hw/timer/imx_epit.c - qemu - Git at Google

 /*
  * IMX EPIT Timer
  *
  * Copyright (c) 2008 OK Labs
  * Copyright (c) 2011 NICTA Pty Ltd
  * Originally written by Hans Jiang
  * Updated by Peter Chubb
  * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
  *
  * This code is licensed under GPL version 2 or later.  See
  * the COPYING file in the top-level directory.
  *
  */

 #include "hw/timer/imx_epit.h"
 #include "hw/misc/imx_ccm.h"
 #include "qemu/main-loop.h"

 #ifndef DEBUG_IMX_EPIT
 #define DEBUG_IMX_EPIT 0
 #endif

 #define DPRINTF(fmt, args...) \
     do { \
         if (DEBUG_IMX_EPIT) { \
             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_EPIT, \
                                              __func__, ##args); \
         } \
     } while (0)

 static char const *imx_epit_reg_name(uint32_t reg)
 {
     switch (reg) {
     case 0:
         return "CR";
     case 1:
         return "SR";
     case 2:
         return "LR";
     case 3:
         return "CMP";
     case 4:
         return "CNT";
     default:
         return "[?]";
     }
 }

 /*
  * Exact clock frequencies vary from board to board.
  * These are typical.
  */
 static const IMXClk imx_epit_clocks[] =  {
     NOCLK,    /* 00 disabled */
     CLK_IPG,  /* 01 ipg_clk, ~532MHz */
     CLK_IPG,  /* 10 ipg_clk_highfreq */
     CLK_32k,  /* 11 ipg_clk_32k -- ~32kHz */
 };

 /*
  * Update interrupt status
  */
 static void imx_epit_update_int(IMXEPITState *s)
 {
     if (s->sr && (s->cr & CR_OCIEN) && (s->cr & CR_EN)) {
         qemu_irq_raise(s->irq);
     } else {
         qemu_irq_lower(s->irq);
     }
 }

 static void imx_epit_set_freq(IMXEPITState *s)
 {
     uint32_t clksrc;
     uint32_t prescaler;

     clksrc = extract32(s->cr, CR_CLKSRC_SHIFT, 2);
     prescaler = 1 + extract32(s->cr, CR_PRESCALE_SHIFT, 12);

     s->freq = imx_ccm_get_clock_frequency(s->ccm,
                                 imx_epit_clocks[clksrc]) / prescaler;

     DPRINTF("Setting ptimer frequency to %u\n", s->freq);

     if (s->freq) {
         ptimer_set_freq(s->timer_reload, s->freq);
         ptimer_set_freq(s->timer_cmp, s->freq);
     }
 }

 static void imx_epit_reset(DeviceState *dev)
 {
     IMXEPITState *s = IMX_EPIT(dev);

     /*
      * Soft reset doesn't touch some bits; hard reset clears them
      */
     s->cr &= (CR_EN|CR_ENMOD|CR_STOPEN|CR_DOZEN|CR_WAITEN|CR_DBGEN);
     s->sr = 0;
     s->lr = EPIT_TIMER_MAX;
     s->cmp = 0;
     s->cnt = 0;
     /* stop both timers */
     ptimer_stop(s->timer_cmp);
     ptimer_stop(s->timer_reload);
     /* compute new frequency */
     imx_epit_set_freq(s);
     /* init both timers to EPIT_TIMER_MAX */
     ptimer_set_limit(s->timer_cmp, EPIT_TIMER_MAX, 1);
     ptimer_set_limit(s->timer_reload, EPIT_TIMER_MAX, 1);
     if (s->freq && (s->cr & CR_EN)) {
         /* if the timer is still enabled, restart it */
         ptimer_run(s->timer_reload, 0);
     }
 }

 static uint32_t imx_epit_update_count(IMXEPITState *s)
 {
     s->cnt = ptimer_get_count(s->timer_reload);

     return s->cnt;
 }

 static uint64_t imx_epit_read(void *opaque, hwaddr offset, unsigned size)
 {
     IMXEPITState *s = IMX_EPIT(opaque);
     uint32_t reg_value = 0;

     switch (offset >> 2) {
     case 0: /* Control Register */
         reg_value = s->cr;
         break;

     case 1: /* Status Register */
         reg_value = s->sr;
         break;

     case 2: /* LR - ticks*/
         reg_value = s->lr;
         break;

     case 3: /* CMP */
         reg_value = s->cmp;
         break;

     case 4: /* CNT */
         imx_epit_update_count(s);
         reg_value = s->cnt;
         break;

     default:
         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
                       HWADDR_PRIx "\n", TYPE_IMX_EPIT, __func__, offset);
         break;
     }

