From: 黄涛 <huangtao@rock-chips.com>
Date: Mon, 25 Jul 2011 08:56:19 +0000 (+0800)
Subject: rk29: cpufreq: support limit by voltage
X-Git-Tag: firefly_0821_release~10089^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3f5a33e9340b25e4af564732af10e7a7df273530;p=firefly-linux-kernel-4.4.55.git

rk29: cpufreq: support limit by voltage
---

diff --git a/arch/arm/mach-rk29/clock.c b/arch/arm/mach-rk29/clock.c
index baab5952c556..524882ff2999 100755
--- a/arch/arm/mach-rk29/clock.c
+++ b/arch/arm/mach-rk29/clock.c
@@ -303,40 +303,12 @@ static struct clk otgphy1_clkin = {
 
 static noinline void delay_500ns(void)
 {
-	if (system_state == SYSTEM_BOOTING) {
-		LOOP(LOOPS_PER_USEC * 1200 / 24);
-	} else {
-		udelay(1);
-	}
+	udelay(1);
 }
 
 static noinline void delay_300us(void)
 {
-	if (system_state == SYSTEM_BOOTING) {
-		LOOP(LOOPS_PER_MSEC * 1200 / 24);
-	} else {
-		mdelay(1);
-	}
-}
-
-static noinline void arm_delay_500ns(void)
-{
-	static unsigned long loops = 0;
-	if (!loops) {
-		loops = general_pll_clk.rate / MHZ;
-		loops = loops * LOOPS_PER_USEC / 24;
-	}
-	LOOP(loops);
-}
-
-static noinline void arm_delay_300us(void)
-{
-	static unsigned long loops = 0;
-	if (!loops) {
-		loops = general_pll_clk.rate / MHZ;
-		loops = loops * LOOPS_PER_MSEC / 24;
-	}
-	LOOP(loops);
+	udelay(300);
 }
 
 #define GENERAL_PLL_IDX     0
@@ -381,6 +353,7 @@ struct arm_pll_set {
 	unsigned long rate;
 	u32 apll_con;
 	u32 clksel0_con;
+	unsigned long lpj;
 };
 
 #define CORE_ACLK_11	(0 << 5)
@@ -401,11 +374,15 @@ struct arm_pll_set {
 #define ACLK_PCLK_81	(3 << 10)
 #define ACLK_PCLK_MASK	(3 << 10)
 
+#define LPJ_600MHZ	2998368ULL
+static unsigned long lpj_gpll;
+
 #define ARM_PLL(_mhz, nr, nf, no, _axi_div, _ahb_div, _apb_div) \
 { \
 	.rate		= _mhz * MHZ, \
 	.apll_con	= PLL_CLKR(nr) | PLL_CLKF(nf >> 1) | PLL_NO_##no, \
 	.clksel0_con	= CORE_ACLK_##_axi_div | ACLK_HCLK_##_ahb_div | ACLK_PCLK_##_apb_div, \
+	.lpj		= LPJ_600MHZ * _mhz / 600, \
 }
 
 static const struct arm_pll_set arm_pll[] = {
@@ -433,7 +410,7 @@ static const struct arm_pll_set arm_pll[] = {
 #define CORE_PARENT_ARM_PLL	(0 << 23)
 #define CORE_PARENT_GENERAL_PLL	(1 << 23)
 
-static int arm_pll_clk_set_rate(struct clk *clk, unsigned long rate)
+static const struct arm_pll_set* arm_pll_clk_get_best_pll_set(unsigned long rate)
 {
 	const struct arm_pll_set *ps, *pt;
 
@@ -452,36 +429,55 @@ static int arm_pll_clk_set_rate(struct clk *clk, unsigned long rate)
 		pt++;
 	}
 
+	return ps;
+}
+
+static int arm_pll_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long flags;
+	const struct arm_pll_set *ps = arm_pll_clk_get_best_pll_set(rate);
+
+	local_irq_save(flags);
 	/* make aclk safe & reparent to general pll */
 	cru_writel((cru_readl(CRU_CLKSEL0_CON) & ~(CORE_PARENT_MASK | CORE_ACLK_MASK)) | CORE_PARENT_GENERAL_PLL | CORE_ACLK_21, CRU_CLKSEL0_CON);
+	loops_per_jiffy = lpj_gpll;
 
