[qemu.git] / hw / ssi / mss-spi.c

/*
 * Block model of SPI controller present in
 * Microsemi's SmartFusion2 and SmartFusion SoCs.
 *
 * Copyright (C) 2017 Subbaraya Sundeep <[email protected]>
 *
 * 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/irq.h"
#include "hw/ssi/mss-spi.h"
#include "qemu/log.h"
#include "qemu/module.h"

#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 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         0x3F
#define FMCOUNT_MASK         0x00FFFF00
#define FMCOUNT_SHIFT        8
#define FRAMESZ_MAX          32

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 {
        s->fifo_depth = 8;
    }
}

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)
{
    MSSSpiState *s = MSS_SPI(d);

    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 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;
        if (fifo32_is_empty(&s->rx_fifo)) {
            qemu_log_mask(LOG_GUEST_ERROR,
                          "%s: Reading empty RX_FIFO\n",
                          __func__);
        } else {
            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);
            return ret;
        }
        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;
            } else if (fifo32_num_used(&s->rx_fifo) == s->fifo_depth) {
                s->regs[R_SPI_STATUS] |= S_RXFIFOFUL;
            }
        }
        s->frame_count--;
        if (!sps) {
            deassert_cs(s);
        }
    }

    if (!s->frame_count) {
        s->frame_count = (s->regs[R_SPI_CONTROL] & FMCOUNT_MASK) >>
                            FMCOUNT_SHIFT;
        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 (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_reset(DEVICE(s));
        }
        break;

    case R_SPI_DFSIZE:
        if (s->enabled) {
            break;
        }
        /*
         * [31:6] bits are reserved bits and for future use.
         * [5:0] are for frame size. Only [5:0] bits are validated
         * during write, [31:6] bits are untouched.
         */
        if ((value & FRAMESZ_MASK) > FRAMESZ_MAX) {
            qemu_log_mask(LOG_GUEST_ERROR, "%s: Incorrect size %u provided."
                         "Maximum frame size is %u\n",
                         __func__, value & FRAMESZ_MASK, FRAMESZ_MAX);
            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)
Commit	Line	Data
268ee7de SS	1	/*
	2	* Block model of SPI controller present in
	3	* Microsemi's SmartFusion2 and SmartFusion SoCs.
	4	*
	5	* Copyright (C) 2017 Subbaraya Sundeep <[email protected]>
	6	*
	7	* Permission is hereby granted, free of charge, to any person obtaining a copy
	8	* of this software and associated documentation files (the "Software"), to deal
	9	* in the Software without restriction, including without limitation the rights
	10	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	11	* copies of the Software, and to permit persons to whom the Software is
	12	* furnished to do so, subject to the following conditions:
	13	*
	14	* The above copyright notice and this permission notice shall be included in
	15	* all copies or substantial portions of the Software.
	16	*
	17	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	18	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	19	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	20	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	21	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	22	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	23	* THE SOFTWARE.
