diff options
Diffstat (limited to 'hw/timer/imx_timer.c')
| -rw-r--r-- | hw/timer/imx_timer.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/hw/timer/imx_timer.c b/hw/timer/imx_timer.c new file mode 100644 index 0000000000..03197e3f54 --- /dev/null +++ b/hw/timer/imx_timer.c @@ -0,0 +1,689 @@ +/* + * IMX31 Timer + * + * Copyright (c) 2008 OK Labs + * Copyright (c) 2011 NICTA Pty Ltd + * Originally written by Hans Jiang + * Updated by Peter Chubb + * + * This code is licensed under GPL version 2 or later. See + * the COPYING file in the top-level directory. + * + */ + +#include "hw/hw.h" +#include "qemu/timer.h" +#include "hw/ptimer.h" +#include "hw/sysbus.h" +#include "hw/arm/imx.h" + +//#define DEBUG_TIMER 1 +#ifdef DEBUG_TIMER +# define DPRINTF(fmt, args...) \ + do { printf("imx_timer: " fmt , ##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, "imx_timer: " fmt, ##args); } while (0) +#else +# define IPRINTF(fmt, args...) do {} while (0) +#endif + +/* + * GPT : General purpose timer + * + * 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) . + */ + + +#define TIMER_MAX 0XFFFFFFFFUL + +/* Control register. Not all of these bits have any effect (yet) */ +#define GPT_CR_EN (1 << 0) /* GPT Enable */ +#define GPT_CR_ENMOD (1 << 1) /* GPT Enable Mode */ +#define GPT_CR_DBGEN (1 << 2) /* GPT Debug mode enable */ +#define GPT_CR_WAITEN (1 << 3) /* GPT Wait Mode Enable */ +#define GPT_CR_DOZEN (1 << 4) /* GPT Doze mode enable */ +#define GPT_CR_STOPEN (1 << 5) /* GPT Stop Mode Enable */ +#define GPT_CR_CLKSRC_SHIFT (6) +#define GPT_CR_CLKSRC_MASK (0x7) + +#define GPT_CR_FRR (1 << 9) /* Freerun or Restart */ +#define GPT_CR_SWR (1 << 15) /* Software Reset */ +#define GPT_CR_IM1 (3 << 16) /* Input capture channel 1 mode (2 bits) */ +#define GPT_CR_IM2 (3 << 18) /* Input capture channel 2 mode (2 bits) */ +#define GPT_CR_OM1 (7 << 20) /* Output Compare Channel 1 Mode (3 bits) */ +#define GPT_CR_OM2 (7 << 23) /* Output Compare Channel 2 Mode (3 bits) */ +#define GPT_CR_OM3 (7 << 26) /* Output Compare Channel 3 Mode (3 bits) */ +#define GPT_CR_FO1 (1 << 29) /* Force Output Compare Channel 1 */ +#define GPT_CR_FO2 (1 << 30) /* Force Output Compare Channel 2 */ +#define GPT_CR_FO3 (1 << 31) /* Force Output Compare Channel 3 */ + +#define GPT_SR_OF1 (1 << 0) +#define GPT_SR_ROV (1 << 5) + +#define GPT_IR_OF1IE (1 << 0) +#define GPT_IR_ROVIE (1 << 5) + +typedef struct { + SysBusDevice busdev; + ptimer_state *timer; + MemoryRegion iomem; + DeviceState *ccm; + + uint32_t cr; + uint32_t pr; + uint32_t sr; + uint32_t ir; + uint32_t ocr1; + uint32_t cnt; + + uint32_t waiting_rov; + qemu_irq irq; +} IMXTimerGState; + +static const VMStateDescription vmstate_imx_timerg = { + .name = "imx-timerg", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(cr, IMXTimerGState), + VMSTATE_UINT32(pr, IMXTimerGState), + VMSTATE_UINT32(sr, IMXTimerGState), + VMSTATE_UINT32(ir, IMXTimerGState), + VMSTATE_UINT32(ocr1, IMXTimerGState), + VMSTATE_UINT32(cnt, IMXTimerGState), + VMSTATE_UINT32(waiting_rov, IMXTimerGState), + VMSTATE_PTIMER(timer, IMXTimerGState), + VMSTATE_END_OF_LIST() + } +}; + +static const IMXClk imx_timerg_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_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); + + DPRINTF("Setting gtimer clksrc %d to frequency %d\n", clksrc, freq); + if (freq) { + ptimer_set_freq(s->timer, freq); + } +} + +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); +} + +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; + return s->cnt; +} + +static void imx_timerg_reload(IMXTimerGState *s, uint32_t timeout) +{ + uint64_t diff_cnt; + + if (!