[qemu.git] / hw / pl011.c

/*
 * Arm PrimeCell PL011 UART
 *
 * Copyright (c) 2006 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 */

#include "hw.h"
#include "qemu-char.h"
#include "primecell.h"

typedef struct {
    uint32_t base;
    uint32_t readbuff;
    uint32_t flags;
    uint32_t lcr;
    uint32_t cr;
    uint32_t dmacr;
    uint32_t int_enabled;
    uint32_t int_level;
    uint32_t read_fifo[16];
    uint32_t ilpr;
    uint32_t ibrd;
    uint32_t fbrd;
    uint32_t ifl;
    int read_pos;
    int read_count;
    int read_trigger;
    CharDriverState *chr;
    qemu_irq irq;
    enum pl011_type type;
} pl011_state;

#define PL011_INT_TX 0x20
#define PL011_INT_RX 0x10

#define PL011_FLAG_TXFE 0x80
#define PL011_FLAG_RXFF 0x40
#define PL011_FLAG_TXFF 0x20
#define PL011_FLAG_RXFE 0x10

static const unsigned char pl011_id[2][8] = {
  { 0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }, /* PL011_ARM */
  { 0x11, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1 }, /* PL011_LUMINARY */
};

static void pl011_update(pl011_state *s)
{
    uint32_t flags;

    flags = s->int_level & s->int_enabled;
    qemu_set_irq(s->irq, flags != 0);
}

static uint32_t pl011_read(void *opaque, target_phys_addr_t offset)
{
    pl011_state *s = (pl011_state *)opaque;
    uint32_t c;

    offset -= s->base;
    if (offset >= 0xfe0 && offset < 0x1000) {
        return pl011_id[s->type][(offset - 0xfe0) >> 2];
    }
    switch (offset >> 2) {
    case 0: /* UARTDR */
        s->flags &= ~PL011_FLAG_RXFF;
        c = s->read_fifo[s->read_pos];
        if (s->read_count > 0) {
            s->read_count--;
            if (++s->read_pos == 16)
                s->read_pos = 0;
        }
        if (s->read_count == 0) {
            s->flags |= PL011_FLAG_RXFE;
        }
        if (s->read_count == s->read_trigger - 1)
            s->int_level &= ~ PL011_INT_RX;
        pl011_update(s);
        qemu_chr_accept_input(s->chr);
        return c;
    case 1: /* UARTCR */
        return 0;
    case 6: /* UARTFR */
        return s->flags;
    case 8: /* UARTILPR */
        return s->ilpr;
    case 9: /* UARTIBRD */
        return s->ibrd;
    case 10: /* UARTFBRD */
        return s->fbrd;
    case 11: /* UARTLCR_H */
        return s->lcr;
    case 12: /* UARTCR */
        return s->cr;
    case 13: /* UARTIFLS */
        return s->ifl;
    case 14: /* UARTIMSC */
        return s->int_enabled;
    case 15: /* UARTRIS */
        return s->int_level;
    case 16: /* UARTMIS */
        return s->int_level & s->int_enabled;
    case 18: /* UARTDMACR */
        return s->dmacr;
    default:
        cpu_abort (cpu_single_env, "pl011_read: Bad offset %x\n", (int)offset);
        return 0;
    }
}

static void pl011_set_read_trigger(pl011_state *s)
{
#if 0
    /* The docs say the RX interrupt is triggered when the FIFO exceeds
       the threshold.  However linux only reads the FIFO in response to an
       interrupt.  Triggering the interrupt when the FIFO is non-empty seems
       to make things work.  */
    if (s->lcr & 0x10)
        s->read_trigger = (s->ifl >> 1) & 0x1c;
    else
#endif
        s->read_trigger = 1;
}

static void pl011_write(void *opaque, target_phys_addr_t offset,
                          uint32_t value)
{
    pl011_state *s = (pl011_state *)opaque;
    unsigned char ch;