 	/* enter slow mode */
 	cru_writel((cru_readl(CRU_MODE_CON) & ~CRU_CPU_MODE_MASK) | CRU_CPU_MODE_SLOW, CRU_MODE_CON);
 
 	/* power down */
 	cru_writel(cru_readl(CRU_APLL_CON) | PLL_PD, CRU_APLL_CON);
+	local_irq_restore(flags);
 
-	arm_delay_500ns();
+	delay_500ns();
 
 	cru_writel(ps->apll_con | PLL_PD, CRU_APLL_CON);
 
-	arm_delay_500ns();
+	delay_500ns();
 
 	/* power up */
 	cru_writel(ps->apll_con, CRU_APLL_CON);
 
-	arm_delay_300us();
+	delay_300us();
 	pll_wait_lock(ARM_PLL_IDX);
 
-	/* reparent to arm pll & set aclk/hclk/pclk */
-	cru_writel((cru_readl(CRU_CLKSEL0_CON) & ~(CORE_PARENT_MASK | CORE_ACLK_MASK | ACLK_HCLK_MASK | ACLK_PCLK_MASK)) | CORE_PARENT_ARM_PLL | ps->clksel0_con, CRU_CLKSEL0_CON);
-
+	local_irq_save(flags);
 	/* enter normal mode */
 	cru_writel((cru_readl(CRU_MODE_CON) & ~CRU_CPU_MODE_MASK) | CRU_CPU_MODE_NORMAL, CRU_MODE_CON);
 
+	loops_per_jiffy = ps->lpj;
+	/* reparent to arm pll & set aclk/hclk/pclk */
+	cru_writel((cru_readl(CRU_CLKSEL0_CON) & ~(CORE_PARENT_MASK | CORE_ACLK_MASK | ACLK_HCLK_MASK | ACLK_PCLK_MASK)) | CORE_PARENT_ARM_PLL | ps->clksel0_con, CRU_CLKSEL0_CON);
+	local_irq_restore(flags);
+
 	return 0;
 }
 
+static long arm_pll_clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	return arm_pll_clk_get_best_pll_set(rate)->rate;
+}
+
 static struct clk *arm_pll_parents[2] = { &xin24m, &xin27m };
 
 static struct clk arm_pll_clk = {
@@ -489,6 +485,7 @@ static struct clk arm_pll_clk = {
 	.parent		= &xin24m,
 	.recalc		= arm_pll_clk_recalc,
 	.set_rate	= arm_pll_clk_set_rate,
+	.round_rate	= arm_pll_clk_round_rate,
 	.clksel_con	= CRU_MODE_CON,
 	.clksel_parent_mask	= 1,
 	.clksel_parent_shift	= 8,
@@ -2520,6 +2517,7 @@ static void __init rk29_clock_common_init(unsigned long ppll_rate, unsigned long
 	}
 
 	clk_set_rate_nolock(&general_pll_clk, ppll_rate);
+	lpj_gpll = div_u64(LPJ_600MHZ * general_pll_clk.rate, 600 * MHZ);
 	clk_set_parent_nolock(&aclk_periph, &general_pll_clk);
 	clk_set_rate_nolock(&aclk_periph, aclk_p);
 	clk_set_rate_nolock(&hclk_periph, hclk_p);
@@ -2623,6 +2621,8 @@ void __init rk29_clock_init2(enum periph_pll ppll_rate, enum codec_pll cpll_rate
 
 	clk_recalculate_root_clocks_nolock();
 
+	loops_per_jiffy = div_u64(LPJ_600MHZ * arm_pll_clk.rate, 600 * MHZ);
+
 	/*
 	 * Only enable those clocks we will need, let the drivers
 	 * enable other clocks as necessary
@@ -2639,7 +2639,9 @@ void __init rk29_clock_init2(enum periph_pll ppll_rate, enum codec_pll cpll_rate
 	printk(KERN_INFO "Clocking rate (apll/dpll/cpll/gpll/core/aclk_cpu/hclk_cpu/pclk_cpu/aclk_periph/hclk_periph/pclk_periph): %ld/%ld/%ld/%ld/%ld/%ld/%ld/%ld/%ld/%ld/%ld MHz",
 	       arm_pll_clk.rate / MHZ, ddr_pll_clk.rate / MHZ, codec_pll_clk.rate / MHZ, general_pll_clk.rate / MHZ, clk_core.rate / MHZ,
 	       aclk_cpu.rate / MHZ, hclk_cpu.rate / MHZ, pclk_cpu.rate / MHZ, aclk_periph.rate / MHZ, hclk_periph.rate / MHZ, pclk_periph.rate / MHZ);
-	printk(KERN_CONT " (20110718)\n");
+	printk(KERN_CONT " (20110725)\n");
+
+	preset_lpj = loops_per_jiffy;
 }
 