     DPRINTF("(%s) = 0x%08x\n", imx_epit_reg_name(offset >> 2), reg_value);

     return reg_value;
 }

 static void imx_epit_reload_compare_timer(IMXEPITState *s)
 {
     if ((s->cr & (CR_EN | CR_OCIEN)) == (CR_EN | CR_OCIEN))  {
         /* if the compare feature is on and timers are running */
         uint32_t tmp = imx_epit_update_count(s);
         uint64_t next;
         if (tmp > s->cmp) {
             /* It'll fire in this round of the timer */
             next = tmp - s->cmp;
         } else { /* catch it next time around */
             next = tmp - s->cmp + ((s->cr & CR_RLD) ? EPIT_TIMER_MAX : s->lr);
         }
         ptimer_set_count(s->timer_cmp, next);
     }
 }

 static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value,
                            unsigned size)
 {
     IMXEPITState *s = IMX_EPIT(opaque);
     uint64_t oldcr;

     DPRINTF("(%s, value = 0x%08x)\n", imx_epit_reg_name(offset >> 2),
             (uint32_t)value);

     switch (offset >> 2) {
     case 0: /* CR */

         oldcr = s->cr;
         s->cr = value & 0x03ffffff;
         if (s->cr & CR_SWR) {
             /* handle the reset */
             imx_epit_reset(DEVICE(s));
         } else {
             imx_epit_set_freq(s);
         }

         if (s->freq && (s->cr & CR_EN) && !(oldcr & CR_EN)) {
             if (s->cr & CR_ENMOD) {
                 if (s->cr & CR_RLD) {
                     ptimer_set_limit(s->timer_reload, s->lr, 1);
                     ptimer_set_limit(s->timer_cmp, s->lr, 1);
                 } else {
                     ptimer_set_limit(s->timer_reload, EPIT_TIMER_MAX, 1);
                     ptimer_set_limit(s->timer_cmp, EPIT_TIMER_MAX, 1);
                 }
             }

             imx_epit_reload_compare_timer(s);
             ptimer_run(s->timer_reload, 0);
             if (s->cr & CR_OCIEN) {
                 ptimer_run(s->timer_cmp, 0);
             } else {
                 ptimer_stop(s->timer_cmp);
             }
         } else if (!(s->cr & CR_EN)) {
             /* stop both timers */
             ptimer_stop(s->timer_reload);
             ptimer_stop(s->timer_cmp);
         } else  if (s->cr & CR_OCIEN) {
             if (!(oldcr & CR_OCIEN)) {
                 imx_epit_reload_compare_timer(s);
                 ptimer_run(s->timer_cmp, 0);
             }
         } else {
             ptimer_stop(s->timer_cmp);
         }
         break;

     case 1: /* SR - ACK*/
         /* writing 1 to OCIF clear the OCIF bit */
         if (value & 0x01) {
             s->sr = 0;
             imx_epit_update_int(s);
         }
         break;

     case 2: /* LR - set ticks */
         s->lr = value;

         if (s->cr & CR_RLD) {
             /* Also set the limit if the LRD bit is set */
             /* If IOVW bit is set then set the timer value */
             ptimer_set_limit(s->timer_reload, s->lr, s->cr & CR_IOVW);
             ptimer_set_limit(s->timer_cmp, s->lr, 0);
         } else if (s->cr & CR_IOVW) {
             /* If IOVW bit is set then set the timer value */
             ptimer_set_count(s->timer_reload, s->lr);
         }

         imx_epit_reload_compare_timer(s);
         break;

     case 3: /* CMP */
         s->cmp = value;

         imx_epit_reload_compare_timer(s);

         break;

     default:
         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
                       HWADDR_PRIx "\n", TYPE_IMX_EPIT, __func__, offset);

         break;
     }
 }
 static void imx_epit_cmp(void *opaque)
 {
     IMXEPITState *s = IMX_EPIT(opaque);

