diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/clocksource/timer-owl.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-owl.c b/drivers/clocksource/timer-owl.c new file mode 100644 index 000000000..ac97420bf --- /dev/null +++ b/drivers/clocksource/timer-owl.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Actions Semi Owl timer + * + * Copyright 2012 Actions Semi Inc. + * Author: Actions Semi, Inc. + * + * Copyright (c) 2017 SUSE Linux GmbH + * Author: Andreas Färber + */ + +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqreturn.h> +#include <linux/sched_clock.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#define OWL_Tx_CTL 0x0 +#define OWL_Tx_CMP 0x4 +#define OWL_Tx_VAL 0x8 + +#define OWL_Tx_CTL_PD BIT(0) +#define OWL_Tx_CTL_INTEN BIT(1) +#define OWL_Tx_CTL_EN BIT(2) + +static void __iomem *owl_timer_base; +static void __iomem *owl_clksrc_base; +static void __iomem *owl_clkevt_base; + +static inline void owl_timer_reset(void __iomem *base) +{ + writel(0, base + OWL_Tx_CTL); + writel(0, base + OWL_Tx_VAL); + writel(0, base + OWL_Tx_CMP); +} + +static inline void owl_timer_set_enabled(void __iomem *base, bool enabled) +{ + u32 ctl = readl(base + OWL_Tx_CTL); + + /* PD bit is cleared when set */ + ctl &= ~OWL_Tx_CTL_PD; + + if (enabled) + ctl |= OWL_Tx_CTL_EN; + else + ctl &= ~OWL_Tx_CTL_EN; + + writel(ctl, base + OWL_Tx_CTL); +} + +static u64 notrace owl_timer_sched_read(void) +{ + return (u64)readl(owl_clksrc_base + OWL_Tx_VAL); +} + +static int owl_timer_set_state_shutdown(struct clock_event_device *evt) +{ + owl_timer_set_enabled(owl_clkevt_base, false); + + return 0; +} + +static int owl_timer_set_state_oneshot(struct clock_event_device *evt) +{ + owl_timer_reset(owl_clkevt_base); + + return 0; +} + +static int owl_timer_tick_resume(struct clock_event_device *evt) +{ + return 0; +} + +static int owl_timer_set_next_event(unsigned long evt, + struct clock_event_device *ev) +{ + void __iomem *base = owl_clkevt_base; + + owl_timer_set_enabled(base, false); + writel(OWL_Tx_CTL_INTEN, base + OWL_Tx_CTL); + writel(0, base + OWL_Tx_VAL); + writel(evt, base + OWL_Tx_CMP); + owl_timer_set_enabled(base, true); + + return 0; +} + +static struct clock_event_device owl_clockevent = { + .name = "owl_tick", + .rating = 200, + .features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_DYNIRQ, + .set_state_shutdown = owl_timer_set_state_shutdown, + .set_state_oneshot = owl_timer_set_state_oneshot, + .tick_resume = owl_timer_tick_resume, + .set_next_event = owl_timer_set_next_event, +}; + +static irqreturn_t owl_timer1_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = (struct clock_event_device *)dev_id; + + writel(OWL_Tx_CTL_PD, owl_clkevt_base + OWL_Tx_CTL); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static int __init owl_timer_init(struct device_node *node) +{ + struct clk *clk; + unsigned long rate; + int timer1_irq, ret; + + owl_timer_base = of_io_request_and_map(node, 0, "owl-timer"); + if (IS_ERR(owl_timer_base)) { + pr_err("Can't map timer registers\n"); + return PTR_ERR(owl_timer_base); + } + + owl_clksrc_base = owl_timer_base + 0x08; + owl_clkevt_base = owl_timer_base + 0x14; + + timer1_irq = of_irq_get_byname(node, "timer1"); + if (timer1_irq <= 0) { + pr_err("Can't parse timer1 IRQ\n"); + return -EINVAL; + } + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) { + ret = PTR_ERR(clk); + pr_err("Failed to get clock for clocksource (%d)\n", ret); + return ret; + } + + rate = clk_get_rate(clk); + + owl_timer_reset(owl_clksrc_base); + owl_timer_set_enabled(owl_clksrc_base, true); + + sched_clock_register(owl_timer_sched_read, 32, rate); + ret = clocksource_mmio_init(owl_clksrc_base + OWL_Tx_VAL, node->name, + rate, 200, 32, clocksource_mmio_readl_up); + if (ret) { + pr_err("Failed to register clocksource (%d)\n", ret); + return ret; + } + + owl_timer_reset(owl_clkevt_base); + + ret = request_irq(timer1_irq, owl_timer1_interrupt, IRQF_TIMER, + "owl-timer", &owl_clockevent); + if (ret) { + pr_err("failed to request irq %d\n", timer1_irq); + return ret; + } + + owl_clockevent.cpumask = cpumask_of(0); + owl_clockevent.irq = timer1_irq; + + clockevents_config_and_register(&owl_clockevent, rate, + 0xf, 0xffffffff); + + return 0; +} +TIMER_OF_DECLARE(owl_s500, "actions,s500-timer", owl_timer_init); +TIMER_OF_DECLARE(owl_s700, "actions,s700-timer", owl_timer_init); +TIMER_OF_DECLARE(owl_s900, "actions,s900-timer", owl_timer_init); |