	24	*/
	25
	26	#include "qemu/osdep.h"
64552b6b	27	#include "hw/irq.h"
268ee7de SS	28	#include "hw/ssi/mss-spi.h"
268ee7de SS	29	#include "qemu/log.h"
0b8fa32f	30	#include "qemu/module.h"
268ee7de SS	31
	32	#ifndef MSS_SPI_ERR_DEBUG
	33	#define MSS_SPI_ERR_DEBUG 0
	34	#endif
	35
	36	#define DB_PRINT_L(lvl, fmt, args...) do { \
	37	if (MSS_SPI_ERR_DEBUG >= lvl) { \
	38	qemu_log("%s: " fmt "\n", __func__, ## args); \
	39	} \
2562755e	40	} while (0)
268ee7de SS	41
	42	#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
	43
	44	#define FIFO_CAPACITY 32
	45
	46	#define R_SPI_CONTROL 0
	47	#define R_SPI_DFSIZE 1
	48	#define R_SPI_STATUS 2
	49	#define R_SPI_INTCLR 3
	50	#define R_SPI_RX 4
	51	#define R_SPI_TX 5
	52	#define R_SPI_CLKGEN 6
	53	#define R_SPI_SS 7
	54	#define R_SPI_MIS 8
	55	#define R_SPI_RIS 9
	56
	57	#define S_TXDONE (1 << 0)
	58	#define S_RXRDY (1 << 1)
	59	#define S_RXCHOVRF (1 << 2)
	60	#define S_RXFIFOFUL (1 << 4)
	61	#define S_RXFIFOFULNXT (1 << 5)
	62	#define S_RXFIFOEMP (1 << 6)
	63	#define S_RXFIFOEMPNXT (1 << 7)
	64	#define S_TXFIFOFUL (1 << 8)
	65	#define S_TXFIFOFULNXT (1 << 9)
	66	#define S_TXFIFOEMP (1 << 10)
	67	#define S_TXFIFOEMPNXT (1 << 11)
	68	#define S_FRAMESTART (1 << 12)
	69	#define S_SSEL (1 << 13)
	70	#define S_ACTIVE (1 << 14)
	71
	72	#define C_ENABLE (1 << 0)
	73	#define C_MODE (1 << 1)
	74	#define C_INTRXDATA (1 << 4)
	75	#define C_INTTXDATA (1 << 5)
	76	#define C_INTRXOVRFLO (1 << 6)
	77	#define C_SPS (1 << 26)
	78	#define C_BIGFIFO (1 << 29)
	79	#define C_RESET (1 << 31)
	80
cda607d5	81	#define FRAMESZ_MASK 0x3F
268ee7de SS	82	#define FMCOUNT_MASK 0x00FFFF00
268ee7de SS	83	#define FMCOUNT_SHIFT 8
cda607d5	84	#define FRAMESZ_MAX 32
268ee7de SS	85
	86	static void txfifo_reset(MSSSpiState *s)
	87	{
	88	fifo32_reset(&s->tx_fifo);
	89
	90	s->regs[R_SPI_STATUS] &= ~S_TXFIFOFUL;
	91	s->regs[R_SPI_STATUS] \|= S_TXFIFOEMP;
	92	}
	93
	94	static void rxfifo_reset(MSSSpiState *s)
	95	{
	96	fifo32_reset(&s->rx_fifo);
	97
	98	s->regs[R_SPI_STATUS] &= ~S_RXFIFOFUL;
	99	s->regs[R_SPI_STATUS] \|= S_RXFIFOEMP;
	100	}
	101
	102	static void set_fifodepth(MSSSpiState *s)
	103	{
	104	unsigned int size = s->regs[R_SPI_DFSIZE] & FRAMESZ_MASK;
	105
	106	if (size <= 8) {
	107	s->fifo_depth = 32;
	108	} else if (size <= 16) {
	109	s->fifo_depth = 16;
268ee7de	110	} else {
cda607d5	111	s->fifo_depth = 8;
268ee7de SS	112	}
	113	}
	114
	115	static void update_mis(MSSSpiState *s)
	116	{
	117	uint32_t reg = s->regs[R_SPI_CONTROL];
	118	uint32_t tmp;
	119
	120	/*
	121	* form the Control register interrupt enable bits
	122	* same as RIS, MIS and Interrupt clear registers for simplicity
	123	*/
	124	tmp = ((reg & C_INTRXOVRFLO) >> 4) \| ((reg & C_INTRXDATA) >> 3) \|
