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* QEMU GRLIB GPTimer Emulator
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* Copyright (c) 2010-2011 AdaCore
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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#include "qemu-timer.h"
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#define UNIT_REG_SIZE 16 /* Size of memory mapped regs for the unit */
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#define GPTIMER_REG_SIZE 16 /* Size of memory mapped regs for a GPTimer */
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#define GPTIMER_MAX_TIMERS 8
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/* GPTimer Config register fields */
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#define GPTIMER_ENABLE (1 << 0)
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#define GPTIMER_RESTART (1 << 1)
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#define GPTIMER_LOAD (1 << 2)
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#define GPTIMER_INT_ENABLE (1 << 3)
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#define GPTIMER_INT_PENDING (1 << 4)
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#define GPTIMER_CHAIN (1 << 5) /* Not supported */
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#define GPTIMER_DEBUG_HALT (1 << 6) /* Not supported */
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/* Memory mapped register offsets */
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#define SCALER_OFFSET 0x00
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#define SCALER_RELOAD_OFFSET 0x04
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#define CONFIG_OFFSET 0x08
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#define COUNTER_OFFSET 0x00
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#define COUNTER_RELOAD_OFFSET 0x04
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#define TIMER_BASE 0x10
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typedef struct GPTimer GPTimer;
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typedef struct GPTimerUnit GPTimerUnit;
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struct ptimer_state *ptimer;
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uint32_t nr_timers; /* Number of timers available */
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uint32_t freq_hz; /* System frequency */
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uint32_t irq_line; /* Base irq line */
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static void grlib_gptimer_enable(GPTimer *timer)
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assert(timer != NULL);
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ptimer_stop(timer->ptimer);
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if (!(timer->config & GPTIMER_ENABLE)) {
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trace_grlib_gptimer_disabled(timer->id, timer->config);
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/* ptimer is triggered when the counter reach 0 but GPTimer is triggered at
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underflow. Set count + 1 to simulate the GPTimer behavior. */
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trace_grlib_gptimer_enable(timer->id, timer->counter + 1);
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ptimer_set_count(timer->ptimer, timer->counter + 1);
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ptimer_run(timer->ptimer, 1);
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static void grlib_gptimer_restart(GPTimer *timer)
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assert(timer != NULL);
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trace_grlib_gptimer_restart(timer->id, timer->reload);
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timer->counter = timer->reload;
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grlib_gptimer_enable(timer);
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static void grlib_gptimer_set_scaler(GPTimerUnit *unit, uint32_t scaler)
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assert(unit != NULL);
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value = unit->freq_hz / (scaler + 1);
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value = unit->freq_hz;
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trace_grlib_gptimer_set_scaler(scaler, value);
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for (i = 0; i < unit->nr_timers; i++) {
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ptimer_set_freq(unit->timers[i].ptimer, value);
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static void grlib_gptimer_hit(void *opaque)
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GPTimer *timer = opaque;
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assert(timer != NULL);
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trace_grlib_gptimer_hit(timer->id);
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if (timer->config & GPTIMER_INT_ENABLE) {
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/* Set the pending bit (only unset by write in the config register) */
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timer->config |= GPTIMER_INT_PENDING;
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qemu_irq_pulse(timer->irq);
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if (timer->config & GPTIMER_RESTART) {
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grlib_gptimer_restart(timer);
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static uint32_t grlib_gptimer_readl(void *opaque, target_phys_addr_t addr)
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GPTimerUnit *unit = opaque;
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target_phys_addr_t timer_addr;
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trace_grlib_gptimer_readl(-1, addr, unit->scaler);
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case SCALER_RELOAD_OFFSET:
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trace_grlib_gptimer_readl(-1, addr, unit->reload);
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trace_grlib_gptimer_readl(-1, addr, unit->config);
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timer_addr = (addr % TIMER_BASE);
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id = (addr - TIMER_BASE) / TIMER_BASE;
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if (id >= 0 && id < unit->nr_timers) {
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/* GPTimer registers */
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switch (timer_addr) {
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value = ptimer_get_count(unit->timers[id].ptimer);
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trace_grlib_gptimer_readl(id, addr, value);
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case COUNTER_RELOAD_OFFSET:
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value = unit->timers[id].reload;
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trace_grlib_gptimer_readl(id, addr, value);
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trace_grlib_gptimer_readl(id, addr, unit->timers[id].config);
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return unit->timers[id].config;
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trace_grlib_gptimer_readl(-1, addr, 0);
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grlib_gptimer_writel(void *opaque, target_phys_addr_t addr, uint32_t value)
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GPTimerUnit *unit = opaque;
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target_phys_addr_t timer_addr;
