/* * Rockchip timer support * * Copyright (C) Daniel Lezcano <daniel.lezcano@linaro.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/clk.h> #include <linux/clockchips.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/sched_clock.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #define TIMER_NAME "rk_timer" #define TIMER_LOAD_COUNT0 0x00 #define TIMER_LOAD_COUNT1 0x04 #define TIMER_CURRENT_VALUE0 0x08 #define TIMER_CURRENT_VALUE1 0x0C #define TIMER_CONTROL_REG3288 0x10 #define TIMER_CONTROL_REG3399 0x1c #define TIMER_INT_STATUS 0x18 #define TIMER_DISABLE 0x0 #define TIMER_ENABLE 0x1 #define TIMER_MODE_FREE_RUNNING (0 << 1) #define TIMER_MODE_USER_DEFINED_COUNT (1 << 1) #define TIMER_INT_UNMASK (1 << 2) struct rk_timer { void __iomem *base; void __iomem *ctrl; struct clk *clk; struct clk *pclk; u32 freq; int irq; }; struct rk_clkevt { struct clock_event_device ce; struct rk_timer timer; }; static struct rk_clkevt *rk_clkevt; static struct rk_timer *rk_clksrc; static inline struct rk_timer *rk_timer(struct clock_event_device *ce) { return &container_of(ce, struct rk_clkevt, ce)->timer; } static inline void rk_timer_disable(struct rk_timer *timer) { writel_relaxed(TIMER_DISABLE, timer->ctrl); } static inline void rk_timer_enable(struct rk_timer *timer, u32 flags) { writel_relaxed(TIMER_ENABLE | flags, timer->ctrl); } static void rk_timer_update_counter(unsigned long cycles, struct rk_timer *timer) { writel_relaxed(cycles, timer->base + TIMER_LOAD_COUNT0); writel_relaxed(0, timer->base + TIMER_LOAD_COUNT1); } static void rk_timer_interrupt_clear(struct rk_timer *timer) { writel_relaxed(1, timer->base + TIMER_INT_STATUS); } static inline int rk_timer_set_next_event(unsigned long cycles, struct clock_event_device *ce) { struct rk_timer *timer = rk_timer(ce); rk_timer_disable(timer); rk_timer_update_counter(cycles, timer); rk_timer_enable(timer, TIMER_MODE_USER_DEFINED_COUNT | TIMER_INT_UNMASK); return 0; } static int rk_timer_shutdown(struct clock_event_device *ce) { struct rk_timer *timer = rk_timer(ce); rk_timer_disable(timer); return 0; } static int rk_timer_set_periodic(struct clock_event_device *ce) { struct rk_timer *timer = rk_timer(ce); rk_timer_disable(timer); rk_timer_update_counter(timer->freq / HZ - 1, timer); rk_timer_enable(timer, TIMER_MODE_FREE_RUNNING | TIMER_INT_UNMASK); return 0; } static irqreturn_t rk_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *ce = dev_id; struct rk_timer *timer = rk_timer(ce); rk_timer_interrupt_clear(timer); if (clockevent_state_oneshot(ce)) rk_timer_disable(timer); ce->event_handler(ce); return IRQ_HANDLED; } static u64 notrace rk_timer_sched_read(void) { return ~readl_relaxed(rk_clksrc->base + TIMER_CURRENT_VALUE0); } static int __init rk_timer_probe(struct rk_timer *timer, struct device_node *np) { struct clk *timer_clk; struct clk *pclk; int ret = -EINVAL, irq; u32 ctrl_reg = TIMER_CONTROL_REG3288; timer->base = of_iomap(np, 0); if (!timer->base) { pr_err("Failed to get base address for '%s'\n", TIMER_NAME); return -ENXIO; } if (of_device_is_compatible(np, "rockchip,rk3399-timer")) ctrl_reg = TIMER_CONTROL_REG3399; timer->ctrl = timer->base + ctrl_reg; pclk = of_clk_get_by_name(np, "pclk"); if (IS_ERR(pclk)) { ret = PTR_ERR(pclk); pr_err("Failed to get