[qemu.git] / hw / pl022.c

/*
 * Arm PrimeCell PL022 Synchronous Serial Port
 *
 * Copyright (c) 2007 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 */

#include "sysbus.h"
#include "ssi.h"
#include "primecell.h"

//#define DEBUG_PL022 1

#ifdef DEBUG_PL022
#define DPRINTF(fmt, ...) \
do { printf("pl022: " fmt , ## __VA_ARGS__); } while (0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__);} while (0)
#endif

#define PL022_CR1_LBM 0x01
#define PL022_CR1_SSE 0x02
#define PL022_CR1_MS  0x04
#define PL022_CR1_SDO 0x08

#define PL022_SR_TFE  0x01
#define PL022_SR_TNF  0x02
#define PL022_SR_RNE  0x04
#define PL022_SR_RFF  0x08
#define PL022_SR_BSY  0x10

#define PL022_INT_ROR 0x01
#define PL022_INT_RT  0x04
#define PL022_INT_RX  0x04
#define PL022_INT_TX  0x08

typedef struct {
    SysBusDevice busdev;
    uint32_t cr0;
    uint32_t cr1;
    uint32_t bitmask;
    uint32_t sr;
    uint32_t cpsr;
    uint32_t is;
    uint32_t im;
    /* The FIFO head points to the next empty entry.  */
    int tx_fifo_head;
    int rx_fifo_head;
    int tx_fifo_len;
    int rx_fifo_len;
    uint16_t tx_fifo[8];
    uint16_t rx_fifo[8];
    qemu_irq irq;
    SSIBus *ssi;
} pl022_state;

static const unsigned char pl022_id[8] =
  { 0x22, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };

static void pl022_update(pl022_state *s)
{
    s->sr = 0;
    if (s->tx_fifo_len == 0)
        s->sr |= PL022_SR_TFE;
    if (s->tx_fifo_len != 8)
        s->sr |= PL022_SR_TNF;
    if (s->rx_fifo_len != 0)
        s->sr |= PL022_SR_RNE;
    if (s->rx_fifo_len == 8)
        s->sr |= PL022_SR_RFF;
    if (s->tx_fifo_len)
        s->sr |= PL022_SR_BSY;
    s->is = 0;
    if (s->rx_fifo_len >= 4)
        s->is |= PL022_INT_RX;
    if (s->tx_fifo_len <= 4)
        s->is |= PL022_INT_TX;

    qemu_set_irq(s->irq, (s->is & s->im) != 0);
}

static void pl022_xfer(pl022_state *s)
{
    int i;
    int o;
    int val;

    if ((s->cr1 & PL022_CR1_SSE) == 0) {
        pl022_update(s);
        DPRINTF("Disabled\n");
        return;
    }

    DPRINTF("Maybe xfer %d/%d\n", s->tx_fifo_len, s->rx_fifo_len);
    i = (s->tx_fifo_head - s->tx_fifo_len) & 7;
    o = s->rx_fifo_head;
    /* ??? We do not emulate the line speed.
       This may break some applications.  The are two problematic cases:
        (a) A driver feeds data into the TX FIFO until it is full,
         and only then drains the RX FIFO.  On real hardware the CPU can
         feed data fast enough that the RX fifo never gets chance to overflow.
        (b) A driver transmits data, deliberately allowing the RX FIFO to
         overflow because it ignores the RX data anyway.

       We choose to support (a) by stalling the transmit engine if it would
       cause the RX FIFO to overflow.  In practice much transmit-only code
       falls into (a) because it flushes the RX FIFO to determine when
       the transfer has completed.  */
    while (s->tx_fifo_len && s->rx_fifo_len < 8) {
        DPRINTF("xfer\n");
        val = s->tx_fifo[i];
        if (s->cr1 & PL022_CR1_LBM) {
            /* Loopback mode.  */
        } else {
            val = ssi_transfer(s->ssi, val);
        }
        s->rx_fifo[o] = val & s->bitmask;
        i = (i + 1) & 7;
        o = (o + 1) & 7;
        s->tx_fifo_len--;
        s->rx_fifo_len++;
    }
    s->rx_fifo_head = o;
    pl022_update(s);
}

static uint32_t pl022_read(void *opaque, a_target_phys_addr offset)
{
    pl022_state *s = (pl022_state *)opaque;
    int val;

