qemu/hw/timer/imx_gpt.c

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/*
* IMX GPT 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_gpt.h"
#include "hw/misc/imx_ccm.h"
#include "qemu/main-loop.h"
/*
* Define to 1 for debug messages
*/
#define DEBUG_TIMER 0
#if DEBUG_TIMER
static char const *imx_gpt_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("%s: " fmt , __func__, ##args); } while (0)
#else
# define DPRINTF(fmt, args...) do {} while (0)
#endif
/*
* Define to 1 for messages about attempts to
* access unimplemented registers or similar.
*/
#define DEBUG_IMPLEMENTATION 1
#if DEBUG_IMPLEMENTATION
# define IPRINTF(fmt, args...) \
do { fprintf(stderr, "%s: " fmt, __func__, ##args); } while (0)
#else
# define IPRINTF(fmt, args...) do {} while (0)
#endif
static const VMStateDescription vmstate_imx_timer_gpt = {
.name = TYPE_IMX_GPT,
.version_id = 3,
.minimum_version_id = 3,
.fields = (VMStateField[]) {
VMSTATE_UINT32(cr, IMXGPTState),
VMSTATE_UINT32(pr, IMXGPTState),
VMSTATE_UINT32(sr, IMXGPTState),
VMSTATE_UINT32(ir, IMXGPTState),
VMSTATE_UINT32(ocr1, IMXGPTState),
VMSTATE_UINT32(ocr2, IMXGPTState),
VMSTATE_UINT32(ocr3, IMXGPTState),
VMSTATE_UINT32(icr1, IMXGPTState),
VMSTATE_UINT32(icr2, IMXGPTState),
VMSTATE_UINT32(cnt, IMXGPTState),
VMSTATE_UINT32(next_timeout, IMXGPTState),
VMSTATE_UINT32(next_int, IMXGPTState),
VMSTATE_UINT32(freq, IMXGPTState),
VMSTATE_PTIMER(timer, IMXGPTState),
VMSTATE_END_OF_LIST()
}
};
static const IMXClk imx_gpt_clocks[] = {
NOCLK, /* 000 No clock source */
IPG, /* 001 ipg_clk, 532MHz*/
IPG, /* 010 ipg_clk_highfreq */
NOCLK, /* 011 not defined */
CLK_32k, /* 100 ipg_clk_32k */
NOCLK, /* 101 not defined */
NOCLK, /* 110 not defined */
NOCLK, /* 111 not defined */
};
static void imx_gpt_set_freq(IMXGPTState *s)
{
uint32_t clksrc = extract32(s->cr, GPT_CR_CLKSRC_SHIFT, 3);
uint32_t freq = imx_clock_frequency(s->ccm, imx_gpt_clocks[clksrc])
/ (1 + s->pr);
s->freq = freq;
DPRINTF("Setting clksrc %d to frequency %d\n", clksrc, freq);
if (freq) {
ptimer_set_freq(s->timer, freq);
}
}
static void imx_gpt_update_int(IMXGPTState *s)
{
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_gpt_update_count(IMXGPTState *s)
{
s->cnt = s->next_timeout - (uint32_t)ptimer_get_count(s->timer);
return s->cnt;
}
static inline uint32_t imx_gpt_find_limit(uint32_t count, uint32_t reg,
uint32_t timeout)
{
if ((count < reg) && (timeout > reg)) {
timeout = reg;
}
return timeout;
}
static void imx_gpt_compute_next_timeout(IMXGPTState *s, bool event)
{
uint32_t timeout = GPT_TIMER_MAX;
uint32_t count = 0;
long long limit;
if (!(s->cr & GPT_CR_EN)) {
/* if not enabled just return */
return;
}
if (event) {
/* This is a timer event */
if ((s->cr & GPT_CR_FRR) && (s->next_timeout != GPT_TIMER_MAX)) {
/*
* if we are in free running mode and we have not reached
* the GPT_TIMER_MAX limit, then update the count
*/
count = imx_gpt_update_count(s);
}
} else {
/* not a timer event, then just update the count */
count = imx_gpt_update_count(s);
}
/* now, find the next timeout related to count */
if (s->ir & GPT_IR_OF1IE) {
timeout = imx_gpt_find_limit(count, s->ocr1, timeout);
}
if (s->ir & GPT_IR_OF2IE) {
timeout = imx_gpt_find_limit(count, s->ocr2, timeout);
}
if (s->ir & GPT_IR_OF3IE) {
timeout = imx_gpt_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 == GPT_TIMER_MAX)) {
s->next_int |= GPT_SR_ROV;
}
/* the new range to count down from */
limit = timeout - imx_gpt_update_count(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_gpt_compute_next_timeout(s, event);
imx_gpt_update_int(s);
} else {
/* New timeout value */
s->next_timeout = timeout;
/* reset the limit to the computed range */
ptimer_set_limit(s->timer, limit, 1);
}
}
static uint64_t imx_gpt_read(void *opaque, hwaddr offset, unsigned size)
{
IMXGPTState *s = IMX_GPT(opaque);
uint32_t reg_value = 0;
uint32_t reg = offset >> 2;
switch (reg) {
case 0: /* Control Register */
reg_value = s->cr;
break;
case 1: /* prescaler */
reg_value = s->pr;
break;