pclk for '%s'\n", TIMER_NAME); goto out_unmap; } ret = clk_prepare_enable(pclk); if (ret) { pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME); goto out_unmap; } timer->pclk = pclk; timer_clk = of_clk_get_by_name(np, "timer"); if (IS_ERR(timer_clk)) { ret = PTR_ERR(timer_clk); pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME); goto out_timer_clk; } ret = clk_prepare_enable(timer_clk); if (ret) { pr_err("Failed to enable timer clock\n"); goto out_timer_clk; } timer->clk = timer_clk; timer->freq = clk_get_rate(timer_clk); irq = irq_of_parse_and_map(np, 0); if (!irq) { ret = -EINVAL; pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME); goto out_irq; } timer->irq = irq; rk_timer_interrupt_clear(timer); rk_timer_disable(timer); return 0; out_irq: clk_disable_unprepare(timer_clk); out_timer_clk: clk_disable_unprepare(pclk); out_unmap: iounmap(timer->base); return ret; } static void __init rk_timer_cleanup(struct rk_timer *timer) { clk_disable_unprepare(timer->clk); clk_disable_unprepare(timer->pclk); iounmap(timer->base); } static int __init rk_clkevt_init(struct device_node *np) { struct clock_event_device *ce; int ret = -EINVAL; rk_clkevt = kzalloc(sizeof(struct rk_clkevt), GFP_KERNEL); if (!rk_clkevt) { ret = -ENOMEM; goto out; } ret = rk_timer_probe(&rk_clkevt->timer, np); if (ret) goto out_probe; ce = &rk_clkevt->ce; ce->name = TIMER_NAME; ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ; ce->set_next_event = rk_timer_set_next_event; ce->set_state_shutdown = rk_timer_shutdown; ce->set_state_periodic = rk_timer_set_periodic; ce->irq = rk_clkevt->timer.irq; ce->cpumask = cpu_possible_mask; ce->rating = 250; ret = request_irq(rk_clkevt->timer.irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce); if (ret) { pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret); goto out_irq; } clockevents_config_and_register(&rk_clkevt->ce, rk_clkevt->timer.freq, 1, UINT_MAX); return 0; out_irq: rk_timer_cleanup(&rk_clkevt->timer); out_probe: kfree(rk_clkevt); out: /* Leave rk_clkevt not NULL to prevent future init */ rk_clkevt = ERR_PTR(ret); return ret; } static int __init rk_clksrc_init(struct device_node *np) { int ret = -EINVAL; rk_clksrc = kzalloc(sizeof(struct rk_timer), GFP_KERNEL); if (!rk_clksrc) { ret = -ENOMEM; goto out; } ret = rk_timer_probe(rk_clksrc, np); if (ret) goto out_probe; rk_timer_update_counter(UINT_MAX, rk_clksrc); rk_timer_enable(rk_clksrc, 0); ret = clocksource_mmio_init(rk_clksrc->base + TIMER_CURRENT_VALUE0, TIMER_NAME, rk_clksrc->freq, 250, 32, clocksource_mmio_readl_down); if (ret) { pr_err("Failed to register clocksource\n"); goto out_clocksource; } sched_clock_register(rk_timer_sched_read, 32, rk_clksrc->freq); return 0; out_clocksource: rk_timer_cleanup(rk_clksrc); out_probe: kfree(rk_clksrc); out: /* Leave rk_clksrc not NULL to prevent future init */ rk_clksrc = ERR_PTR(ret); return ret; } static int __init rk_timer_init(struct device_node *np) { if (!rk_clkevt) return rk_clkevt_init(np); if (!rk_clksrc) return rk_clksrc_init(np); pr_err("Too many timer definitions for '%s'\n", TIMER_NAME); return -EINVAL; } TIMER_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer", rk_timer_init); TIMER_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer", rk_timer_init);