     DPRINTF("sr was %d\n", s->sr);

     s->sr = 1;
     imx_epit_update_int(s);
 }

 static const MemoryRegionOps imx_epit_ops = {
     .read = imx_epit_read,
     .write = imx_epit_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 static const VMStateDescription vmstate_imx_timer_epit = {
     .name = TYPE_IMX_EPIT,
     .version_id = 2,
     .minimum_version_id = 2,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(cr, IMXEPITState),
         VMSTATE_UINT32(sr, IMXEPITState),
         VMSTATE_UINT32(lr, IMXEPITState),
         VMSTATE_UINT32(cmp, IMXEPITState),
         VMSTATE_UINT32(cnt, IMXEPITState),
         VMSTATE_UINT32(freq, IMXEPITState),
         VMSTATE_PTIMER(timer_reload, IMXEPITState),
         VMSTATE_PTIMER(timer_cmp, IMXEPITState),
         VMSTATE_END_OF_LIST()
     }
 };

 static void imx_epit_realize(DeviceState *dev, Error **errp)
 {
     IMXEPITState *s = IMX_EPIT(dev);
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     QEMUBH *bh;

     DPRINTF("\n");

     sysbus_init_irq(sbd, &s->irq);
     memory_region_init_io(&s->iomem, OBJECT(s), &imx_epit_ops, s, TYPE_IMX_EPIT,
                           0x00001000);
     sysbus_init_mmio(sbd, &s->iomem);

     s->timer_reload = ptimer_init(NULL);

     bh = qemu_bh_new(imx_epit_cmp, s);
     s->timer_cmp = ptimer_init(bh);
 }

 static void imx_epit_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc  = DEVICE_CLASS(klass);

     dc->realize = imx_epit_realize;
     dc->reset = imx_epit_reset;
     dc->vmsd = &vmstate_imx_timer_epit;
     dc->desc = "i.MX periodic timer";
 }

 static const TypeInfo imx_epit_info = {
     .name = TYPE_IMX_EPIT,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(IMXEPITState),
     .class_init = imx_epit_class_init,
 };

 static void imx_epit_register_types(void)
 {
     type_register_static(&imx_epit_info);
 }

 type_init(imx_epit_register_types)
	/*
	* IMX EPIT Timer
	*
	* Copyright (c) 2008 OK Labs
	* Copyright (c) 2011 NICTA Pty Ltd
	* Originally written by Hans Jiang
	* Updated by Peter Chubb
	* Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
	*
	* This code is licensed under GPL version 2 or later. See
	* the COPYING file in the top-level directory.
	*
	*/

	#include "hw/timer/imx_epit.h"
	#include "hw/misc/imx_ccm.h"
	#include "qemu/main-loop.h"

	#ifndef DEBUG_IMX_EPIT
	#define DEBUG_IMX_EPIT 0
	#endif

	#define DPRINTF(fmt, args...) \
	do { \
	if (DEBUG_IMX_EPIT) { \
	fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_EPIT, \
	__func__, ##args); \
	} \
	} while (0)

	static char const *imx_epit_reg_name(uint32_t reg)
	{
	switch (reg) {
	case 0:
	return "CR";
	case 1:
	return "SR";
	case 2:
	return "LR";
	case 3:
	return "CMP";
	case 4:
	return "CNT";
	default:
	return "[?]";
	}
	}

	/*
	* Exact clock frequencies vary from board to board.
	* These are typical.
	*/
	static const IMXClk imx_epit_clocks[] = {
	NOCLK, /* 00 disabled */
	CLK_IPG, /* 01 ipg_clk, ~532MHz */
	CLK_IPG, /* 10 ipg_clk_highfreq */
	CLK_32k, /* 11 ipg_clk_32k -- ~32kHz */
	};

	/*
	* Update interrupt status
	*/
	static void imx_epit_update_int(IMXEPITState *s)
	{
	if (s->sr && (s->cr & CR_OCIEN) && (s->cr & CR_EN)) {
	qemu_irq_raise(s->irq);
	} else {
	qemu_irq_lower(s->irq);
	}
	}

	static void imx_epit_set_freq(IMXEPITState *s)
	{
	uint32_t clksrc;
	uint32_t prescaler;

	clksrc = extract32(s->cr, CR_CLKSRC_SHIFT, 2);
	prescaler = 1 + extract32(s->cr, CR_PRESCALE_SHIFT, 12);

	s->freq = imx_ccm_get_clock_frequency(s->ccm,
	imx_epit_clocks[clksrc]) / prescaler;