(s->cr & GPT_CR_FRR)) { + IPRINTF("IMX_timerg_reload --- called in reset-mode\n"); + 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; + } else { + diff_cnt = 0; + } + ptimer_set_count(s->timer, diff_cnt); +} + +static uint64_t imx_timerg_read(void *opaque, hwaddr offset, + unsigned size) +{ + IMXTimerGState *s = (IMXTimerGState *)opaque; + + DPRINTF("g-read(offset=%x)", offset >> 2); + switch (offset >> 2) { + case 0: /* Control Register */ + DPRINTF(" cr = %x\n", s->cr); + return s->cr; + + case 1: /* prescaler */ + DPRINTF(" pr = %x\n", s->pr); + return s->pr; + + case 2: /* Status Register */ + DPRINTF(" sr = %x\n", s->sr); + return s->sr; + + case 3: /* Interrupt Register */ + DPRINTF(" ir = %x\n", s->ir); + return s->ir; + + case 4: /* Output Compare Register 1 */ + DPRINTF(" ocr1 = %x\n", s->ocr1); + return s->ocr1; + + + case 9: /* cnt */ + imx_timerg_update_counts(s); + DPRINTF(" cnt = %x\n", s->cnt); + return s->cnt; + } + + IPRINTF("imx_timerg_read: Bad offset %x\n", + (int)offset >> 2); + return 0; +} + +static void imx_timerg_reset(DeviceState *dev) +{ + IMXTimerGState *s = container_of(dev, IMXTimerGState, busdev.qdev); + + /* + * Soft reset doesn't touch some bits; hard reset clears them + */ + s->cr &= ~(GPT_CR_EN|GPT_CR_DOZEN|GPT_CR_WAITEN|GPT_CR_DBGEN); + s->sr = 0; + s->pr = 0; + s->ir = 0; + s->cnt = 0; + s->ocr1 = TIMER_MAX; + ptimer_stop(s->timer); + ptimer_set_limit(s->timer, TIMER_MAX, 1); + imx_timerg_set_freq(s); +} + +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; + } + ptimer_run(s->timer, + (value & GPT_CR_FRR) && (s->ocr1 != TIMER_MAX)); + } else { + ptimer_stop(s->timer); + }; + } + return; + } + + case 1: /* Prescaler */ + s->pr = value & 0xfff; + imx_timerg_set_freq(s); + return; + + 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; + imx_timerg_update(s); + return; + + case 3: /* IR -- interrupt register */ + s->ir = value & 0x3f; + imx_timerg_update(s); + return; + + case 4: /* OCR1 -- output compare register */ + /* 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->ocr1 = value; + return; + + default: + IPRINTF("imx_timerg_write: Bad offset %x\n", + (int)offset >> 2); + } +} + +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; + } + + 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 |= GPT_SR_OF1; + imx_timerg_update(s); +} + +static const MemoryRegionOps imx_timerg_ops = { + .read = imx_timerg_read, + .write = imx_timerg_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + + +static int imx_timerg_init(SysBusDevice *dev) +{ + IMXTimerGState *s = FROM_SYSBUS(IMXTimerGState, dev); + QEMUBH *bh; + + sysbus_init_irq(dev, &s->irq); + memory_region_init_io(&s->iomem, &imx_timerg_ops, + s, "imxg-timer", + 0x00001000); + sysbus_init_mmio(dev, &s->iomem); + + bh = qemu_bh_new(imx_timerg_timeout, s); + s->timer = ptimer_init(bh); + + /* Hard reset resets extra bits in CR */ + s->cr = 0; + return 0; +} + + + +/* + * EPIT: Enhanced periodic interrupt timer + */ + +#define CR_EN (1 << 0) +#define CR_ENMOD (1 << 1) +#define CR_OCIEN (1 << 2) +#define CR_RLD (1 << 3) +#define CR_PRESCALE_SHIFT (4) +#define CR_PRESCALE_MASK (0xfff) +#define CR_SWR (1 << 16) +#define CR_IOVW (1 << 17) +#define CR_DBGEN (1 << 18) +#define CR_EPIT (1 << 19) +#define CR_DOZEN (1 << 20) +#define CR_STOPEN (1 << 21) +#define CR_CLKSRC_SHIFT (24) +#define CR_CLKSRC_MASK (0x3 << CR_CLKSRC_SHIFT) + + +/* + * Exact clock frequencies vary from board to board. + * These are typical. + */ +static const IMXClk imx_timerp_clocks[] = { + 0, /* disabled */ + IPG, /* ipg_clk, ~532MHz */ + IPG, /* ipg_clk_highfreq */ + CLK_32k, /* ipg_clk_32k -- ~32kHz */ +}; + +typedef struct { + SysBusDevice busdev; + ptimer_state *timer; + MemoryRegion iomem; + DeviceState *ccm; + + uint32_t cr; + uint32_t lr; + uint32_t cmp; + + uint32_t freq; + int int_level; + qemu_irq irq; +} IMXTimerPState; + +/* + * Update interrupt status + */ +static void imx_timerp_update(IMXTimerPState *s) +{ + if (s->int_level && (s->cr & CR_OCIEN)) { + qemu_irq_raise(s->irq); + } else { + qemu_irq_lower(s->irq); + } +} + +static void imx_timerp_reset(DeviceState *dev) +{ + IMXTimerPState *s = container_of(dev, IMXTimerPState, busdev.qdev); + + s->cr = 0; + s->lr = TIMER_MAX; + s->int_level = 0; + s->cmp = 0; + ptimer_stop(s->timer); + ptimer_set_count(s->timer, TIMER_MAX); +} + +static uint64_t imx_timerp_read(void *opaque, hwaddr offset, + unsigned size) +{ + IMXTimerPState *s = (IMXTimerPState *)opaque; + + DPRINTF("p-read(offset=%x)", offset >> 2); + switch (offset >> 2) { + case 0: /* Control Register */ + DPRINTF("cr %x\n", s->cr); + return s->cr; + + case 1: /* Status Register */ + DPRINTF("int_level %x\n", s->int_level); + return s->int_level; + + case 2: /* LR - ticks*/ + DPRINTF("lr %x\n", s->lr); + return s->lr; + + case 3: /* CMP */ + DPRINTF("cmp %x\n", s->cmp); + return s->cmp; + + case 4: /* CNT */ + return ptimer_get_count(s->timer); + } + IPRINTF("imx_timerp_read: Bad offset %x\n", + (int)offset >> 2); + return 0; +} + +static void set_timerp_freq(IMXTimerPState *s) +{ + int clksrc; + unsigned prescaler; + uint32_t freq; + + clksrc = (s->cr & CR_CLKSRC_MASK) >> CR_CLKSRC_SHIFT; + prescaler = 1 + ((s->cr >> CR_PRESCALE_SHIFT) & CR_PRESCALE_MASK); + freq = imx_clock_frequency(s->ccm, imx_timerp_clocks[clksrc]) / prescaler; + + s->freq = freq; + DPRINTF("Setting ptimer frequency to %u\n", freq); + + if (freq) { + ptimer_set_freq(s->timer, freq); + } +} + +static void imx_timerp_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + IMXTimerPState *s = (IMXTimerPState *)opaque; + DPRINTF("p-write(offset=%x, value = %x)\n", (unsigned int)offset >> 2, + (unsigned int)value); + + switch (offset >> 2) { + case 0: /* CR */ + if (value & CR_SWR) { + imx_timerp_reset(&s->busdev.qdev); + value &= ~CR_SWR; + } + s->cr = value & 0x03ffffff; + set_timerp_freq(s); + + if (s->freq && (s->cr & CR_EN)) { + if (!