powerpc/mpic: add global timer support (36ca09be) · Commits · 戴 / test

arch/powerpc/include/asm/mpic_timer.h

0 → 100644

+46 −0

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		/*
		* arch/powerpc/include/asm/mpic_timer.h
		*
		* Header file for Mpic Global Timer
		*
		* Copyright 2013 Freescale Semiconductor, Inc.
		*
		* Author: Wang Dongsheng <Dongsheng.Wang@freescale.com>
		* Li Yang <leoli@freescale.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of the GNU General Public License as published by the
		* Free Software Foundation; either version 2 of the License, or (at your
		* option) any later version.
		*/

		#ifndef __MPIC_TIMER__
		#define __MPIC_TIMER__

		#include <linux/interrupt.h>
		#include <linux/time.h>

		struct mpic_timer {
		void *dev;
		struct cascade_priv *cascade_handle;
		unsigned int num;
		unsigned int irq;
		};

		#ifdef CONFIG_MPIC_TIMER
		struct mpic_timer mpic_request_timer(irq_handler_t fn, void dev,
		const struct timeval *time);
		void mpic_start_timer(struct mpic_timer *handle);
		void mpic_stop_timer(struct mpic_timer *handle);
		void mpic_get_remain_time(struct mpic_timer handle, struct timeval time);
		void mpic_free_timer(struct mpic_timer *handle);
		#else
		struct mpic_timer mpic_request_timer(irq_handler_t fn, void dev,
		const struct timeval *time) { return NULL; }
		void mpic_start_timer(struct mpic_timer *handle) { }
		void mpic_stop_timer(struct mpic_timer *handle) { }
		void mpic_get_remain_time(struct mpic_timer handle, struct timeval time) { }
		void mpic_free_timer(struct mpic_timer *handle) { }
		#endif

		#endif

arch/powerpc/platforms/Kconfig

+12 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,18 @@ config MPIC
		bool
		default n

		config MPIC_TIMER
		bool "MPIC Global Timer"
		depends on MPIC && FSL_SOC
		default n
		help
		The MPIC global timer is a hardware timer inside the
		Freescale PIC complying with OpenPIC standard. When the
		specified interval times out, the hardware timer generates
		an interrupt. The driver currently is only tested on fsl
		chip, but it can potentially support other global timers
		complying with the OpenPIC standard.

		config PPC_EPAPR_HV_PIC
		bool
		default n

arch/powerpc/sysdev/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)

		mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o mpic_pasemi_msi.o
		obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y)
		obj-$(CONFIG_MPIC_TIMER) += mpic_timer.o
		mpic-msgr-obj-$(CONFIG_MPIC_MSGR) += mpic_msgr.o
		obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) $(mpic-msgr-obj-y)
		obj-$(CONFIG_PPC_EPAPR_HV_PIC) += ehv_pic.o

arch/powerpc/sysdev/mpic_timer.c

0 → 100644

+593 −0

Original line number	Diff line number	Diff line
		/*
		* MPIC timer driver
		*
		* Copyright 2013 Freescale Semiconductor, Inc.
		* Author: Dongsheng Wang <Dongsheng.Wang@freescale.com>
		* Li Yang <leoli@freescale.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of the GNU General Public License as published by the
		* Free Software Foundation; either version 2 of the License, or (at your
		* option) any later version.
		*/

		#include <linux/kernel.h>
		#include <linux/init.h>
		#include <linux/module.h>
		#include <linux/errno.h>
		#include <linux/mm.h>
		#include <linux/interrupt.h>
		#include <linux/slab.h>
		#include <linux/of.h>
		#include <linux/of_device.h>
		#include <linux/syscore_ops.h>
		#include <sysdev/fsl_soc.h>
		#include <asm/io.h>

		#include <asm/mpic_timer.h>

		#define FSL_GLOBAL_TIMER 0x1

		/* Clock Ratio
		* Divide by 64 0x00000300
		* Divide by 32 0x00000200
		* Divide by 16 0x00000100
		* Divide by 8 0x00000000 (Hardware default div)
		*/
		#define MPIC_TIMER_TCR_CLKDIV 0x00000300

