1 // SPDX-License-Identifier: GPL-2.0-only
17  *  - timer 0 - NR_CPUs for per cpu timer
18  *  - one timer for clocksource
19  *  - one timer for watchdog driver.
20  * It is also worth notice that APB timer does not support true one-shot mode,
21  * free-running mode will be used here to emulate one-shot mode.
22  * APB timer can also be used as broadcast timer along with per cpu local APIC
34 #include <linux/cpu.h>
39 #include <asm/intel-mid.h>
60 	int					cpu;  member
69 	return apbt_virt_address + adev->num * APBTMRS_REG_SIZE;  in adev_virt_addr()
93 	apbt_address = (phys_addr_t)mtmr->phys_addr;  in apbt_set_mapping()
104 	apbt_freq = mtmr->freq_hz;  in apbt_set_mapping()
114 		 (int)(mtmr->phys_addr & 0xff) / APBTMRS_REG_SIZE);  in apbt_set_mapping()
115 	phy_cs_timer_id = (unsigned int)(mtmr->phys_addr & 0xff) /  in apbt_set_mapping()
143 		return -ENODEV;  in apbt_clockevent_register()
146 	adev->num = smp_processor_id();  in apbt_clockevent_register()
147 	adev->timer = dw_apb_clockevent_init(smp_processor_id(), "apbt0",  in apbt_clockevent_register()
149 		APBT_CLOCKEVENT_RATING - 100 : APBT_CLOCKEVENT_RATING,  in apbt_clockevent_register()
152 	adev->timer->eoi = NULL;  in apbt_clockevent_register()
155 		global_clock_event = &adev->timer->ced;  in apbt_clockevent_register()
157 		       global_clock_event->name);  in apbt_clockevent_register()
160 	dw_apb_clockevent_register(adev->timer);  in apbt_clockevent_register()
170 	irq_modify_status(adev->irq, 0, IRQ_MOVE_PCNTXT);  in apbt_setup_irq()
171 	irq_set_affinity(adev->irq, cpumask_of(adev->cpu));  in apbt_setup_irq()
174 /* Should be called with per cpu */
178 	int cpu;  in apbt_setup_secondary_clock()  local
180 	/* Don't register boot CPU clockevent */  in apbt_setup_secondary_clock()
181 	cpu = smp_processor_id();  in apbt_setup_secondary_clock()
182 	if (!cpu)  in apbt_setup_secondary_clock()
186 	if (!adev->timer) {  in apbt_setup_secondary_clock()
187 		adev->timer = dw_apb_clockevent_init(cpu, adev->name,  in apbt_setup_secondary_clock()
189 			adev->irq, apbt_freq);  in apbt_setup_secondary_clock()
190 		adev->timer->eoi = NULL;  in apbt_setup_secondary_clock()
192 		dw_apb_clockevent_resume(adev->timer);  in apbt_setup_secondary_clock()
195 	printk(KERN_INFO "Registering CPU %d clockevent device %s, cpu %08x\n",  in apbt_setup_secondary_clock()
196 	       cpu, adev->name, adev->cpu);  in apbt_setup_secondary_clock()
199 	dw_apb_clockevent_register(adev->timer);  in apbt_setup_secondary_clock()
205  * this notify handler process CPU hotplug events. in case of S0i3, nonboot
207  * per cpu timer irq registered so that we do need to do free_irq/request_irq.
210  * without the notifier chain. currently, cpu 0 may get interrupts from other
211  * cpu timers during the offline process due to the ordering of notification.
214 static int apbt_cpu_dead(unsigned int cpu)  in apbt_cpu_dead()  argument
216 	struct apbt_dev *adev = &per_cpu(cpu_apbt_dev, cpu);  in apbt_cpu_dead()
218 	dw_apb_clockevent_pause(adev->timer);  in apbt_cpu_dead()
220 		pr_debug("skipping APBT CPU %u offline\n", cpu);  in apbt_cpu_dead()
222 		pr_debug("APBT clockevent for cpu %u offline\n", cpu);  in apbt_cpu_dead()
223 		dw_apb_clockevent_stop(adev->timer);  in apbt_cpu_dead()
264 	} while ((now - start) < 200000UL);  in apbt_clocksource_register()
277  * per CPU timer if possible.
278  * returns 1 if per cpu apbt is setup
279  * returns 0 if no per cpu apbt is chosen
317 		printk(KERN_INFO "apbt: disabled per cpu timer\n");  in apbt_time_init()
327 	/* here we set up per CPU timer data structure */  in apbt_time_init()
330 		adev->num = i;  in apbt_time_init()
331 		adev->cpu = i;  in apbt_time_init()
334 			adev->irq = p_mtmr->irq;  in apbt_time_init()
336 			printk(KERN_ERR "Failed to get timer for cpu %d\n", i);  in apbt_time_init()
337 		snprintf(adev->name, sizeof(adev->name) - 1, "apbt%d", i);  in apbt_time_init()