[qemu.git] / hw / arm_timer.c

/* 
 * ARM PrimeCell Timer modules.
 *
 * Copyright (c) 2005-2006 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 */

#include "vl.h"
#include "arm_pic.h"

/* Common timer implementation.  */

#define TIMER_CTRL_ONESHOT      (1 << 0)
#define TIMER_CTRL_32BIT        (1 << 1)
#define TIMER_CTRL_DIV1         (0 << 2)
#define TIMER_CTRL_DIV16        (1 << 2)
#define TIMER_CTRL_DIV256       (2 << 2)
#define TIMER_CTRL_IE           (1 << 5)
#define TIMER_CTRL_PERIODIC     (1 << 6)
#define TIMER_CTRL_ENABLE       (1 << 7)

typedef struct {
    int64_t next_time;
    int64_t expires;
    int64_t loaded;
    QEMUTimer *timer;
    uint32_t control;
    uint32_t count;
    uint32_t limit;
    int raw_freq;
    int freq;
    int int_level;
    void *pic;
    int irq;
} arm_timer_state;

/* Calculate the new expiry time of the given timer.  */

static void arm_timer_reload(arm_timer_state *s)
{
    int64_t delay;

    s->loaded = s->expires;
    delay = muldiv64(s->count, ticks_per_sec, s->freq);
    if (delay == 0)
        delay = 1;
    s->expires += delay;
}

/* Check all active timers, and schedule the next timer interrupt.  */

static void arm_timer_update(arm_timer_state *s, int64_t now)
{
    int64_t next;

    /* Ignore disabled timers.  */
    if ((s->control & TIMER_CTRL_ENABLE) == 0)
        return;
    /* Ignore expired one-shot timers.  */
    if (s->count == 0 && (s->control & TIMER_CTRL_ONESHOT))
        return;
    if (s->expires - now <= 0) {
        /* Timer has expired.  */
        s->int_level = 1;
        if (s->control & TIMER_CTRL_ONESHOT) {
            /* One-shot.  */
            s->count = 0;
        } else {
            if ((s->control & TIMER_CTRL_PERIODIC) == 0) {
                /* Free running.  */
                if (s->control & TIMER_CTRL_32BIT)
                    s->count = 0xffffffff;
                else
                    s->count = 0xffff;
            } else {
                  /* Periodic.  */
                  s->count = s->limit;
            }
        }
    }
    while (s->expires - now <= 0) {
        arm_timer_reload(s);
    }
    /* Update interrupts.  */
    if (s->int_level && (s->control & TIMER_CTRL_IE)) {
        pic_set_irq_new(s->pic, s->irq, 1);
    } else {
        pic_set_irq_new(s->pic, s->irq, 0);
    }

    next = now;
    if (next - s->expires < 0)
        next = s->expires;

    /* Schedule the next timer interrupt.  */
    if (next == now) {
        qemu_del_timer(s->timer);
        s->next_time = 0;
    } else if (next != s->next_time) {
        qemu_mod_timer(s->timer, next);
        s->next_time = next;
    }
}

/* Return the current value of the timer.  */
static uint32_t arm_timer_getcount(arm_timer_state *s, int64_t now)
{
    int64_t left;
    int64_t period;

    if (s->count == 0)
        return 0;
    if ((s->control & TIMER_CTRL_ENABLE) == 0)
        return s->count;
    left = s->expires - now;
    period = s->expires - s->loaded;
    /* If the timer should have expired then return 0.  This can happen
       when the host timer signal doesnt occur immediately.  It's better to
       have a timer appear to sit at zero for a while than have it wrap
       around before the guest interrupt is raised.  */
    /* ??? Could we trigger the interrupt here?  */
    if (left < 0)
        return 0;
    /* We need to calculate count * elapsed / period without overfowing.
       Scale both elapsed and period so they fit in a 32-bit int.  */
    while (period != (int32_t)period) {
        period >>= 1;
        left >>= 1;
    }
    return ((uint64_t)s->count * (uint64_t)(int32_t)left)
            / (int32_t)period;
}

uint32_t arm_timer_read(void *opaque, target_phys_addr_t offset)
{
    arm_timer_state *s = (arm_timer_state *)opaque;

