Commit 5ec694b5 authored by Jean-Christophe DUBOIS's avatar Jean-Christophe DUBOIS Committed by Peter Maydell
Browse files

i.MX: Implement a more complete version of the GPT timer.



* implement compare 1 2 and 3 registers
* simplify Debug printf
Signed-off-by: default avatarJean-Christophe DUBOIS <jcd@tribudubois.net>
Message-id: 1369898943-1993-2-git-send-email-jcd@tribudubois.net
Reviewed-by: default avatarPeter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 2acafb1a
......@@ -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,
......