 void __init rk29_clock_init(enum periph_pll ppll_rate)
diff --git a/arch/arm/mach-rk29/cpufreq.c b/arch/arm/mach-rk29/cpufreq.c
index f789128ba6ec..46d8551404e8 100755
--- a/arch/arm/mach-rk29/cpufreq.c
+++ b/arch/arm/mach-rk29/cpufreq.c
@@ -24,12 +24,10 @@
 #include <linux/init.h>
 #include <linux/regulator/consumer.h>
 #include <linux/suspend.h>
+#include <linux/tick.h>
+#include <linux/workqueue.h>
 #include <mach/cpufreq.h>
 
-#define dprintk(fmt, ...) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
-
-#define SLEEP_FREQ	(800 * 1000) /* Use 800MHz when entering sleep */
-
 static int no_cpufreq_access;
 
 static struct cpufreq_frequency_table default_freq_table[] = {
@@ -47,12 +45,93 @@ static struct cpufreq_frequency_table default_freq_table[] = {
 };
 static struct cpufreq_frequency_table *freq_table = default_freq_table;
 static struct clk *arm_clk;
+static DEFINE_MUTEX(mutex);
+
+#ifdef CONFIG_REGULATOR
 static struct regulator *vcore;
 static int vcore_uV;
+#define CONFIG_RK29_CPU_FREQ_LIMIT
+#endif
+
+#ifdef CONFIG_RK29_CPU_FREQ_LIMIT
+static struct workqueue_struct *wq;
+static void rk29_cpufreq_work_func(struct work_struct *work);
+static DECLARE_DELAYED_WORK(rk29_cpufreq_work, rk29_cpufreq_work_func);
+#define WORK_DELAY HZ
+
+static int limit = 1;
+module_param(limit, int, 0644);
+
+#define LIMIT_SECS	30
+static int limit_secs = LIMIT_SECS;
+module_param(limit_secs, int, 0644);
+
+static int limit_temp;
+module_param(limit_temp, int, 0444);
+
+#define LIMIT_AVG_VOLTAGE	1225000 /* vU */
+#else /* !CONFIG_RK29_CPU_FREQ_LIMIT */
+#define LIMIT_AVG_VOLTAGE	1400000 /* vU */
+#endif /* CONFIG_RK29_CPU_FREQ_LIMIT */
+
+enum {
+	DEBUG_CHANGE	= 1U << 0,
+	DEBUG_LIMIT	= 1U << 1,
+};
+static uint debug_mask = DEBUG_CHANGE;
+module_param(debug_mask, uint, 0644);
+#define dprintk(mask, fmt, ...) do { if (mask & debug_mask) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
+
+#define LIMIT_AVG_FREQ	(816 * 1000) /* kHz */
+static unsigned int limit_avg_freq = LIMIT_AVG_FREQ;
+static int rk29_cpufreq_set_limit_avg_freq(const char *val, struct kernel_param *kp)
+{
+	int err = param_set_uint(val, kp);
+	if (!err) {
+		board_update_cpufreq_table(freq_table);
+	}
+	return err;
+}
+module_param_call(limit_avg_freq, rk29_cpufreq_set_limit_avg_freq, param_get_uint, &limit_avg_freq, 0644);
+
+static int limit_avg_index = -1;
+
+static unsigned int limit_avg_voltage = LIMIT_AVG_VOLTAGE;
+static int rk29_cpufreq_set_limit_avg_voltage(const char *val, struct kernel_param *kp)
+{
+	int err = param_set_uint(val, kp);
+	if (!err) {
+		board_update_cpufreq_table(freq_table);
+	}
+	return err;
+}
+module_param_call(limit_avg_voltage, rk29_cpufreq_set_limit_avg_voltage, param_get_uint, &limit_avg_voltage, 0644);
+
+static bool rk29_cpufreq_is_ondemand_policy(struct cpufreq_policy *policy)
+{
+	return (policy && policy->governor && (policy->governor->name[0] == 'o'));
+}
 
