@@ -73,27 +73,14 @@ static void imx_epit_update_int(IMXEPITState *s)
}
}
-/*
- * Must be called from within a ptimer_transaction_begin/commit block
- * for both s->timer_cmp and s->timer_reload.
- */
-static void imx_epit_set_freq(IMXEPITState *s)
+static uint32_t imx_epit_get_freq(IMXEPITState *s)
{
- uint32_t clksrc;
- uint32_t prescaler;
-
- clksrc = extract32(s->cr, CR_CLKSRC_SHIFT, CR_CLKSRC_BITS);
- prescaler = 1 + extract32(s->cr, CR_PRESCALE_SHIFT, CR_PRESCALE_BITS);
-
- 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);
- }
+ uint32_t clksrc = extract32(s->cr, CR_CLKSRC_SHIFT, CR_CLKSRC_BITS);
+ uint32_t prescaler = 1 + extract32(s->cr, CR_PRESCALE_SHIFT, CR_PRESCALE_BITS);
+ uint32_t f_in = imx_ccm_get_clock_frequency(s->ccm, imx_epit_clocks[clksrc]);
+ uint32_t freq = f_in / prescaler;
+ DPRINTF("ptimer frequency is %u\n", freq);
+ return freq;
}
/*
@@ -110,32 +97,23 @@ static void imx_epit_reset(IMXEPITState *s, bool is_hard_reset)
s->sr = 0;
s->lr = EPIT_TIMER_MAX;
s->cmp = 0;
- s->cnt = 0;
ptimer_transaction_begin(s->timer_cmp);
ptimer_transaction_begin(s->timer_reload);
- /* stop both timers */
+
+ /*
+ * The reset switches off the input clock, so even if the CR.EN is still
+ * set, the timers are no longer running.
+ */
+ assert(imx_epit_get_freq(s) == 0);
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);
- }
ptimer_transaction_commit(s->timer_cmp);
ptimer_transaction_commit(s->timer_reload);
}
-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);
@@ -159,8 +137,7 @@ static uint64_t imx_epit_read(void *opaque, hwaddr offset, unsigned size)
break;
case 4: /* CNT */
- imx_epit_update_count(s);
- reg_value = s->cnt;
+ reg_value = ptimer_get_count(s->timer_reload);
break;
default:
@@ -179,7 +156,7 @@ 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);
+ uint32_t tmp = ptimer_get_count(s->timer_reload);
uint64_t next;
if (tmp > s->cmp) {
/* It'll fire in this round of the timer */
@@ -193,6 +170,7 @@ static void imx_epit_reload_compare_timer(IMXEPITState *s)
static void imx_epit_write_cr(IMXEPITState *s, uint32_t value)
{
+ uint32_t freq = 0;
uint32_t oldcr = s->cr;
s->cr = value & 0x03ffffff;
@@ -217,12 +195,19 @@ static void imx_epit_write_cr(IMXEPITState *s, uint32_t value)
ptimer_transaction_begin(s->timer_cmp);
ptimer_transaction_begin(s->timer_reload);
- /* Update the frequency. Has been done already in case of a reset. */
+ /*
+ * Update the frequency. In case of a reset the input clock was
+ * switched off, so this can be skipped.
+ */
if (!(s->cr & CR_SWR)) {
- imx_epit_set_freq(s);
+ freq = imx_epit_get_freq(s);
+ if (freq) {
+ ptimer_set_freq(s->timer_reload, freq);
+ ptimer_set_freq(s->timer_cmp, freq);
+ }
}
- if (s->freq && (s->cr & CR_EN) && !(oldcr & CR_EN)) {
+ if (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);
@@ -356,15 +341,13 @@ static const MemoryRegionOps imx_epit_ops = {
static const VMStateDescription vmstate_imx_timer_epit = {
.name = TYPE_IMX_EPIT,
- .version_id = 2,
- .minimum_version_id = 2,
+ .version_id = 3,
+ .minimum_version_id = 3,
.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()
@@ -74,9 +74,7 @@ struct IMXEPITState {
uint32_t sr;
uint32_t lr;
uint32_t cmp;
- uint32_t cnt;
- uint32_t freq;
qemu_irq irq;
};