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// 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);
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