_mis(s);
> +    irq = !!(s->regs[R_SPI_MIS]);
> +
> +    qemu_set_irq(s->irq, irq);
> +}
> +
> +static void mss_spi_reset(DeviceState *d)
> +{
> +    mss_spi_do_reset(MSS_SPI(d));
> +}
> +
> +static uint64_t
> +spi_read(void *opaque, hwaddr addr, unsigned int size)
> +{
> +    MSSSpiState *s = opaque;
> +    uint32_t ret = 0;
> +
> +    addr >>= 2;
> +    switch (addr) {
> +    case R_SPI_RX:
> +        s->regs[R_SPI_STATUS] &= ~S_RXFIFOFUL;
> +        s->regs[R_SPI_STATUS] &= ~S_RXCHOVRF;
> +        ret = fifo32_pop(&s->rx_fifo);
> +        if (fifo32_is_empty(&s->rx_fifo)) {
> +            s->regs[R_SPI_STATUS] |= S_RXFIFOEMP;
> +        }
> +        break;
> +
> +    case R_SPI_MIS:
> +        update_mis(s);
> +        ret = s->regs[R_SPI_MIS];
> +        break;
> +
> +    default:
> +        if (addr < ARRAY_SIZE(s->regs)) {
> +            ret = s->regs[addr];
> +        } else {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                         "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__,
> +                         addr * 4);

I think return here to avoid the next print statement and irq update.

> +        }
> +        break;
> +    }
> +
> +    DB_PRINT("addr=0x%" HWADDR_PRIx " = 0x%" PRIx32, addr * 4, ret);
> +    spi_update_irq(s);
> +    return ret;
> +}
> +
> +static void assert_cs(MSSSpiState *s)
> +{
> +    qemu_set_irq(s->cs_line, 0);
> +}
> +
> +static void deassert_cs(MSSSpiState *s)
> +{
> +    qemu_set_irq(s->cs_line, 1);
> +}
> +
> +static void spi_flush_txfifo(MSSSpiState *s)
> +{
> +    uint32_t tx;
> +    uint32_t rx;
> +    bool sps = !!(s->regs[R_SPI_CONTROL] & C_SPS);
> +
> +    /*
> +     * Chip Select(CS) is automatically controlled by this controller.
> +     * If SPS bit is set in Control register then CS is asserted
> +     * until all the frames set in frame count of Control register are
> +     * transferred. If SPS is not set then CS pulses between frames.
> +     * Note that Slave Select register specifies which of the CS line
> +     * has to be controlled automatically by controller. Bits SS[7:1] are for
> +     * masters in FPGA fabric since we model only Microcontroller subsystem
> +     * of Smartfusion2 we control only one CS(SS[0]) line.
> +     */
> +    while (!fifo32_is_empty(&s->tx_fifo) && s->frame_count) {
> +        assert_cs(s);
> +
> +        s->regs[R_SPI_STATUS] &= ~(S_TXDONE | S_RXRDY);
> +
> +        tx = fifo32_pop(&s->tx_fifo);
> +        DB_PRINT("data tx:0x%" PRIx32, tx);
> +        rx = ssi_transfer(s->spi, tx);
> +        DB_PRINT("data rx:0x%" PRIx32, rx);
> +
> +        if (fifo32_num_used(&s->rx_fifo) == s->fifo_depth) {
> +            s->regs[R_SPI_STATUS] |= S_RXCHOVRF;
> +            s->regs[R_SPI_RIS] |= S_RXCHOVRF;
> +        } else {
> +            fifo32_push(&s->rx_fifo, rx);
> +            s->regs[R_SPI_STATUS] &= ~S_RXFIFOEMP;
> +            if (fifo32_num_used(&s->rx_fifo) == (s->fifo_depth - 1)) {
> +                s->regs[R_SPI_STATUS] |= S_RXFIFOFULNXT;
> +            }
> +            if (fifo32_num_used(&s->rx_fifo) == s->fifo_depth) {

I'd use an else if to indicate that both can't happen at the same time.

