[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 "hw.h"
#include "primecell.h"

//#define DEBUG_PL022 1

#ifdef DEBUG_PL022
#define DPRINTF(fmt, args...) \
do { printf("pl022: " fmt , ##args); } while (0)
#define BADF(fmt, args...) \
do { fprintf(stderr, "pl022: error: " fmt , ##args); exit(1);} while (0)
#else
#define DPRINTF(fmt, args...) do {} while(0)
#define BADF(fmt, args...) \
do { fprintf(stderr, "pl022: error: " fmt , ##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 {
    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;
    int (*xfer_cb)(void *, int);
    void *opaque;
} 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 if (s->xfer_cb) {
            val = s->xfer_cb(s->opaque, val);
        } else {
            val = 0;
        }
        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, target_phys_addr_t 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, target_phys_addr_t 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 *pl022_readfn[] = {
   pl022_read,
   pl022_read,
   pl022_read
};

static CPUWriteMemoryFunc *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;
}

void pl022_init(uint32_t base, qemu_irq irq, int (*xfer_cb)(void *, int),
                void * opaque)
{
    int iomemtype;
    pl022_state *s;

    s = (pl022_state *)qemu_mallocz(sizeof(pl022_state));
    iomemtype = cpu_register_io_memory(0, pl022_readfn,
                                       pl022_writefn, s);
    cpu_register_physical_memory(base, 0x00001000, iomemtype);
    s->irq = irq;
    s->xfer_cb = xfer_cb;
    s->opaque = opaque;
    pl022_reset(s);
    register_savevm("pl022_ssp", -1, 1, pl022_save, pl022_load, s);
}
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
87ecb68b PB	10	#include "hw.h"
87ecb68b PB	11	#include "primecell.h"
9ee6e8bb PB	12
	13	//#define DEBUG_PL022 1
	14
	15	#ifdef DEBUG_PL022
	16	#define DPRINTF(fmt, args...) \
	17	do { printf("pl022: " fmt , ##args); } while (0)
	18	#define BADF(fmt, args...) \
	19	do { fprintf(stderr, "pl022: error: " fmt , ##args); exit(1);} while (0)
	20	#else
	21	#define DPRINTF(fmt, args...) do {} while(0)
	22	#define BADF(fmt, args...) \
	23	do { fprintf(stderr, "pl022: error: " fmt , ##args);} while (0)
	24	#endif
	25
	26	#define PL022_CR1_LBM 0x01
	27	#define PL022_CR1_SSE 0x02
	28	#define PL022_CR1_MS 0x04
	29	#define PL022_CR1_SDO 0x08
	30
	31	#define PL022_SR_TFE 0x01
	32	#define PL022_SR_TNF 0x02
	33	#define PL022_SR_RNE 0x04
	34	#define PL022_SR_RFF 0x08
	35	#define PL022_SR_BSY 0x10
	36
	37	#define PL022_INT_ROR 0x01
	38	#define PL022_INT_RT 0x04
	39	#define PL022_INT_RX 0x04
	40	#define PL022_INT_TX 0x08
	41
	42	typedef struct {
9ee6e8bb PB	43	uint32_t cr0;
	44	uint32_t cr1;
	45	uint32_t bitmask;
	46	uint32_t sr;
	47	uint32_t cpsr;
	48	uint32_t is;
	49	uint32_t im;
	50	/* The FIFO head points to the next empty entry. */
	51	int tx_fifo_head;
	52	int rx_fifo_head;
	53	int tx_fifo_len;
	54	int rx_fifo_len;
	55	uint16_t tx_fifo[8];
	56	uint16_t rx_fifo[8];
	57	qemu_irq irq;
	58	int (xfer_cb)(void , int);
	59	void *opaque;
	60	} pl022_state;
	61
	62	static const unsigned char pl022_id[8] =
	63	{ 0x22, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
	64
	65	static void pl022_update(pl022_state *s)
	66	{
	67	s->sr = 0;
	68	if (s->tx_fifo_len == 0)
