4  * SPDX-License-Identifier: Apache-2.0
14  * 64/32-bit timers in Nuvoton NPCX series. Via these two kinds of timers, the
18  * - A system timer based on an ITIM64 (Internal 64-bit timer) instance, clocked
20  * - Provide a 64-bit cycles reading and ticks computation based on it.
21  * - Its prescaler is set to 1 and provide the kernel cycles reading without
23  * - After ec entered "sleep/deep sleep" power state which is used for better
26  * - A event timer based on an ITIM32 (Internal 32-bit timer) instance, clocked
29  * - Provide a system clock timeout notification. In its ISR, the driver informs
31  * - Its prescaler is set to 1 and the formula between event timer's cycles and
33  * - Compensate reading of ITIM64 which clock is gating after ec entered
39 #include <zephyr/drivers/timer/system_timer.h>
72 /* Announced cycles in system timer before executing sys_clock_announce() */
77 /* Current target cycles of time-out signal in event timer */
79 /* Total cycles of system timer stopped in "sleep/deep sleep" mode */
81 /* Current cycles in event timer when ec entered "sleep/deep sleep" mode */
89 	/* Read 64-bit counter value from two 32-bit registers */  in npcx_itim_get_sys_cyc64()
91 		cnt64h_check = sys_tmr->ITCNT64H;  in npcx_itim_get_sys_cyc64()
92 		cnt64l = sys_tmr->ITCNT64L;  in npcx_itim_get_sys_cyc64()
93 		cnt64h = sys_tmr->ITCNT64H;  in npcx_itim_get_sys_cyc64()
96 	cnt64h = NPCX_ITIM64_MAX_HALF_CNT - cnt64h;  in npcx_itim_get_sys_cyc64()
97 	cnt64l = NPCX_ITIM64_MAX_HALF_CNT - cnt64l + 1;  in npcx_itim_get_sys_cyc64()
99 	/* Return current value of 64-bit counter value of system timer */  in npcx_itim_get_sys_cyc64()
112 	/* Enable event timer and wait for it to take effect */  in npcx_itim_evt_enable()
113 	evt_tmr->ITCTS32 |= BIT(NPCX_ITCTSXX_ITEN);  in npcx_itim_evt_enable()
120 	while (!IS_BIT_SET(evt_tmr->ITCTS32, NPCX_ITCTSXX_ITEN)) {  in npcx_itim_evt_enable()
121 		if (npcx_itim_get_sys_cyc64() - cyc_start >  in npcx_itim_evt_enable()
124 			if (!IS_BIT_SET(evt_tmr->ITCTS32, NPCX_ITCTSXX_ITEN)) {  in npcx_itim_evt_enable()
125 				LOG_ERR("Timeout: enabling EVT timer!");  in npcx_itim_evt_enable()
126 				return -ETIMEDOUT;  in npcx_itim_evt_enable()
136 	/* Disable event timer and no need to wait for it to take effect */  in npcx_itim_evt_disable()
137 	evt_tmr->ITCTS32 &= ~BIT(NPCX_ITCTSXX_ITEN);  in npcx_itim_evt_disable()
144 	 * Get desired cycles of event timer from the requested ticks which  in npcx_itim_start_evt_tmr_by_tick()
165 			dcycles = next_cycs - curr;  in npcx_itim_start_evt_tmr_by_tick()
173 	/* Disable event timer if needed before configuring counter */  in npcx_itim_start_evt_tmr_by_tick()
174 	if (IS_BIT_SET(evt_tmr->ITCTS32, NPCX_ITCTSXX_ITEN)) {  in npcx_itim_start_evt_tmr_by_tick()
178 	/* Upload counter of event timer */  in npcx_itim_start_evt_tmr_by_tick()
179 	evt_tmr->ITCNT32 = MAX(cyc_evt_timeout - 1, 1);  in npcx_itim_start_evt_tmr_by_tick()
