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author | 2016-06-03 03:33:22 +0000 | |
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committer | 2016-06-03 03:33:23 +0000 | |
commit | da27230f80795d0028333713f036d44c53cb0e68 (patch) | |
tree | b3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/hw/timer/aspeed_timer.c | |
parent | 0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff) | |
parent | 437fd90c0250dee670290f9b714253671a990160 (diff) |
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/hw/timer/aspeed_timer.c')
-rw-r--r-- | qemu/hw/timer/aspeed_timer.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/qemu/hw/timer/aspeed_timer.c b/qemu/hw/timer/aspeed_timer.c new file mode 100644 index 000000000..51e8303cd --- /dev/null +++ b/qemu/hw/timer/aspeed_timer.c @@ -0,0 +1,449 @@ +/* + * ASPEED AST2400 Timer + * + * Andrew Jeffery <andrew@aj.id.au> + * + * Copyright (C) 2016 IBM Corp. + * + * This code is licensed under the GPL version 2 or later. See + * the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "hw/ptimer.h" +#include "hw/sysbus.h" +#include "hw/timer/aspeed_timer.h" +#include "qemu-common.h" +#include "qemu/bitops.h" +#include "qemu/main-loop.h" +#include "qemu/timer.h" +#include "trace.h" + +#define TIMER_NR_REGS 4 + +#define TIMER_CTRL_BITS 4 +#define TIMER_CTRL_MASK ((1 << TIMER_CTRL_BITS) - 1) + +#define TIMER_CLOCK_USE_EXT true +#define TIMER_CLOCK_EXT_HZ 1000000 +#define TIMER_CLOCK_USE_APB false +#define TIMER_CLOCK_APB_HZ 24000000 + +#define TIMER_REG_STATUS 0 +#define TIMER_REG_RELOAD 1 +#define TIMER_REG_MATCH_FIRST 2 +#define TIMER_REG_MATCH_SECOND 3 + +#define TIMER_FIRST_CAP_PULSE 4 + +enum timer_ctrl_op { + op_enable = 0, + op_external_clock, + op_overflow_interrupt, + op_pulse_enable +}; + +/** + * Avoid mutual references between AspeedTimerCtrlState and AspeedTimer + * structs, as it's a waste of memory. The ptimer BH callback needs to know + * whether a specific AspeedTimer is enabled, but this information is held in + * AspeedTimerCtrlState. So, provide a helper to hoist ourselves from an + * arbitrary AspeedTimer to AspeedTimerCtrlState. + */ +static inline AspeedTimerCtrlState *timer_to_ctrl(AspeedTimer *t) +{ + const AspeedTimer (*timers)[] = (void *)t - (t->id * sizeof(*t)); + return container_of(timers, AspeedTimerCtrlState, timers); +} + +static inline bool timer_ctrl_status(AspeedTimer *t, enum timer_ctrl_op op) +{ + return !!(timer_to_ctrl(t)->ctrl & BIT(t->id * TIMER_CTRL_BITS + op)); +} + +static inline bool timer_enabled(AspeedTimer *t) +{ + return timer_ctrl_status(t, op_enable); +} + +static inline bool timer_overflow_interrupt(AspeedTimer *t) +{ + return timer_ctrl_status(t, op_overflow_interrupt); +} + +static inline bool timer_can_pulse(AspeedTimer *t) +{ + return t->id >= TIMER_FIRST_CAP_PULSE; +} + +static void aspeed_timer_expire(void *opaque) +{ + AspeedTimer *t = opaque; + + /* Only support interrupts on match values of zero for the moment - this is + * sufficient to boot an aspeed_defconfig Linux kernel. + * + * TODO: matching on arbitrary values (see e.g. hw/timer/a9gtimer.c) + */ + bool match = !(t->match[0] && t->match[1]); + bool interrupt = timer_overflow_interrupt(t) || match; + if (timer_enabled(t) && interrupt) { + t->level = !t->level; + qemu_set_irq(t->irq, t->level); + } +} + +static uint64_t aspeed_timer_get_value(AspeedTimer *t, int reg) +{ + uint64_t value; + + switch (reg) { + case TIMER_REG_STATUS: + value = ptimer_get_count(t->timer); + break; + case TIMER_REG_RELOAD: + value = t->reload; + break; + case TIMER_REG_MATCH_FIRST: + case TIMER_REG_MATCH_SECOND: + value = t->match[reg - 2]; + break; + default: + qemu_log_mask(LOG_UNIMP, "%s: Programming error: unexpected reg: %d\n", + __func__, reg); + value = 0; + break; + } + return value; +} + +static uint64_t aspeed_timer_read(void *opaque, hwaddr offset, unsigned size) +{ + AspeedTimerCtrlState *s = opaque; + const int reg = (offset & 0xf) / 4; + uint64_t value; + + switch (offset) { + case 0x30: /* Control Register */ + value = s->ctrl; + break; + case 0x34: /* Control Register 2 */ + value = s->ctrl2; + break; + case 0x00 ... 0x2c: /* Timers 1 - 4 */ + value = aspeed_timer_get_value(&s->timers[(offset >> 4)], reg); + break; + case 0x40 ... 