// SPDX-License-Identifier: GPL-2.0+ // // Copyright 2017-2019 NXP #include <linux/interrupt.h> #include <linux/clockchips.h> #include "timer-of.h" #define CMP_OFFSET 0x10000 #define CNTCV_LO 0x8 #define CNTCV_HI 0xc #define CMPCV_LO (CMP_OFFSET + 0x20) #define CMPCV_HI (CMP_OFFSET + 0x24) #define CMPCR (CMP_OFFSET + 0x2c) #define SYS_CTR_EN 0x1 #define SYS_CTR_IRQ_MASK 0x2 #define SYS_CTR_CLK_DIV 0x3 static void __iomem *sys_ctr_base __ro_after_init; static u32 cmpcr __ro_after_init; static void sysctr_timer_enable(bool enable) { writel(enable ? cmpcr | SYS_CTR_EN : cmpcr, sys_ctr_base + CMPCR); } static void sysctr_irq_acknowledge(void) { /* * clear the enable bit(EN =0) will clear * the status bit(ISTAT = 0), then the interrupt * signal will be negated(acknowledged). */ sysctr_timer_enable(false); } static inline u64 sysctr_read_counter(void) { u32 cnt_hi, tmp_hi, cnt_lo; do { cnt_hi = readl_relaxed(sys_ctr_base + CNTCV_HI); cnt_lo = readl_relaxed(sys_ctr_base + CNTCV_LO); tmp_hi = readl_relaxed(sys_ctr_base + CNTCV_HI); } while (tmp_hi != cnt_hi); return ((u64) cnt_hi << 32) | cnt_lo; } static int sysctr_set_next_event(unsigned long delta, struct clock_event_device *evt) { u32 cmp_hi, cmp_lo; u64 next; sysctr_timer_enable(false); next = sysctr_read_counter(); next += delta; cmp_hi = (next >> 32) & 0x00fffff; cmp_lo = next & 0xffffffff; writel_relaxed(cmp_hi, sys_ctr_base + CMPCV_HI); writel_relaxed(cmp_lo, sys_ctr_base + CMPCV_LO); sysctr_timer_enable(true); return 0; } static int sysctr_set_state_oneshot(struct clock_event_device *evt) { return 0; } static int sysctr_set_state_shutdown(struct clock_event_device *evt) { sysctr_timer_enable(false); return 0; } static irqreturn_t sysctr_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; sysctr_irq_acknowledge(); evt->event_handler(evt); return IRQ_HANDLED; } static struct timer_of to_sysctr = { .flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE, .clkevt = { .name = "i.MX system counter timer", .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ, .set_state_oneshot = sysctr_set_state_oneshot, .set_next_event = sysctr_set_next_event, .set_state_shutdown = sysctr_set_state_shutdown, .rating = 200, }, .of_irq = { .handler = sysctr_timer_interrupt, .flags = IRQF_TIMER, }, .of_clk = { .name = "per", }, }; static void __init sysctr_clockevent_init(void) { to_sysctr.clkevt.cpumask = cpu_possible_mask; clockevents_config_and_register(&to_sysctr.clkevt, timer_of_rate(&to_sysctr), 0xff, 0x7fffffff); } static int __init sysctr_timer_init(struct device_node *np) { int ret = 0; ret = timer_of_init(np, &to_sysctr); if (ret) return ret; if (!of_property_read_bool(np, "nxp,no-divider")) { /* system counter clock is divided by 3 internally */ to_sysctr.of_clk.rate /= SYS_CTR_CLK_DIV; } sys_ctr_base = timer_of_base(&to_sysctr); cmpcr = readl(sys_ctr_base + CMPCR); cmpcr &= ~SYS_CTR_EN; sysctr_clockevent_init(); return 0; } TIMER_OF_DECLARE(sysctr_timer, "nxp,sysctr-timer", sysctr_timer_init);