| /* |
| * ARMv7M SysTick timer |
| * |
| * Copyright (c) 2006-2007 CodeSourcery. |
| * Written by Paul Brook |
| * Copyright (c) 2017 Linaro Ltd |
| * Written by Peter Maydell |
| * |
| * This code is licensed under the GPL (version 2 or later). |
| */ |
| |
| #ifndef HW_TIMER_ARMV7M_SYSTICK_H |
| #define HW_TIMER_ARMV7M_SYSTICK_H |
| |
| #include "hw/sysbus.h" |
| #include "qom/object.h" |
| |
| #define TYPE_SYSTICK "armv7m_systick" |
| |
| typedef struct SysTickState SysTickState; |
| DECLARE_INSTANCE_CHECKER(SysTickState, SYSTICK, |
| TYPE_SYSTICK) |
| |
| struct SysTickState { |
| /*< private >*/ |
| SysBusDevice parent_obj; |
| /*< public >*/ |
| |
| uint32_t control; |
| uint32_t reload; |
| int64_t tick; |
| QEMUTimer *timer; |
| MemoryRegion iomem; |
| qemu_irq irq; |
| }; |
| |
| /* |
| * Multiplication factor to convert from system clock ticks to qemu timer |
| * ticks. This should be set (by board code, usually) to a value |
| * equal to NANOSECONDS_PER_SECOND / frq, where frq is the clock frequency |
| * in Hz of the CPU. |
| * |
| * This value is used by the systick device when it is running in |
| * its "use the CPU clock" mode (ie when SYST_CSR.CLKSOURCE == 1) to |
| * set how fast the timer should tick. |
| * |
| * TODO: we should refactor this so that rather than using a global |
| * we use a device property or something similar. This is complicated |
| * because (a) the property would need to be plumbed through from the |
| * board code down through various layers to the systick device |
| * and (b) the property needs to be modifiable after realize, because |
| * the stellaris board uses this to implement the behaviour where the |
| * guest can reprogram the PLL registers to downclock the CPU, and the |
| * systick device needs to react accordingly. Possibly this should |
| * be deferred until we have a good API for modelling clock trees. |
| */ |
| extern int system_clock_scale; |
| |
| #endif |