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