linux/drivers/clocksource/timer-sprd.c
Baolin Wang 067bc91447 clocksource/drivers/spreadtrum: Add timer driver for the Spreadtrum SC9860 platform
The Spreadtrum SC9860 platform will use the architected timers as local
clock events, but we also need a broadcast timer device to wake up the
CPUs when the CPUs are in sleep mode.

The Spreadtrum timer can support 32-bit or 64-bit counters, as well as
supporting period mode or one-shot mode.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1515418139-23276-8-git-send-email-daniel.lezcano@linaro.org
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-08 17:57:24 +01:00

160 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017 Spreadtrum Communications Inc.
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include "timer-of.h"
#define TIMER_NAME "sprd_timer"
#define TIMER_LOAD_LO 0x0
#define TIMER_LOAD_HI 0x4
#define TIMER_VALUE_LO 0x8
#define TIMER_VALUE_HI 0xc
#define TIMER_CTL 0x10
#define TIMER_CTL_PERIOD_MODE BIT(0)
#define TIMER_CTL_ENABLE BIT(1)
#define TIMER_CTL_64BIT_WIDTH BIT(16)
#define TIMER_INT 0x14
#define TIMER_INT_EN BIT(0)
#define TIMER_INT_RAW_STS BIT(1)
#define TIMER_INT_MASK_STS BIT(2)
#define TIMER_INT_CLR BIT(3)
#define TIMER_VALUE_SHDW_LO 0x18
#define TIMER_VALUE_SHDW_HI 0x1c
#define TIMER_VALUE_LO_MASK GENMASK(31, 0)
static void sprd_timer_enable(void __iomem *base, u32 flag)
{
u32 val = readl_relaxed(base + TIMER_CTL);
val |= TIMER_CTL_ENABLE;
if (flag & TIMER_CTL_64BIT_WIDTH)
val |= TIMER_CTL_64BIT_WIDTH;
else
val &= ~TIMER_CTL_64BIT_WIDTH;
if (flag & TIMER_CTL_PERIOD_MODE)
val |= TIMER_CTL_PERIOD_MODE;
else
val &= ~TIMER_CTL_PERIOD_MODE;
writel_relaxed(val, base + TIMER_CTL);
}
static void sprd_timer_disable(void __iomem *base)
{
u32 val = readl_relaxed(base + TIMER_CTL);
val &= ~TIMER_CTL_ENABLE;
writel_relaxed(val, base + TIMER_CTL);
}
static void sprd_timer_update_counter(void __iomem *base, unsigned long cycles)
{
writel_relaxed(cycles & TIMER_VALUE_LO_MASK, base + TIMER_LOAD_LO);
writel_relaxed(0, base + TIMER_LOAD_HI);
}
static void sprd_timer_enable_interrupt(void __iomem *base)
{
writel_relaxed(TIMER_INT_EN, base + TIMER_INT);
}
static void sprd_timer_clear_interrupt(void __iomem *base)
{
u32 val = readl_relaxed(base + TIMER_INT);
val |= TIMER_INT_CLR;
writel_relaxed(val, base + TIMER_INT);
}
static int sprd_timer_set_next_event(unsigned long cycles,
struct clock_event_device *ce)
{
struct timer_of *to = to_timer_of(ce);
sprd_timer_disable(timer_of_base(to));
sprd_timer_update_counter(timer_of_base(to), cycles);
sprd_timer_enable(timer_of_base(to), 0);
return 0;
}
static int sprd_timer_set_periodic(struct clock_event_device *ce)
{
struct timer_of *to = to_timer_of(ce);
sprd_timer_disable(timer_of_base(to));
sprd_timer_update_counter(timer_of_base(to), timer_of_period(to));
sprd_timer_enable(timer_of_base(to), TIMER_CTL_PERIOD_MODE);
return 0;
}
static int sprd_timer_shutdown(struct clock_event_device *ce)
{
struct timer_of *to = to_timer_of(ce);
sprd_timer_disable(timer_of_base(to));
return 0;
}
static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *ce = (struct clock_event_device *)dev_id;
struct timer_of *to = to_timer_of(ce);
sprd_timer_clear_interrupt(timer_of_base(to));
if (clockevent_state_oneshot(ce))
sprd_timer_disable(timer_of_base(to));
ce->event_handler(ce);
return IRQ_HANDLED;
}
static struct timer_of to = {
.flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
.clkevt = {
.name = TIMER_NAME,
.rating = 300,
.features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = sprd_timer_shutdown,
.set_state_periodic = sprd_timer_set_periodic,
.set_next_event = sprd_timer_set_next_event,
.cpumask = cpu_possible_mask,
},
.of_irq = {
.handler = sprd_timer_interrupt,
.flags = IRQF_TIMER | IRQF_IRQPOLL,
},
};
static int __init sprd_timer_init(struct device_node *np)
{
int ret;
ret = timer_of_init(np, &to);
if (ret)
return ret;
sprd_timer_enable_interrupt(timer_of_base(&to));
clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
1, UINT_MAX);
return 0;
}
TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);