	DPRINTF("Setting ptimer frequency to %u\n", s->freq);

	if (s->freq) {
	ptimer_set_freq(s->timer_reload, s->freq);
	ptimer_set_freq(s->timer_cmp, s->freq);
	}
	}

	static void imx_epit_reset(DeviceState *dev)
	{
	IMXEPITState *s = IMX_EPIT(dev);

	/*
	* Soft reset doesn't touch some bits; hard reset clears them
	*/
	s->cr &= (CR_EN\|CR_ENMOD\|CR_STOPEN\|CR_DOZEN\|CR_WAITEN\|CR_DBGEN);
	s->sr = 0;
	s->lr = EPIT_TIMER_MAX;
	s->cmp = 0;
	s->cnt = 0;
	/* stop both timers */
	ptimer_stop(s->timer_cmp);
	ptimer_stop(s->timer_reload);
	/* compute new frequency */
	imx_epit_set_freq(s);
	/* init both timers to EPIT_TIMER_MAX */
	ptimer_set_limit(s->timer_cmp, EPIT_TIMER_MAX, 1);
	ptimer_set_limit(s->timer_reload, EPIT_TIMER_MAX, 1);
	if (s->freq && (s->cr & CR_EN)) {
	/* if the timer is still enabled, restart it */
	ptimer_run(s->timer_reload, 0);
	}
	}

	static uint32_t imx_epit_update_count(IMXEPITState *s)
	{
	s->cnt = ptimer_get_count(s->timer_reload);

	return s->cnt;
	}

	static uint64_t imx_epit_read(void *opaque, hwaddr offset, unsigned size)
	{
	IMXEPITState *s = IMX_EPIT(opaque);
	uint32_t reg_value = 0;

	switch (offset >> 2) {
	case 0: /* Control Register */
	reg_value = s->cr;
	break;

	case 1: /* Status Register */
	reg_value = s->sr;
	break;

	case 2: /* LR - ticks*/
	reg_value = s->lr;
	break;

	case 3: /* CMP */
	reg_value = s->cmp;
	break;

	case 4: /* CNT */
	imx_epit_update_count(s);
	reg_value = s->cnt;
	break;

	default:
	qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
	HWADDR_PRIx "\n", TYPE_IMX_EPIT, __func__, offset);
	break;
	}

	DPRINTF("(%s) = 0x%08x\n", imx_epit_reg_name(offset >> 2), reg_value);

	return reg_value;
	}

	static void imx_epit_reload_compare_timer(IMXEPITState *s)
	{
	if ((s->cr & (CR_EN \| CR_OCIEN)) == (CR_EN \| CR_OCIEN)) {
	/* if the compare feature is on and timers are running */
	uint32_t tmp = imx_epit_update_count(s);
	uint64_t next;
	if (tmp > s->cmp) {
	/* It'll fire in this round of the timer */
	next = tmp - s->cmp;
	} else { /* catch it next time around */
	next = tmp - s->cmp + ((s->cr & CR_RLD) ? EPIT_TIMER_MAX : s->lr);
	}
	ptimer_set_count(s->timer_cmp, next);
	}
	}

	static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value,
	unsigned size)
	{
	IMXEPITState *s = IMX_EPIT(opaque);
	uint64_t oldcr;

	DPRINTF("(%s, value = 0x%08x)\n", imx_epit_reg_name(offset >> 2),
	(uint32_t)value);

	switch (offset >> 2) {
	case 0: /* CR */

	oldcr = s->cr;
	s->cr = value & 0x03ffffff;
	if (s->cr & CR_SWR) {
	/* handle the reset */
	imx_epit_reset(DEVICE(s));
	} else {
	imx_epit_set_freq(s);
	}

	if (s->freq && (s->cr & CR_EN) && !(oldcr & CR_EN)) {
	if (s->cr & CR_ENMOD) {
	if (s->cr & CR_RLD) {
	ptimer_set_limit(s->timer_reload, s->lr, 1);
	ptimer_set_limit(s->timer_cmp, s->lr, 1);
	} else {
	ptimer_set_limit(s->timer_reload, EPIT_TIMER_MAX, 1);
	ptimer_set_limit(s->timer_cmp, EPIT_TIMER_MAX, 1);
	}
	}