    offset -= s->base;
    switch (offset >> 2) {
    case 0: /* UARTDR */
        /* ??? Check if transmitter is enabled.  */
        ch = value;
        if (s->chr)
            qemu_chr_write(s->chr, &ch, 1);
        s->int_level |= PL011_INT_TX;
        pl011_update(s);
        break;
    case 1: /* UARTCR */
        s->cr = value;
        break;
    case 6: /* UARTFR */
        /* Writes to Flag register are ignored.  */
        break;
    case 8: /* UARTUARTILPR */
        s->ilpr = value;
        break;
    case 9: /* UARTIBRD */
        s->ibrd = value;
        break;
    case 10: /* UARTFBRD */
        s->fbrd = value;
        break;
    case 11: /* UARTLCR_H */
        s->lcr = value;
        pl011_set_read_trigger(s);
        break;
    case 12: /* UARTCR */
        /* ??? Need to implement the enable and loopback bits.  */
        s->cr = value;
        break;
    case 13: /* UARTIFS */
        s->ifl = value;
        pl011_set_read_trigger(s);
        break;
    case 14: /* UARTIMSC */
        s->int_enabled = value;
        pl011_update(s);
        break;
    case 17: /* UARTICR */
        s->int_level &= ~value;
        pl011_update(s);
        break;
    case 18: /* UARTDMACR */
        s->dmacr = value;
        if (value & 3)
            cpu_abort(cpu_single_env, "PL011: DMA not implemented\n");
        break;
    default:
        cpu_abort (cpu_single_env, "pl011_write: Bad offset %x\n", (int)offset);
    }
}

static int pl011_can_receive(void *opaque)
{
    pl011_state *s = (pl011_state *)opaque;

    if (s->lcr & 0x10)
        return s->read_count < 16;
    else
        return s->read_count < 1;
}

static void pl011_put_fifo(void *opaque, uint32_t value)
{
    pl011_state *s = (pl011_state *)opaque;
    int slot;

    slot = s->read_pos + s->read_count;
    if (slot >= 16)
        slot -= 16;
    s->read_fifo[slot] = value;
    s->read_count++;
    s->flags &= ~PL011_FLAG_RXFE;
    if (s->cr & 0x10 || s->read_count == 16) {
        s->flags |= PL011_FLAG_RXFF;
    }
    if (s->read_count == s->read_trigger) {
        s->int_level |= PL011_INT_RX;
        pl011_update(s);
    }
}

static void pl011_receive(void *opaque, const uint8_t *buf, int size)
{
    pl011_put_fifo(opaque, *buf);
}

static void pl011_event(void *opaque, int event)
{
    if (event == CHR_EVENT_BREAK)
        pl011_put_fifo(opaque, 0x400);
}

static CPUReadMemoryFunc *pl011_readfn[] = {
   pl011_read,
   pl011_read,
   pl011_read
};

static CPUWriteMemoryFunc *pl011_writefn[] = {
   pl011_write,
   pl011_write,
   pl011_write
};

void pl011_init(uint32_t base, qemu_irq irq,
                CharDriverState *chr, enum pl011_type type)
{
    int iomemtype;
    pl011_state *s;