	125	((reg & C_INTTXDATA) >> 5);
	126	s->regs[R_SPI_MIS] \|= tmp & s->regs[R_SPI_RIS];
	127	}
	128
	129	static void spi_update_irq(MSSSpiState *s)
	130	{
	131	int irq;
	132
	133	update_mis(s);
	134	irq = !!(s->regs[R_SPI_MIS]);
	135
	136	qemu_set_irq(s->irq, irq);
	137	}
	138
	139	static void mss_spi_reset(DeviceState *d)
	140	{
	141	MSSSpiState *s = MSS_SPI(d);
	142
	143	memset(s->regs, 0, sizeof s->regs);
	144	s->regs[R_SPI_CONTROL] = 0x80000102;
	145	s->regs[R_SPI_DFSIZE] = 0x4;
	146	s->regs[R_SPI_STATUS] = S_SSEL \| S_TXFIFOEMP \| S_RXFIFOEMP;
	147	s->regs[R_SPI_CLKGEN] = 0x7;
	148	s->regs[R_SPI_RIS] = 0x0;
	149
	150	s->fifo_depth = 4;
	151	s->frame_count = 1;
	152	s->enabled = false;
	153
	154	rxfifo_reset(s);
	155	txfifo_reset(s);
	156	}
	157
	158	static uint64_t
	159	spi_read(void *opaque, hwaddr addr, unsigned int size)
	160	{
	161	MSSSpiState *s = opaque;
	162	uint32_t ret = 0;
	163
	164	addr >>= 2;
	165	switch (addr) {
	166	case R_SPI_RX:
	167	s->regs[R_SPI_STATUS] &= ~S_RXFIFOFUL;
	168	s->regs[R_SPI_STATUS] &= ~S_RXCHOVRF;
c0bccee9 PMD	169	if (fifo32_is_empty(&s->rx_fifo)) {
	170	qemu_log_mask(LOG_GUEST_ERROR,
	171	"%s: Reading empty RX_FIFO\n",
	172	__func__);
	173	} else {
	174	ret = fifo32_pop(&s->rx_fifo);
	175	}
268ee7de SS	176	if (fifo32_is_empty(&s->rx_fifo)) {
	177	s->regs[R_SPI_STATUS] \|= S_RXFIFOEMP;
	178	}
	179	break;
	180
	181	case R_SPI_MIS:
	182	update_mis(s);
	183	ret = s->regs[R_SPI_MIS];
	184	break;
	185
	186	default:
	187	if (addr < ARRAY_SIZE(s->regs)) {
	188	ret = s->regs[addr];
	189	} else {
	190	qemu_log_mask(LOG_GUEST_ERROR,
	191	"%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__,
	192	addr * 4);
	193	return ret;
	194	}
	195	break;
	196	}
	197
	198	DB_PRINT("addr=0x%" HWADDR_PRIx " = 0x%" PRIx32, addr * 4, ret);
	199	spi_update_irq(s);
	200	return ret;
	201	}
	202
	203	static void assert_cs(MSSSpiState *s)
	204	{
	205	qemu_set_irq(s->cs_line, 0);
	206	}
	207
	208	static void deassert_cs(MSSSpiState *s)
	209	{
	210	qemu_set_irq(s->cs_line, 1);
	211	}
	212
	213	static void spi_flush_txfifo(MSSSpiState *s)
	214	{
	215	uint32_t tx;
	216	uint32_t rx;
	217	bool sps = !!(s->regs[R_SPI_CONTROL] & C_SPS);
	218
	219	/*
	220	* Chip Select(CS) is automatically controlled by this controller.
	221	* If SPS bit is set in Control register then CS is asserted
	222	* until all the frames set in frame count of Control register are
	223	* transferred. If SPS is not set then CS pulses between frames.
	224	* Note that Slave Select register specifies which of the CS line
	225	* has to be controlled automatically by controller. Bits SS[7:1] are for
	226	* masters in FPGA fabric since we model only Microcontroller subsystem
	227	* of Smartfusion2 we control only one CS(SS[0]) line.
