xemu/include/hw/timer/cmsdk-apb-dualtimer.h
Peter Maydell 4f4c6206ca hw/timer/cmsdk-apb-dualtimer: Implement CMSDK dual timer module
The Arm Cortex-M System Design Kit includes a "dual-input timer module"
which combines two programmable down-counters. Implement a model
of this device.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180820141116.9118-4-peter.maydell@linaro.org
2018-08-24 13:17:41 +01:00

73 lines
2.2 KiB
C

/*
* ARM CMSDK APB dual-timer emulation
*
* Copyright (c) 2018 Linaro Limited
* Written by Peter Maydell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 or
* (at your option) any later version.
*/
/*
* This is a model of the "APB dual-input timer" which is part of the Cortex-M
* System Design Kit (CMSDK) and documented in the Cortex-M System
* Design Kit Technical Reference Manual (ARM DDI0479C):
* https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
*
* QEMU interface:
* + QOM property "pclk-frq": frequency at which the timer is clocked
* + sysbus MMIO region 0: the register bank
* + sysbus IRQ 0: combined timer interrupt TIMINTC
* + sysbus IRO 1: timer block 1 interrupt TIMINT1
* + sysbus IRQ 2: timer block 2 interrupt TIMINT2
*/
#ifndef CMSDK_APB_DUALTIMER_H
#define CMSDK_APB_DUALTIMER_H
#include "hw/sysbus.h"
#include "hw/ptimer.h"
#define TYPE_CMSDK_APB_DUALTIMER "cmsdk-apb-dualtimer"
#define CMSDK_APB_DUALTIMER(obj) OBJECT_CHECK(CMSDKAPBDualTimer, (obj), \
TYPE_CMSDK_APB_DUALTIMER)
typedef struct CMSDKAPBDualTimer CMSDKAPBDualTimer;
/* One of the two identical timer modules in the dual-timer module */
typedef struct CMSDKAPBDualTimerModule {
CMSDKAPBDualTimer *parent;
struct ptimer_state *timer;
qemu_irq timerint;
/*
* We must track the guest LOAD and VALUE register state by hand
* rather than leaving this state only in the ptimer limit/count,
* because if CONTROL.SIZE is 0 then only the low 16 bits of the
* counter actually counts, but the high half is still guest
* accessible.
*/
uint32_t load;
uint32_t value;
uint32_t control;
uint32_t intstatus;
} CMSDKAPBDualTimerModule;
#define CMSDK_APB_DUALTIMER_NUM_MODULES 2
struct CMSDKAPBDualTimer {
/*< private >*/
SysBusDevice parent_obj;
/*< public >*/
MemoryRegion iomem;
qemu_irq timerintc;
uint32_t pclk_frq;
CMSDKAPBDualTimerModule timermod[CMSDK_APB_DUALTIMER_NUM_MODULES];
uint32_t timeritcr;
uint32_t timeritop;
};
#endif