	69	s->sr \|= PL022_SR_TFE;
	70	if (s->tx_fifo_len != 8)
	71	s->sr \|= PL022_SR_TNF;
	72	if (s->rx_fifo_len != 0)
	73	s->sr \|= PL022_SR_RNE;
	74	if (s->rx_fifo_len == 8)
	75	s->sr \|= PL022_SR_RFF;
	76	if (s->tx_fifo_len)
	77	s->sr \|= PL022_SR_BSY;
	78	s->is = 0;
	79	if (s->rx_fifo_len >= 4)
	80	s->is \|= PL022_INT_RX;
	81	if (s->tx_fifo_len <= 4)
	82	s->is \|= PL022_INT_TX;
	83
	84	qemu_set_irq(s->irq, (s->is & s->im) != 0);
	85	}
	86
	87	static void pl022_xfer(pl022_state *s)
	88	{
	89	int i;
	90	int o;
	91	int val;
	92
	93	if ((s->cr1 & PL022_CR1_SSE) == 0) {
	94	pl022_update(s);
	95	DPRINTF("Disabled\n");
	96	return;
	97	}
	98
	99	DPRINTF("Maybe xfer %d/%d\n", s->tx_fifo_len, s->rx_fifo_len);
	100	i = (s->tx_fifo_head - s->tx_fifo_len) & 7;
	101	o = s->rx_fifo_head;
	102	/* ??? We do not emulate the line speed.
	103	This may break some applications. The are two problematic cases:
	104	(a) A driver feeds data into the TX FIFO until it is full,
	105	and only then drains the RX FIFO. On real hardware the CPU can
	106	feed data fast enough that the RX fifo never gets chance to overflow.
107	(b) A driver transmits data, deliberately allowing the RX FIFO to
108	overflow because it ignores the RX data anyway.
109
110	We choose to support (a) by stalling the transmit engine if it would
111	cause the RX FIFO to overflow. In practice much transmit-only code
112	falls into (a) because it flushes the RX FIFO to determine when
113	the transfer has completed. */
114	while (s->tx_fifo_len && s->rx_fifo_len < 8) {
115	DPRINTF("xfer\n");
116	val = s->tx_fifo[i];
117	if (s->cr1 & PL022_CR1_LBM) {
118	/* Loopback mode. */
119	} else if (s->xfer_cb) {
120	val = s->xfer_cb(s->opaque, val);
121	} else {
122	val = 0;
123	}
124	s->rx_fifo[o] = val & s->bitmask;
125	i = (i + 1) & 7;
126	o = (o + 1) & 7;
127	s->tx_fifo_len--;
128	s->rx_fifo_len++;
129	}
130	s->rx_fifo_head = o;
131	pl022_update(s);
132	}
133
134	static uint32_t pl022_read(void *opaque, target_phys_addr_t offset)
135	{
136	pl022_state s = (pl022_state )opaque;
137	int val;
138
9ee6e8bb PB	139	if (offset >= 0xfe0 && offset < 0x1000) {
	140	return pl022_id[(offset - 0xfe0) >> 2];
	141	}
	142	switch (offset) {
	143	case 0x00: /* CR0 */
	144	return s->cr0;
	145	case 0x04: /* CR1 */
	146	return s->cr1;
	147	case 0x08: /* DR */
	148	if (s->rx_fifo_len) {
	149	val = s->rx_fifo[(s->rx_fifo_head - s->rx_fifo_len) & 7];
	150	DPRINTF("RX %02x\n", val);
	151	s->rx_fifo_len--;
	152	pl022_xfer(s);
	153	} else {
	154	val = 0;
	155	}
	156	return val;
	157	case 0x0c: /* SR */
	158	return s->sr;
	159	case 0x10: /* CPSR */
	160	return s->cpsr;
	161	case 0x14: /* IMSC */
	162	return s->im;
	163	case 0x18: /* RIS */
	164	return s->is;
	165	case 0x1c: /* MIS */
	166	return s->im & s->is;
	167	case 0x20: /* DMACR */
	168	/* Not implemented. */
	169	return 0;
	170	default:
2ac71179	171	hw_error("pl022_read: Bad offset %x\n", (int)offset);
9ee6e8bb PB	172	return 0;
	173	}
	174	}
	175
	176	static void pl022_write(void *opaque, target_phys_addr_t offset,
	177	uint32_t value)
	178	{
	179	pl022_state s = (pl022_state )opaque;
	180
9ee6e8bb PB	181	switch (offset) {
	182	case 0x00: /* CR0 */
	183	s->cr0 = value;
	184	/* Clock rate and format are ignored. */
	185	s->bitmask = (1 << ((value & 15) + 1)) - 1;
