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authorJean-Christophe DUBOIS <jcd@tribudubois.net>2013-06-25 18:34:13 +0100
committerPeter Maydell <peter.maydell@linaro.org>2013-06-25 18:34:13 +0100
commit5ec694b52a3a486fbc5a6eb6d6da4692c27d6575 (patch)
tree580edb2eff64161285d9bdf4fdf145e4b8926ff8
parent2acafb1a7b8b5ff4da48fccd7ce217cb07f36ffa (diff)
downloadqemu-arm-5ec694b52a3a486fbc5a6eb6d6da4692c27d6575.tar.gz
i.MX: Implement a more complete version of the GPT timer.
* implement compare 1 2 and 3 registers * simplify Debug printf Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net> Message-id: 1369898943-1993-2-git-send-email-jcd@tribudubois.net Reviewed-by: Peter Chubb <peter.chubb@nicta.com.au> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/timer/imx_gpt.c443
1 files changed, 269 insertions, 174 deletions
diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c
index d8c4f0baee..ecf6e53006 100644
--- a/hw/timer/imx_gpt.c
+++ b/hw/timer/imx_gpt.c
@@ -5,6 +5,7 @@
* Copyright (c) 2011 NICTA Pty Ltd
* Originally written by Hans Jiang
* Updated by Peter Chubb
+ * Updated by Jean-Christophe Dubois
*
* This code is licensed under GPL version 2 or later. See
* the COPYING file in the top-level directory.
@@ -18,10 +19,44 @@
#include "hw/sysbus.h"
#include "hw/arm/imx.h"
-//#define DEBUG_TIMER 1
-#ifdef DEBUG_TIMER
+#define TYPE_IMX_GPT "imx.gpt"
+
+/*
+ * Define to 1 for debug messages
+ */
+#define DEBUG_TIMER 0
+#if DEBUG_TIMER
+
+static char const *imx_timerg_reg_name(uint32_t reg)
+{
+ switch (reg) {
+ case 0:
+ return "CR";
+ case 1:
+ return "PR";
+ case 2:
+ return "SR";
+ case 3:
+ return "IR";
+ case 4:
+ return "OCR1";
+ case 5:
+ return "OCR2";
+ case 6:
+ return "OCR3";
+ case 7:
+ return "ICR1";
+ case 8:
+ return "ICR2";
+ case 9:
+ return "CNT";
+ default:
+ return "[?]";
+ }
+}
+
# define DPRINTF(fmt, args...) \
- do { printf("imx_timer: " fmt , ##args); } while (0)
+ do { printf("%s: " fmt , __func__, ##args); } while (0)
#else
# define DPRINTF(fmt, args...) do {} while (0)
#endif
@@ -33,7 +68,7 @@
#define DEBUG_IMPLEMENTATION 1
#if DEBUG_IMPLEMENTATION
# define IPRINTF(fmt, args...) \
- do { fprintf(stderr, "imx_timer: " fmt, ##args); } while (0)
+ do { fprintf(stderr, "%s: " fmt, __func__, ##args); } while (0)
#else
# define IPRINTF(fmt, args...) do {} while (0)
#endif
@@ -43,16 +78,7 @@
*
* This timer counts up continuously while it is enabled, resetting itself
* to 0 when it reaches TIMER_MAX (in freerun mode) or when it
- * reaches the value of ocr1 (in periodic mode). WE simulate this using a
- * QEMU ptimer counting down from ocr1 and reloading from ocr1 in
- * periodic mode, or counting from ocr1 to zero, then TIMER_MAX - ocr1.
- * waiting_rov is set when counting from TIMER_MAX.
- *
- * In the real hardware, there are three comparison registers that can
- * trigger interrupts, and compare channel 1 can be used to
- * force-reset the timer. However, this is a `bare-bones'
- * implementation: only what Linux 3.x uses has been implemented
- * (free-running timer from 0 to OCR1 or TIMER_MAX) .
