/* * Allwinner SoCs hstimer driver. * * Copyright (C) 2013 Maxime Ripard * * Maxime Ripard <maxime.ripard@free-electrons.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/clk.h> #include <linux/clockchips.h> #include <linux/clocksource.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/irqreturn.h> #include <linux/reset.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #define TIMER_IRQ_EN_REG 0x00 #define TIMER_IRQ_EN(val) BIT(val) #define TIMER_IRQ_ST_REG 0x04 #define TIMER_CTL_REG(val) (0x20 * (val) + 0x10) #define TIMER_CTL_ENABLE BIT(0) #define TIMER_CTL_RELOAD BIT(1) #define TIMER_CTL_CLK_PRES(val) (((val) & 0x7) << 4) #define TIMER_CTL_ONESHOT BIT(7) #define TIMER_INTVAL_LO_REG(val) (0x20 * (val) + 0x14) #define TIMER_INTVAL_HI_REG(val) (0x20 * (val) + 0x18) #define TIMER_CNTVAL_LO_REG(val) (0x20 * (val) + 0x1c) #define TIMER_CNTVAL_HI_REG(val) (0x20 * (val) + 0x20) #define TIMER_SYNC_TICKS 3 struct sun5i_timer { void __iomem *base; struct clk *clk; struct notifier_block clk_rate_cb; u32 ticks_per_jiffy; }; #define to_sun5i_timer(x) \ container_of(x, struct sun5i_timer, clk_rate_cb) struct sun5i_timer_clksrc { struct sun5i_timer timer; struct clocksource clksrc; }; #define to_sun5i_timer_clksrc(x) \ container_of(x, struct sun5i_timer_clksrc, clksrc) struct sun5i_timer_clkevt { struct sun5i_timer timer; struct clock_event_device clkevt; }; #define to_sun5i_timer_clkevt(x) \ container_of(x, struct sun5i_timer_clkevt, clkevt) /* * When we disable a timer, we need to wait at least for 2 cycles of * the timer source clock. We will use for that the clocksource timer * that is already setup and runs at the same frequency than the other * timers, and we never will be disabled. */ static void sun5i_clkevt_sync(struct sun5i_timer_clkevt *ce) { u32 old = readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1)); while ((old - readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS) cpu_relax(); } static void sun5i_clkevt_time_stop(struct sun5i_timer_clkevt *ce, u8 timer) { u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer)); writel(val & ~TIMER_CTL_ENABLE, ce->timer.base + TIMER_CTL_REG(timer)); sun5i_clkevt_sync(ce); } static void sun5i_clkevt_time_setup(struct sun5i_timer_clkevt *ce, u8 timer, u32 delay) { writel(delay, ce->timer.base + TIMER_INTVAL_LO_REG(timer)); } static void sun5i_clkevt_time_start(struct sun5i_timer_clkevt *ce, u8 timer, bool periodic) { u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer)); if (periodic) val &= ~TIMER_CTL_ONESHOT; else val |= TIMER_CTL_ONESHOT; writel(val | TIMER_CTL_ENABLE | TIMER_CTL_RELOAD, ce->timer.base + TIMER_CTL_REG(timer)); } static int sun5i_clkevt_shutdown(struct clock_event_device *clkevt) { struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); sun5i_clkevt_time_stop(ce, 0); return 0; } static int sun5i_clkevt_set_oneshot(struct clock_event_device *clkevt) { struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); sun5i_clkevt_time_stop(ce, 0); sun5i_clkevt_time_start(ce, 0, false); return 0; } static int sun5i_clkevt_set_periodic(struct clock_event_device *clkevt) { struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); sun5i_clkevt_time_stop(ce, 0); sun5i_clkevt_time_setup(ce, 0, ce->timer.ticks_per_jiffy); sun5i_clkevt_time_start(ce, 0, true); return 0; } static int sun5i_clkevt_next_event(unsigned long evt, struct clock_event_device *clkevt) { struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); sun5i_clkevt_time_stop(ce, 0); sun5i_clkevt_time_setup(ce, 0, evt - TIMER_SYNC_TICKS); sun5i_clkevt_time_start(ce, 0, false); return 0; } static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id) { struct sun5i_timer_clkevt *ce = (struct sun5i_timer_clkevt *)dev_id; writel(0x1, ce->timer.base + TIMER_IRQ_ST_REG); ce->clkevt.event_handler(&ce->clkevt); return IRQ_HANDLED; } static u64 sun5i_clksrc_read(struct clocksource *clksrc) { struct sun5i_timer_clksrc *cs = to_sun5i_timer_clksrc(clksrc); return ~readl(cs->timer.base + TIMER_CNTVAL_LO_REG(1)); } static int sun5i_rate_cb_clksrc(struct notifier_block *nb, unsigned long event, void *data) { struct clk_notifier_data *ndata = data; struct sun5i_timer *timer = to_sun5i_timer(nb); struct sun5i_timer_clksrc *cs = container_of(timer, struct sun5i_timer_clksrc, timer); switch (event) { case PRE_RATE_CHANGE: clocksource_unregister(&cs->clksrc); break; case POST_RATE_CHANGE: clocksource_register_hz(&cs->clksrc, ndata->new_rate); break; default: break; } return NOTIFY_DONE; } static int __init