1 // SPDX-License-Identifier: GPL-2.0
3  * IXP4 timer driver
6  * Based on arch/arm/mach-ixp4xx/common.c
8  * Copyright 2003-2004 (C) MontaVista, Software, Inc.
22 #include <linux/platform_data/timer-ixp4xx.h>
25  * Constants to make it easy to access Timer Control/Status registers
28 #define IXP4XX_OST1_OFFSET	0x04  /* Timer 1 Timestamp */
29 #define IXP4XX_OSRT1_OFFSET	0x08  /* Timer 1 Reload */
30 #define IXP4XX_OST2_OFFSET	0x0C  /* Timer 2 Timestamp */
31 #define IXP4XX_OSRT2_OFFSET	0x10  /* Timer 2 Reload */
32 #define IXP4XX_OSWT_OFFSET	0x14  /* Watchdog Timer */
35 #define IXP4XX_OSST_OFFSET	0x20  /* Timer Status */
38  * Timer register values and bit definitions
67  * A local singleton used by sched_clock and delay timer reads, which are
80 	return __raw_readl(local_ixp4xx_timer->base + IXP4XX_OSTS_OFFSET);  in ixp4xx_read_timer()
96 	struct clock_event_device *evt = &tmr->clkevt;  in ixp4xx_timer_interrupt()
100 		     tmr->base + IXP4XX_OSST_OFFSET);  in ixp4xx_timer_interrupt()
102 	evt->event_handler(evt);  in ixp4xx_timer_interrupt()
113 	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_set_next_event()
117 		     tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_set_next_event()
127 	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_shutdown()
129 	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_shutdown()
139 		     tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_set_oneshot()
149 	val = tmr->latch & ~IXP4XX_OST_RELOAD_MASK;  in ixp4xx_set_periodic()
151 	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_set_periodic()
161 	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_resume()
163 	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_resume()
169  * IXP4xx timer tick
170  * We use OS timer1 on the CPU for the timer tick and the timestamp
182 		return -ENOMEM;  in ixp4xx_timer_register()
183 	tmr->base = base;  in ixp4xx_timer_register()
184 	tmr->tick_rate = timer_freq;  in ixp4xx_timer_register()
187 	 * The timer register doesn't allow to specify the two least  in ixp4xx_timer_register()
192 	tmr->latch = DIV_ROUND_CLOSEST(timer_freq,  in ixp4xx_timer_register()
199 	__raw_writel(0, tmr->base + IXP4XX_OSRT1_OFFSET);  in ixp4xx_timer_register()
201 	/* Clear any pending interrupt on timer 1 */  in ixp4xx_timer_register()
203 		     tmr->base + IXP4XX_OSST_OFFSET);  in ixp4xx_timer_register()
205 	/* Reset time-stamp counter */  in ixp4xx_timer_register()
206 	__raw_writel(0, tmr->base + IXP4XX_OSTS_OFFSET);  in ixp4xx_timer_register()
211 	tmr->clkevt.name = "ixp4xx timer1";  in ixp4xx_timer_register()
212 	tmr->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;  in ixp4xx_timer_register()
213 	tmr->clkevt.rating = 200;  in ixp4xx_timer_register()
214 	tmr->clkevt.set_state_shutdown = ixp4xx_shutdown;  in ixp4xx_timer_register()
215 	tmr->clkevt.set_state_periodic = ixp4xx_set_periodic;  in ixp4xx_timer_register()
216 	tmr->clkevt.set_state_oneshot = ixp4xx_set_oneshot;  in ixp4xx_timer_register()
217 	tmr->clkevt.tick_resume = ixp4xx_resume;  in ixp4xx_timer_register()
218 	tmr->clkevt.set_next_event = ixp4xx_set_next_event;  in ixp4xx_timer_register()
219 	tmr->clkevt.cpumask = cpumask_of(0);  in ixp4xx_timer_register()
220 	tmr->clkevt.irq = timer_irq;  in ixp4xx_timer_register()
222 			  IRQF_TIMER, "IXP4XX-TIMER1", tmr);  in ixp4xx_timer_register()
224 		pr_crit("no timer IRQ\n");  in ixp4xx_timer_register()
225 		return -ENODEV;  in ixp4xx_timer_register()
227 	clockevents_config_and_register(&tmr->clkevt, timer_freq,  in ixp4xx_timer_register()
233 	/* Also use this timer for delays */  in ixp4xx_timer_register()
234 	tmr->delay_timer.read_current_timer = ixp4xx_read_timer;  in ixp4xx_timer_register()
235 	tmr->delay_timer.freq = timer_freq;  in ixp4xx_timer_register()
236 	register_current_timer_delay(&tmr->delay_timer);  in ixp4xx_timer_register()
243  * ixp4xx_timer_setup() - Timer setup function to be called from boardfiles
244  * @timerbase: physical base of timer block
245  * @timer_irq: Linux IRQ number for the timer
246  * @timer_freq: Fixed frequency of the timer
256 		pr_crit("IXP4xx: can't remap timer\n");  in ixp4xx_timer_setup()
272 		pr_crit("IXP4xx: can't remap timer\n");  in ixp4xx_of_timer_init()
273 		return -ENODEV;  in ixp4xx_of_timer_init()
279 		ret = -EINVAL;  in ixp4xx_of_timer_init()
293 TIMER_OF_DECLARE(ixp4xx, "intel,ixp4xx-timer", ixp4xx_of_timer_init);