    switch (offset >> 2) {
    case 0: /* TimerLoad */
    case 6: /* TimerBGLoad */
        return s->limit;
    case 1: /* TimerValue */
        return arm_timer_getcount(s, qemu_get_clock(vm_clock));
    case 2: /* TimerControl */
        return s->control;
    case 4: /* TimerRIS */
        return s->int_level;
    case 5: /* TimerMIS */
        if ((s->control & TIMER_CTRL_IE) == 0)
            return 0;
        return s->int_level;
    default:
        cpu_abort (cpu_single_env, "arm_timer_read: Bad offset %x\n", offset);
        return 0;
    }
}

static void arm_timer_write(void *opaque, target_phys_addr_t offset,
                            uint32_t value)
{
    arm_timer_state *s = (arm_timer_state *)opaque;
    int64_t now;

    now = qemu_get_clock(vm_clock);
    switch (offset >> 2) {
    case 0: /* TimerLoad */
        s->limit = value;
        s->count = value;
        s->expires = now;
        arm_timer_reload(s);
        break;
    case 1: /* TimerValue */
        /* ??? Linux seems to want to write to this readonly register.
           Ignore it.  */
        break;
    case 2: /* TimerControl */
        if (s->control & TIMER_CTRL_ENABLE) {
            /* Pause the timer if it is running.  This may cause some
               inaccuracy dure to rounding, but avoids a whole lot of other
               messyness.  */
            s->count = arm_timer_getcount(s, now);
        }
        s->control = value;
        s->freq = s->raw_freq;
        /* ??? Need to recalculate expiry time after changing divisor.  */
        switch ((value >> 2) & 3) {
        case 1: s->freq >>= 4; break;
        case 2: s->freq >>= 8; break;
        }
        if (s->control & TIMER_CTRL_ENABLE) {
            /* Restart the timer if still enabled.  */
            s->expires = now;
            arm_timer_reload(s);
        }
        break;
    case 3: /* TimerIntClr */
        s->int_level = 0;
        break;
    case 6: /* TimerBGLoad */
        s->limit = value;
        break;
    default:
        cpu_abort (cpu_single_env, "arm_timer_write: Bad offset %x\n", offset);
    }
    arm_timer_update(s, now);
}

static void arm_timer_tick(void *opaque)
{
    int64_t now;

    now = qemu_get_clock(vm_clock);
    arm_timer_update((arm_timer_state *)opaque, now);
}

static void *arm_timer_init(uint32_t freq, void *pic, int irq)
{
    arm_timer_state *s;

    s = (arm_timer_state *)qemu_mallocz(sizeof(arm_timer_state));
    s->pic = pic;
    s->irq = irq;
    s->raw_freq = s->freq = 1000000;
    s->control = TIMER_CTRL_IE;
    s->count = 0xffffffff;

    s->timer = qemu_new_timer(vm_clock, arm_timer_tick, s);
    /* ??? Save/restore.  */
    return s;
}

/* ARM PrimeCell SP804 dual timer module.
   Docs for this device don't seem to be publicly available.  This
   implementation is based on gueswork, the linux kernel sources and the
   Integrator/CP timer modules.  */

typedef struct {
    /* Include a pseudo-PIC device to merge the two interrupt sources.  */
    arm_pic_handler handler;
    void *timer[2];
    int level[2];
    uint32_t base;
    /* The output PIC device.  */
    void *pic;
    int irq;
} sp804_state;

static void sp804_set_irq(void *opaque, int irq, int level)
{
    sp804_state *s = (sp804_state *)opaque;

    s->level[irq] = level;
    pic_set_irq_new(s->pic, s->irq, s->level[0] || s->level[1]);
}

static uint32_t sp804_read(void *opaque, target_phys_addr_t offset)
{
    sp804_state *s = (sp804_state *)opaque;