	186	break;
	187	case 0x04: /* CR1 */
	188	s->cr1 = value;
	189	if ((s->cr1 & (PL022_CR1_MS \| PL022_CR1_SSE))
	190	== (PL022_CR1_MS \| PL022_CR1_SSE)) {
	191	BADF("SPI slave mode not implemented\n");
	192	}
	193	pl022_xfer(s);
	194	break;
	195	case 0x08: /* DR */
	196	if (s->tx_fifo_len < 8) {
	197	DPRINTF("TX %02x\n", value);
	198	s->tx_fifo[s->tx_fifo_head] = value & s->bitmask;
	199	s->tx_fifo_head = (s->tx_fifo_head + 1) & 7;
	200	s->tx_fifo_len++;
	201	pl022_xfer(s);
	202	}
	203	break;
	204	case 0x10: /* CPSR */
	205	/* Prescaler. Ignored. */
	206	s->cpsr = value & 0xff;
	207	break;
	208	case 0x14: /* IMSC */
	209	s->im = value;
	210	pl022_update(s);
	211	break;
	212	case 0x20: /* DMACR */
2ac71179 PB	213	if (value) {
	214	hw_error("pl022: DMA not implemented\n");
	215	}
9ee6e8bb PB	216	break;
9ee6e8bb PB	217	default:
2ac71179	218	hw_error("pl022_write: Bad offset %x\n", (int)offset);
9ee6e8bb PB	219	}
	220	}
	221
	222	static void pl022_reset(pl022_state *s)
	223	{
	224	s->rx_fifo_len = 0;
	225	s->tx_fifo_len = 0;
	226	s->im = 0;
	227	s->is = PL022_INT_TX;
	228	s->sr = PL022_SR_TFE \| PL022_SR_TNF;
	229	}
	230
	231	static CPUReadMemoryFunc *pl022_readfn[] = {
	232	pl022_read,
	233	pl022_read,
	234	pl022_read
	235	};
	236
	237	static CPUWriteMemoryFunc *pl022_writefn[] = {
	238	pl022_write,
	239	pl022_write,
	240	pl022_write
	241	};
	242
23e39294 PB	243	static void pl022_save(QEMUFile f, void opaque)
	244	{
	245	pl022_state s = (pl022_state )opaque;
	246	int i;
	247
	248	qemu_put_be32(f, s->cr0);
	249	qemu_put_be32(f, s->cr1);
	250	qemu_put_be32(f, s->bitmask);
	251	qemu_put_be32(f, s->sr);
	252	qemu_put_be32(f, s->cpsr);
	253	qemu_put_be32(f, s->is);
	254	qemu_put_be32(f, s->im);
	255	qemu_put_be32(f, s->tx_fifo_head);
	256	qemu_put_be32(f, s->rx_fifo_head);
	257	qemu_put_be32(f, s->tx_fifo_len);
	258	qemu_put_be32(f, s->rx_fifo_len);
	259	for (i = 0; i < 8; i++) {
	260	qemu_put_be16(f, s->tx_fifo[i]);
	261	qemu_put_be16(f, s->rx_fifo[i]);
	262	}
	263	}
	264
	265	static int pl022_load(QEMUFile f, void opaque, int version_id)
	266	{
	267	pl022_state s = (pl022_state )opaque;
	268	int i;
	269
	270	if (version_id != 1)
	271	return -EINVAL;
	272
	273	s->cr0 = qemu_get_be32(f);
	274	s->cr1 = qemu_get_be32(f);
	275	s->bitmask = qemu_get_be32(f);
	276	s->sr = qemu_get_be32(f);
	277	s->cpsr = qemu_get_be32(f);
	278	s->is = qemu_get_be32(f);
	279	s->im = qemu_get_be32(f);
	280	s->tx_fifo_head = qemu_get_be32(f);
	281	s->rx_fifo_head = qemu_get_be32(f);
	282	s->tx_fifo_len = qemu_get_be32(f);
	283	s->rx_fifo_len = qemu_get_be32(f);
	284	for (i = 0; i < 8; i++) {
	285	s->tx_fifo[i] = qemu_get_be16(f);
	286	s->rx_fifo[i] = qemu_get_be16(f);
	287	}
	288
	289	return 0;
	290	}
	291
9ee6e8bb PB	292	void pl022_init(uint32_t base, qemu_irq irq, int (xfer_cb)(void , int),
	293	void * opaque)
	294	{
	295	int iomemtype;
	296	pl022_state *s;
	297
	298	s = (pl022_state *)qemu_mallocz(sizeof(pl022_state));
	299	iomemtype = cpu_register_io_memory(0, pl022_readfn,
	300	pl022_writefn, s);
	301	cpu_register_physical_memory(base, 0x00001000, iomemtype);
9ee6e8bb PB	302	s->irq = irq;
	303	s->xfer_cb = xfer_cb;
	304	s->opaque = opaque;
	305	pl022_reset(s);
23e39294	306	register_savevm("pl022_ssp", -1, 1, pl022_save, pl022_load, s);
9ee6e8bb	307	}