	imx_epit_reload_compare_timer(s);
	ptimer_run(s->timer_reload, 0);
	if (s->cr & CR_OCIEN) {
	ptimer_run(s->timer_cmp, 0);
	} else {
	ptimer_stop(s->timer_cmp);
	}
	} else if (!(s->cr & CR_EN)) {
	/* stop both timers */
	ptimer_stop(s->timer_reload);
	ptimer_stop(s->timer_cmp);
	} else if (s->cr & CR_OCIEN) {
	if (!(oldcr & CR_OCIEN)) {
	imx_epit_reload_compare_timer(s);
	ptimer_run(s->timer_cmp, 0);
	}
	} else {
	ptimer_stop(s->timer_cmp);
	}
	break;

	case 1: /* SR - ACK*/
	/* writing 1 to OCIF clear the OCIF bit */
	if (value & 0x01) {
	s->sr = 0;
	imx_epit_update_int(s);
	}
	break;

	case 2: /* LR - set ticks */
	s->lr = value;

	if (s->cr & CR_RLD) {
	/* Also set the limit if the LRD bit is set */
	/* If IOVW bit is set then set the timer value */
	ptimer_set_limit(s->timer_reload, s->lr, s->cr & CR_IOVW);
	ptimer_set_limit(s->timer_cmp, s->lr, 0);
	} else if (s->cr & CR_IOVW) {
	/* If IOVW bit is set then set the timer value */
	ptimer_set_count(s->timer_reload, s->lr);
	}

	imx_epit_reload_compare_timer(s);
	break;

	case 3: /* CMP */
	s->cmp = value;

	imx_epit_reload_compare_timer(s);

	break;

	default:
	qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
	HWADDR_PRIx "\n", TYPE_IMX_EPIT, __func__, offset);

	break;
	}
	}
	static void imx_epit_cmp(void *opaque)
	{
	IMXEPITState *s = IMX_EPIT(opaque);

	DPRINTF("sr was %d\n", s->sr);

	s->sr = 1;
	imx_epit_update_int(s);
	}

	static const MemoryRegionOps imx_epit_ops = {
	.read = imx_epit_read,
	.write = imx_epit_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	static const VMStateDescription vmstate_imx_timer_epit = {
	.name = TYPE_IMX_EPIT,
	.version_id = 2,
	.minimum_version_id = 2,
	.fields = (VMStateField[]) {
	VMSTATE_UINT32(cr, IMXEPITState),
	VMSTATE_UINT32(sr, IMXEPITState),
	VMSTATE_UINT32(lr, IMXEPITState),
	VMSTATE_UINT32(cmp, IMXEPITState),
	VMSTATE_UINT32(cnt, IMXEPITState),
	VMSTATE_UINT32(freq, IMXEPITState),
	VMSTATE_PTIMER(timer_reload, IMXEPITState),
	VMSTATE_PTIMER(timer_cmp, IMXEPITState),
	VMSTATE_END_OF_LIST()
	}
	};

	static void imx_epit_realize(DeviceState dev, Error *errp)
	{
	IMXEPITState *s = IMX_EPIT(dev);
	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
	QEMUBH *bh;

	DPRINTF("\n");

	sysbus_init_irq(sbd, &s->irq);
	memory_region_init_io(&s->iomem, OBJECT(s), &imx_epit_ops, s, TYPE_IMX_EPIT,
	0x00001000);
	sysbus_init_mmio(sbd, &s->iomem);

	s->timer_reload = ptimer_init(NULL);

	bh = qemu_bh_new(imx_epit_cmp, s);
	s->timer_cmp = ptimer_init(bh);
	}

	static void imx_epit_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = imx_epit_realize;
	dc->reset = imx_epit_reset;
	dc->vmsd = &vmstate_imx_timer_epit;
	dc->desc = "i.MX periodic timer";
	}

	static const TypeInfo imx_epit_info = {
	.name = TYPE_IMX_EPIT,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(IMXEPITState),
	.class_init = imx_epit_class_init,
	};

	static void imx_epit_register_types(void)
	{
	type_register_static(&imx_epit_info);
	}

	type_init(imx_epit_register_types)