    /* ??? Don't know the PrimeCell ID for this device.  */
    offset -= s->base;
    if (offset < 0x20) {
        return arm_timer_read(s->timer[0], offset);
    } else {
        return arm_timer_read(s->timer[1], offset - 0x20);
    }
}

static void sp804_write(void *opaque, target_phys_addr_t offset,
                        uint32_t value)
{
    sp804_state *s = (sp804_state *)opaque;

    offset -= s->base;
    if (offset < 0x20) {
        arm_timer_write(s->timer[0], offset, value);
    } else {
        arm_timer_write(s->timer[1], offset - 0x20, value);
    }
}

static CPUReadMemoryFunc *sp804_readfn[] = {
   sp804_read,
   sp804_read,
   sp804_read
};

static CPUWriteMemoryFunc *sp804_writefn[] = {
   sp804_write,
   sp804_write,
   sp804_write
};

void sp804_init(uint32_t base, void *pic, int irq)
{
    int iomemtype;
    sp804_state *s;

    s = (sp804_state *)qemu_mallocz(sizeof(sp804_state));
    s->handler = sp804_set_irq;
    s->base = base;
    s->pic = pic;
    s->irq = irq;
    /* ??? The timers are actually configurable between 32kHz and 1MHz, but
       we don't implement that.  */
    s->timer[0] = arm_timer_init(1000000, s, 0);
    s->timer[1] = arm_timer_init(1000000, s, 1);
    iomemtype = cpu_register_io_memory(0, sp804_readfn,
                                       sp804_writefn, s);
    cpu_register_physical_memory(base, 0x00000fff, iomemtype);
    /* ??? Save/restore.  */
}


/* Integrator/CP timer module.  */

typedef struct {
    void *timer[3];
    uint32_t base;
} icp_pit_state;

static uint32_t icp_pit_read(void *opaque, target_phys_addr_t offset)
{
    icp_pit_state *s = (icp_pit_state *)opaque;
    int n;

    /* ??? Don't know the PrimeCell ID for this device.  */
    offset -= s->base;
    n = offset >> 8;
    if (n > 3)
        cpu_abort(cpu_single_env, "sp804_read: Bad timer %d\n", n);

    return arm_timer_read(s->timer[n], offset & 0xff);
}

static void icp_pit_write(void *opaque, target_phys_addr_t offset,
                          uint32_t value)
{
    icp_pit_state *s = (icp_pit_state *)opaque;
    int n;

    offset -= s->base;
    n = offset >> 8;
    if (n > 3)
        cpu_abort(cpu_single_env, "sp804_write: Bad timer %d\n", n);

    arm_timer_write(s->timer[n], offset & 0xff, value);
}


static CPUReadMemoryFunc *icp_pit_readfn[] = {
   icp_pit_read,
   icp_pit_read,
   icp_pit_read
};

static CPUWriteMemoryFunc *icp_pit_writefn[] = {
   icp_pit_write,
   icp_pit_write,
   icp_pit_write
};

void icp_pit_init(uint32_t base, void *pic, int irq)
{
    int iomemtype;
    icp_pit_state *s;

    s = (icp_pit_state *)qemu_mallocz(sizeof(icp_pit_state));
    s->base = base;
    /* Timer 0 runs at the system clock speed (40MHz).  */
    s->timer[0] = arm_timer_init(40000000, pic, irq);
    /* The other two timers run at 1MHz.  */
    s->timer[1] = arm_timer_init(1000000, pic, irq + 1);
    s->timer[2] = arm_timer_init(1000000, pic, irq + 2);