    if (offset >= 0xfe0 && offset < 0x1000) {
        return pl022_id[(offset - 0xfe0) >> 2];
    }
    switch (offset) {
    case 0x00: /* CR0 */
      return s->cr0;
    case 0x04: /* CR1 */
      return s->cr1;
    case 0x08: /* DR */
        if (s->rx_fifo_len) {
            val = s->rx_fifo[(s->rx_fifo_head - s->rx_fifo_len) & 7];
            DPRINTF("RX %02x\n", val);
            s->rx_fifo_len--;
            pl022_xfer(s);
        } else {
            val = 0;
        }
        return val;
    case 0x0c: /* SR */
        return s->sr;
    case 0x10: /* CPSR */
        return s->cpsr;
    case 0x14: /* IMSC */
        return s->im;
    case 0x18: /* RIS */
        return s->is;
    case 0x1c: /* MIS */
        return s->im & s->is;
    case 0x20: /* DMACR */
        /* Not implemented.  */
        return 0;
    default:
        hw_error("pl022_read: Bad offset %x\n", (int)offset);
        return 0;
    }
}

static void pl022_write(void *opaque, a_target_phys_addr offset,
                        uint32_t value)
{
    pl022_state *s = (pl022_state *)opaque;

    switch (offset) {
    case 0x00: /* CR0 */
        s->cr0 = value;
        /* Clock rate and format are ignored.  */
        s->bitmask = (1 << ((value & 15) + 1)) - 1;
        break;
    case 0x04: /* CR1 */
        s->cr1 = value;
        if ((s->cr1 & (PL022_CR1_MS | PL022_CR1_SSE))
                   == (PL022_CR1_MS | PL022_CR1_SSE)) {
            BADF("SPI slave mode not implemented\n");
        }
        pl022_xfer(s);
        break;
    case 0x08: /* DR */
        if (s->tx_fifo_len < 8) {
            DPRINTF("TX %02x\n", value);
            s->tx_fifo[s->tx_fifo_head] = value & s->bitmask;
            s->tx_fifo_head = (s->tx_fifo_head + 1) & 7;
            s->tx_fifo_len++;
            pl022_xfer(s);
        }
        break;
    case 0x10: /* CPSR */
        /* Prescaler.  Ignored.  */
        s->cpsr = value & 0xff;
        break;
    case 0x14: /* IMSC */
        s->im = value;
        pl022_update(s);
        break;
    case 0x20: /* DMACR */
        if (value) {
            hw_error("pl022: DMA not implemented\n");
        }
        break;
    default:
        hw_error("pl022_write: Bad offset %x\n", (int)offset);
    }
}

static void pl022_reset(pl022_state *s)
{
    s->rx_fifo_len = 0;
    s->tx_fifo_len = 0;
    s->im = 0;
    s->is = PL022_INT_TX;
    s->sr = PL022_SR_TFE | PL022_SR_TNF;
}

static CPUReadMemoryFunc * const pl022_readfn[] = {
   pl022_read,
   pl022_read,
   pl022_read
};

static CPUWriteMemoryFunc * const pl022_writefn[] = {
   pl022_write,
   pl022_write,
   pl022_write
};

static void pl022_save(QEMUFile *f, void *opaque)
{
    pl022_state *s = (pl022_state *)opaque;
    int i;

    qemu_put_be32(f, s->cr0);
    qemu_put_be32(f, s->cr1);
    qemu_put_be32(f, s->bitmask);
    qemu_put_be32(f, s->sr);
    qemu_put_be32(f, s->cpsr);
    qemu_put_be32(f, s->is);
    qemu_put_be32(f, s->im);
    qemu_put_be32(f, s->tx_fifo_head);
    qemu_put_be32(f, s->rx_fifo_head);
    qemu_put_be32(f, s->tx_fifo_len);
    qemu_put_be32(f, s->rx_fifo_len);
    for (i = 0; i < 8; i++) {
        qemu_put_be16(f, s->tx_fifo[i]);
        qemu_put_be16(f, s->rx_fifo[i]);
    }
}

static int pl022_load(QEMUFile *f, void *opaque, int version_id)
{
    pl022_state *s = (pl022_state *)opaque;
    int i;

    if (version_id != 1)
        return -EINVAL;

    s->cr0 = qemu_get_be32(f);
    s->cr1 = qemu_get_be32(f);
    s->bitmask = qemu_get_be32(f);
    s->sr = qemu_get_be32(f);
    s->cpsr = qemu_get_be32(f);
    s->is = qemu_get_be32(f);
    s->im = qemu_get_be32(f);
    s->tx_fifo_head = qemu_get_be32(f);
    s->rx_fifo_head = qemu_get_be32(f);
    s->tx_fifo_len = qemu_get_be32(f);
    s->rx_fifo_len = qemu_get_be32(f);
    for (i = 0; i < 8; i++) {
        s->tx_fifo[i] = qemu_get_be16(f);
        s->rx_fifo[i] = qemu_get_be16(f);
    }