> +                s->regs[R_SPI_STATUS] |= S_RXFIFOFUL;
> +            }
> +        }
> +        s->frame_count--;
> +        if (!sps) {
> +            deassert_cs(s);
> +            assert_cs(s);

Do you need the asert here? Can't you just wait for it to hit the
start of the loop?

Does it deassert assert and deassert after a transfer has finished?

> +        }
> +    }
> +
> +    if (!sps) {
> +        deassert_cs(s);
> +    }
> +
> +    if (!s->frame_count) {
> +        s->frame_count = (s->regs[R_SPI_CONTROL] & FMCOUNT_MASK) >>
> +                            FMCOUNT_SHIFT;
> +        if (sps) {
> +            deassert_cs(s);
> +        }
> +        s->regs[R_SPI_RIS] |= S_TXDONE | S_RXRDY;
> +        s->regs[R_SPI_STATUS] |= S_TXDONE | S_RXRDY;
> +   }
> +}
> +
> +static void spi_write(void *opaque, hwaddr addr,
> +            uint64_t val64, unsigned int size)
> +{
> +    MSSSpiState *s = opaque;
> +    uint32_t value = val64;
> +
> +    DB_PRINT("addr=0x%" HWADDR_PRIx " =0x%" PRIx32, addr, value);
> +    addr >>= 2;
> +
> +    switch (addr) {
> +    case R_SPI_TX:
> +        /* adding to already full FIFO */
> +        if (fifo32_num_used(&s->tx_fifo) == s->fifo_depth) {
> +            break;
> +        }
> +        s->regs[R_SPI_STATUS] &= ~S_TXFIFOEMP;
> +        fifo32_push(&s->tx_fifo, value);
> +        if (fifo32_num_used(&s->tx_fifo) == (s->fifo_depth - 1)) {
> +            s->regs[R_SPI_STATUS] |= S_TXFIFOFULNXT;
> +        }