    iomemtype = cpu_register_io_memory(0, icp_pit_readfn,
                                       icp_pit_writefn, s);
    cpu_register_physical_memory(base, 0x00000fff, iomemtype);
    /* ??? Save/restore.  */
}
Commit	Line	Data
cdbdb648 PB	1	/*
	2	* ARM PrimeCell Timer modules.
	3	*
	4	* Copyright (c) 2005-2006 CodeSourcery.
	5	* Written by Paul Brook
	6	*
	7	* This code is licenced under the GPL.
	8	*/
	9
	10	#include "vl.h"
	11	#include "arm_pic.h"
	12
	13	/* Common timer implementation. */
	14
	15	#define TIMER_CTRL_ONESHOT (1 << 0)
	16	#define TIMER_CTRL_32BIT (1 << 1)
	17	#define TIMER_CTRL_DIV1 (0 << 2)
	18	#define TIMER_CTRL_DIV16 (1 << 2)
	19	#define TIMER_CTRL_DIV256 (2 << 2)
	20	#define TIMER_CTRL_IE (1 << 5)
	21	#define TIMER_CTRL_PERIODIC (1 << 6)
	22	#define TIMER_CTRL_ENABLE (1 << 7)
	23
	24	typedef struct {
	25	int64_t next_time;
	26	int64_t expires;
	27	int64_t loaded;
	28	QEMUTimer *timer;
	29	uint32_t control;
	30	uint32_t count;
	31	uint32_t limit;
	32	int raw_freq;
	33	int freq;
	34	int int_level;
	35	void *pic;
	36	int irq;
	37	} arm_timer_state;
	38
	39	/* Calculate the new expiry time of the given timer. */
	40
	41	static void arm_timer_reload(arm_timer_state *s)
	42	{
	43	int64_t delay;
	44
	45	s->loaded = s->expires;
	46	delay = muldiv64(s->count, ticks_per_sec, s->freq);
	47	if (delay == 0)
	48	delay = 1;
	49	s->expires += delay;
	50	}
	51
	52	/* Check all active timers, and schedule the next timer interrupt. */
	53
	54	static void arm_timer_update(arm_timer_state *s, int64_t now)
	55	{
	56	int64_t next;
	57
	58	/* Ignore disabled timers. */
	59	if ((s->control & TIMER_CTRL_ENABLE) == 0)
	60	return;
	61	/* Ignore expired one-shot timers. */
	62	if (s->count == 0 && (s->control & TIMER_CTRL_ONESHOT))
	63	return;
	64	if (s->expires - now <= 0) {
65	/* Timer has expired. */
66	s->int_level = 1;
67	if (s->control & TIMER_CTRL_ONESHOT) {
68	/* One-shot. */
69	s->count = 0;
70	} else {
71	if ((s->control & TIMER_CTRL_PERIODIC) == 0) {
72	/* Free running. */
73	if (s->control & TIMER_CTRL_32BIT)
74	s->count = 0xffffffff;
75	else
76	s->count = 0xffff;
77	} else {
78	/* Periodic. */
79	s->count = s->limit;
80	}
81	}
82	}
83	while (s->expires - now <= 0) {
84	arm_timer_reload(s);
85	}
86	/* Update interrupts. */
87	if (s->int_level && (s->control & TIMER_CTRL_IE)) {
88	pic_set_irq_new(s->pic, s->irq, 1);
89	} else {
90	pic_set_irq_new(s->pic, s->irq, 0);
91	}
92
93	next = now;
94	if (next - s->expires < 0)
95	next = s->expires;
96
97	/* Schedule the next timer interrupt. */
98	if (next == now) {
99	qemu_del_timer(s->timer);
100	s->next_time = 0;
101	} else if (next != s->next_time) {
102	qemu_mod_timer(s->timer, next);
103	s->next_time = next;
104	}
105	}
106
107	/* Return the current value of the timer. */
108	static uint32_t arm_timer_getcount(arm_timer_state *s, int64_t now)
109	{
ec2db7de	110	int64_t left;
cdbdb648 PB	111	int64_t period;
	112
	113	if (s->count == 0)
	114	return 0;
	115	if ((s->control & TIMER_CTRL_ENABLE) == 0)
	116	return s->count;
ec2db7de	117	left = s->expires - now;
cdbdb648 PB	118	period = s->expires - s->loaded;
	119	/* If the timer should have expired then return 0. This can happen
	120	when the host timer signal doesnt occur immediately. It's better to
	121	have a timer appear to sit at zero for a while than have it wrap
	122	around before the guest interrupt is raised. */
	123	/* ??? Could we trigger the interrupt here? */
ec2db7de	124	if (left < 0)
cdbdb648 PB	125	return 0;