0x8c: /* Timers 5 - 8 */ + value = aspeed_timer_get_value(&s->timers[(offset >> 4) - 1], reg); + break; + /* Illegal */ + case 0x38: + case 0x3C: + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + value = 0; + break; + } + trace_aspeed_timer_read(offset, size, value); + return value; +} + +static void aspeed_timer_set_value(AspeedTimerCtrlState *s, int timer, int reg, + uint32_t value) +{ + AspeedTimer *t; + + trace_aspeed_timer_set_value(timer, reg, value); + t = &s->timers[timer]; + switch (reg) { + case TIMER_REG_STATUS: + if (timer_enabled(t)) { + ptimer_set_count(t->timer, value); + } + break; + case TIMER_REG_RELOAD: + t->reload = value; + ptimer_set_limit(t->timer, value, 1); + break; + case TIMER_REG_MATCH_FIRST: + case TIMER_REG_MATCH_SECOND: + if (value) { + /* Non-zero match values are unsupported. As such an interrupt will + * always be triggered when the timer reaches zero even if the + * overflow interrupt control bit is clear. + */ + qemu_log_mask(LOG_UNIMP, "%s: Match value unsupported by device: " + "0x%" PRIx32 "\n", __func__, value); + } else { + t->match[reg - 2] = value; + } + break; + default: + qemu_log_mask(LOG_UNIMP, "%s: Programming error: unexpected reg: %d\n", + __func__, reg); + break; + } +} + +/* Control register operations are broken out into helpers that can be + * explictly called on aspeed_timer_reset(), but also from + * aspeed_timer_ctrl_op(). + */ + +static void aspeed_timer_ctrl_enable(AspeedTimer *t, bool enable) +{ + trace_aspeed_timer_ctrl_enable(t->id, enable); + if (enable) { + ptimer_run(t->timer, 0); + } else { + ptimer_stop(t->timer); + ptimer_set_limit(t->timer, t->reload, 1); + } +} + +static void aspeed_timer_ctrl_external_clock(AspeedTimer *t, bool enable) +{ + trace_aspeed_timer_ctrl_external_clock(t->id, enable); + if (enable) { + ptimer_set_freq(t->timer, TIMER_CLOCK_EXT_HZ); + } else { + ptimer_set_freq(t->timer, TIMER_CLOCK_APB_HZ); + } +} + +static void aspeed_timer_ctrl_overflow_interrupt(AspeedTimer *t, bool enable) +{ + trace_aspeed_timer_ctrl_overflow_interrupt(t->id, enable); +} + +static void aspeed_timer_ctrl_pulse_enable(AspeedTimer *t, bool enable) +{ + if (timer_can_pulse(t)) { + trace_aspeed_timer_ctrl_pulse_enable(t->id, enable); + } else { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Timer does not support pulse mode\n", __func__); + } +} + +/** + * Given the actions are fixed in number and completely described in helper + * functions, dispatch with a lookup table rather than manage control flow with + * a switch statement. + */ +static void (*const ctrl_ops[])(AspeedTimer *, bool) = { + [op_enable] = aspeed_timer_ctrl_enable, + [op_external_clock] = aspeed_timer_ctrl_external_clock, + [op_overflow_interrupt] = aspeed_timer_ctrl_overflow_interrupt, + [op_pulse_enable] = aspeed_timer_ctrl_pulse_enable, +}; + +/** + * Conditionally affect changes chosen by a timer's control bit. + * + * The aspeed_timer_ctrl_op() interface is convenient for the + * aspeed_timer_set_ctrl() function as the "no change" early exit can be + * calculated for all operations, which cleans up the caller code. However the + * interface isn't convenient for the reset function where we want to enter a + * specific state without artificially constructing old and new values that + * will fall through the change guard (and motivates extracting the actions + * out to helper functions). + * + * @t: The timer to manipulate + * @op: The type of operation to be performed + * @old: The old state of the timer's control bits + * @new: The incoming state for the timer's control bits + */ +static void aspeed_timer_ctrl_op(AspeedTimer *t, enum timer_ctrl_op op, + uint8_t old, uint8_t new) +{ + const uint8_t mask = BIT(op); + const bool enable = !!(new & mask); + const bool changed = ((old ^ new) & mask); + if (!changed) { + return; + } + ctrl_ops[op](t, enable); +} + +static void aspeed_timer_set_ctrl(AspeedTimerCtrlState *s, uint32_t reg) +{ + int i; + int shift; + uint8_t t_old, t_new; + AspeedTimer *t; + const uint8_t enable_mask = BIT(op_enable); + + /* Handle a dependency between the 'enable' and remaining three + * configuration bits - i.e. if more than one bit in the control set has + * changed, including the 'enable' bit, then we want either disable the + * timer and perform configuration, or perform configuration and then + * enable the timer + */ + for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { + t = &s->timers[i]; + shift = (i * TIMER_CTRL_BITS); + t_old = (s->ctrl >> shift) & TIMER_CTRL_MASK; + t_new = (reg >> shift) & TIMER_CTRL_MASK; + + /* If we are disabling, do so first */ + if ((t_old & enable_mask) && !