sun5i_setup_clocksource(struct device_node *node, void __iomem *base, struct clk *clk, int irq) { struct sun5i_timer_clksrc *cs; unsigned long rate; int ret; cs = kzalloc(sizeof(*cs), GFP_KERNEL); if (!cs) return -ENOMEM; ret = clk_prepare_enable(clk); if (ret) { pr_err("Couldn't enable parent clock\n"); goto err_free; } rate = clk_get_rate(clk); if (!rate) { pr_err("Couldn't get parent clock rate\n"); ret = -EINVAL; goto err_disable_clk; } cs->timer.base = base; cs->timer.clk = clk; cs->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clksrc; cs->timer.clk_rate_cb.next = NULL; ret = clk_notifier_register(clk, &cs->timer.clk_rate_cb); if (ret) { pr_err("Unable to register clock notifier.\n"); goto err_disable_clk; } writel(~0, base + TIMER_INTVAL_LO_REG(1)); writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD, base + TIMER_CTL_REG(1)); cs->clksrc.name = node->name; cs->clksrc.rating = 340; cs->clksrc.read = sun5i_clksrc_read; cs->clksrc.mask = CLOCKSOURCE_MASK(32); cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS; ret = clocksource_register_hz(&cs->clksrc, rate); if (ret) { pr_err("Couldn't register clock source.\n"); goto err_remove_notifier; } return 0; err_remove_notifier: clk_notifier_unregister(clk, &cs->timer.clk_rate_cb); err_disable_clk: clk_disable_unprepare(clk); err_free: kfree(cs); return ret; } static int sun5i_rate_cb_clkevt(struct notifier_block *nb, unsigned long event, void *data) { struct clk_notifier_data *ndata = data; struct sun5i_timer *timer = to_sun5i_timer(nb); struct sun5i_timer_clkevt *ce = container_of(timer, struct sun5i_timer_clkevt, timer); if (event == POST_RATE_CHANGE) { clockevents_update_freq(&ce->clkevt, ndata->new_rate); ce->timer.ticks_per_jiffy = DIV_ROUND_UP(ndata->new_rate, HZ); } return NOTIFY_DONE; } static int __init sun5i_setup_clockevent(struct device_node *node, void __iomem *base, struct clk *clk, int irq) { struct sun5i_timer_clkevt *ce; unsigned long rate; int ret; u32 val; ce = kzalloc(sizeof(*ce), GFP_KERNEL); if (!ce) return -ENOMEM; ret = clk_prepare_enable(clk); if (ret) { pr_err("Couldn't enable parent clock\n"); goto err_free; } rate = clk_get_rate(clk); if (!rate) { pr_err("Couldn't get parent clock rate\n"); ret = -EINVAL; goto err_disable_clk; } ce->timer.base = base; ce->timer.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ); ce->timer.clk = clk; ce->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clkevt; ce->timer.clk_rate_cb.next = NULL; ret = clk_notifier_register(clk, &ce->timer.clk_rate_cb); if (ret) { pr_err("Unable to register clock notifier.\n"); goto err_disable_clk; } ce->clkevt.name = node->name; ce->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; ce->clkevt.set_next_event = sun5i_clkevt_next_event; ce->clkevt.set_state_shutdown = sun5i_clkevt_shutdown; ce->clkevt.set_state_periodic = sun5i_clkevt_set_periodic; ce->clkevt.set_state_oneshot = sun5i_clkevt_set_oneshot; ce->clkevt.tick_resume = sun5i_clkevt_shutdown; ce->clkevt.rating = 340; ce->clkevt.irq = irq; ce->clkevt.cpumask = cpu_possible_mask; /* Enable timer0 interrupt */ val = readl(base + TIMER_IRQ_EN_REG); writel(val | TIMER_IRQ_EN(0), base + TIMER_IRQ_EN_REG); clockevents_config_and_register(&ce->clkevt, rate, TIMER_SYNC_TICKS, 0xffffffff); ret = request_irq(irq, sun5i_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, "sun5i_timer0", ce); if (ret) { pr_err("Unable to register interrupt\n"); goto err_remove_notifier; } return 0; err_remove_notifier: clk_notifier_unregister(clk, &ce->timer.clk_rate_cb); err_disable_clk: clk_disable_unprepare(clk); err_free: kfree(ce); return ret; } static int __init sun5i_timer_init(struct device_node *node) { struct reset_control *rstc; void __iomem *timer_base; struct clk *clk; int irq, ret; timer_base = of_io_request_and_map(node, 0, of_node_full_name(node)); if (IS_ERR(timer_base)) { pr_err("Can't map registers\n"); return PTR_ERR(timer_base); } irq = irq_of_parse_and_map(node, 0); if (irq <= 0) { pr_err("Can't parse IRQ\n"); return -EINVAL; } clk = of_clk_get(node, 0); if (IS_ERR(clk)) { pr_err("Can't get timer clock\n"); return PTR_ERR(clk); } rstc = of_reset_control_get(node, NULL); if (!IS_ERR(rstc)) reset_control_deassert(rstc); ret = sun5i_setup_clocksource(node, timer_base, clk, irq); if (ret) return ret; return sun5i_setup_clockevent(node, timer_base, clk, irq); } TIMER_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer", sun5i_timer_init); TIMER_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer", sun5i_timer_init);