		#define MPIC_TIMER_TCR_ROVR_OFFSET 24

		#define TIMER_STOP 0x80000000
		#define TIMERS_PER_GROUP 4
		#define MAX_TICKS (~0U >> 1)
		#define MAX_TICKS_CASCADE (~0U)
		#define TIMER_OFFSET(num) (1 << (TIMERS_PER_GROUP - 1 - num))

		/* tv_usec should be less than ONE_SECOND, otherwise use tv_sec */
		#define ONE_SECOND 1000000

		struct timer_regs {
		u32 gtccr;
		u32 res0[3];
		u32 gtbcr;
		u32 res1[3];
		u32 gtvpr;
		u32 res2[3];
		u32 gtdr;
		u32 res3[3];
		};

		struct cascade_priv {
		u32 tcr_value; /* TCR register: CASC & ROVR value */
		unsigned int cascade_map; /* cascade map */
		unsigned int timer_num; /* cascade control timer */
		};

		struct timer_group_priv {
		struct timer_regs __iomem *regs;
		struct mpic_timer timer[TIMERS_PER_GROUP];
		struct list_head node;
		unsigned int timerfreq;
		unsigned int idle;
		unsigned int flags;
		spinlock_t lock;
		void __iomem *group_tcr;
		};

		static struct cascade_priv cascade_timer[] = {
		/* cascade timer 0 and 1 */
		{0x1, 0xc, 0x1},
		/* cascade timer 1 and 2 */
		{0x2, 0x6, 0x2},
		/* cascade timer 2 and 3 */
		{0x4, 0x3, 0x3}
		};

		static LIST_HEAD(timer_group_list);

		static void convert_ticks_to_time(struct timer_group_priv *priv,
		const u64 ticks, struct timeval *time)
		{
		u64 tmp_sec;

		time->tv_sec = (__kernel_time_t)div_u64(ticks, priv->timerfreq);
		tmp_sec = (u64)time->tv_sec * (u64)priv->timerfreq;

		time->tv_usec = (__kernel_suseconds_t)
		div_u64((ticks - tmp_sec) * 1000000, priv->timerfreq);

		return;
		}

		/* the time set by the user is converted to "ticks" */
		static int convert_time_to_ticks(struct timer_group_priv *priv,
		const struct timeval time, u64 ticks)
		{
		u64 max_value; /* prevent u64 overflow */
		u64 tmp = 0;

		u64 tmp_sec;
		u64 tmp_ms;
		u64 tmp_us;

		max_value = div_u64(ULLONG_MAX, priv->timerfreq);

		if (time->tv_sec > max_value \|\|
		(time->tv_sec == max_value && time->tv_usec > 0))
		return -EINVAL;

		tmp_sec = (u64)time->tv_sec * (u64)priv->timerfreq;
		tmp += tmp_sec;

		tmp_ms = time->tv_usec / 1000;
		tmp_ms = div_u64((u64)tmp_ms * (u64)priv->timerfreq, 1000);
		tmp += tmp_ms;

		tmp_us = time->tv_usec % 1000;
		tmp_us = div_u64((u64)tmp_us * (u64)priv->timerfreq, 1000000);
		tmp += tmp_us;

		*ticks = tmp;

		return 0;
		}

		/* detect whether there is a cascade timer available */
		static struct mpic_timer *detect_idle_cascade_timer(
		struct timer_group_priv *priv)
		{
		struct cascade_priv *casc_priv;
		unsigned int map;
		unsigned int array_size = ARRAY_SIZE(cascade_timer);
		unsigned int num;
		unsigned int i;
		unsigned long flags;

		casc_priv = cascade_timer;
		for (i = 0; i < array_size; i++) {
		spin_lock_irqsave(&priv->lock, flags);
		map = casc_priv->cascade_map & priv->idle;
		if (map == casc_priv->cascade_map) {
		num = casc_priv->timer_num;
		priv->timer[num].cascade_handle = casc_priv;

		/* set timer busy */
		priv->idle &= ~casc_priv->cascade_map;
		spin_unlock_irqrestore(&priv->lock, flags);
		return &priv->timer[num];
		}
		spin_unlock_irqrestore(&priv->lock, flags);
		casc_priv++;
		}

		return NULL;
		}

		static int set_cascade_timer(struct timer_group_priv *priv, u64 ticks,
		unsigned int num)
		{
		struct cascade_priv *casc_priv;
		u32 tcr;
		u32 tmp_ticks;
		u32 rem_ticks;