else if here as well

Thanks,
Alistair

> +        if (fifo32_num_used(&s->tx_fifo) == s->fifo_depth) {
> +            s->regs[R_SPI_STATUS] |= S_TXFIFOFUL;
> +        }
> +        if (s->enabled) {
> +            spi_flush_txfifo(s);
> +        }
> +        break;
> +
> +    case R_SPI_CONTROL:
> +        s->regs[R_SPI_CONTROL] = value;
> +        if (value & C_BIGFIFO) {
> +            set_fifodepth(s);
> +        } else {
> +            s->fifo_depth = 4;
> +        }
> +        s->enabled = value & C_ENABLE;
> +        s->frame_count = (value & FMCOUNT_MASK) >> FMCOUNT_SHIFT;
> +        if (value & C_RESET) {
> +            mss_spi_do_reset(s);
> +        }
> +        break;
> +
> +    case R_SPI_DFSIZE:
> +        if (s->enabled) {
> +            break;
> +        }
> +        s->regs[R_SPI_DFSIZE] = value;
> +        break;
> +
> +    case R_SPI_INTCLR:
> +        s->regs[R_SPI_INTCLR] = value;
> +        if (value & S_TXDONE) {
> +            s->regs[R_SPI_RIS] &= ~S_TXDONE;
> +        }
> +        if (value & S_RXRDY) {
> +            s->regs[R_SPI_RIS] &= ~S_RXRDY;
> +        }
> +        if (value & S_RXCHOVRF) {
> +            s->regs[R_SPI_RIS] &= ~S_RXCHOVRF;
> +        }
> +        break;
> +
> +    case R_SPI_MIS:
> +    case R_SPI_STATUS:
> +    case R_SPI_RIS:
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                         "%s: Write to read only register 0x%" HWADDR_PRIx "\n",
> +                         __func__, addr * 4);
> +        break;
> +
> +    default:
> +        if (addr < ARRAY_SIZE(s->regs)) {
> +            s->regs[addr] = value;
> +        } else {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                         "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__,
> +                         addr * 4);
> +        }
> +        break;
> +    }
> +
> +    spi_update_irq(s);
> +}
> +
> +static const MemoryRegionOps spi_ops = {
> +    .read = spi_read,
> +    .write = spi_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .valid = {
> +        .min_access_size = 1,
> +        .max_access_size = 4
> +    }
> +};
> +
> +static void mss_spi_realize(DeviceState *dev, Error **errp)
> +{
> +    MSSSpiState *s = MSS_SPI(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +
> +    s->spi = ssi_create_bus(dev, "spi");
> +
> +    sysbus_init_irq(sbd, &s->irq);
> +    ssi_auto_connect_slaves(dev, &s->cs_line, s->spi);
> +    sysbus_init_irq(sbd, &s->cs_line);
> +
> +    memory_region_init_io(&s->mmio, OBJECT(s), &spi_ops, s,
> +                          TYPE_MSS_SPI, R_SPI_MAX * 4);
> +    sysbus_init_mmio(sbd, &s->mmio);
> +
> +    fifo32_create(&s->tx_fifo, FIFO_CAPACITY);
> +    fifo32_create(&s->rx_fifo, FIFO_CAPACITY);
> +}
> +
> +static const VMStateDescription vmstate_mss_spi = {
> +    .name = TYPE_MSS_SPI,
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_FIFO32(tx_fifo, MSSSpiState),
> +        VMSTATE_FIFO32(rx_fifo, MSSSpiState),
> +        VMSTATE_UINT32_ARRAY(regs, MSSSpiState, R_SPI_MAX),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static void mss_spi_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->realize = mss_spi_realize;
> +    dc->reset = mss_spi_reset;
> +    dc->vmsd = &vmstate_mss_spi;
> +}
> +
> +static const TypeInfo mss_spi_info = {
> +    .name           = TYPE_MSS_SPI,
> +    .parent         = TYPE_SYS_BUS_DEVICE,
> +    .instance_size  = sizeof(MSSSpiState),
> +    .class_init     = mss_spi_class_init,
> +};
> +
> +static void mss_spi_register_types(void)
> +{
> +    type_register_static(&mss_spi_info);
> +}
> +
> +type_init(mss_spi_register_types)
> diff --git a/include/hw/ssi/mss-spi.h b/include/hw/ssi/mss-spi.h
> new file mode 100644
> index 0000000..6c8c0b1
> --- /dev/null
> +++ b/include/hw/ssi/mss-spi.h
> @@ -0,0 +1,62 @@
> +/*
> + * Microsemi SmartFusion2 SPI
> + *
> + * Copyright (c) 2017 Subbaraya Sundeep <sundeep.lkml@gmail.com>
> + *
> + * 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.
> + */
> +
> +#ifndef HW_MSS_SPI_H
> +#define HW_MSS_SPI_H
> +
> +#include "qemu/osdep.h"
> +#include "hw/sysbus.h"
> +#include "hw/hw.h"
> +#include "hw/ssi/ssi.h"
> +#include "qemu/fifo32.h"
> +#include "sysemu/sysemu.h"
> +#include "qemu/log.h"
> +
> +#define TYPE_MSS_SPI   "mss-spi"
> +#define MSS_SPI(obj)   OBJECT_CHECK(MSSSpiState, (obj), TYPE_MSS_SPI)
> +
> +#define R_SPI_MAX             16
> +
> +typedef struct MSSSpiState {
> +    SysBusDevice parent_obj;
> +
> +    MemoryRegion mmio;
> +
> +    qemu_irq irq;
> +
> +    qemu_irq cs_line;
> +
> +    SSIBus *spi;
> +
> +    Fifo32 rx_fifo;
> +    Fifo32 tx_fifo;
> +
> +    int fifo_depth;
> +    uint32_t frame_count;
> +    bool enabled;
> +
> +    uint32_t regs[R_SPI_MAX];
> +} MSSSpiState;
> +
> +#endif /* HW_MSS_SPI_H */
> --
> 2.5.0
>