MIPS: ralink: Add support for systick timer found on newer ralink SoC (1f2acc5a) · Commits · 戴 / test

arch/mips/ralink/Kconfig

+7 −0

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		if RALINK

		config CLKEVT_RT3352
		bool
		depends on SOC_RT305X \|\| SOC_MT7620
		default y
		select CLKSRC_OF
		select CLKSRC_MMIO

		choice
		prompt "Ralink SoC selection"
		default SOC_RT305X

arch/mips/ralink/Makefile

+2 −0

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		@@ -8,6 +8,8 @@

		obj-y := prom.o of.o reset.o clk.o irq.o timer.o

		obj-$(CONFIG_CLKEVT_RT3352) += cevt-rt3352.o

		obj-$(CONFIG_SOC_RT288X) += rt288x.o
		obj-$(CONFIG_SOC_RT305X) += rt305x.o
		obj-$(CONFIG_SOC_RT3883) += rt3883.o

arch/mips/ralink/cevt-rt3352.c

0 → 100644

+145 −0

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		/*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file "COPYING" in the main directory of this archive
		* for more details.
		*
		* Copyright (C) 2013 by John Crispin <blogic@openwrt.org>
		*/

		#include <linux/clockchips.h>
		#include <linux/clocksource.h>
		#include <linux/interrupt.h>
		#include <linux/reset.h>
		#include <linux/init.h>
		#include <linux/time.h>
		#include <linux/of.h>
		#include <linux/of_irq.h>
		#include <linux/of_address.h>

		#include <asm/mach-ralink/ralink_regs.h>

		#define SYSTICK_FREQ (50 * 1000)

		#define SYSTICK_CONFIG 0x00
		#define SYSTICK_COMPARE 0x04
		#define SYSTICK_COUNT 0x08

		/* route systick irq to mips irq 7 instead of the r4k-timer */
		#define CFG_EXT_STK_EN 0x2
		/* enable the counter */
		#define CFG_CNT_EN 0x1

		struct systick_device {
		void __iomem *membase;
		struct clock_event_device dev;
		int irq_requested;
		int freq_scale;
		};

		static void systick_set_clock_mode(enum clock_event_mode mode,
		struct clock_event_device *evt);

		static int systick_next_event(unsigned long delta,
		struct clock_event_device *evt)
		{
		struct systick_device *sdev;
		u32 count;

		sdev = container_of(evt, struct systick_device, dev);
		count = ioread32(sdev->membase + SYSTICK_COUNT);
		count = (count + delta) % SYSTICK_FREQ;
		iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);

		return 0;
		}

		static void systick_event_handler(struct clock_event_device *dev)
		{
		/* noting to do here */
		}

		static irqreturn_t systick_interrupt(int irq, void *dev_id)
		{
		struct clock_event_device dev = (struct clock_event_device ) dev_id;

		dev->event_handler(dev);

		return IRQ_HANDLED;
		}

		static struct systick_device systick = {
		.dev = {
		/*
		* cevt-r4k uses 300, make sure systick
		* gets used if available
		*/
		.rating = 310,
		.features = CLOCK_EVT_FEAT_ONESHOT,
		.set_next_event = systick_next_event,
		.set_mode = systick_set_clock_mode,
		.event_handler = systick_event_handler,
		},
		};

		static struct irqaction systick_irqaction = {
		.handler = systick_interrupt,
		.flags = IRQF_PERCPU \| IRQF_TIMER,
		.dev_id = &systick.dev,
		};

		static void systick_set_clock_mode(enum clock_event_mode mode,
		struct clock_event_device *evt)
		{
		struct systick_device *sdev;

		sdev = container_of(evt, struct systick_device, dev);

		switch (mode) {
		case CLOCK_EVT_MODE_ONESHOT:
		if (!sdev->irq_requested)
		setup_irq(systick.dev.irq, &systick_irqaction);
		sdev->irq_requested = 1;
		iowrite32(CFG_EXT_STK_EN \| CFG_CNT_EN,
		systick.membase + SYSTICK_CONFIG);
		break;

		case CLOCK_EVT_MODE_SHUTDOWN:
		if (sdev->irq_requested)
		free_irq(systick.dev.irq, &systick_irqaction);
		sdev->irq_requested = 0;
		iowrite32(0, systick.membase + SYSTICK_CONFIG);
		break;

		default:
		pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name);
		break;
		}
		}

		static void __init ralink_systick_init(struct device_node *np)
		{
		systick.membase = of_iomap(np, 0);
		if (!systick.membase)
		return;

		systick_irqaction.name = np->name;
		systick.dev.name = np->name;
		clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
		systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
		systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
		systick.dev.irq = irq_of_parse_and_map(np, 0);
		if (!systick.dev.irq) {
		pr_err("%s: request_irq failed", np->name);
		return;
		}

		clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
		SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);

		clockevents_register_device(&systick.dev);

		pr_info("%s: runing - mult: %d, shift: %d\n",
		np->name, systick.dev.mult, systick.dev.shift);
		}

		CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);

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