 int board_update_cpufreq_table(struct cpufreq_frequency_table *table)
 {
+	mutex_lock(&mutex);
+	if (arm_clk) {
+		unsigned int i;
+
+		limit_avg_freq = 0;
+		limit_avg_index = -1;
+		for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+			table[i].frequency = clk_round_rate(arm_clk, table[i].frequency * 1000) / 1000;
+			if (table[i].index <= limit_avg_voltage && limit_avg_freq < table[i].frequency) {
+				limit_avg_freq = table[i].frequency;
+				limit_avg_index = i;
+			}
+		}
+		if (!limit_avg_freq)
+			limit_avg_freq = LIMIT_AVG_FREQ;
+	}
 	freq_table = table;
+	mutex_unlock(&mutex);
 	return 0;
 }
 
@@ -61,16 +140,68 @@ static int rk29_cpufreq_verify(struct cpufreq_policy *policy)
 	return cpufreq_frequency_table_verify(policy, freq_table);
 }
 
-static int rk29_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation)
+#ifdef CONFIG_RK29_CPU_FREQ_LIMIT
+static void rk29_cpufreq_limit(struct cpufreq_policy *policy, unsigned int relation, int *index)
+{
+	int c, ms;
+	ktime_t now;
+	static ktime_t last = { .tv64 = 0 };
+	cputime64_t wall;
+	u64 idle_time_us;
+	static u64 last_idle_time_us;
+	unsigned int cur = policy->cur;
+
+	if (!limit || !wq || !rk29_cpufreq_is_ondemand_policy(policy) ||
+	    (limit_avg_index < 0) || (relation & MASK_FURTHER_CPUFREQ)) {
+		limit_temp = 0;
+		last.tv64 = 0;
+		return;
+	}
+
+	idle_time_us = get_cpu_idle_time_us(0, &wall);
+	now = ktime_get();
+	if (!last.tv64) {
+		last = now;
+		last_idle_time_us = idle_time_us;
+		return;
+	}
+
+	limit_temp -= idle_time_us - last_idle_time_us; // -1000
+	dprintk(DEBUG_LIMIT, "idle %lld us (%lld - %lld)\n", idle_time_us - last_idle_time_us, idle_time_us, last_idle_time_us);
+	last_idle_time_us = idle_time_us;
+
+	ms = div_u64(ktime_us_delta(now, last), 1000);
+	dprintk(DEBUG_LIMIT, "%d kHz (%d uV) elapsed %d ms (%lld - %lld)\n", cur, vcore_uV, ms, now.tv64, last.tv64);
+	last = now;
+
+	if (cur <= 408 * 1000)
+		c = -325;
+	else if (cur <= 624 * 1000)
+		c = -202;
+	else if (cur <= limit_avg_freq)
+		c = -78;
+	else
+		c = 325;
+	limit_temp += c * ms;
+
+	if (limit_temp < 0)
+		limit_temp = 0;
+	if (limit_temp > 325 * limit_secs * 1000)
+		*index = limit_avg_index;
+	dprintk(DEBUG_LIMIT, "c %d temp %d (%s) index %d", c, limit_temp, limit_temp > 325 * limit_secs * 1000 ? "overheat" : "normal", *index);
+}
+#else
+#define rk29_cpufreq_limit(...) do {} while (0)
+#endif
+
+static int rk29_cpufreq_do_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation)
 {
 	int index;
+	int new_vcore_uV;
 	struct cpufreq_freqs freqs;
 	const struct cpufreq_frequency_table *freq;
 	int err = 0;
 
-	if (policy->cpu != 0)
-		return -EINVAL;
-
 	if ((relation & ENABLE_FURTHER_CPUFREQ) &&
 	    (relation & DISABLE_FURTHER_CPUFREQ)) {
 		/* Invalidate both if both marked */
@@ -88,12 +219,12 @@ static int rk29_cpufreq_target(struct cpufreq_policy *policy, unsigned int targe
 	}
 	if (relation & DISABLE_FURTHER_CPUFREQ)
 		no_cpufreq_access++;
-	relation &= ~MASK_FURTHER_CPUFREQ;
 