	126	/* We need to calculate count * elapsed / period without overfowing.
	127	Scale both elapsed and period so they fit in a 32-bit int. */
	128	while (period != (int32_t)period) {
	129	period >>= 1;
ec2db7de	130	left >>= 1;
cdbdb648	131	}
ec2db7de	132	return ((uint64_t)s->count * (uint64_t)(int32_t)left)
cdbdb648 PB	133	/ (int32_t)period;
	134	}
	135
	136	uint32_t arm_timer_read(void *opaque, target_phys_addr_t offset)
	137	{
	138	arm_timer_state s = (arm_timer_state )opaque;
	139
	140	switch (offset >> 2) {
	141	case 0: /* TimerLoad */
	142	case 6: /* TimerBGLoad */
	143	return s->limit;
	144	case 1: /* TimerValue */
	145	return arm_timer_getcount(s, qemu_get_clock(vm_clock));
	146	case 2: /* TimerControl */
	147	return s->control;
	148	case 4: /* TimerRIS */
	149	return s->int_level;
	150	case 5: /* TimerMIS */
	151	if ((s->control & TIMER_CTRL_IE) == 0)
	152	return 0;
	153	return s->int_level;
	154	default:
	155	cpu_abort (cpu_single_env, "arm_timer_read: Bad offset %x\n", offset);
	156	return 0;
	157	}
	158	}
	159
	160	static void arm_timer_write(void *opaque, target_phys_addr_t offset,
	161	uint32_t value)
	162	{
	163	arm_timer_state s = (arm_timer_state )opaque;
	164	int64_t now;
	165
	166	now = qemu_get_clock(vm_clock);
	167	switch (offset >> 2) {
	168	case 0: /* TimerLoad */
	169	s->limit = value;
	170	s->count = value;
	171	s->expires = now;
	172	arm_timer_reload(s);
	173	break;
	174	case 1: /* TimerValue */
	175	/* ??? Linux seems to want to write to this readonly register.
	176	Ignore it. */
	177	break;
	178	case 2: /* TimerControl */
	179	if (s->control & TIMER_CTRL_ENABLE) {
	180	/* Pause the timer if it is running. This may cause some
	181	inaccuracy dure to rounding, but avoids a whole lot of other
	182	messyness. */
	183	s->count = arm_timer_getcount(s, now);
	184	}
	185	s->control = value;
	186	s->freq = s->raw_freq;
	187	/* ??? Need to recalculate expiry time after changing divisor. */
	188	switch ((value >> 2) & 3) {
	189	case 1: s->freq >>= 4; break;
	190	case 2: s->freq >>= 8; break;
	191	}
	192	if (s->control & TIMER_CTRL_ENABLE) {
	193	/* Restart the timer if still enabled. */
	194	s->expires = now;
	195	arm_timer_reload(s);
	196	}
197	break;
198	case 3: /* TimerIntClr */
199	s->int_level = 0;
200	break;
201	case 6: /* TimerBGLoad */
202	s->limit = value;
203	break;
204	default:
205	cpu_abort (cpu_single_env, "arm_timer_write: Bad offset %x\n", offset);
206	}
207	arm_timer_update(s, now);
208	}
209
210	static void arm_timer_tick(void *opaque)
211	{
212	int64_t now;
213
214	now = qemu_get_clock(vm_clock);
215	arm_timer_update((arm_timer_state *)opaque, now);
216	}
217
218	static void arm_timer_init(uint32_t freq, void pic, int irq)
219	{
220	arm_timer_state *s;
221
222	s = (arm_timer_state *)qemu_mallocz(sizeof(arm_timer_state));
223	s->pic = pic;
224	s->irq = irq;
225	s->raw_freq = s->freq = 1000000;
226	s->control = TIMER_CTRL_IE;
227	s->count = 0xffffffff;
228
229	s->timer = qemu_new_timer(vm_clock, arm_timer_tick, s);
230	/* ??? Save/restore. */
231	return s;
232	}
233
234	/* ARM PrimeCell SP804 dual timer module.
235	Docs for this device don't seem to be publicly available. This
236	implementation is based on gueswork, the linux kernel sources and the
237	Integrator/CP timer modules. */
238
239	typedef struct {
240	/* Include a pseudo-PIC device to merge the two interrupt sources. */
241	arm_pic_handler handler;
242	void *timer[2];
243	int level[2];
244	uint32_t base;
245	/* The output PIC device. */
246	void *pic;
247	int irq;
248	} sp804_state;
249