		/* set group tcr reg for cascade */
		casc_priv = priv->timer[num].cascade_handle;
		if (!casc_priv)
		return -EINVAL;

		tcr = casc_priv->tcr_value \|
		(casc_priv->tcr_value << MPIC_TIMER_TCR_ROVR_OFFSET);
		setbits32(priv->group_tcr, tcr);

		tmp_ticks = div_u64_rem(ticks, MAX_TICKS_CASCADE, &rem_ticks);

		out_be32(&priv->regs[num].gtccr, 0);
		out_be32(&priv->regs[num].gtbcr, tmp_ticks \| TIMER_STOP);

		out_be32(&priv->regs[num - 1].gtccr, 0);
		out_be32(&priv->regs[num - 1].gtbcr, rem_ticks);

		return 0;
		}

		static struct mpic_timer get_cascade_timer(struct timer_group_priv priv,
		u64 ticks)
		{
		struct mpic_timer *allocated_timer;

		/* Two cascade timers: Support the maximum time */
		const u64 max_ticks = (u64)MAX_TICKS * (u64)MAX_TICKS_CASCADE;
		int ret;

		if (ticks > max_ticks)
		return NULL;

		/* detect idle timer */
		allocated_timer = detect_idle_cascade_timer(priv);
		if (!allocated_timer)
		return NULL;

		/* set ticks to timer */
		ret = set_cascade_timer(priv, ticks, allocated_timer->num);
		if (ret < 0)
		return NULL;

		return allocated_timer;
		}

		static struct mpic_timer get_timer(const struct timeval time)
		{
		struct timer_group_priv *priv;
		struct mpic_timer *timer;

		u64 ticks;
		unsigned int num;
		unsigned int i;
		unsigned long flags;
		int ret;

		list_for_each_entry(priv, &timer_group_list, node) {
		ret = convert_time_to_ticks(priv, time, &ticks);
		if (ret < 0)
		return NULL;

		if (ticks > MAX_TICKS) {
		if (!(priv->flags & FSL_GLOBAL_TIMER))
		return NULL;

		timer = get_cascade_timer(priv, ticks);
		if (!timer)
		continue;

		return timer;
		}

		for (i = 0; i < TIMERS_PER_GROUP; i++) {
		/* one timer: Reverse allocation */
		num = TIMERS_PER_GROUP - 1 - i;
		spin_lock_irqsave(&priv->lock, flags);
		if (priv->idle & (1 << i)) {
		/* set timer busy */
		priv->idle &= ~(1 << i);
		/* set ticks & stop timer */
		out_be32(&priv->regs[num].gtbcr,
		ticks \| TIMER_STOP);
		out_be32(&priv->regs[num].gtccr, 0);
		priv->timer[num].cascade_handle = NULL;
		spin_unlock_irqrestore(&priv->lock, flags);
		return &priv->timer[num];
		}
		spin_unlock_irqrestore(&priv->lock, flags);
		}
		}

		return NULL;
		}

		/**
		* mpic_start_timer - start hardware timer
		* @handle: the timer to be started.
		*
		* It will do ->fn(->dev) callback from the hardware interrupt at
		* the ->timeval point in the future.
		*/
		void mpic_start_timer(struct mpic_timer *handle)
		{
		struct timer_group_priv *priv = container_of(handle,
		struct timer_group_priv, timer[handle->num]);

		clrbits32(&priv->regs[handle->num].gtbcr, TIMER_STOP);
		}
		EXPORT_SYMBOL(mpic_start_timer);

		/**
		* mpic_stop_timer - stop hardware timer
		* @handle: the timer to be stoped
		*
		* The timer periodically generates an interrupt. Unless user stops the timer.
		*/
		void mpic_stop_timer(struct mpic_timer *handle)
		{
		struct timer_group_priv *priv = container_of(handle,
		struct timer_group_priv, timer[handle->num]);
		struct cascade_priv *casc_priv;

		setbits32(&priv->regs[handle->num].gtbcr, TIMER_STOP);

		casc_priv = priv->timer[handle->num].cascade_handle;
		if (casc_priv) {
		out_be32(&priv->regs[handle->num].gtccr, 0);
		out_be32(&priv->regs[handle->num - 1].gtccr, 0);
		} else {
		out_be32(&priv->regs[handle->num].gtccr, 0);
		}
		}
		EXPORT_SYMBOL(mpic_stop_timer);