-	if (cpufreq_frequency_table_target(policy, freq_table, target_freq, relation, &index)) {
+	if (cpufreq_frequency_table_target(policy, freq_table, target_freq, relation & ~MASK_FURTHER_CPUFREQ, &index)) {
 		pr_err("invalid target_freq: %d\n", target_freq);
 		return -EINVAL;
 	}
+	rk29_cpufreq_limit(policy, relation, &index);
 	freq = &freq_table[index];
 
 	if (policy->cur == freq->frequency)
@@ -102,45 +233,103 @@ static int rk29_cpufreq_target(struct cpufreq_policy *policy, unsigned int targe
 	freqs.old = policy->cur;
 	freqs.new = freq->frequency;
 	freqs.cpu = 0;
-	dprintk("%dHz r %d(%c) selected %dHz (%duV)\n",
-		target_freq, relation, relation == CPUFREQ_RELATION_L ? 'L' : 'H',
-		freq->frequency, freq->index);
+	new_vcore_uV = freq->index;
+	dprintk(DEBUG_CHANGE, "%d Hz r %d(%c) selected %d Hz (%d uV)\n",
+		target_freq, relation, relation & CPUFREQ_RELATION_H ? 'H' : 'L',
+		freq->frequency, new_vcore_uV);
 
 #ifdef CONFIG_REGULATOR
-	if (vcore && freqs.new > freqs.old && vcore_uV != freq->index) {
-		err = regulator_set_voltage(vcore, freq->index, freq->index);
+	if (vcore && freqs.new > freqs.old && vcore_uV != new_vcore_uV) {
+		int err = regulator_set_voltage(vcore, new_vcore_uV, new_vcore_uV);
 		if (err) {
-			pr_err("fail to set vcore (%duV) for %dkHz: %d\n",
-				freq->index, freqs.new, err);
-			goto err_vol;
+			pr_err("fail to set vcore (%d uV) for %d kHz: %d\n",
+				new_vcore_uV, freqs.new, err);
+			return err;
+		} else {
+			vcore_uV = new_vcore_uV;
 		}
-		vcore_uV = freq->index;
 	}
 #endif
 
 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
-	dprintk("pre change\n");
+	dprintk(DEBUG_CHANGE, "pre change\n");
 	clk_set_rate(arm_clk, freqs.new * 1000);
-	dprintk("post change\n");
+	dprintk(DEBUG_CHANGE, "post change\n");
 	freqs.new = clk_get_rate(arm_clk) / 1000;
 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 
 #ifdef CONFIG_REGULATOR
-	if (vcore && freqs.new < freqs.old && vcore_uV != freq->index) {
-		err = regulator_set_voltage(vcore, freq->index, freq->index);
+	if (vcore && freqs.new < freqs.old && vcore_uV != new_vcore_uV) {
+		int err = regulator_set_voltage(vcore, new_vcore_uV, new_vcore_uV);
 		if (err) {
-			pr_err("fail to set vcore (%duV) for %dkHz: %d\n",
-				freq->index, freqs.new, err);
+			pr_err("fail to set vcore (%d uV) for %d kHz: %d\n",
+				new_vcore_uV, freqs.new, err);
+		} else {
+			vcore_uV = new_vcore_uV;
 		}
-		vcore_uV = freq->index;
 	}
 #endif
-	dprintk("ok, got %dkHz\n", freqs.new);
+	dprintk(DEBUG_CHANGE, "ok, got %d kHz\n", freqs.new);
 