+ * reaches the value of one of the ocrX (in periodic mode).
*/
#define TIMER_MAX 0XFFFFFFFFUL
@@ -79,9 +105,13 @@
#define GPT_CR_FO3 (1 << 31) /* Force Output Compare Channel 3 */
#define GPT_SR_OF1 (1 << 0)
+#define GPT_SR_OF2 (1 << 1)
+#define GPT_SR_OF3 (1 << 2)
#define GPT_SR_ROV (1 << 5)
#define GPT_IR_OF1IE (1 << 0)
+#define GPT_IR_OF2IE (1 << 1)
+#define GPT_IR_OF3IE (1 << 2)
#define GPT_IR_ROVIE (1 << 5)
typedef struct {
@@ -101,15 +131,19 @@ typedef struct {
uint32_t icr2;
uint32_t cnt;
- uint32_t waiting_rov;
+ uint32_t next_timeout;
+ uint32_t next_int;
+
+ uint32_t freq;
+
qemu_irq irq;
} IMXTimerGState;
static const VMStateDescription vmstate_imx_timerg = {
- .name = "imx-timerg",
- .version_id = 2,
- .minimum_version_id = 2,
- .minimum_version_id_old = 2,
+ .name = TYPE_IMX_GPT,
+ .version_id = 3,
+ .minimum_version_id = 3,
+ .minimum_version_id_old = 3,
.fields = (VMStateField[]) {
VMSTATE_UINT32(cr, IMXTimerGState),
VMSTATE_UINT32(pr, IMXTimerGState),
@@ -121,7 +155,9 @@ static const VMStateDescription vmstate_imx_timerg = {
VMSTATE_UINT32(icr1, IMXTimerGState),
VMSTATE_UINT32(icr2, IMXTimerGState),
VMSTATE_UINT32(cnt, IMXTimerGState),
- VMSTATE_UINT32(waiting_rov, IMXTimerGState),
+ VMSTATE_UINT32(next_timeout, IMXTimerGState),
+ VMSTATE_UINT32(next_int, IMXTimerGState),
+ VMSTATE_UINT32(freq, IMXTimerGState),
VMSTATE_PTIMER(timer, IMXTimerGState),
VMSTATE_END_OF_LIST()
}
@@ -138,16 +174,14 @@ static const IMXClk imx_timerg_clocks[] = {
NOCLK, /* 111 not defined */
};
-
static void imx_timerg_set_freq(IMXTimerGState *s)
{
- int clksrc;
- uint32_t freq;
-
- clksrc = (s->cr >> GPT_CR_CLKSRC_SHIFT) & GPT_CR_CLKSRC_MASK;
- freq = imx_clock_frequency(s->ccm, imx_timerg_clocks[clksrc]) / (1 + s->pr);
+ uint32_t clksrc = extract32(s->cr, GPT_CR_CLKSRC_SHIFT, 3);
+ uint32_t freq = imx_clock_frequency(s->ccm, imx_timerg_clocks[clksrc])
+ / (1 + s->pr);
+ s->freq = freq;
- DPRINTF("Setting gtimer clksrc %d to frequency %d\n", clksrc, freq);
+ DPRINTF("Setting clksrc %d to frequency %d\n", clksrc, freq);
if (freq) {
ptimer_set_freq(s->timer, freq);
@@ -156,111 +190,176 @@ static void imx_timerg_set_freq(IMXTimerGState *s)
static void imx_timerg_update(IMXTimerGState *s)
{
- uint32_t flags = s->sr & s->ir & (GPT_SR_OF1 | GPT_SR_ROV);
-
- DPRINTF("g-timer SR: %s %s IR=%s %s, %s\n",
- s->sr & GPT_SR_OF1 ? "OF1" : "",
- s->sr & GPT_SR_ROV ? "ROV" : "",
- s->ir & GPT_SR_OF1 ? "OF1" : "",
- s->ir & GPT_SR_ROV ? "ROV" : "",
- s->cr & GPT_CR_EN ? "CR_EN" : "Not Enabled");
-
- qemu_set_irq(s->irq, (s->cr & GPT_CR_EN) && flags);
+ if ((s->sr & s->ir) && (s->cr & GPT_CR_EN)) {
+ qemu_irq_raise(s->irq);
+ } else {
+ qemu_irq_lower(s->irq);