	228	*/
	229	while (!fifo32_is_empty(&s->tx_fifo) && s->frame_count) {
	230	assert_cs(s);
	231
	232	s->regs[R_SPI_STATUS] &= ~(S_TXDONE \| S_RXRDY);
	233
	234	tx = fifo32_pop(&s->tx_fifo);
	235	DB_PRINT("data tx:0x%" PRIx32, tx);
	236	rx = ssi_transfer(s->spi, tx);
	237	DB_PRINT("data rx:0x%" PRIx32, rx);
	238
	239	if (fifo32_num_used(&s->rx_fifo) == s->fifo_depth) {
240	s->regs[R_SPI_STATUS] \|= S_RXCHOVRF;
241	s->regs[R_SPI_RIS] \|= S_RXCHOVRF;
242	} else {
243	fifo32_push(&s->rx_fifo, rx);
244	s->regs[R_SPI_STATUS] &= ~S_RXFIFOEMP;
245	if (fifo32_num_used(&s->rx_fifo) == (s->fifo_depth - 1)) {
246	s->regs[R_SPI_STATUS] \|= S_RXFIFOFULNXT;
247	} else if (fifo32_num_used(&s->rx_fifo) == s->fifo_depth) {
248	s->regs[R_SPI_STATUS] \|= S_RXFIFOFUL;
249	}
250	}
251	s->frame_count--;
252	if (!sps) {
253	deassert_cs(s);
254	}
255	}
256
257	if (!s->frame_count) {
258	s->frame_count = (s->regs[R_SPI_CONTROL] & FMCOUNT_MASK) >>
259	FMCOUNT_SHIFT;
260	deassert_cs(s);
261	s->regs[R_SPI_RIS] \|= S_TXDONE \| S_RXRDY;
262	s->regs[R_SPI_STATUS] \|= S_TXDONE \| S_RXRDY;
263	}
264	}
265
266	static void spi_write(void *opaque, hwaddr addr,
267	uint64_t val64, unsigned int size)
268	{
269	MSSSpiState *s = opaque;
270	uint32_t value = val64;
271
272	DB_PRINT("addr=0x%" HWADDR_PRIx " =0x%" PRIx32, addr, value);
273	addr >>= 2;
274
275	switch (addr) {
276	case R_SPI_TX:
277	/* adding to already full FIFO */
278	if (fifo32_num_used(&s->tx_fifo) == s->fifo_depth) {
279	break;
280	}
281	s->regs[R_SPI_STATUS] &= ~S_TXFIFOEMP;
282	fifo32_push(&s->tx_fifo, value);
283	if (fifo32_num_used(&s->tx_fifo) == (s->fifo_depth - 1)) {
284	s->regs[R_SPI_STATUS] \|= S_TXFIFOFULNXT;
285	} else if (fifo32_num_used(&s->tx_fifo) == s->fifo_depth) {
286	s->regs[R_SPI_STATUS] \|= S_TXFIFOFUL;
287	}
288	if (s->enabled) {
289	spi_flush_txfifo(s);
290	}
291	break;
292
293	case R_SPI_CONTROL:
294	s->regs[R_SPI_CONTROL] = value;
295	if (value & C_BIGFIFO) {
296	set_fifodepth(s);
297	} else {
298	s->fifo_depth = 4;
299	}
300	s->enabled = value & C_ENABLE;
301	s->frame_count = (value & FMCOUNT_MASK) >> FMCOUNT_SHIFT;
302	if (value & C_RESET) {
303	mss_spi_reset(DEVICE(s));
304	}
305	break;
306
307	case R_SPI_DFSIZE:
308	if (s->enabled) {
309	break;
310	}
cda607d5 SS	311	/*
	312	* [31:6] bits are reserved bits and for future use.
	313	* [5:0] are for frame size. Only [5:0] bits are validated
	314	* during write, [31:6] bits are untouched.
	315	*/
	316	if ((value & FRAMESZ_MASK) > FRAMESZ_MAX) {
	317	qemu_log_mask(LOG_GUEST_ERROR, "%s: Incorrect size %u provided."