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value &= 0xFFFF; /* clean up the value */
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unit->scaler = value;
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trace_grlib_gptimer_writel(-1, addr, unit->scaler);
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case SCALER_RELOAD_OFFSET:
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value &= 0xFFFF; /* clean up the value */
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unit->reload = value;
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trace_grlib_gptimer_writel(-1, addr, unit->reload);
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grlib_gptimer_set_scaler(unit, value);
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/* Read Only (disable timer freeze not supported) */
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trace_grlib_gptimer_writel(-1, addr, 0);
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timer_addr = (addr % TIMER_BASE);
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id = (addr - TIMER_BASE) / TIMER_BASE;
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if (id >= 0 && id < unit->nr_timers) {
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/* GPTimer registers */
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switch (timer_addr) {
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trace_grlib_gptimer_writel(id, addr, value);
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unit->timers[id].counter = value;
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grlib_gptimer_enable(&unit->timers[id]);
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case COUNTER_RELOAD_OFFSET:
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trace_grlib_gptimer_writel(id, addr, value);
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unit->timers[id].reload = value;
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trace_grlib_gptimer_writel(id, addr, value);
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if (value & GPTIMER_INT_PENDING) {
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/* clear pending bit */
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value &= ~GPTIMER_INT_PENDING;
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/* keep pending bit */
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value |= unit->timers[id].config & GPTIMER_INT_PENDING;
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unit->timers[id].config = value;
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/* gptimer_restart calls gptimer_enable, so if "enable" and "load"
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bits are present, we just have to call restart. */
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if (value & GPTIMER_LOAD) {
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grlib_gptimer_restart(&unit->timers[id]);
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} else if (value & GPTIMER_ENABLE) {
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grlib_gptimer_enable(&unit->timers[id]);
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/* These fields must always be read as 0 */
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value &= ~(GPTIMER_LOAD & GPTIMER_DEBUG_HALT);
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unit->timers[id].config = value;
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trace_grlib_gptimer_writel(-1, addr, value);
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static CPUReadMemoryFunc * const grlib_gptimer_read[] = {
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NULL, NULL, grlib_gptimer_readl,
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static CPUWriteMemoryFunc * const grlib_gptimer_write[] = {
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NULL, NULL, grlib_gptimer_writel,
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static void grlib_gptimer_reset(DeviceState *d)
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GPTimerUnit *unit = container_of(d, GPTimerUnit, busdev.qdev);
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assert(unit != NULL);
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unit->config = unit->nr_timers;
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unit->config |= unit->irq_line << 3;
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unit->config |= 1 << 8; /* separate interrupt */
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unit->config |= 1 << 9; /* Disable timer freeze */
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for (i = 0; i < unit->nr_timers; i++) {
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GPTimer *timer = &unit->timers[i];
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ptimer_stop(timer->ptimer);
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ptimer_set_count(timer->ptimer, 0);
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ptimer_set_freq(timer->ptimer, unit->freq_hz);
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static int grlib_gptimer_init(SysBusDevice *dev)
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GPTimerUnit *unit = FROM_SYSBUS(typeof(*unit), dev);
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assert(unit->nr_timers > 0);
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assert(unit->nr_timers <= GPTIMER_MAX_TIMERS);
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unit->timers = qemu_mallocz(sizeof unit->timers[0] * unit->nr_timers);
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for (i = 0; i < unit->nr_timers; i++) {
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GPTimer *timer = &unit->timers[i];
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timer->bh = qemu_bh_new(grlib_gptimer_hit, timer);
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timer->ptimer = ptimer_init(timer->bh);
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/* One IRQ line for each timer */
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sysbus_init_irq(dev, &timer->irq);
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ptimer_set_freq(timer->ptimer, unit->freq_hz);
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timer_regs = cpu_register_io_memory(grlib_gptimer_read,
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unit, DEVICE_NATIVE_ENDIAN);
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if (timer_regs < 0) {
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sysbus_init_mmio(dev, UNIT_REG_SIZE + GPTIMER_REG_SIZE * unit->nr_timers,
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static SysBusDeviceInfo grlib_gptimer_info = {
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.init = grlib_gptimer_init,
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.qdev.name = "grlib,gptimer",
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.qdev.reset = grlib_gptimer_reset,
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.qdev.size = sizeof(GPTimerUnit),
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.qdev.props = (Property[]) {
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DEFINE_PROP_UINT32("frequency", GPTimerUnit, freq_hz, 40000000),
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DEFINE_PROP_UINT32("irq-line", GPTimerUnit, irq_line, 8),
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DEFINE_PROP_UINT32("nr-timers", GPTimerUnit, nr_timers, 2),
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DEFINE_PROP_END_OF_LIST()
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static void grlib_gptimer_register(void)
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sysbus_register_withprop(&grlib_gptimer_info);
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device_init(grlib_gptimer_register)