+ }
}
static uint32_t imx_timerg_update_counts(IMXTimerGState *s)
{
- uint64_t target = s->waiting_rov ? TIMER_MAX : s->ocr1;
- uint64_t cnt = ptimer_get_count(s->timer);
- s->cnt = target - cnt;
+ s->cnt = s->next_timeout - (uint32_t)ptimer_get_count(s->timer);
+
return s->cnt;
}
-static void imx_timerg_reload(IMXTimerGState *s, uint32_t timeout)
+static inline uint32_t imx_timerg_find_limit(uint32_t count, uint32_t reg,
+ uint32_t timeout)
{
- uint64_t diff_cnt;
+ if ((count < reg) && (timeout > reg)) {
+ timeout = reg;
+ }
+
+ return timeout;
+}
- if (!(s->cr & GPT_CR_FRR)) {
- IPRINTF("IMX_timerg_reload --- called in reset-mode\n");
+static void imx_timerg_compute_next_timeout(IMXTimerGState *s, bool event)
+{
+ uint32_t timeout = TIMER_MAX;
+ uint32_t count = 0;
+ long long limit;
+
+ if (!(s->cr & GPT_CR_EN)) {
+ /* if not enabled just return */
return;
}
- /*
- * For small timeouts, qemu sometimes runs too slow.
- * Better deliver a late interrupt than none.
- *
- * In Reset mode (FRR bit clear)
- * the ptimer reloads itself from OCR1;
- * in free-running mode we need to fake
- * running from 0 to ocr1 to TIMER_MAX
- */
- if (timeout > s->cnt) {
- diff_cnt = timeout - s->cnt;
+ if (event) {
+ /* This is a timer event */
+
+ if ((s->cr & GPT_CR_FRR) && (s->next_timeout != TIMER_MAX)) {
+ /*
+ * if we are in free running mode and we have not reached
+ * the TIMER_MAX limit, then update the count
+ */
+ count = imx_timerg_update_counts(s);
+ }
} else {
- diff_cnt = 0;
+ /* not a timer event, then just update the count */
+
+ count = imx_timerg_update_counts(s);
+ }
+
+ /* now, find the next timeout related to count */
+
+ if (s->ir & GPT_IR_OF1IE) {
+ timeout = imx_timerg_find_limit(count, s->ocr1, timeout);
+ }
+ if (s->ir & GPT_IR_OF2IE) {
+ timeout = imx_timerg_find_limit(count, s->ocr2, timeout);
+ }
+ if (s->ir & GPT_IR_OF3IE) {
+ timeout = imx_timerg_find_limit(count, s->ocr3, timeout);
+ }
+
+ /* find the next set of interrupts to raise for next timer event */
+
+ s->next_int = 0;
+ if ((s->ir & GPT_IR_OF1IE) && (timeout == s->ocr1)) {
+ s->next_int |= GPT_SR_OF1;
+ }
+ if ((s->ir & GPT_IR_OF2IE) && (timeout == s->ocr2)) {
+ s->next_int |= GPT_SR_OF2;
+ }
+ if ((s->ir & GPT_IR_OF3IE) && (timeout == s->ocr3)) {
+ s->next_int |= GPT_SR_OF3;
+ }
+ if ((s->ir & GPT_IR_ROVIE) && (timeout == TIMER_MAX)) {
+ s->next_int |= GPT_SR_ROV;
+ }
+
+ /* the new range to count down from */
+ limit = timeout - imx_timerg_update_counts(s);
+
+ if (limit < 0) {
+ /*
+ * if we reach here, then QEMU is running too slow and we pass the
+ * timeout limit while computing it. Let's deliver the interrupt
+ * and compute a new limit.