	318	"Maximum frame size is %u\n",
	319	__func__, value & FRAMESZ_MASK, FRAMESZ_MAX);
	320	break;
	321	}
268ee7de SS	322	s->regs[R_SPI_DFSIZE] = value;
	323	break;
	324
	325	case R_SPI_INTCLR:
	326	s->regs[R_SPI_INTCLR] = value;
	327	if (value & S_TXDONE) {
	328	s->regs[R_SPI_RIS] &= ~S_TXDONE;
	329	}
	330	if (value & S_RXRDY) {
	331	s->regs[R_SPI_RIS] &= ~S_RXRDY;
	332	}
	333	if (value & S_RXCHOVRF) {
	334	s->regs[R_SPI_RIS] &= ~S_RXCHOVRF;
	335	}
	336	break;
	337
	338	case R_SPI_MIS:
	339	case R_SPI_STATUS:
	340	case R_SPI_RIS:
	341	qemu_log_mask(LOG_GUEST_ERROR,
	342	"%s: Write to read only register 0x%" HWADDR_PRIx "\n",
	343	__func__, addr * 4);
	344	break;
	345
	346	default:
	347	if (addr < ARRAY_SIZE(s->regs)) {
	348	s->regs[addr] = value;
	349	} else {
	350	qemu_log_mask(LOG_GUEST_ERROR,
	351	"%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__,
	352	addr * 4);
	353	}
	354	break;
	355	}
	356
	357	spi_update_irq(s);
	358	}
	359
	360	static const MemoryRegionOps spi_ops = {
	361	.read = spi_read,
	362	.write = spi_write,
	363	.endianness = DEVICE_NATIVE_ENDIAN,
	364	.valid = {
	365	.min_access_size = 1,
	366	.max_access_size = 4
	367	}
	368	};
	369
	370	static void mss_spi_realize(DeviceState dev, Error *errp)
	371	{
	372	MSSSpiState *s = MSS_SPI(dev);
	373	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
	374
	375	s->spi = ssi_create_bus(dev, "spi");
	376
	377	sysbus_init_irq(sbd, &s->irq);
	378	ssi_auto_connect_slaves(dev, &s->cs_line, s->spi);
	379	sysbus_init_irq(sbd, &s->cs_line);
	380
	381	memory_region_init_io(&s->mmio, OBJECT(s), &spi_ops, s,
	382	TYPE_MSS_SPI, R_SPI_MAX * 4);
	383	sysbus_init_mmio(sbd, &s->mmio);
	384
	385	fifo32_create(&s->tx_fifo, FIFO_CAPACITY);
386	fifo32_create(&s->rx_fifo, FIFO_CAPACITY);
387	}
388
389	static const VMStateDescription vmstate_mss_spi = {
390	.name = TYPE_MSS_SPI,
391	.version_id = 1,
392	.minimum_version_id = 1,
393	.fields = (VMStateField[]) {
394	VMSTATE_FIFO32(tx_fifo, MSSSpiState),
395	VMSTATE_FIFO32(rx_fifo, MSSSpiState),
396	VMSTATE_UINT32_ARRAY(regs, MSSSpiState, R_SPI_MAX),
397	VMSTATE_END_OF_LIST()
398	}
399	};
400
401	static void mss_spi_class_init(ObjectClass klass, void data)
402	{
403	DeviceClass *dc = DEVICE_CLASS(klass);
404
405	dc->realize = mss_spi_realize;
406	dc->reset = mss_spi_reset;
407	dc->vmsd = &vmstate_mss_spi;
408	}
409
410	static const TypeInfo mss_spi_info = {
411	.name = TYPE_MSS_SPI,
412	.parent = TYPE_SYS_BUS_DEVICE,
413	.instance_size = sizeof(MSSSpiState),
414	.class_init = mss_spi_class_init,
415	};
416
417	static void mss_spi_register_types(void)
418	{
419	type_register_static(&mss_spi_info);
420	}
421
422	type_init(mss_spi_register_types)