		/**
		* mpic_get_remain_time - get timer time
		* @handle: the timer to be selected.
		* @time: time for timer
		*
		* Query timer remaining time.
		*/
		void mpic_get_remain_time(struct mpic_timer handle, struct timeval time)
		{
		struct timer_group_priv *priv = container_of(handle,
		struct timer_group_priv, timer[handle->num]);
		struct cascade_priv *casc_priv;

		u64 ticks;
		u32 tmp_ticks;

		casc_priv = priv->timer[handle->num].cascade_handle;
		if (casc_priv) {
		tmp_ticks = in_be32(&priv->regs[handle->num].gtccr);
		ticks = ((u64)tmp_ticks & UINT_MAX) * (u64)MAX_TICKS_CASCADE;
		tmp_ticks = in_be32(&priv->regs[handle->num - 1].gtccr);
		ticks += tmp_ticks;
		} else {
		ticks = in_be32(&priv->regs[handle->num].gtccr);
		}

		convert_ticks_to_time(priv, ticks, time);
		}
		EXPORT_SYMBOL(mpic_get_remain_time);

		/**
		* mpic_free_timer - free hardware timer
		* @handle: the timer to be removed.
		*
		* Free the timer.
		*
		* Note: can not be used in interrupt context.
		*/
		void mpic_free_timer(struct mpic_timer *handle)
		{
		struct timer_group_priv *priv = container_of(handle,
		struct timer_group_priv, timer[handle->num]);

		struct cascade_priv *casc_priv;
		unsigned long flags;

		mpic_stop_timer(handle);

		casc_priv = priv->timer[handle->num].cascade_handle;

		free_irq(priv->timer[handle->num].irq, priv->timer[handle->num].dev);

		spin_lock_irqsave(&priv->lock, flags);
		if (casc_priv) {
		u32 tcr;
		tcr = casc_priv->tcr_value \| (casc_priv->tcr_value <<
		MPIC_TIMER_TCR_ROVR_OFFSET);
		clrbits32(priv->group_tcr, tcr);
		priv->idle \|= casc_priv->cascade_map;
		priv->timer[handle->num].cascade_handle = NULL;
		} else {
		priv->idle \|= TIMER_OFFSET(handle->num);
		}
		spin_unlock_irqrestore(&priv->lock, flags);
		}
		EXPORT_SYMBOL(mpic_free_timer);

		/**
		* mpic_request_timer - get a hardware timer
		* @fn: interrupt handler function
		* @dev: callback function of the data
		* @time: time for timer
		*
		* This executes the "request_irq", returning NULL
		* else "handle" on success.
		*/
		struct mpic_timer mpic_request_timer(irq_handler_t fn, void dev,
		const struct timeval *time)
		{
		struct mpic_timer *allocated_timer;
		int ret;

		if (list_empty(&timer_group_list))
		return NULL;

		if (!(time->tv_sec + time->tv_usec) \|\|
		time->tv_sec < 0 \|\| time->tv_usec < 0)
		return NULL;

		if (time->tv_usec > ONE_SECOND)
		return NULL;

		allocated_timer = get_timer(time);
		if (!allocated_timer)
		return NULL;

		ret = request_irq(allocated_timer->irq, fn,
		IRQF_TRIGGER_LOW, "global-timer", dev);
		if (ret) {
		mpic_free_timer(allocated_timer);
		return NULL;
		}

		allocated_timer->dev = dev;

		return allocated_timer;
		}
		EXPORT_SYMBOL(mpic_request_timer);

		static int timer_group_get_freq(struct device_node *np,
		struct timer_group_priv *priv)
		{
		u32 div;

		if (priv->flags & FSL_GLOBAL_TIMER) {
		struct device_node *dn;

		dn = of_find_compatible_node(NULL, NULL, "fsl,mpic");
		if (dn) {
		of_property_read_u32(dn, "clock-frequency",
		&priv->timerfreq);
		of_node_put(dn);
		}
		}

		if (priv->timerfreq <= 0)
		return -EINVAL;

