[ARM] 4374/3: i.MX/MX1 clock event source (89bba435) · Commits · e / devices / android_kernel_teracube_emerald

arch/arm/Kconfig

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -242,6 +242,8 @@ config ARCH_H720X
	config ARCH_IMX		config ARCH_IMX
	bool "IMX"		bool "IMX"
	select GENERIC_GPIO		select GENERIC_GPIO
			select GENERIC_TIME
			select GENERIC_CLOCKEVENTS
	help		help
	Support for Motorola's i.MX family of processors (MX1, MXL).		Support for Motorola's i.MX family of processors (MX1, MXL).

arch/arm/mach-imx/time.c

+107 −14

Original line number	Original line	Diff line number	Diff line
	@@ -3,6 +3,7 @@
	*		*
	* Copyright (C) 2000-2001 Deep Blue Solutions		* Copyright (C) 2000-2001 Deep Blue Solutions
	* Copyright (C) 2002 Shane Nay (shane@minirl.com)		* Copyright (C) 2002 Shane Nay (shane@minirl.com)
			* Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com)
	*		*
	* This program is free software; you can redistribute it and/or modify		* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as		* it under the terms of the GNU General Public License version 2 as
	@@ -15,6 +16,7 @@
	#include <linux/irq.h>		#include <linux/irq.h>
	#include <linux/time.h>		#include <linux/time.h>
	#include <linux/clocksource.h>		#include <linux/clocksource.h>
			#include <linux/clockchips.h>

	#include <asm/hardware.h>		#include <asm/hardware.h>
	#include <asm/io.h>		#include <asm/io.h>
	@@ -25,7 +27,8 @@
	/* Use timer 1 as system timer */		/* Use timer 1 as system timer */
	#define TIMER_BASE IMX_TIM1_BASE		#define TIMER_BASE IMX_TIM1_BASE

	static unsigned long evt_diff;		static struct clock_event_device clockevent_imx;
			static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED;

	/*		/*
	* IRQ handler for the timer		* IRQ handler for the timer
	@@ -33,25 +36,20 @@ static unsigned long evt_diff;
	static irqreturn_t		static irqreturn_t
	imx_timer_interrupt(int irq, void *dev_id)		imx_timer_interrupt(int irq, void *dev_id)
	{		{
			struct clock_event_device *evt = &clockevent_imx;
	uint32_t tstat;		uint32_t tstat;
			irqreturn_t ret = IRQ_NONE;

	/* clear the interrupt */		/* clear the interrupt */
	tstat = IMX_TSTAT(TIMER_BASE);		tstat = IMX_TSTAT(TIMER_BASE);
	IMX_TSTAT(TIMER_BASE) = 0;		IMX_TSTAT(TIMER_BASE) = 0;

	if (tstat & TSTAT_COMP) {		if (tstat & TSTAT_COMP) {
	do {		evt->event_handler(evt);
			ret = IRQ_HANDLED;
	write_seqlock(&xtime_lock);
	timer_tick();
	write_sequnlock(&xtime_lock);
	IMX_TCMP(TIMER_BASE) += evt_diff;

	} while (unlikely((int32_t)(IMX_TCMP(TIMER_BASE)
	- IMX_TCN(TIMER_BASE)) < 0));
	}		}

	return IRQ_HANDLED;		return ret;
	}		}

	static struct irqaction imx_timer_irq = {		static struct irqaction imx_timer_irq = {
	@@ -70,10 +68,8 @@ static void __init imx_timer_hardware_init(void)
	*/		*/
	IMX_TCTL(TIMER_BASE) = 0;		IMX_TCTL(TIMER_BASE) = 0;
	IMX_TPRER(TIMER_BASE) = 0;		IMX_TPRER(TIMER_BASE) = 0;
	IMX_TCMP(TIMER_BASE) = LATCH - 1;