250	static void sp804_set_irq(void *opaque, int irq, int level)
251	{
252	sp804_state s = (sp804_state )opaque;
253
254	s->level[irq] = level;
255	pic_set_irq_new(s->pic, s->irq, s->level[0] \|\| s->level[1]);
256	}
257
258	static uint32_t sp804_read(void *opaque, target_phys_addr_t offset)
259	{
260	sp804_state s = (sp804_state )opaque;
261
262	/* ??? Don't know the PrimeCell ID for this device. */
263	offset -= s->base;
264	if (offset < 0x20) {
265	return arm_timer_read(s->timer[0], offset);
266	} else {
267	return arm_timer_read(s->timer[1], offset - 0x20);
268	}
269	}
270
271	static void sp804_write(void *opaque, target_phys_addr_t offset,
272	uint32_t value)
273	{
274	sp804_state s = (sp804_state )opaque;
275
276	offset -= s->base;
277	if (offset < 0x20) {
278	arm_timer_write(s->timer[0], offset, value);
279	} else {
280	arm_timer_write(s->timer[1], offset - 0x20, value);
281	}
282	}
283
284	static CPUReadMemoryFunc *sp804_readfn[] = {
285	sp804_read,
286	sp804_read,
287	sp804_read
288	};
289
290	static CPUWriteMemoryFunc *sp804_writefn[] = {
291	sp804_write,
292	sp804_write,
293	sp804_write
294	};
295
296	void sp804_init(uint32_t base, void *pic, int irq)
297	{
298	int iomemtype;
299	sp804_state *s;
300
301	s = (sp804_state *)qemu_mallocz(sizeof(sp804_state));
302	s->handler = sp804_set_irq;
303	s->base = base;
304	s->pic = pic;
305	s->irq = irq;
306	/* ??? The timers are actually configurable between 32kHz and 1MHz, but
307	we don't implement that. */
308	s->timer[0] = arm_timer_init(1000000, s, 0);
309	s->timer[1] = arm_timer_init(1000000, s, 1);
310	iomemtype = cpu_register_io_memory(0, sp804_readfn,
311	sp804_writefn, s);
312	cpu_register_physical_memory(base, 0x00000fff, iomemtype);
313	/* ??? Save/restore. */
314	}
315
316
317	/* Integrator/CP timer module. */
318
319	typedef struct {
320	void *timer[3];
321	uint32_t base;
322	} icp_pit_state;
323
324	static uint32_t icp_pit_read(void *opaque, target_phys_addr_t offset)
325	{
326	icp_pit_state s = (icp_pit_state )opaque;
327	int n;
328
329	/* ??? Don't know the PrimeCell ID for this device. */
330	offset -= s->base;
331	n = offset >> 8;
332	if (n > 3)
333	cpu_abort(cpu_single_env, "sp804_read: Bad timer %d\n", n);
334
335	return arm_timer_read(s->timer[n], offset & 0xff);
336	}
337
338	static void icp_pit_write(void *opaque, target_phys_addr_t offset,
339	uint32_t value)
340	{
341	icp_pit_state s = (icp_pit_state )opaque;
342	int n;
343
344	offset -= s->base;
345	n = offset >> 8;
346	if (n > 3)
347	cpu_abort(cpu_single_env, "sp804_write: Bad timer %d\n", n);
348
349	arm_timer_write(s->timer[n], offset & 0xff, value);
350	}
351
352
353	static CPUReadMemoryFunc *icp_pit_readfn[] = {
354	icp_pit_read,
355	icp_pit_read,
356	icp_pit_read
357	};
358
359	static CPUWriteMemoryFunc *icp_pit_writefn[] = {
360	icp_pit_write,
361	icp_pit_write,
362	icp_pit_write
363	};
364
365	void icp_pit_init(uint32_t base, void *pic, int irq)
366	{
367	int iomemtype;
368	icp_pit_state *s;
369
370	s = (icp_pit_state *)qemu_mallocz(sizeof(icp_pit_state));
371	s->base = base;
372	/* Timer 0 runs at the system clock speed (40MHz). */
373	s->timer[0] = arm_timer_init(40000000, pic, irq);
374	/* The other two timers run at 1MHz. */
375	s->timer[1] = arm_timer_init(1000000, pic, irq + 1);
376	s->timer[2] = arm_timer_init(1000000, pic, irq + 2);
377
378	iomemtype = cpu_register_io_memory(0, icp_pit_readfn,
379	icp_pit_writefn, s);
380	cpu_register_physical_memory(base, 0x00000fff, iomemtype);
381	/* ??? Save/restore. */
382	}
383