(s->cr & CR_ENMOD)) { + ptimer_set_count(s->timer, s->lr); + } + ptimer_run(s->timer, 0); + } else { + ptimer_stop(s->timer); + } + break; + + case 1: /* SR - ACK*/ + s->int_level = 0; + imx_timerp_update(s); + break; + + case 2: /* LR - set ticks */ + s->lr = value; + ptimer_set_limit(s->timer, value, !!(s->cr & CR_IOVW)); + break; + + case 3: /* CMP */ + s->cmp = value; + if (value) { + IPRINTF( + "Values for EPIT comparison other than zero not supported\n" + ); + } + break; + + default: + IPRINTF("imx_timerp_write: Bad offset %x\n", + (int)offset >> 2); + } +} + +static void imx_timerp_tick(void *opaque) +{ + IMXTimerPState *s = (IMXTimerPState *)opaque; + + DPRINTF("imxp tick\n"); + if (!(s->cr & CR_RLD)) { + ptimer_set_count(s->timer, TIMER_MAX); + } + s->int_level = 1; + imx_timerp_update(s); +} + +void imx_timerp_create(const hwaddr addr, + qemu_irq irq, + DeviceState *ccm) +{ + IMXTimerPState *pp; + DeviceState *dev; + + dev = sysbus_create_simple("imx_timerp", addr, irq); + pp = container_of(dev, IMXTimerPState, busdev.qdev); + pp->ccm = ccm; +} + +static const MemoryRegionOps imx_timerp_ops = { + .read = imx_timerp_read, + .write = imx_timerp_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static const VMStateDescription vmstate_imx_timerp = { + .name = "imx-timerp", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(cr, IMXTimerPState), + VMSTATE_UINT32(lr, IMXTimerPState), + VMSTATE_UINT32(cmp, IMXTimerPState), + VMSTATE_UINT32(freq, IMXTimerPState), + VMSTATE_INT32(int_level, IMXTimerPState), + VMSTATE_PTIMER(timer, IMXTimerPState), + VMSTATE_END_OF_LIST() + } +}; + +static int imx_timerp_init(SysBusDevice *dev) +{ + IMXTimerPState *s = FROM_SYSBUS(IMXTimerPState, dev); + QEMUBH *bh; + + DPRINTF("imx_timerp_init\n"); + + sysbus_init_irq(dev, &s->irq); + memory_region_init_io(&s->iomem, &imx_timerp_ops, + s, "imxp-timer", + 0x00001000); + sysbus_init_mmio(dev, &s->iomem); + + bh = qemu_bh_new(imx_timerp_tick, s); + s->timer = ptimer_init(bh); + + return 0; +} + + +void imx_timerg_create(const hwaddr addr, + qemu_irq irq, + DeviceState *ccm) +{ + IMXTimerGState *pp; + DeviceState *dev; + + dev = sysbus_create_simple("imx_timerg", addr, irq); + pp = container_of(dev, IMXTimerGState, busdev.qdev); + pp->ccm = ccm; +} + +static void imx_timerg_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); + k->init = imx_timerg_init; + dc->vmsd = &vmstate_imx_timerg; + dc->reset = imx_timerg_reset; + dc->desc = "i.MX general timer"; +} + +static void imx_timerp_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); + k->init = imx_timerp_init; + dc->vmsd = &vmstate_imx_timerp; + dc->reset = imx_timerp_reset; + dc->desc = "i.MX periodic timer"; +} + +static const TypeInfo imx_timerp_info = { + .name = "imx_timerp", + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(IMXTimerPState), + .class_init = imx_timerp_class_init, +}; + +static const TypeInfo imx_timerg_info = { + .name = "imx_timerg", + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(IMXTimerGState), + .class_init = imx_timerg_class_init, +}; + +static void imx_timer_register_types(void) +{ + type_register_static(&imx_timerp_info); + type_register_static(&imx_timerg_info); +} + +type_init(imx_timer_register_types) |