181 	/* Enable event timer and start ticking */  in npcx_itim_start_evt_tmr_by_tick()
192 	evt_tmr->ITCTS32 |= BIT(NPCX_ITCTSXX_TO_STS);  in npcx_itim_evt_isr()
197 		uint32_t delta_ticks = (uint32_t)((curr - cyc_sys_announced) / SYS_CYCLES_PER_TICK);  in npcx_itim_evt_isr()
207 		/* Enable event timer for ticking and wait to it take effect */  in npcx_itim_evt_isr()
232 	/* Return current value of 32-bit counter of event timer  */  in npcx_itim_get_evt_cyc32()
239 	uint8_t  sys_cts = evt_tmr->ITCTS32;  in npcx_itim_evt_elapsed_cyc32()
242 	/* Event has been triggered but timer ISR doesn't handle it */  in npcx_itim_evt_elapsed_cyc32()
246 		cnt2 = cyc_evt_timeout - cnt2 - 1;  in npcx_itim_evt_elapsed_cyc32()
249 	/* Return elapsed cycles of 32-bit counter of event timer  */  in npcx_itim_evt_elapsed_cyc32()
254 /* System timer api functions */
265 	/* Start a event timer in ticks */  in sys_clock_set_timeout()
280 	uint64_t delta_cycle = npcx_itim_get_sys_cyc64() - cyc_sys_announced;  in sys_clock_elapsed()
297 	/* Return how many cycles since system kernel timer start counting */  in sys_clock_cycle_get_32()
308 	/* Return how many cycles since system kernel timer start counting */  in sys_clock_cycle_get_64()
312 /* Platform specific system timer functions */
321 	uint32_t cyc_evt_elapsed_in_deep = npcx_itim_evt_elapsed_cyc32() -  in npcx_clock_compensate_system_timer()
342 		return -ENODEV;  in sys_clock_driver_init()
350 			LOG_ERR("Turn on timer %d clock failed.", i);  in sys_clock_driver_init()
356 	 * In npcx series, we use ITIM64 as system kernel timer. Its source  in sys_clock_driver_init()
369 		return -EINVAL;  in sys_clock_driver_init()
373 	 * Step 1. Use a ITIM64 timer as system kernel timer for counting.  in sys_clock_driver_init()
374 	 * Configure 64-bit timer counter and its prescaler to 1 first.  in sys_clock_driver_init()
376 	sys_tmr->ITPRE64 = 0;  in sys_clock_driver_init()
377 	sys_tmr->ITCNT64L = NPCX_ITIM64_MAX_HALF_CNT;  in sys_clock_driver_init()
378 	sys_tmr->ITCNT64H = NPCX_ITIM64_MAX_HALF_CNT;  in sys_clock_driver_init()
383 	sys_tmr->ITCTS64 = BIT(NPCX_ITCTSXX_TO_STS);  in sys_clock_driver_init()
384 	/* Enable 64-bit timer and start ticking */  in sys_clock_driver_init()
385 	sys_tmr->ITCTS64 |= BIT(NPCX_ITCTSXX_ITEN);  in sys_clock_driver_init()
388 	 * Step 2. Use a ITIM32 timer for event handling (ex. timeout event).  in sys_clock_driver_init()
389 	 * Configure 32-bit timer's prescaler to 1 first.  in sys_clock_driver_init()
391 	evt_tmr->ITPRE32 = 0;  in sys_clock_driver_init()
394 	 * interrupt/wake-up sources, and clear timeout status bit before  in sys_clock_driver_init()
397 	evt_tmr->ITCTS32 = BIT(NPCX_ITCTSXX_CKSEL) | BIT(NPCX_ITCTSXX_TO_WUE)  in sys_clock_driver_init()
403 	/* Configure event timer's ISR */  in sys_clock_driver_init()
406 	/* Enable event timer interrupt */  in sys_clock_driver_init()
410 		/* Start a event timer in one tick */  in sys_clock_driver_init()