From 230058106ab26de9b876158dbe27d60719f01f51 Mon Sep 17 00:00:00 2001 From: Peter Chubb Date: Tue, 20 Aug 2013 14:54:32 +0100 Subject: hw/timer/imx_epit: Simplify and fix imx_epit implementation When imx_epit.c was last refactored, a common usecase (comparison register zero) broke. This patch fixes that, and simplifies the code yet more. It also fixes a major thinko in the reset path --- the wrong bits in the control register were being cleared. Signed-off-by: Peter Chubb Reviewed-by: Jean-Christophe DUBOIS Signed-off-by: Peter Maydell --- hw/timer/imx_epit.c | 94 ++++++++++++++++++++--------------------------------- 1 file changed, 36 insertions(+), 58 deletions(-) (limited to 'hw/timer') diff --git a/hw/timer/imx_epit.c b/hw/timer/imx_epit.c index 117dc7bcbb..dc73d6525d 100644 --- a/hw/timer/imx_epit.c +++ b/hw/timer/imx_epit.c @@ -43,7 +43,7 @@ static char const *imx_epit_reg_name(uint32_t reg) } # define DPRINTF(fmt, args...) \ - do { printf("%s: " fmt , __func__, ##args); } while (0) + do { fprintf(stderr, "%s: " fmt , __func__, ##args); } while (0) #else # define DPRINTF(fmt, args...) do {} while (0) #endif @@ -152,7 +152,7 @@ static void imx_epit_reset(DeviceState *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->cr &= (CR_EN|CR_ENMOD|CR_STOPEN|CR_DOZEN|CR_WAITEN|CR_DBGEN); s->sr = 0; s->lr = TIMER_MAX; s->cmp = 0; @@ -167,7 +167,7 @@ static void imx_epit_reset(DeviceState *dev) ptimer_set_limit(s->timer_reload, TIMER_MAX, 1); if (s->freq && (s->cr & CR_EN)) { /* if the timer is still enabled, restart it */ - ptimer_run(s->timer_reload, 1); + ptimer_run(s->timer_reload, 0); } } @@ -218,17 +218,17 @@ static uint64_t imx_epit_read(void *opaque, hwaddr offset, unsigned size) static void imx_epit_reload_compare_timer(IMXEPITState *s) { - if ((s->cr & CR_OCIEN) && s->cmp) { - /* if the compare feature is on */ + 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) { - /* reinit the cmp timer if required */ - ptimer_set_count(s->timer_cmp, tmp - s->cmp); - if ((s->cr & CR_EN)) { - /* Restart the cmp timer if required */ - ptimer_run(s->timer_cmp, 0); - } + /* 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) ? TIMER_MAX : s->lr); } + ptimer_set_count(s->timer_cmp, next); } } @@ -237,11 +237,14 @@ static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value, { IMXEPITState *s = IMX_EPIT(opaque); uint32_t reg = offset >> 2; + uint64_t oldcr; DPRINTF("(%s, value = 0x%08x)\n", imx_epit_reg_name(reg), (uint32_t)value); switch (reg) { case 0: /* CR */ + + oldcr = s->cr; s->cr = value & 0x03ffffff; if (s->cr & CR_SWR) { /* handle the reset */ @@ -250,22 +253,35 @@ static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value, imx_epit_set_freq(s); } - if (s->freq && (s->cr & CR_EN)) { + 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, TIMER_MAX, 1); + ptimer_set_limit(s->timer_cmp, TIMER_MAX, 1); } } imx_epit_reload_compare_timer(s); - - ptimer_run(s->timer_reload, 1); - } else { + 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; @@ -284,13 +300,13 @@ static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value, /* 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 */ @@ -306,51 +322,14 @@ static void imx_epit_write(void *opaque, hwaddr offset, uint64_t value, break; } } - -static void imx_epit_timeout(void *opaque) -{ - IMXEPITState *s = IMX_EPIT(opaque); - - DPRINTF("\n"); - - if (!(s->cr & CR_EN)) { - return; - } - - if (s->cr & CR_RLD) { - ptimer_set_limit(s->timer_reload, s->lr, 1); - } else { - ptimer_set_limit(s->timer_reload, TIMER_MAX, 1); - } - - if (s->cr & CR_OCIEN) { - /* if compare register is 0 then we handle the interrupt here */ - if (s->cmp == 0) { - s->sr = 1; - imx_epit_update_int(s); - } else if (s->cmp <= s->lr) { - /* We should launch the compare register */ - ptimer_set_count(s->timer_cmp, s->lr - s->cmp); - ptimer_run(s->timer_cmp, 0); - } else { - IPRINTF("s->lr < s->cmp\n"); - } - } -} - static void imx_epit_cmp(void *opaque) { IMXEPITState *s = IMX_EPIT(opaque); - DPRINTF("\n"); - - ptimer_stop(s->timer_cmp); + DPRINTF("sr was %d\n", s->sr); - /* compare register is not 0 */ - if (s->cmp) { - s->sr = 1; - imx_epit_update_int(s); - } + s->sr = 1; + imx_epit_update_int(s); } void imx_timerp_create(const hwaddr addr, qemu_irq irq, DeviceState *ccm) @@ -400,8 +379,7 @@ static void imx_epit_realize(DeviceState *dev, Error **errp) 0x00001000); sysbus_init_mmio(sbd, &s->iomem); - bh = qemu_bh_new(imx_epit_timeout, s); - s->timer_reload = ptimer_init(bh); + s->timer_reload = ptimer_init(NULL); bh = qemu_bh_new(imx_epit_cmp, s); s->timer_cmp = ptimer_init(bh); -- cgit v1.2.1