		if (priv->flags & FSL_GLOBAL_TIMER) {
		div = (1 << (MPIC_TIMER_TCR_CLKDIV >> 8)) * 8;
		priv->timerfreq /= div;
		}

		return 0;
		}

		static int timer_group_get_irq(struct device_node *np,
		struct timer_group_priv *priv)
		{
		const u32 all_timer[] = { 0, TIMERS_PER_GROUP };
		const u32 *p;
		u32 offset;
		u32 count;

		unsigned int i;
		unsigned int j;
		unsigned int irq_index = 0;
		unsigned int irq;
		int len;

		p = of_get_property(np, "fsl,available-ranges", &len);
		if (p && len % (2 * sizeof(u32)) != 0) {
		pr_err("%s: malformed available-ranges property.\n",
		np->full_name);
		return -EINVAL;
		}

		if (!p) {
		p = all_timer;
		len = sizeof(all_timer);
		}

		len /= 2 * sizeof(u32);

		for (i = 0; i < len; i++) {
		offset = p[i * 2];
		count = p[i * 2 + 1];
		for (j = 0; j < count; j++) {
		irq = irq_of_parse_and_map(np, irq_index);
		if (!irq) {
		pr_err("%s: irq parse and map failed.\n",
		np->full_name);
		return -EINVAL;
		}

		/* Set timer idle */
		priv->idle \|= TIMER_OFFSET((offset + j));
		priv->timer[offset + j].irq = irq;
		priv->timer[offset + j].num = offset + j;
		irq_index++;
		}
		}

		return 0;
		}

		static void timer_group_init(struct device_node *np)
		{
		struct timer_group_priv *priv;
		unsigned int i = 0;
		int ret;

		priv = kzalloc(sizeof(struct timer_group_priv), GFP_KERNEL);
		if (!priv) {
		pr_err("%s: cannot allocate memory for group.\n",
		np->full_name);
		return;
		}

		if (of_device_is_compatible(np, "fsl,mpic-global-timer"))
		priv->flags \|= FSL_GLOBAL_TIMER;

		priv->regs = of_iomap(np, i++);
		if (!priv->regs) {
		pr_err("%s: cannot ioremap timer register address.\n",
		np->full_name);
		goto out;
		}

		if (priv->flags & FSL_GLOBAL_TIMER) {
		priv->group_tcr = of_iomap(np, i++);
		if (!priv->group_tcr) {
		pr_err("%s: cannot ioremap tcr address.\n",
		np->full_name);
		goto out;
		}
		}

		ret = timer_group_get_freq(np, priv);
		if (ret < 0) {
		pr_err("%s: cannot get timer frequency.\n", np->full_name);
		goto out;
		}

		ret = timer_group_get_irq(np, priv);
		if (ret < 0) {
		pr_err("%s: cannot get timer irqs.\n", np->full_name);
		goto out;
		}

		spin_lock_init(&priv->lock);

		/* Init FSL timer hardware */
		if (priv->flags & FSL_GLOBAL_TIMER)
		setbits32(priv->group_tcr, MPIC_TIMER_TCR_CLKDIV);

		list_add_tail(&priv->node, &timer_group_list);

		return;

		out:
		if (priv->regs)
		iounmap(priv->regs);

		if (priv->group_tcr)
		iounmap(priv->group_tcr);

		kfree(priv);
		}

		static void mpic_timer_resume(void)
		{
		struct timer_group_priv *priv;

		list_for_each_entry(priv, &timer_group_list, node) {
		/* Init FSL timer hardware */
		if (priv->flags & FSL_GLOBAL_TIMER)
		setbits32(priv->group_tcr, MPIC_TIMER_TCR_CLKDIV);
		}
		}

		static const struct of_device_id mpic_timer_ids[] = {
		{ .compatible = "fsl,mpic-global-timer", },
		{},
		};

		static struct syscore_ops mpic_timer_syscore_ops = {
		.resume = mpic_timer_resume,
		};

		static int __init mpic_timer_init(void)
		{
		struct device_node *np = NULL;

		for_each_matching_node(np, mpic_timer_ids)
		timer_group_init(np);

		register_syscore_ops(&mpic_timer_syscore_ops);

		if (list_empty(&timer_group_list))
		return -ENODEV;

		return 0;
		}
		subsys_initcall(mpic_timer_init);

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