+ */
+ s->sr |= s->next_int;
+
+ imx_timerg_compute_next_timeout(s, event);
+
+ imx_timerg_update(s);
+ } else {
+ /* New timeout value */
+ s->next_timeout = timeout;
+
+ /* reset the limit to the computed range */
+ ptimer_set_limit(s->timer, limit, 1);
}
- ptimer_set_count(s->timer, diff_cnt);
}
static uint64_t imx_timerg_read(void *opaque, hwaddr offset,
unsigned size)
{
IMXTimerGState *s = (IMXTimerGState *)opaque;
+ uint32_t reg_value = 0;
+ uint32_t reg = offset >> 2;
- DPRINTF("g-read(offset=%x)", (unsigned int)(offset >> 2));
- switch (offset >> 2) {
+ switch (reg) {
case 0: /* Control Register */
- DPRINTF(" cr = %x\n", s->cr);
- return s->cr;
+ reg_value = s->cr;
+ break;
case 1: /* prescaler */
- DPRINTF(" pr = %x\n", s->pr);
- return s->pr;
+ reg_value = s->pr;
+ break;
case 2: /* Status Register */
- DPRINTF(" sr = %x\n", s->sr);
- return s->sr;
+ reg_value = s->sr;
+ break;
case 3: /* Interrupt Register */
- DPRINTF(" ir = %x\n", s->ir);
- return s->ir;
+ reg_value = s->ir;
+ break;
case 4: /* Output Compare Register 1 */
- DPRINTF(" ocr1 = %x\n", s->ocr1);
- return s->ocr1;
+ reg_value = s->ocr1;
+ break;
case 5: /* Output Compare Register 2 */
- DPRINTF(" ocr2 = %x\n", s->ocr2);
- return s->ocr2;
+ reg_value = s->ocr2;
+ break;
case 6: /* Output Compare Register 3 */
- DPRINTF(" ocr3 = %x\n", s->ocr3);
- return s->ocr3;
+ reg_value = s->ocr3;
+ break;
case 7: /* input Capture Register 1 */
- DPRINTF(" icr1 = %x\n", s->icr1);
- return s->icr1;
+ qemu_log_mask(LOG_UNIMP, "icr1 feature is not implemented\n");
+ reg_value = s->icr1;
+ break;
case 8: /* input Capture Register 2 */
- DPRINTF(" icr2 = %x\n", s->icr2);
- return s->icr2;
+ qemu_log_mask(LOG_UNIMP, "icr2 feature is not implemented\n");
+ reg_value = s->icr2;
+ break;
case 9: /* cnt */
imx_timerg_update_counts(s);
- DPRINTF(" cnt = %x\n", s->cnt);
- return s->cnt;
+ reg_value = s->cnt;
+ break;
+
+ default:
+ IPRINTF("Bad offset %x\n", reg);
+ break;
}
- IPRINTF("imx_timerg_read: Bad offset %x\n",
- (int)offset >> 2);
+ DPRINTF("(%s) = 0x%08x\n", imx_timerg_reg_name(reg), reg_value);
- return 0;
+ return reg_value;
}
static void imx_timerg_reset(DeviceState *dev)
{
IMXTimerGState *s = container_of(dev, IMXTimerGState, busdev.qdev);
+ /* stop timer */
+ ptimer_stop(s->timer);
+
/*
