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/* * A devfreq driver for NVIDIA Tegra SoCs * * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved. * Copyright (C) 2014 Google, Inc * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ #include <linux/clk.h>#include <linux/cpufreq.h>#include <linux/devfreq.h>#include <linux/interrupt.h>#include <linux/io.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/pm_opp.h>#include <linux/reset.h> #include "governor.h" #define ACTMON_GLB_STATUS					0x0#define ACTMON_GLB_PERIOD_CTRL					0x4 #define ACTMON_DEV_CTRL						0x0#define ACTMON_DEV_CTRL_K_VAL_SHIFT				10#define ACTMON_DEV_CTRL_ENB_PERIODIC				BIT(18)#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN			BIT(20)#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN			BIT(21)#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT	23#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT	26#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN		BIT(29)#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN		BIT(30)#define ACTMON_DEV_CTRL_ENB					BIT(31) #define ACTMON_DEV_UPPER_WMARK					0x4#define ACTMON_DEV_LOWER_WMARK					0x8#define ACTMON_DEV_INIT_AVG					0xc#define ACTMON_DEV_AVG_UPPER_WMARK				0x10#define ACTMON_DEV_AVG_LOWER_WMARK				0x14#define ACTMON_DEV_COUNT_WEIGHT					0x18#define ACTMON_DEV_AVG_COUNT					0x20#define ACTMON_DEV_INTR_STATUS					0x24 #define ACTMON_INTR_STATUS_CLEAR				0xffffffff #define ACTMON_DEV_INTR_CONSECUTIVE_UPPER			BIT(31)#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER			BIT(30) #define ACTMON_ABOVE_WMARK_WINDOW				1#define ACTMON_BELOW_WMARK_WINDOW				3#define ACTMON_BOOST_FREQ_STEP					16000 /* activity counter is incremented every 256 memory transactions, and each * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is * 4 * 256 = 1024. */#define ACTMON_COUNT_WEIGHT					0x400 /* * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128 */#define ACTMON_AVERAGE_WINDOW_LOG2			6#define ACTMON_SAMPLING_PERIOD				12 /* ms */#define ACTMON_DEFAULT_AVG_BAND				6  /* 1/10 of % */ #define KHZ							1000 /* Assume that the bus is saturated if the utilization is 25% */#define BUS_SATURATION_RATIO					25 /** * struct tegra_devfreq_device_config - configuration specific to an ACTMON * device * * Coefficients and thresholds are in % */struct tegra_devfreq_device_config {	u32		offset;	u32		irq_mask; 	unsigned int	boost_up_coeff;	unsigned int	boost_down_coeff;	unsigned int	boost_up_threshold;	unsigned int	boost_down_threshold;	u32		avg_dependency_threshold;}; enum tegra_actmon_device {	MCALL = 0,	MCCPU,}; static struct tegra_devfreq_device_config actmon_device_configs[] = {	{		/* MCALL */		.offset = 0x1c0,		.irq_mask = 1 << 26,		.boost_up_coeff = 200,		.boost_down_coeff = 50,		.boost_up_threshold = 60,		.boost_down_threshold = 40,	},	{		/* MCCPU */		.offset = 0x200,		.irq_mask = 1 << 25,		.boost_up_coeff = 800,		.boost_down_coeff = 90,		.boost_up_threshold = 27,		.boost_down_threshold = 10,		.avg_dependency_threshold = 50000,	},}; /** * struct tegra_devfreq_device - state specific to an ACTMON device * * Frequencies are in kHz. */struct tegra_devfreq_device {	const struct tegra_devfreq_device_config *config; 	void __iomem	*regs;	u32		avg_band_freq;	u32		avg_count; 	unsigned long	target_freq;	unsigned long	boost_freq;}; struct tegra_devfreq {	struct devfreq		*devfreq; 	struct platform_device	*pdev;	struct reset_control	*reset;	struct clk		*clock;	void __iomem		*regs; 	spinlock_t		lock; 	struct clk		*emc_clock;	unsigned long		max_freq;	unsigned long		cur_freq;	struct notifier_block	rate_change_nb; 	struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];}; struct tegra_actmon_emc_ratio {	unsigned long cpu_freq;	unsigned long emc_freq;}; static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {	{ 1400000, ULONG_MAX },	{ 1200000,    750000 },	{ 1100000,    600000 },	{ 1000000,    500000 },	{  800000,    375000 },	{  500000,    200000 },	{  250000,    100000 },}; static unsigned long do_percent(unsigned long val, unsigned int pct){	return val * pct / 100;} static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq_device *dev){	u32 avg = dev->avg_count;	u32 band = dev->avg_band_freq * ACTMON_SAMPLING_PERIOD; 	writel(avg + band, dev->regs + ACTMON_DEV_AVG_UPPER_WMARK);	avg = max(avg, band);	writel(avg - band, dev->regs + ACTMON_DEV_AVG_LOWER_WMARK);} static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,				       struct tegra_devfreq_device *dev){	u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; 	writel(do_percent(val, dev->config->boost_up_threshold),	       dev->regs + ACTMON_DEV_UPPER_WMARK); 	writel(do_percent(val, dev->config->boost_down_threshold),	       dev->regs + ACTMON_DEV_LOWER_WMARK);} static void actmon_write_barrier(struct tegra_devfreq *tegra){	/* ensure the update has reached the ACTMON */	wmb();	readl(tegra->regs + ACTMON_GLB_STATUS);} static irqreturn_t actmon_isr(int irq, void *data){	struct tegra_devfreq *tegra = data;	struct tegra_devfreq_device *dev = NULL;	unsigned long flags;	u32 val;	unsigned int i; 	val = readl(tegra->regs + ACTMON_GLB_STATUS); 	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {		if (val & tegra->devices[i].config->irq_mask) {			dev = tegra->devices + i;			break;		}	} 	if (!dev)		return IRQ_NONE; 	spin_lock_irqsave(&tegra->lock, flags); 	dev->avg_count = readl(dev->regs + ACTMON_DEV_AVG_COUNT);	tegra_devfreq_update_avg_wmark(dev); 	val = readl(dev->regs + ACTMON_DEV_INTR_STATUS);	if (val & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {		val = readl(dev->regs + ACTMON_DEV_CTRL) |			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 		/*		 * new_boost = min(old_boost * up_coef + step, max_freq)		 */		dev->boost_freq = do_percent(dev->boost_freq,					     dev->config->boost_up_coeff);		dev->boost_freq += ACTMON_BOOST_FREQ_STEP;		if (dev->boost_freq >= tegra->max_freq) {			dev->boost_freq = tegra->max_freq;			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;		}		writel(val, dev->regs + ACTMON_DEV_CTRL);	} else if (val & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {		val = readl(dev->regs + ACTMON_DEV_CTRL) |			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN; 		/*		 * new_boost = old_boost * down_coef		 * or 0 if (old_boost * down_coef < step / 2)		 */		dev->boost_freq = do_percent(dev->boost_freq,					     dev->config->boost_down_coeff);		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) {			dev->boost_freq = 0;			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;		}		writel(val, dev->regs + ACTMON_DEV_CTRL);	} 	if (dev->config->avg_dependency_threshold) {		val = readl(dev->regs + ACTMON_DEV_CTRL);		if (dev->avg_count >= dev->config->avg_dependency_threshold)			val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;		else if (dev->boost_freq == 0)			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;		writel(val, dev->regs + ACTMON_DEV_CTRL);	} 	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS); 	actmon_write_barrier(tegra); 	spin_unlock_irqrestore(&tegra->lock, flags); 	return IRQ_WAKE_THREAD;} static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,					    unsigned long cpu_freq){	unsigned int i;	struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios; 	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {		if (cpu_freq >= ratio->cpu_freq) {			if (ratio->emc_freq >= tegra->max_freq)				return tegra->max_freq;			else				return ratio->emc_freq;		}	} 	return 0;} static void actmon_update_target(struct tegra_devfreq *tegra,				 struct tegra_devfreq_device *dev){	unsigned long cpu_freq = 0;	unsigned long static_cpu_emc_freq = 0;	unsigned int avg_sustain_coef;	unsigned long flags; 	if (dev->config->avg_dependency_threshold) {		cpu_freq = cpufreq_get(0);		static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);	} 	spin_lock_irqsave(&tegra->lock, flags); 	dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;	avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;	dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);	dev->target_freq += dev->boost_freq; 	if (dev->avg_count >= dev->config->avg_dependency_threshold)		dev->target_freq = max(dev->target_freq, static_cpu_emc_freq); 	spin_unlock_irqrestore(&tegra->lock, flags);} static irqreturn_t actmon_thread_isr(int irq, void *data){	struct tegra_devfreq *tegra = data; 	mutex_lock(&tegra->devfreq->lock);	