    return 0;
}

static int pl022_init(SysBusDevice *dev)
{
    pl022_state *s = FROM_SYSBUS(pl022_state, dev);
    int iomemtype;

    iomemtype = cpu_register_io_memory(pl022_readfn,
                                       pl022_writefn, s);
    sysbus_init_mmio(dev, 0x1000, iomemtype);
    sysbus_init_irq(dev, &s->irq);
    s->ssi = ssi_create_bus(&dev->qdev, "ssi");
    pl022_reset(s);
    register_savevm("pl022_ssp", -1, 1, pl022_save, pl022_load, s);
    return 0;
}

static void pl022_register_devices(void)
{
    sysbus_register_dev("pl022", sizeof(pl022_state), pl022_init);
}

device_init(pl022_register_devices)
Commit	Line	Data
9ee6e8bb PB	1	/*
	2	* Arm PrimeCell PL022 Synchronous Serial Port
	3	*
	4	* Copyright (c) 2007 CodeSourcery.
	5	* Written by Paul Brook
	6	*
	7	* This code is licenced under the GPL.
	8	*/
	9
5493e33f PB	10	#include "sysbus.h"
5493e33f PB	11	#include "ssi.h"
87ecb68b	12	#include "primecell.h"
9ee6e8bb PB	13
	14	//#define DEBUG_PL022 1
	15
	16	#ifdef DEBUG_PL022
001faf32 BS	17	#define DPRINTF(fmt, ...) \
	18	do { printf("pl022: " fmt , ## __VA_ARGS__); } while (0)
	19	#define BADF(fmt, ...) \
	20	do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
9ee6e8bb	21	#else
001faf32 BS	22	#define DPRINTF(fmt, ...) do {} while(0)
	23	#define BADF(fmt, ...) \
	24	do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__);} while (0)
9ee6e8bb PB	25	#endif
	26
	27	#define PL022_CR1_LBM 0x01
	28	#define PL022_CR1_SSE 0x02
	29	#define PL022_CR1_MS 0x04
	30	#define PL022_CR1_SDO 0x08
	31
	32	#define PL022_SR_TFE 0x01
	33	#define PL022_SR_TNF 0x02
	34	#define PL022_SR_RNE 0x04
	35	#define PL022_SR_RFF 0x08
	36	#define PL022_SR_BSY 0x10
	37
	38	#define PL022_INT_ROR 0x01
	39	#define PL022_INT_RT 0x04
	40	#define PL022_INT_RX 0x04
	41	#define PL022_INT_TX 0x08
	42
	43	typedef struct {
5493e33f	44	SysBusDevice busdev;
9ee6e8bb PB	45	uint32_t cr0;
	46	uint32_t cr1;
	47	uint32_t bitmask;
	48	uint32_t sr;
	49	uint32_t cpsr;
	50	uint32_t is;
	51	uint32_t im;
	52	/* The FIFO head points to the next empty entry. */
	53	int tx_fifo_head;
	54	int rx_fifo_head;
	55	int tx_fifo_len;
	56	int rx_fifo_len;
	57	uint16_t tx_fifo[8];
	58	uint16_t rx_fifo[8];
	59	qemu_irq irq;
5493e33f	60	SSIBus *ssi;
9ee6e8bb PB	61	} pl022_state;
	62
	63	static const unsigned char pl022_id[8] =
	64	{ 0x22, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
	65
	66	static void pl022_update(pl022_state *s)
	67	{
	68	s->sr = 0;
	69	if (s->tx_fifo_len == 0)
	70	s->sr \|= PL022_SR_TFE;
	71	if (s->tx_fifo_len != 8)
	72	s->sr \|= PL022_SR_TNF;
	73	if (s->rx_fifo_len != 0)
	74	s->sr \|= PL022_SR_RNE;
	75	if (s->rx_fifo_len == 8)
	76	s->sr \|= PL022_SR_RFF;
	77	if (s->tx_fifo_len)
	78	s->sr \|= PL022_SR_BSY;
	79	s->is = 0;
	80	if (s->rx_fifo_len >= 4)
	81	s->is \|= PL022_INT_RX;
	82	if (s->tx_fifo_len <= 4)
	83	s->is \|= PL022_INT_TX;
	84
	85	qemu_set_irq(s->irq, (s->is & s->im) != 0);
	86	}
	87
	88	static void pl022_xfer(pl022_state *s)
	89	{
	90	int i;
	91	int o;
	92	int val;
	93
	94	if ((s->cr1 & PL022_CR1_SSE) == 0) {
	95	pl022_update(s);
	96	DPRINTF("Disabled\n");
	97	return;
	98	}