(t_new & enable_mask)) { + aspeed_timer_ctrl_enable(t, false); + } + aspeed_timer_ctrl_op(t, op_external_clock, t_old, t_new); + aspeed_timer_ctrl_op(t, op_overflow_interrupt, t_old, t_new); + aspeed_timer_ctrl_op(t, op_pulse_enable, t_old, t_new); + /* If we are enabling, do so last */ + if (!(t_old & enable_mask) && (t_new & enable_mask)) { + aspeed_timer_ctrl_enable(t, true); + } + } + s->ctrl = reg; +} + +static void aspeed_timer_set_ctrl2(AspeedTimerCtrlState *s, uint32_t value) +{ + trace_aspeed_timer_set_ctrl2(value); +} + +static void aspeed_timer_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + const uint32_t tv = (uint32_t)(value & 0xFFFFFFFF); + const int reg = (offset & 0xf) / 4; + AspeedTimerCtrlState *s = opaque; + + switch (offset) { + /* Control Registers */ + case 0x30: + aspeed_timer_set_ctrl(s, tv); + break; + case 0x34: + aspeed_timer_set_ctrl2(s, tv); + break; + /* Timer Registers */ + case 0x00 ... 0x2c: + aspeed_timer_set_value(s, (offset >> TIMER_NR_REGS), reg, tv); + break; + case 0x40 ... 0x8c: + aspeed_timer_set_value(s, (offset >> TIMER_NR_REGS) - 1, reg, tv); + break; + /* Illegal */ + case 0x38: + case 0x3C: + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + break; + } +} + +static const MemoryRegionOps aspeed_timer_ops = { + .read = aspeed_timer_read, + .write = aspeed_timer_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid.min_access_size = 4, + .valid.max_access_size = 4, + .valid.unaligned = false, +}; + +static void aspeed_init_one_timer(AspeedTimerCtrlState *s, uint8_t id) +{ + QEMUBH *bh; + AspeedTimer *t = &s->timers[id]; + + t->id = id; + bh = qemu_bh_new(aspeed_timer_expire, t); + t->timer = ptimer_init(bh); +} + +static void aspeed_timer_realize(DeviceState *dev, Error **errp) +{ + int i; + SysBusDevice *sbd = SYS_BUS_DEVICE(dev); + AspeedTimerCtrlState *s = ASPEED_TIMER(dev); + + for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { + aspeed_init_one_timer(s, i); + sysbus_init_irq(sbd, &s->timers[i].irq); + } + memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_timer_ops, s, + TYPE_ASPEED_TIMER, 0x1000); + sysbus_init_mmio(sbd, &s->iomem); +} + +static void aspeed_timer_reset(DeviceState *dev) +{ + int i; + AspeedTimerCtrlState *s = ASPEED_TIMER(dev); + + for (i = 0; i < ASPEED_TIMER_NR_TIMERS; i++) { + AspeedTimer *t = &s->timers[i]; + /* Explictly call helpers to avoid any conditional behaviour through + * aspeed_timer_set_ctrl(). + */ + aspeed_timer_ctrl_enable(t, false); + aspeed_timer_ctrl_external_clock(t, TIMER_CLOCK_USE_APB); + aspeed_timer_ctrl_overflow_interrupt(t, false); + aspeed_timer_ctrl_pulse_enable(t, false); + t->level = 0; + t->reload = 0; + t->match[0] = 0; + t->match[1] = 0; + } + s->ctrl = 0; + s->ctrl2 = 0; +} + +static const VMStateDescription vmstate_aspeed_timer = { + .name = "aspeed.timer", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT8(id, AspeedTimer), + VMSTATE_INT32(level, AspeedTimer), + VMSTATE_PTIMER(timer, AspeedTimer), + VMSTATE_UINT32(reload, AspeedTimer), + VMSTATE_UINT32_ARRAY(match, AspeedTimer, 2), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription vmstate_aspeed_timer_state = { + .name = "aspeed.timerctrl", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(ctrl, AspeedTimerCtrlState), + VMSTATE_UINT32(ctrl2, AspeedTimerCtrlState), + VMSTATE_STRUCT_ARRAY(timers, AspeedTimerCtrlState, + ASPEED_TIMER_NR_TIMERS, 1, vmstate_aspeed_timer, + AspeedTimer), + VMSTATE_END_OF_LIST() + } +}; + +static void timer_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = aspeed_timer_realize; + dc->reset = aspeed_timer_reset; + dc->desc = "ASPEED Timer"; + dc->vmsd = &vmstate_aspeed_timer_state; +} + +static const TypeInfo aspeed_timer_info = { + .name = TYPE_ASPEED_TIMER, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(AspeedTimerCtrlState), + .class_init = timer_class_init, +}; + +static void aspeed_timer_register_types(void) +{ + type_register_static(&aspeed_timer_info); +} + +type_init(aspeed_timer_register_types) |