update_devfreq(tegra->devfreq);	mutex_unlock(&tegra->devfreq->lock); 	return IRQ_HANDLED;} static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,				       unsigned long action, void *ptr){	struct clk_notifier_data *data = ptr;	struct tegra_devfreq *tegra = container_of(nb, struct tegra_devfreq,						   rate_change_nb);	unsigned int i;	unsigned long flags; 	spin_lock_irqsave(&tegra->lock, flags); 	switch (action) {	case POST_RATE_CHANGE:		tegra->cur_freq = data->new_rate / KHZ; 		for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)			tegra_devfreq_update_wmark(tegra, tegra->devices + i); 		actmon_write_barrier(tegra);		break;	case PRE_RATE_CHANGE:		/* fall through */	case ABORT_RATE_CHANGE:		break;	}; 	spin_unlock_irqrestore(&tegra->lock, flags); 	return NOTIFY_OK;} static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,					  struct tegra_devfreq_device *dev){	u32 val; 	dev->avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;	dev->target_freq = tegra->cur_freq; 	dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;	writel(dev->avg_count, dev->regs + ACTMON_DEV_INIT_AVG); 	tegra_devfreq_update_avg_wmark(dev);	tegra_devfreq_update_wmark(tegra, dev); 	writel(ACTMON_COUNT_WEIGHT, dev->regs + ACTMON_DEV_COUNT_WEIGHT);	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS); 	val = 0;	val |= ACTMON_DEV_CTRL_ENB_PERIODIC |	       ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN |	       ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;	val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)		<< ACTMON_DEV_CTRL_K_VAL_SHIFT;	val |= (ACTMON_BELOW_WMARK_WINDOW - 1)		<< ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;	val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)		<< ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;	val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN |	       ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN; 	writel(val, dev->regs + ACTMON_DEV_CTRL); 	actmon_write_barrier(tegra); 	val = readl(dev->regs + ACTMON_DEV_CTRL);	val |= ACTMON_DEV_CTRL_ENB;	writel(val, dev->regs + ACTMON_DEV_CTRL); 	actmon_write_barrier(tegra);} static int tegra_devfreq_suspend(struct device *dev){	struct platform_device *pdev;	struct tegra_devfreq *tegra;	struct tegra_devfreq_device *actmon_dev;	unsigned int i;	u32 val; 	pdev = container_of(dev, struct platform_device, dev);	tegra = platform_get_drvdata(pdev); 	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {		actmon_dev = &tegra->devices[i]; 		val = readl(actmon_dev->regs + ACTMON_DEV_CTRL);		val &= ~ACTMON_DEV_CTRL_ENB;		writel(val, actmon_dev->regs + ACTMON_DEV_CTRL); 		writel(ACTMON_INTR_STATUS_CLEAR,		       actmon_dev->regs + ACTMON_DEV_INTR_STATUS); 		actmon_write_barrier(tegra);	} 	return 0;} static int tegra_devfreq_resume(struct device *dev){	struct platform_device *pdev;	struct tegra_devfreq *tegra;	struct tegra_devfreq_device *actmon_dev;	unsigned int i; 	pdev = container_of(dev, struct platform_device, dev);	tegra = platform_get_drvdata(pdev); 	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {		actmon_dev = &tegra->devices[i]; 		tegra_actmon_configure_device(tegra, actmon_dev);	} 	return 0;} static int tegra_devfreq_target(struct device *dev, unsigned long *freq,				u32 flags){	struct platform_device *pdev;	struct tegra_devfreq *tegra;	struct dev_pm_opp *opp;	unsigned long rate = *freq * KHZ; 	pdev = container_of(dev, struct platform_device, dev);	tegra = platform_get_drvdata(pdev); 	rcu_read_lock();	opp = devfreq_recommended_opp(dev, &rate, flags);	if (IS_ERR(opp)) {		rcu_read_unlock();		dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);		return PTR_ERR(opp);	}	rate = dev_pm_opp_get_freq(opp);	rcu_read_unlock(); 	/* TODO: Once we have per-user clk constraints, set a floor */	clk_set_rate(tegra->emc_clock, rate); 	/* TODO: Set voltage as well */ 	return 0;} static int tegra_devfreq_get_dev_status(struct device *dev,					struct devfreq_dev_status *stat){	struct platform_device *pdev;	struct tegra_devfreq *tegra;	struct tegra_devfreq_device *actmon_dev; 	pdev = container_of(dev, struct platform_device, dev);	tegra = platform_get_drvdata(pdev); 

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