	99
	100	DPRINTF("Maybe xfer %d/%d\n", s->tx_fifo_len, s->rx_fifo_len);
	101	i = (s->tx_fifo_head - s->tx_fifo_len) & 7;
	102	o = s->rx_fifo_head;
	103	/* ??? We do not emulate the line speed.
	104	This may break some applications. The are two problematic cases:
	105	(a) A driver feeds data into the TX FIFO until it is full,
	106	and only then drains the RX FIFO. On real hardware the CPU can
	107	feed data fast enough that the RX fifo never gets chance to overflow.
	108	(b) A driver transmits data, deliberately allowing the RX FIFO to
	109	overflow because it ignores the RX data anyway.
	110
	111	We choose to support (a) by stalling the transmit engine if it would
	112	cause the RX FIFO to overflow. In practice much transmit-only code
	113	falls into (a) because it flushes the RX FIFO to determine when
	114	the transfer has completed. */
	115	while (s->tx_fifo_len && s->rx_fifo_len < 8) {
	116	DPRINTF("xfer\n");
	117	val = s->tx_fifo[i];
	118	if (s->cr1 & PL022_CR1_LBM) {
	119	/* Loopback mode. */
9ee6e8bb	120	} else {
5493e33f	121	val = ssi_transfer(s->ssi, val);
9ee6e8bb PB	122	}
	123	s->rx_fifo[o] = val & s->bitmask;
	124	i = (i + 1) & 7;
	125	o = (o + 1) & 7;
	126	s->tx_fifo_len--;
	127	s->rx_fifo_len++;
	128	}
	129	s->rx_fifo_head = o;
	130	pl022_update(s);
	131	}
	132
99a0949b	133	static uint32_t pl022_read(void *opaque, a_target_phys_addr offset)
9ee6e8bb PB	134	{
	135	pl022_state s = (pl022_state )opaque;
	136	int val;
	137
9ee6e8bb PB	138	if (offset >= 0xfe0 && offset < 0x1000) {
	139	return pl022_id[(offset - 0xfe0) >> 2];
	140	}
	141	switch (offset) {
	142	case 0x00: /* CR0 */
	143	return s->cr0;
	144	case 0x04: /* CR1 */
	145	return s->cr1;
	146	case 0x08: /* DR */
	147	if (s->rx_fifo_len) {
	148	val = s->rx_fifo[(s->rx_fifo_head - s->rx_fifo_len) & 7];
	149	DPRINTF("RX %02x\n", val);
	150	s->rx_fifo_len--;
	151	pl022_xfer(s);
	152	} else {
	153	val = 0;
	154	}
	155	return val;
	156	case 0x0c: /* SR */
	157	return s->sr;
	158	case 0x10: /* CPSR */
	159	return s->cpsr;
	160	case 0x14: /* IMSC */
	161	return s->im;
	162	case 0x18: /* RIS */
	163	return s->is;
	164	case 0x1c: /* MIS */
	165	return s->im & s->is;
	166	case 0x20: /* DMACR */
	167	/* Not implemented. */
	168	return 0;
	169	default:
2ac71179	170	hw_error("pl022_read: Bad offset %x\n", (int)offset);
9ee6e8bb PB	171	return 0;
	172	}
	173	}
	174
99a0949b	175	static void pl022_write(void *opaque, a_target_phys_addr offset,
9ee6e8bb PB	176	uint32_t value)
	177	{
	178	pl022_state s = (pl022_state )opaque;
	179
9ee6e8bb PB	180	switch (offset) {
	181	case 0x00: /* CR0 */
	182	s->cr0 = value;
	183	/* Clock rate and format are ignored. */
	184	s->bitmask = (1 << ((value & 15) + 1)) - 1;
	185	break;
	186	case 0x04: /* CR1 */
	187	s->cr1 = value;
	188	if ((s->cr1 & (PL022_CR1_MS \| PL022_CR1_SSE))
	189	== (PL022_CR1_MS \| PL022_CR1_SSE)) {
	190	BADF("SPI slave mode not implemented\n");
	191	}
	192	pl022_xfer(s);
	193	break;
	194	case 0x08: /* DR */
	195	if (s->tx_fifo_len < 8) {
	196	DPRINTF("TX %02x\n", value);
	197	s->tx_fifo[s->tx_fifo_head] = value & s->bitmask;
	198	s->tx_fifo_head = (s->tx_fifo_head + 1) & 7;