	IMX_TCTL(TIMER_BASE) = TCTL_FRR \| TCTL_CLK_PCLK1 \| TCTL_IRQEN \| TCTL_TEN;		IMX_TCTL(TIMER_BASE) = TCTL_FRR \| TCTL_CLK_PCLK1 \| TCTL_TEN;
	evt_diff = LATCH;
	}		}

	cycle_t imx_get_cycles(void)		cycle_t imx_get_cycles(void)
	@@ -99,11 +95,108 @@ static int __init imx_clocksource_init(void)
	return 0;		return 0;
	}		}

			static int imx_set_next_event(unsigned long evt,
			struct clock_event_device *unused)
			{
			unsigned long tcmp;

			tcmp = IMX_TCN(TIMER_BASE) + evt;
			IMX_TCMP(TIMER_BASE) = tcmp;

			return (int32_t)(tcmp - IMX_TCN(TIMER_BASE)) < 0 ? -ETIME : 0;
			}

			#ifdef DEBUG
			static const char *clock_event_mode_label[]={
			[CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC",
			[CLOCK_EVT_MODE_ONESHOT] = "CLOCK_EVT_MODE_ONESHOT",
			[CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN",
			[CLOCK_EVT_MODE_UNUSED] = "CLOCK_EVT_MODE_UNUSED"
			};
			#endif /DEBUG/

			static void imx_set_mode(enum clock_event_mode mode, struct clock_event_device *evt)
			{
			unsigned long flags;

			/*
			* The timer interrupt generation is disabled at least
			* for enough time to call imx_set_next_event()
			*/
			local_irq_save(flags);
			/* Disable interrupt in GPT module */
			IMX_TCTL(TIMER_BASE) &= ~TCTL_IRQEN;
			if (mode != clockevent_mode) {
			/* Set event time into far-far future */
			IMX_TCMP(TIMER_BASE) = IMX_TCN(TIMER_BASE) - 3;
			/* Clear pending interrupt */
			IMX_TSTAT(TIMER_BASE) &= ~TSTAT_COMP;
			}

			#ifdef DEBUG
			printk(KERN_INFO "imx_set_mode: changing mode from %s to %s\n",
			clock_event_mode_label[clockevent_mode], clock_event_mode_label[mode]);
			#endif /DEBUG/

			/* Remember timer mode */
			clockevent_mode = mode;
			local_irq_restore(flags);

			switch (mode) {
			case CLOCK_EVT_MODE_PERIODIC:
			printk(KERN_ERR "imx_set_mode: Periodic mode is not supported for i.MX\n");
			break;
			case CLOCK_EVT_MODE_ONESHOT:
			/*
			* Do not put overhead of interrupt enable/disable into
			* imx_set_next_event(), the core has about 4 minutes
			* to call imx_set_next_event() or shutdown clock after
			* mode switching
			*/
			local_irq_save(flags);
			IMX_TCTL(TIMER_BASE) \|= TCTL_IRQEN;
			local_irq_restore(flags);
			break;
			case CLOCK_EVT_MODE_SHUTDOWN:
			case CLOCK_EVT_MODE_UNUSED:
			/* Left event sources disabled, no more interrupts appears */
			break;
			}
			}

			static struct clock_event_device clockevent_imx = {
			.name = "imx_timer1",
			.features = CLOCK_EVT_FEAT_ONESHOT,
			.shift = 32,
			.set_mode = imx_set_mode,
			.set_next_event = imx_set_next_event,
			.rating = 200,
			};

			static int __init imx_clockevent_init(void)
			{
			clockevent_imx.mult = div_sc(imx_get_perclk1(), NSEC_PER_SEC,
			clockevent_imx.shift);
			clockevent_imx.max_delta_ns =
			clockevent_delta2ns(0xfffffffe, &clockevent_imx);
			clockevent_imx.min_delta_ns =
			clockevent_delta2ns(0xf, &clockevent_imx);

			clockevent_imx.cpumask = cpumask_of_cpu(0);

			clockevents_register_device(&clockevent_imx);

			return 0;
			}


	static void __init imx_timer_init(void)		static void __init imx_timer_init(void)
	{		{
	imx_timer_hardware_init();		imx_timer_hardware_init();
	imx_clocksource_init();		imx_clocksource_init();

			imx_clockevent_init();

	/*		/*
	* Make irqs happen for the system timer		* Make irqs happen for the system timer
	*/		*/