diff options
Diffstat (limited to 'drivers/clocksource/timer-rda.c')
| -rw-r--r-- | drivers/clocksource/timer-rda.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-rda.c b/drivers/clocksource/timer-rda.c new file mode 100644 index 0000000000..fd1199c189 --- /dev/null +++ b/drivers/clocksource/timer-rda.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * RDA8810PL SoC timer driver + * + * Copyright RDA Microelectronics Company Limited + * Copyright (c) 2017 Andreas Färber + * Copyright (c) 2018 Manivannan Sadhasivam + * + * RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER (64 bit). + * Each timer provides optional interrupt support. In this driver, OSTIMER is + * used for clockevents and HWTIMER is used for clocksource. + */ + +#include <linux/init.h> +#include <linux/interrupt.h> + +#include "timer-of.h" + +#define RDA_OSTIMER_LOADVAL_L 0x000 +#define RDA_OSTIMER_CTRL 0x004 +#define RDA_HWTIMER_LOCKVAL_L 0x024 +#define RDA_HWTIMER_LOCKVAL_H 0x028 +#define RDA_TIMER_IRQ_MASK_SET 0x02c +#define RDA_TIMER_IRQ_MASK_CLR 0x030 +#define RDA_TIMER_IRQ_CLR 0x034 + +#define RDA_OSTIMER_CTRL_ENABLE BIT(24) +#define RDA_OSTIMER_CTRL_REPEAT BIT(28) +#define RDA_OSTIMER_CTRL_LOAD BIT(30) + +#define RDA_TIMER_IRQ_MASK_OSTIMER BIT(0) + +#define RDA_TIMER_IRQ_CLR_OSTIMER BIT(0) + +static int rda_ostimer_start(void __iomem *base, bool periodic, u64 cycles) +{ + u32 ctrl, load_l; + + load_l = (u32)cycles; + ctrl = ((cycles >> 32) & 0xffffff); + ctrl |= RDA_OSTIMER_CTRL_LOAD | RDA_OSTIMER_CTRL_ENABLE; + if (periodic) + ctrl |= RDA_OSTIMER_CTRL_REPEAT; + + /* Enable ostimer interrupt first */ + writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER, + base + RDA_TIMER_IRQ_MASK_SET); + + /* Write low 32 bits first, high 24 bits are with ctrl */ + writel_relaxed(load_l, base + RDA_OSTIMER_LOADVAL_L); + writel_relaxed(ctrl, base + RDA_OSTIMER_CTRL); + + return 0; +} + +static int rda_ostimer_stop(void __iomem *base) +{ + /* Disable ostimer interrupt first */ + writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER, + base + RDA_TIMER_IRQ_MASK_CLR); + + writel_relaxed(0, base + RDA_OSTIMER_CTRL); + + return 0; +} + +static int rda_ostimer_set_state_shutdown(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + + rda_ostimer_stop(timer_of_base(to)); + + return 0; +} + +static int rda_ostimer_set_state_oneshot(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + + rda_ostimer_stop(timer_of_base(to)); + + return 0; +} + +static int rda_ostimer_set_state_periodic(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + unsigned long cycles_per_jiffy; + + rda_ostimer_stop(timer_of_base(to)); + + cycles_per_jiffy = ((unsigned long long)NSEC_PER_SEC / HZ * + evt->mult) >> evt->shift; + rda_ostimer_start(timer_of_base(to), true, cycles_per_jiffy); + + return 0; +} + +static int rda_ostimer_tick_resume(struct clock_event_device *evt) +{ + return 0; +} + +static int rda_ostimer_set_next_event(unsigned long evt, + struct clock_event_device *ev) +{ + struct timer_of *to = to_timer_of(ev); + + rda_ostimer_start(timer_of_base(to), false, evt); + + return 0; +} + +static irqreturn_t rda_ostimer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + struct timer_of *to = to_timer_of(evt); + + /* clear timer int */ + writel_relaxed(RDA_TIMER_IRQ_CLR_OSTIMER, + timer_of_base(to) + RDA_TIMER_IRQ_CLR); + + if (evt->event_handler) + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct timer_of rda_ostimer_of = { + .flags = TIMER_OF_IRQ | TIMER_OF_BASE, + + .clkevt = { + .name = "rda-ostimer", + .rating = 250, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_DYNIRQ, + .set_state_shutdown = rda_ostimer_set_state_shutdown, + .set_state_oneshot = rda_ostimer_set_state_oneshot, + .set_state_periodic = rda_ostimer_set_state_periodic, + .tick_resume = rda_ostimer_tick_resume, + .set_next_event = rda_ostimer_set_next_event, + }, + + .of_base = { + .name = "rda-timer", + .index = 0, + }, + + .of_irq = { + .name = "ostimer", + .handler = rda_ostimer_interrupt, + .flags = IRQF_TIMER, + }, +}; + +static u64 rda_hwtimer_read(struct clocksource *cs) +{ + void __iomem *base = timer_of_base(&rda_ostimer_of); + u32 lo, hi; + + /* Always read low 32 bits first */ + do { + lo = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_L); + hi = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H); + } while (hi != readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H)); + + return ((u64)hi << 32) | lo; +} + +static struct clocksource rda_hwtimer_clocksource = { + .name = "rda-timer", + .rating = 400, + .read = rda_hwtimer_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int __init rda_timer_init(struct device_node *np) +{ + unsigned long rate = 2000000; + int ret; + + ret = timer_of_init(np, &rda_ostimer_of); + if (ret) + return ret; + + clocksource_register_hz(&rda_hwtimer_clocksource, rate); + + clockevents_config_and_register(&rda_ostimer_of.clkevt, rate, + 0x2, UINT_MAX); + + return 0; +} + +TIMER_OF_DECLARE(rda8810pl, "rda,8810pl-timer", rda_timer_init); |