12 /* This is a model of the "APB timer" which is part of the Cortex-M
13  * System Design Kit (CMSDK) and documented in the Cortex-M System
15  * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
19  * when EXTIN is low), or as a 'timer clock' (timer runs at frequency
20  * of EXTIN clock, not PCLK frequency). We don't model this.
25  * for one clock cycle before reloading from the RELOAD register,
27  * interrupt (as there is no further 1->0 transition).
38 #include "hw/qdev-clock.h"
39 #include "hw/timer/cmsdk-apb-timer.h"
73     qemu_set_irq(s->timerint, !!(s->intstatus & R_INTSTATUS_IRQ_MASK));  in cmsdk_apb_timer_update()
83         r = s->ctrl;  in cmsdk_apb_timer_read()
86         r = ptimer_get_count(s->timer);  in cmsdk_apb_timer_read()
89         r = ptimer_get_limit(s->timer);  in cmsdk_apb_timer_read()
92         r = s->intstatus;  in cmsdk_apb_timer_read()
95         r = timer_id[(offset - A_PID4) / 4];  in cmsdk_apb_timer_read()
117             /* Bits [1] and [2] enable using EXTIN as either clock or  in cmsdk_apb_timer_write()
123         s->ctrl = value & 0xf;  in cmsdk_apb_timer_write()
124         ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_write()
125         if (s->ctrl & R_CTRL_EN_MASK) {  in cmsdk_apb_timer_write()
126             ptimer_run(s->timer, ptimer_get_limit(s->timer) == 0);  in cmsdk_apb_timer_write()
128             ptimer_stop(s->timer);  in cmsdk_apb_timer_write()
130         ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_write()
134         ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_write()
136             ptimer_stop(s->timer);  in cmsdk_apb_timer_write()
138         ptimer_set_limit(s->timer, value, 1);  in cmsdk_apb_timer_write()
139         if (value && (s->ctrl & R_CTRL_EN_MASK)) {  in cmsdk_apb_timer_write()
142              * was an expired one-shot timer)  in cmsdk_apb_timer_write()
144             ptimer_run(s->timer, 0);  in cmsdk_apb_timer_write()
146         ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_write()
149         ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_write()
150         if (!value && !ptimer_get_limit(s->timer)) {  in cmsdk_apb_timer_write()
151             ptimer_stop(s->timer);  in cmsdk_apb_timer_write()
153         ptimer_set_count(s->timer, value);  in cmsdk_apb_timer_write()
154         if (value && (s->ctrl & R_CTRL_EN_MASK)) {  in cmsdk_apb_timer_write()
155             ptimer_run(s->timer, ptimer_get_limit(s->timer) == 0);  in cmsdk_apb_timer_write()
157         ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_write()
162         s->intstatus &= ~value;  in cmsdk_apb_timer_write()
187     if (s->ctrl & R_CTRL_IRQEN_MASK) {  in cmsdk_apb_timer_tick()
188         s->intstatus |= R_INTSTATUS_IRQ_MASK;  in cmsdk_apb_timer_tick()
198     s->ctrl = 0;  in cmsdk_apb_timer_reset()
199     s->intstatus = 0;  in cmsdk_apb_timer_reset()
200     ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_reset()
201     ptimer_stop(s->timer);  in cmsdk_apb_timer_reset()
203     ptimer_set_limit(s->timer, 0, 1);  in cmsdk_apb_timer_reset()
204     ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_reset()
211     ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_clk_update()
212     ptimer_set_period_from_clock(s->timer, s->pclk, 1);  in cmsdk_apb_timer_clk_update()
213     ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_clk_update()
221     memory_region_init_io(&s->iomem, obj, &cmsdk_apb_timer_ops,  in cmsdk_apb_timer_init()
222                           s, "cmsdk-apb-timer", 0x1000);  in cmsdk_apb_timer_init()
223     sysbus_init_mmio(sbd, &s->iomem);  in cmsdk_apb_timer_init()
224     sysbus_init_irq(sbd, &s->timerint);  in cmsdk_apb_timer_init()
225     s->pclk = qdev_init_clock_in(DEVICE(s), "pclk",  in cmsdk_apb_timer_init()
233     if (!clock_has_source(s->pclk)) {  in cmsdk_apb_timer_realize()
234         error_setg(errp, "CMSDK APB timer: pclk clock must be connected");  in cmsdk_apb_timer_realize()
238     s->timer = ptimer_init(cmsdk_apb_timer_tick, s,  in cmsdk_apb_timer_realize()
244     ptimer_transaction_begin(s->timer);  in cmsdk_apb_timer_realize()
245     ptimer_set_period_from_clock(s->timer, s->pclk, 1);  in cmsdk_apb_timer_realize()
246     ptimer_transaction_commit(s->timer);  in cmsdk_apb_timer_realize()
250     .name = "cmsdk-apb-timer",
268     dc->realize = cmsdk_apb_timer_realize;  in cmsdk_apb_timer_class_init()
269     dc->vmsd = &cmsdk_apb_timer_vmstate;  in cmsdk_apb_timer_class_init()