case 2: /* Status Register */
reg_value = s->sr;
break;
case 3: /* Interrupt Register */
reg_value = s->ir;
break;
case 4: /* Output Compare Register 1 */
reg_value = s->ocr1;
break;
case 5: /* Output Compare Register 2 */
reg_value = s->ocr2;
break;
case 6: /* Output Compare Register 3 */
reg_value = s->ocr3;
break;
case 7: /* input Capture Register 1 */
qemu_log_mask(LOG_UNIMP, "icr1 feature is not implemented\n");
reg_value = s->icr1;
break;
case 8: /* input Capture Register 2 */
qemu_log_mask(LOG_UNIMP, "icr2 feature is not implemented\n");
reg_value = s->icr2;
break;
case 9: /* cnt */
imx_gpt_update_count(s);
reg_value = s->cnt;
break;
default:
IPRINTF("Bad offset %x\n", reg);
break;
}
DPRINTF("(%s) = 0x%08x\n", imx_gpt_reg_name(reg), reg_value);
return reg_value;
}
static void imx_gpt_reset(DeviceState *dev)
{
IMXGPTState *s = IMX_GPT(dev);
/* stop timer */
ptimer_stop(s->timer);
/*
* Soft reset doesn't touch some bits; hard reset clears them
*/
s->cr &= ~(GPT_CR_EN|GPT_CR_ENMOD|GPT_CR_STOPEN|GPT_CR_DOZEN|
GPT_CR_WAITEN|GPT_CR_DBGEN);
s->sr = 0;
s->pr = 0;
s->ir = 0;
s->cnt = 0;
s->ocr1 = GPT_TIMER_MAX;
s->ocr2 = GPT_TIMER_MAX;
s->ocr3 = GPT_TIMER_MAX;
s->icr1 = 0;
s->icr2 = 0;
s->next_timeout = GPT_TIMER_MAX;
s->next_int = 0;
/* compute new freq */
imx_gpt_set_freq(s);
/* reset the limit to GPT_TIMER_MAX */
ptimer_set_limit(s->timer, GPT_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_gpt_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
IMXGPTState *s = IMX_GPT(opaque);
uint32_t oldreg;
uint32_t reg = offset >> 2;
DPRINTF("(%s, value = 0x%08x)\n", imx_gpt_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_gpt_reset(DEVICE(s));
} else {
/* set our freq, as the source might have changed */
imx_gpt_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 = GPT_TIMER_MAX;
ptimer_set_count(s->timer, GPT_TIMER_MAX);
imx_gpt_compute_next_timeout(s, false);
}
ptimer_run(s->timer, 1);
} else {
/* stop timer */
ptimer_stop(s->timer);
}
}
}
break;
case 1: /* Prescaler */
s->pr = value & 0xfff;
imx_gpt_set_freq(s);
break;
case 2: /* SR */
s->sr &= ~(value & 0x3f);
imx_gpt_update_int(s);
break;
case 3: /* IR -- interrupt register */
s->ir = value & 0x3f;
imx_gpt_update_int(s);
imx_gpt_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->next_timeout = GPT_TIMER_MAX;
ptimer_set_limit(s->timer, GPT_TIMER_MAX, 1);
}
/* compute the new timeout */
imx_gpt_compute_next_timeout(s, false);
break;
case 5: /* OCR2 -- output compare register */
s->ocr2 = value;
/* compute the new timeout */
imx_gpt_compute_next_timeout(s, false);
break;
case 6: /* OCR3 -- output compare register */
s->ocr3 = value;
/* compute the new timeout */
imx_gpt_compute_next_timeout(s, false);
break;
default:
IPRINTF("Bad offset %x\n", reg);
break;
}
}
static void imx_gpt_timeout(void *opaque)
{
IMXGPTState *s = IMX_GPT(opaque);
DPRINTF("\n");
s->sr |= s->next_int;
s->next_int = 0;
imx_gpt_compute_next_timeout(s, true);
imx_gpt_update_int(s);
if (s->freq && (s->cr & GPT_CR_EN)) {
ptimer_run(s->timer, 1);
}
}
static const MemoryRegionOps imx_gpt_ops = {
.read = imx_gpt_read,
.write = imx_gpt_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void imx_gpt_realize(DeviceState *dev, Error **errp)
{
IMXGPTState *s = IMX_GPT(dev);
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
QEMUBH *bh;
sysbus_init_irq(sbd, &s->irq);
memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpt_ops, s, TYPE_IMX_GPT,
0x00001000);
sysbus_init_mmio(sbd, &s->iomem);
bh = qemu_bh_new(imx_gpt_timeout, s);
s->timer = ptimer_init(bh);
}
static void imx_gpt_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = imx_gpt_realize;
dc->reset = imx_gpt_reset;
dc->vmsd = &vmstate_imx_timer_gpt;
dc->desc = "i.MX general timer";
}
static const TypeInfo imx_gpt_info = {
.name = TYPE_IMX_GPT,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(IMXGPTState),
.class_init = imx_gpt_class_init,
};
static void imx_gpt_register_types(void)
{
type_register_static(&imx_gpt_info);
}
type_init(imx_gpt_register_types)