* Soft reset doesn't touch some bits; hard reset clears them
*/
@@ -275,89 +374,110 @@ static void imx_timerg_reset(DeviceState *dev)
s->ocr3 = TIMER_MAX;
s->icr1 = 0;
s->icr2 = 0;
- ptimer_stop(s->timer);
- ptimer_set_limit(s->timer, TIMER_MAX, 1);
- ptimer_set_count(s->timer, TIMER_MAX);
+
+ s->next_timeout = TIMER_MAX;
+ s->next_int = 0;
+
+ /* compute new freq */
imx_timerg_set_freq(s);
+
+ /* reset the limit to TIMER_MAX */
+ ptimer_set_limit(s->timer, TIMER_MAX, 1);
+
+ /* if the timer is still enabled, restart it */
+ if (s->freq && (s->cr & GPT_CR_EN)) {
+ ptimer_run(s->timer, 1);
+ }
}
static void imx_timerg_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
IMXTimerGState *s = (IMXTimerGState *)opaque;
- DPRINTF("g-write(offset=%x, value = 0x%x)\n", (unsigned int)offset >> 2,
- (unsigned int)value);
-
- switch (offset >> 2) {
- case 0: {
- uint32_t oldcr = s->cr;
- /* CR */
- if (value & GPT_CR_SWR) { /* force reset */
- value &= ~GPT_CR_SWR;
- imx_timerg_reset(&s->busdev.qdev);
- imx_timerg_update(s);
- }
-
- s->cr = value & ~0x7c00;
- imx_timerg_set_freq(s);
- if ((oldcr ^ value) & GPT_CR_EN) {
- if (value & GPT_CR_EN) {
- if (value & GPT_CR_ENMOD) {
- ptimer_set_count(s->timer, s->ocr1);
- s->cnt = 0;
+ uint32_t oldreg;
+ uint32_t reg = offset >> 2;
+
+ DPRINTF("(%s, value = 0x%08x)\n", imx_timerg_reg_name(reg),
+ (uint32_t)value);
+
+ switch (reg) {
+ case 0:
+ oldreg = s->cr;
+ s->cr = value & ~0x7c14;
+ if (s->cr & GPT_CR_SWR) { /* force reset */
+ /* handle the reset */
+ imx_timerg_reset(DEVICE(s));
+ } else {
+ /* set our freq, as the source might have changed */
+ imx_timerg_set_freq(s);
+
+ if ((oldreg ^ s->cr) & GPT_CR_EN) {
+ if (s->cr & GPT_CR_EN) {
+ if (s->cr & GPT_CR_ENMOD) {
+ s->next_timeout = TIMER_MAX;
+ ptimer_set_count(s->timer, TIMER_MAX);
+ imx_timerg_compute_next_timeout(s, false);
+ }
+ ptimer_run(s->timer, 1);
+ } else {
+ /* stop timer */
+ ptimer_stop(s->timer);
}
- ptimer_run(s->timer,
- (value & GPT_CR_FRR) && (s->ocr1 != TIMER_MAX));
- } else {
- ptimer_stop(s->timer);
- };
+ }
}
- return;
- }
+ break;
case 1: /* Prescaler */
s->pr = value & 0xfff;
imx_timerg_set_freq(s);
- return;
+ break;
case 2: /* SR */
- /*
- * No point in implementing the status register bits to do with
- * external interrupt sources.
