diff options
Diffstat (limited to 'hw/timer/stellaris-gptm.c')
| -rw-r--r-- | hw/timer/stellaris-gptm.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/hw/timer/stellaris-gptm.c b/hw/timer/stellaris-gptm.c new file mode 100644 index 000000000..fd71c79be --- /dev/null +++ b/hw/timer/stellaris-gptm.c @@ -0,0 +1,332 @@ +/* + * Luminary Micro Stellaris General Purpose Timer Module + * + * Copyright (c) 2006 CodeSourcery. + * Written by Paul Brook + * + * This code is licensed under the GPL. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qemu/timer.h" +#include "qapi/error.h" +#include "migration/vmstate.h" +#include "hw/qdev-clock.h" +#include "hw/timer/stellaris-gptm.h" + +static void gptm_update_irq(gptm_state *s) +{ + int level; + level = (s->state & s->mask) != 0; + qemu_set_irq(s->irq, level); +} + +static void gptm_stop(gptm_state *s, int n) +{ + timer_del(s->timer[n]); +} + +static void gptm_reload(gptm_state *s, int n, int reset) +{ + int64_t tick; + if (reset) { + tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + } else { + tick = s->tick[n]; + } + + if (s->config == 0) { + /* 32-bit CountDown. */ + uint32_t count; + count = s->load[0] | (s->load[1] << 16); + tick += clock_ticks_to_ns(s->clk, count); + } else if (s->config == 1) { + /* 32-bit RTC. 1Hz tick. */ + tick += NANOSECONDS_PER_SECOND; + } else if (s->mode[n] == 0xa) { + /* PWM mode. Not implemented. */ + } else { + qemu_log_mask(LOG_UNIMP, + "GPTM: 16-bit timer mode unimplemented: 0x%x\n", + s->mode[n]); + return; + } + s->tick[n] = tick; + timer_mod(s->timer[n], tick); +} + +static void gptm_tick(void *opaque) +{ + gptm_state **p = (gptm_state **)opaque; + gptm_state *s; + int n; + + s = *p; + n = p - s->opaque; + if (s->config == 0) { + s->state |= 1; + if ((s->control & 0x20)) { + /* Output trigger. */ + qemu_irq_pulse(s->trigger); + } + if (s->mode[0] & 1) { + /* One-shot. */ + s->control &= ~1; + } else { + /* Periodic. */ + gptm_reload(s, 0, 0); + } + } else if (s->config == 1) { + /* RTC. */ + uint32_t match; + s->rtc++; + match = s->match[0] | (s->match[1] << 16); + if (s->rtc > match) + s->rtc = 0; + if (s->rtc == 0) { + s->state |= 8; + } + gptm_reload(s, 0, 0); + } else if (s->mode[n] == 0xa) { + /* PWM mode. Not implemented. */ + } else { + qemu_log_mask(LOG_UNIMP, + "GPTM: 16-bit timer mode unimplemented: 0x%x\n", + s->mode[n]); + } + gptm_update_irq(s); +} + +static uint64_t gptm_read(void *opaque, hwaddr offset, + unsigned size) +{ + gptm_state *s = (gptm_state *)opaque; + + switch (offset) { + case 0x00: /* CFG */ + return s->config; + case 0x04: /* TAMR */ + return s->mode[0]; + case 0x08: /* TBMR */ + return s->mode[1]; + case 0x0c: /* CTL */ + return s->control; + case 0x18: /* IMR */ + return s->mask; + case 0x1c: /* RIS */ + return s->state; + case 0x20: /* MIS */ + return s->state & s->mask; + case 0x24: /* CR */ + return 0; + case 0x28: /* TAILR */ + return s->load[0] | ((s->config < 4) ? (s->load[1] << 16) : 0); + case 0x2c: /* TBILR */ + return s->load[1]; + case 0x30: /* TAMARCHR */ + return s->match[0] | ((s->config < 4) ? (s->match[1] << 16) : 0); + case 0x34: /* TBMATCHR */ + return s->match[1]; + case 0x38: /* TAPR */ + return s->prescale[0]; + case 0x3c: /* TBPR */ + return s->prescale[1]; + case 0x40: /* TAPMR */ + return s->match_prescale[0]; + case 0x44: /* TBPMR */ + return s->match_prescale[1]; + case 0x48: /* TAR */ + if (s->config == 1) { + return s->rtc; + } + qemu_log_mask(LOG_UNIMP, + "GPTM: read of TAR but timer read not supported\n"); + return 0; + case 0x4c: /* TBR */ + qemu_log_mask(LOG_UNIMP, + "GPTM: read of TBR but timer read not supported\n"); + return 0; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "GPTM: read at bad offset 0x02%" HWADDR_PRIx "\n", + offset); + return 0; + } +} + +static void gptm_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + gptm_state *s = (gptm_state *)opaque; + uint32_t oldval; + + /* + * The timers should be disabled before changing the configuration. + * We take advantage of this and defer everything until the timer + * is enabled. + */ + switch (offset) { + case 