    s = (pl011_state *)qemu_mallocz(sizeof(pl011_state));
    iomemtype = cpu_register_io_memory(0, pl011_readfn,
                                       pl011_writefn, s);
    cpu_register_physical_memory(base, 0x00001000, iomemtype);
    s->base = base;
    s->irq = irq;
    s->type = type;
    s->chr = chr;
    s->read_trigger = 1;
    s->ifl = 0x12;
    s->cr = 0x300;
    s->flags = 0x90;
    if (chr){
        qemu_chr_add_handlers(chr, pl011_can_receive, pl011_receive,
                              pl011_event, s);
    }
    /* ??? Save/restore.  */
}
Commit	Line	Data
5fafdf24	1	/*
cdbdb648 PB	2	* Arm PrimeCell PL011 UART
	3	*
	4	* Copyright (c) 2006 CodeSourcery.
	5	* Written by Paul Brook
	6	*
	7	* This code is licenced under the GPL.
	8	*/
	9
87ecb68b PB	10	#include "hw.h"
	11	#include "qemu-char.h"
	12	#include "primecell.h"
cdbdb648 PB	13
	14	typedef struct {
	15	uint32_t base;
	16	uint32_t readbuff;
	17	uint32_t flags;
	18	uint32_t lcr;
	19	uint32_t cr;
	20	uint32_t dmacr;
	21	uint32_t int_enabled;
	22	uint32_t int_level;
	23	uint32_t read_fifo[16];
	24	uint32_t ilpr;
	25	uint32_t ibrd;
	26	uint32_t fbrd;
	27	uint32_t ifl;
	28	int read_pos;
	29	int read_count;
	30	int read_trigger;
	31	CharDriverState *chr;
d537cf6c	32	qemu_irq irq;
9ee6e8bb	33	enum pl011_type type;
cdbdb648 PB	34	} pl011_state;
	35
	36	#define PL011_INT_TX 0x20
	37	#define PL011_INT_RX 0x10
	38
	39	#define PL011_FLAG_TXFE 0x80
	40	#define PL011_FLAG_RXFF 0x40
	41	#define PL011_FLAG_TXFF 0x20
	42	#define PL011_FLAG_RXFE 0x10
	43
9ee6e8bb PB	44	static const unsigned char pl011_id[2][8] = {
	45	{ 0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }, /* PL011_ARM */
	46	{ 0x11, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1 }, /* PL011_LUMINARY */
	47	};
cdbdb648 PB	48
	49	static void pl011_update(pl011_state *s)
	50	{
	51	uint32_t flags;
3b46e624	52
cdbdb648	53	flags = s->int_level & s->int_enabled;
d537cf6c	54	qemu_set_irq(s->irq, flags != 0);
cdbdb648 PB	55	}
	56
	57	static uint32_t pl011_read(void *opaque, target_phys_addr_t offset)
	58	{
	59	pl011_state s = (pl011_state )opaque;
	60	uint32_t c;
	61
	62	offset -= s->base;
	63	if (offset >= 0xfe0 && offset < 0x1000) {
9ee6e8bb	64	return pl011_id[s->type][(offset - 0xfe0) >> 2];
cdbdb648 PB	65	}
	66	switch (offset >> 2) {
	67	case 0: /* UARTDR */
	68	s->flags &= ~PL011_FLAG_RXFF;
	69	c = s->read_fifo[s->read_pos];
	70	if (s->read_count > 0) {
	71	s->read_count--;
	72	if (++s->read_pos == 16)
	73	s->read_pos = 0;
	74	}
	75	if (s->read_count == 0) {
	76	s->flags \|= PL011_FLAG_RXFE;
	77	}
	78	if (s->read_count == s->read_trigger - 1)
	79	s->int_level &= ~ PL011_INT_RX;
	80	pl011_update(s);
bd9bdce6	81	qemu_chr_accept_input(s->chr);
cdbdb648 PB	82	return c;
	83	case 1: /* UARTCR */
	84	return 0;
	85	case 6: /* UARTFR */
	86	return s->flags;
	87	case 8: /* UARTILPR */
	88	return s->ilpr;
	89	case 9: /* UARTIBRD */
	90	return s->ibrd;
	91	case 10: /* UARTFBRD */
	92	return s->fbrd;
	93	case 11: /* UARTLCR_H */
	94	return s->lcr;
	95	case 12: /* UARTCR */
	96	return s->cr;
	97	case 13: /* UARTIFLS */
	98	return s->ifl;
	99	case 14: /* UARTIMSC */
	100	return s->int_enabled;
	101	case 15: /* UARTRIS */
	102	return s->int_level;
	103	case 16: /* UARTMIS */
	104	return s->int_level & s->int_enabled;
	105	case 18: /* UARTDMACR */
	106	return s->dmacr;
	107	default:
4d1165fa	108	cpu_abort (cpu_single_env, "pl011_read: Bad offset %x\n", (int)offset);
cdbdb648 PB	109	return 0;
	110	}
	111	}
	112
	113	static void pl011_set_read_trigger(pl011_state *s)
	114	{
	115	#if 0
	116	/* The docs say the RX interrupt is triggered when the FIFO exceeds
	117	the threshold. However linux only reads the FIFO in response to an
	118	interrupt. Triggering the interrupt when the FIFO is non-empty seems
	119	to make things work. */