	199	s->tx_fifo_len++;
	200	pl022_xfer(s);
	201	}
	202	break;
	203	case 0x10: /* CPSR */
	204	/* Prescaler. Ignored. */
	205	s->cpsr = value & 0xff;
	206	break;
	207	case 0x14: /* IMSC */
	208	s->im = value;
	209	pl022_update(s);
	210	break;
	211	case 0x20: /* DMACR */
2ac71179 PB	212	if (value) {
	213	hw_error("pl022: DMA not implemented\n");
	214	}
9ee6e8bb PB	215	break;
9ee6e8bb PB	216	default:
2ac71179	217	hw_error("pl022_write: Bad offset %x\n", (int)offset);
9ee6e8bb PB	218	}
	219	}
	220
	221	static void pl022_reset(pl022_state *s)
	222	{
	223	s->rx_fifo_len = 0;
	224	s->tx_fifo_len = 0;
	225	s->im = 0;
	226	s->is = PL022_INT_TX;
	227	s->sr = PL022_SR_TFE \| PL022_SR_TNF;
	228	}
	229
d60efc6b	230	static CPUReadMemoryFunc * const pl022_readfn[] = {
9ee6e8bb PB	231	pl022_read,
	232	pl022_read,
	233	pl022_read
	234	};
	235
d60efc6b	236	static CPUWriteMemoryFunc * const pl022_writefn[] = {
9ee6e8bb PB	237	pl022_write,
	238	pl022_write,
	239	pl022_write
	240	};
	241
23e39294 PB	242	static void pl022_save(QEMUFile f, void opaque)
	243	{
	244	pl022_state s = (pl022_state )opaque;
	245	int i;
	246
	247	qemu_put_be32(f, s->cr0);
	248	qemu_put_be32(f, s->cr1);
	249	qemu_put_be32(f, s->bitmask);
	250	qemu_put_be32(f, s->sr);
	251	qemu_put_be32(f, s->cpsr);
	252	qemu_put_be32(f, s->is);
	253	qemu_put_be32(f, s->im);
	254	qemu_put_be32(f, s->tx_fifo_head);
	255	qemu_put_be32(f, s->rx_fifo_head);
	256	qemu_put_be32(f, s->tx_fifo_len);
	257	qemu_put_be32(f, s->rx_fifo_len);
	258	for (i = 0; i < 8; i++) {
	259	qemu_put_be16(f, s->tx_fifo[i]);
	260	qemu_put_be16(f, s->rx_fifo[i]);
	261	}
	262	}
	263
	264	static int pl022_load(QEMUFile f, void opaque, int version_id)
	265	{
	266	pl022_state s = (pl022_state )opaque;
	267	int i;
	268
	269	if (version_id != 1)
	270	return -EINVAL;
	271
	272	s->cr0 = qemu_get_be32(f);
	273	s->cr1 = qemu_get_be32(f);
	274	s->bitmask = qemu_get_be32(f);
	275	s->sr = qemu_get_be32(f);
	276	s->cpsr = qemu_get_be32(f);
	277	s->is = qemu_get_be32(f);
	278	s->im = qemu_get_be32(f);
	279	s->tx_fifo_head = qemu_get_be32(f);
	280	s->rx_fifo_head = qemu_get_be32(f);
	281	s->tx_fifo_len = qemu_get_be32(f);
	282	s->rx_fifo_len = qemu_get_be32(f);
	283	for (i = 0; i < 8; i++) {
	284	s->tx_fifo[i] = qemu_get_be16(f);
	285	s->rx_fifo[i] = qemu_get_be16(f);
	286	}
	287
	288	return 0;
	289	}
	290
81a322d4	291	static int pl022_init(SysBusDevice *dev)
9ee6e8bb	292	{
5493e33f	293	pl022_state *s = FROM_SYSBUS(pl022_state, dev);
9ee6e8bb	294	int iomemtype;
9ee6e8bb	295
1eed09cb	296	iomemtype = cpu_register_io_memory(pl022_readfn,
9ee6e8bb	297	pl022_writefn, s);
5493e33f PB	298	sysbus_init_mmio(dev, 0x1000, iomemtype);
5493e33f PB	299	sysbus_init_irq(dev, &s->irq);
02e2da45	300	s->ssi = ssi_create_bus(&dev->qdev, "ssi");
9ee6e8bb	301	pl022_reset(s);
23e39294	302	register_savevm("pl022_ssp", -1, 1, pl022_save, pl022_load, s);
81a322d4	303	return 0;
9ee6e8bb	304	}
5493e33f PB	305
	306	static void pl022_register_devices(void)
	307	{
	308	sysbus_register_dev("pl022", sizeof(pl022_state), pl022_init);
	309	}
	310
	311	device_init(pl022_register_devices)