0x00: /* CFG */ + s->config = value; + break; + case 0x04: /* TAMR */ + s->mode[0] = value; + break; + case 0x08: /* TBMR */ + s->mode[1] = value; + break; + case 0x0c: /* CTL */ + oldval = s->control; + s->control = value; + /* TODO: Implement pause. */ + if ((oldval ^ value) & 1) { + if (value & 1) { + gptm_reload(s, 0, 1); + } else { + gptm_stop(s, 0); + } + } + if (((oldval ^ value) & 0x100) && s->config >= 4) { + if (value & 0x100) { + gptm_reload(s, 1, 1); + } else { + gptm_stop(s, 1); + } + } + break; + case 0x18: /* IMR */ + s->mask = value & 0x77; + gptm_update_irq(s); + break; + case 0x24: /* CR */ + s->state &= ~value; + break; + case 0x28: /* TAILR */ + s->load[0] = value & 0xffff; + if (s->config < 4) { + s->load[1] = value >> 16; + } + break; + case 0x2c: /* TBILR */ + s->load[1] = value & 0xffff; + break; + case 0x30: /* TAMARCHR */ + s->match[0] = value & 0xffff; + if (s->config < 4) { + s->match[1] = value >> 16; + } + break; + case 0x34: /* TBMATCHR */ + s->match[1] = value >> 16; + break; + case 0x38: /* TAPR */ + s->prescale[0] = value; + break; + case 0x3c: /* TBPR */ + s->prescale[1] = value; + break; + case 0x40: /* TAPMR */ + s->match_prescale[0] = value; + break; + case 0x44: /* TBPMR */ + s->match_prescale[0] = value; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "GPTM: write at bad offset 0x02%" HWADDR_PRIx "\n", + offset); + } + gptm_update_irq(s); +} + +static const MemoryRegionOps gptm_ops = { + .read = gptm_read, + .write = gptm_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static const VMStateDescription vmstate_stellaris_gptm = { + .name = "stellaris_gptm", + .version_id = 2, + .minimum_version_id = 2, + .fields = (VMStateField[]) { + VMSTATE_UINT32(config, gptm_state), + VMSTATE_UINT32_ARRAY(mode, gptm_state, 2), + VMSTATE_UINT32(control, gptm_state), + VMSTATE_UINT32(state, gptm_state), + VMSTATE_UINT32(mask, gptm_state), + VMSTATE_UNUSED(8), + VMSTATE_UINT32_ARRAY(load, gptm_state, 2), + VMSTATE_UINT32_ARRAY(match, gptm_state, 2), + VMSTATE_UINT32_ARRAY(prescale, gptm_state, 2), + VMSTATE_UINT32_ARRAY(match_prescale, gptm_state, 2), + VMSTATE_UINT32(rtc, gptm_state), + VMSTATE_INT64_ARRAY(tick, gptm_state, 2), + VMSTATE_TIMER_PTR_ARRAY(timer, gptm_state, 2), + VMSTATE_CLOCK(clk, gptm_state), + VMSTATE_END_OF_LIST() + } +}; + +static void stellaris_gptm_init(Object *obj) +{ + DeviceState *dev = DEVICE(obj); + gptm_state *s = STELLARIS_GPTM(obj); + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + + sysbus_init_irq(sbd, &s->irq); + qdev_init_gpio_out(dev, &s->trigger, 1); + + memory_region_init_io(&s->iomem, obj, &gptm_ops, s, + "gptm", 0x1000); + sysbus_init_mmio(sbd, &s->iomem); + + s->opaque[0] = s->opaque[1] = s; + + /* + * TODO: in an ideal world we would model the effects of changing + * the input clock frequency while the countdown timer is active. + * The best way to do this would be to convert the device to use + * ptimer instead of hand-rolling its own timer. This would also + * make it easy to implement reading the current count from the + * TAR and TBR registers. + */ + s->clk = qdev_init_clock_in(dev, "clk", NULL, NULL, 0); +} + +static void stellaris_gptm_realize(DeviceState *dev, Error **errp) +{ + gptm_state *s = STELLARIS_GPTM(dev); + + if (!clock_has_source(s->clk)) { + error_setg(errp, "stellaris-gptm: clk must be connected"); + return; + } + + s->timer[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, gptm_tick, &s->opaque[0]); + s->timer[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, gptm_tick, &s->opaque[1]); +} + +static void stellaris_gptm_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->vmsd = &vmstate_stellaris_gptm; + dc->realize = stellaris_gptm_realize; +} + +static const TypeInfo stellaris_gptm_info = { + .name = TYPE_STELLARIS_GPTM, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(gptm_state), + .instance_init = stellaris_gptm_init, + .class_init = stellaris_gptm_class_init, +}; + +static void stellaris_gptm_register_types(void) +{ + type_register_static(&stellaris_gptm_info); +} + +type_init(stellaris_gptm_register_types) |