	120	if (s->lcr & 0x10)
	121	s->read_trigger = (s->ifl >> 1) & 0x1c;
	122	else
	123	#endif
	124	s->read_trigger = 1;
	125	}
	126
	127	static void pl011_write(void *opaque, target_phys_addr_t offset,
	128	uint32_t value)
	129	{
	130	pl011_state s = (pl011_state )opaque;
	131	unsigned char ch;
	132
	133	offset -= s->base;
	134	switch (offset >> 2) {
	135	case 0: /* UARTDR */
	136	/* ??? Check if transmitter is enabled. */
	137	ch = value;
	138	if (s->chr)
	139	qemu_chr_write(s->chr, &ch, 1);
	140	s->int_level \|= PL011_INT_TX;
	141	pl011_update(s);
	142	break;
	143	case 1: /* UARTCR */
	144	s->cr = value;
	145	break;
9ee6e8bb PB	146	case 6: /* UARTFR */
	147	/* Writes to Flag register are ignored. */
	148	break;
cdbdb648 PB	149	case 8: /* UARTUARTILPR */
	150	s->ilpr = value;
	151	break;
	152	case 9: /* UARTIBRD */
	153	s->ibrd = value;
	154	break;
	155	case 10: /* UARTFBRD */
	156	s->fbrd = value;
	157	break;
	158	case 11: /* UARTLCR_H */
	159	s->lcr = value;
	160	pl011_set_read_trigger(s);
	161	break;
	162	case 12: /* UARTCR */
	163	/* ??? Need to implement the enable and loopback bits. */
	164	s->cr = value;
	165	break;
	166	case 13: /* UARTIFS */
	167	s->ifl = value;
	168	pl011_set_read_trigger(s);
	169	break;
	170	case 14: /* UARTIMSC */
	171	s->int_enabled = value;
	172	pl011_update(s);
	173	break;
	174	case 17: /* UARTICR */
	175	s->int_level &= ~value;
	176	pl011_update(s);
	177	break;
	178	case 18: /* UARTDMACR */
	179	s->dmacr = value;
	180	if (value & 3)
	181	cpu_abort(cpu_single_env, "PL011: DMA not implemented\n");
	182	break;
	183	default:
4d1165fa	184	cpu_abort (cpu_single_env, "pl011_write: Bad offset %x\n", (int)offset);
cdbdb648 PB	185	}
	186	}
	187
aa1f17c1	188	static int pl011_can_receive(void *opaque)
cdbdb648 PB	189	{
	190	pl011_state s = (pl011_state )opaque;
	191
	192	if (s->lcr & 0x10)
	193	return s->read_count < 16;
	194	else
	195	return s->read_count < 1;
	196	}
	197
cc9c9ffc	198	static void pl011_put_fifo(void *opaque, uint32_t value)
cdbdb648 PB	199	{
	200	pl011_state s = (pl011_state )opaque;
	201	int slot;
	202
	203	slot = s->read_pos + s->read_count;
	204	if (slot >= 16)
	205	slot -= 16;
cc9c9ffc	206	s->read_fifo[slot] = value;
cdbdb648 PB	207	s->read_count++;
	208	s->flags &= ~PL011_FLAG_RXFE;
	209	if (s->cr & 0x10 \|\| s->read_count == 16) {
	210	s->flags \|= PL011_FLAG_RXFF;
	211	}
	212	if (s->read_count == s->read_trigger) {
	213	s->int_level \|= PL011_INT_RX;
	214	pl011_update(s);
	215	}
	216	}
	217
cc9c9ffc AJ	218	static void pl011_receive(void opaque, const uint8_t buf, int size)
	219	{
	220	pl011_put_fifo(opaque, *buf);
	221	}
	222
cdbdb648 PB	223	static void pl011_event(void *opaque, int event)
cdbdb648 PB	224	{
cc9c9ffc AJ	225	if (event == CHR_EVENT_BREAK)
cc9c9ffc AJ	226	pl011_put_fifo(opaque, 0x400);
cdbdb648 PB	227	}
	228
	229	static CPUReadMemoryFunc *pl011_readfn[] = {
	230	pl011_read,
	231	pl011_read,
	232	pl011_read
	233	};
	234
	235	static CPUWriteMemoryFunc *pl011_writefn[] = {
	236	pl011_write,
	237	pl011_write,
	238	pl011_write
	239	};
	240
d537cf6c	241	void pl011_init(uint32_t base, qemu_irq irq,
9ee6e8bb	242	CharDriverState *chr, enum pl011_type type)
cdbdb648 PB	243	{
	244	int iomemtype;
	245	pl011_state *s;
	246
	247	s = (pl011_state *)qemu_mallocz(sizeof(pl011_state));
	248	iomemtype = cpu_register_io_memory(0, pl011_readfn,
	249	pl011_writefn, s);
187337f8	250	cpu_register_physical_memory(base, 0x00001000, iomemtype);
cdbdb648	251	s->base = base;
cdbdb648	252	s->irq = irq;
9ee6e8bb	253	s->type = type;
cdbdb648 PB	254	s->chr = chr;
	255	s->read_trigger = 1;
	256	s->ifl = 0x12;
	257	s->cr = 0x300;
	258	s->flags = 0x90;
5fafdf24	259	if (chr){
aa1f17c1	260	qemu_chr_add_handlers(chr, pl011_can_receive, pl011_receive,
e5b0bc44	261	pl011_event, s);
cdbdb648 PB	262	}
	263	/* ??? Save/restore. */
	264	}
	265