Commit 067bc914 authored by Baolin Wang's avatar Baolin Wang Committed by Ingo Molnar
Browse files

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: default avatarBaolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: default avatarPhilippe 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: default avatarIngo Molnar <mingo@kernel.org>
parent 286f30db

drivers/clocksource/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -441,6 +441,13 @@ config MTK_TIMER 
	help

	  Support for Mediatek timer driver.



config SPRD_TIMER

	bool "Spreadtrum timer driver" if COMPILE_TEST

	depends on HAS_IOMEM

	select TIMER_OF

	help

	  Enables support for the Spreadtrum timer driver.



config SYS_SUPPORTS_SH_MTU2

        bool

drivers/clocksource/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ obj-$(CONFIG_CLKSRC_TI_32K) += timer-ti-32k.o 
obj-$(CONFIG_CLKSRC_NPS)	+= timer-nps.o

obj-$(CONFIG_OXNAS_RPS_TIMER)	+= timer-oxnas-rps.o

obj-$(CONFIG_OWL_TIMER)		+= owl-timer.o

obj-$(CONFIG_SPRD_TIMER)	+= timer-sprd.o



obj-$(CONFIG_ARC_TIMERS)		+= arc_timer.o

obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o

drivers/clocksource/timer-sprd.c

0 → 100644
+159 −0
Original line number Diff line number Diff line 
// 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);

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