- */
- value &= GPT_SR_OF1 | GPT_SR_ROV;
- s->sr &= ~value;
+ s->sr &= ~(value & 0x3f);
imx_timerg_update(s);
- return;
+ break;
case 3: /* IR -- interrupt register */
s->ir = value & 0x3f;
imx_timerg_update(s);
- return;
+
+ imx_timerg_compute_next_timeout(s, false);
+
+ break;
case 4: /* OCR1 -- output compare register */
+ s->ocr1 = value;
+
/* In non-freerun mode, reset count when this register is written */
if (!(s->cr & GPT_CR_FRR)) {
- s->waiting_rov = 0;
- ptimer_set_limit(s->timer, value, 1);
- } else {
- imx_timerg_update_counts(s);
- if (value > s->cnt) {
- s->waiting_rov = 0;
- imx_timerg_reload(s, value);
- } else {
- s->waiting_rov = 1;
- imx_timerg_reload(s, TIMER_MAX - s->cnt);
- }
+ s->next_timeout = TIMER_MAX;
+ ptimer_set_limit(s->timer, TIMER_MAX, 1);
}
- s->ocr1 = value;
- return;
+
+ /* compute the new timeout */
+ imx_timerg_compute_next_timeout(s, false);
+
+ break;
case 5: /* OCR2 -- output compare register */
+ s->ocr2 = value;
+
+ /* compute the new timeout */
+ imx_timerg_compute_next_timeout(s, false);
+
+ break;
+
case 6: /* OCR3 -- output compare register */
+ s->ocr3 = value;
+
+ /* compute the new timeout */
+ imx_timerg_compute_next_timeout(s, false);
+
+ break;
+
default:
- IPRINTF("imx_timerg_write: Bad offset %x\n",
- (int)offset >> 2);
+ IPRINTF("Bad offset %x\n", reg);
+ break;
}
}
@@ -365,41 +485,18 @@ static void imx_timerg_timeout(void *opaque)
{
IMXTimerGState *s = (IMXTimerGState *)opaque;
- DPRINTF("imx_timerg_timeout, waiting rov=%d\n", s->waiting_rov);
- if (s->cr & GPT_CR_FRR) {
- /*
- * Free running timer from 0 -> TIMERMAX
- * Generates interrupt at TIMER_MAX and at cnt==ocr1
- * If ocr1 == TIMER_MAX, then no need to reload timer.
- */
- if (s->ocr1 == TIMER_MAX) {
- DPRINTF("s->ocr1 == TIMER_MAX, FRR\n");
- s->sr |= GPT_SR_OF1 | GPT_SR_ROV;
- imx_timerg_update(s);
- return;
- }
+ DPRINTF("\n");
- if (s->waiting_rov) {
- /*
- * We were waiting for cnt==TIMER_MAX
- */
- s->sr |= GPT_SR_ROV;
- s->waiting_rov = 0;
- s->cnt = 0;
- imx_timerg_reload(s, s->ocr1);
- } else {
- /* Must have got a cnt==ocr1 timeout. */
- s->sr |= GPT_SR_OF1;
- s->cnt = s->ocr1;
- s->waiting_rov = 1;
- imx_timerg_reload(s, TIMER_MAX);
- }
- imx_timerg_update(s);
- return;
- }
+ s->sr |= s->next_int;
+ s->next_int = 0;
+
+ imx_timerg_compute_next_timeout(s, true);
- s->sr |= GPT_SR_OF1;
imx_timerg_update(s);
+
+ if (s->freq && (s->cr & GPT_CR_EN)) {
+ ptimer_run(s->timer, 1);
+ }
}
static const MemoryRegionOps imx_timerg_ops = {
@@ -416,7 +513,7 @@ static int imx_timerg_init(SysBusDevice *dev)
sysbus_init_irq(dev, &s->irq);
memory_region_init_io(&s->iomem, &imx_timerg_ops,
- s, "imxg-timer",
+ s, TYPE_IMX_GPT,
0x00001000);
sysbus_init_mmio(dev, &s->iomem);
@@ -428,14 +525,12 @@ static int imx_timerg_init(SysBusDevice *dev)
return 0;
}
-void imx_timerg_create(const hwaddr addr,
- qemu_irq irq,
- DeviceState *ccm)
+void imx_timerg_create(const hwaddr addr, qemu_irq irq, DeviceState *ccm)
{
IMXTimerGState *pp;
DeviceState *dev;
- dev = sysbus_create_simple("imx_timerg", addr, irq);
+ dev = sysbus_create_simple(TYPE_IMX_GPT, addr, irq);
pp = container_of(dev, IMXTimerGState, busdev.qdev);
pp->ccm = ccm;
}
@@ -451,7 +546,7 @@ static void imx_timerg_class_init(ObjectClass *klass, void *data)
}
static const TypeInfo imx_timerg_info = {
- .name = "imx_timerg",
+ .name = TYPE_IMX_GPT,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(IMXTimerGState),
.class_init = imx_timerg_class_init,