-err_vol:
 	return err;
 }
 
+static int rk29_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation)
+{
+	int err;
+
+	if (!policy || policy->cpu != 0)
+		return -EINVAL;
+
+	mutex_lock(&mutex);
+	err = rk29_cpufreq_do_target(policy, target_freq, relation);
+	mutex_unlock(&mutex);
+
+	return err;
+}
+
+#ifdef CONFIG_RK29_CPU_FREQ_LIMIT
+static int rk29_cpufreq_notifier_policy(struct notifier_block *nb,
+		unsigned long val, void *data)
+{
+	struct cpufreq_policy *policy = data;
+	bool is_ondemand;
+
+	if (val != CPUFREQ_NOTIFY)
+		return 0;
+
+	is_ondemand = rk29_cpufreq_is_ondemand_policy(policy);
+	if (!wq && is_ondemand) {
+		dprintk(DEBUG_LIMIT, "start wq\n");
+		wq = create_singlethread_workqueue("rk29_cpufreqd");
+		if (wq)
+			queue_delayed_work(wq, &rk29_cpufreq_work, WORK_DELAY);
+	} else if (wq && !is_ondemand) {
+		dprintk(DEBUG_LIMIT, "stop wq\n");
+		cancel_delayed_work(&rk29_cpufreq_work);
+		destroy_workqueue(wq);
+		wq = NULL;
+	}
+
+	return 0;
+}
+
+static struct notifier_block notifier_policy_block = {
+	.notifier_call = rk29_cpufreq_notifier_policy
+};
+
+static void rk29_cpufreq_work_func(struct work_struct *work)
+{
+	struct cpufreq_policy *policy = cpufreq_cpu_get(0);
+
+	if (policy) {
+		cpufreq_driver_target(policy, policy->cur, CPUFREQ_RELATION_L);
+		cpufreq_cpu_put(policy);
+	}
+	queue_delayed_work(wq, &rk29_cpufreq_work, WORK_DELAY);
+}
+#endif
+
 static int __init rk29_cpufreq_init(struct cpufreq_policy *policy)
 {
 	arm_clk = clk_get(NULL, "arm_pll");
@@ -158,19 +347,40 @@ static int __init rk29_cpufreq_init(struct cpufreq_policy *policy)
 	}
 #endif
 
+	board_update_cpufreq_table(freq_table);	/* force update frequency */
 	BUG_ON(cpufreq_frequency_table_cpuinfo(policy, freq_table));
 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
 	policy->cur = clk_get_rate(arm_clk) / 1000;
 
-	policy->cpuinfo.transition_latency = 400 * NSEC_PER_USEC; // make default sampling_rate to 40000
+	policy->cpuinfo.transition_latency = 40 * NSEC_PER_USEC; // make default sampling_rate to 40000
 
+#ifdef CONFIG_RK29_CPU_FREQ_LIMIT
+	if (rk29_cpufreq_is_ondemand_policy(policy)) {
+		dprintk(DEBUG_LIMIT, "start wq\n");
+		wq = create_singlethread_workqueue("rk29_cpufreqd");
+		if (wq)
+			queue_delayed_work(wq, &rk29_cpufreq_work, WORK_DELAY);
+	}
+	cpufreq_register_notifier(&notifier_policy_block, CPUFREQ_POLICY_NOTIFIER);
+#endif
 	return 0;
 }
 
 static int rk29_cpufreq_exit(struct cpufreq_policy *policy)
 {
+#ifdef CONFIG_RK29_CPU_FREQ_LIMIT
+	cpufreq_unregister_notifier(&notifier_policy_block, CPUFREQ_POLICY_NOTIFIER);
+	if (wq) {
+		dprintk(DEBUG_LIMIT, "stop wq\n");
+		cancel_delayed_work(&rk29_cpufreq_work);
+		destroy_workqueue(wq);
+		wq = NULL;
+	}
+#endif
+#ifdef CONFIG_REGULATOR
 	if (vcore)
 		regulator_put(vcore);
+#endif
 	clk_put(arm_clk);
 	return 0;
 }
@@ -181,7 +391,7 @@ static struct freq_attr *rk29_cpufreq_attr[] = {
 };
 
 static struct cpufreq_driver rk29_cpufreq_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS,
 	.init		= rk29_cpufreq_init,
 	.exit		= rk29_cpufreq_exit,
 	.verify		= rk29_cpufreq_verify,
@@ -193,22 +403,33 @@ static struct cpufreq_driver rk29_cpufreq_driver = {
 static int rk29_cpufreq_pm_notifier_event(struct notifier_block *this,
 		unsigned long event, void *ptr)
 {
-	int ret;
+	int ret = NOTIFY_DONE;
+	struct cpufreq_policy *policy = cpufreq_cpu_get(0);
+
+	if (!policy)
+		return ret;
+
+	if (!rk29_cpufreq_is_ondemand_policy(policy))
+		goto out;
 
 	switch (event) {
 	case PM_SUSPEND_PREPARE:
-		ret = cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
-				DISABLE_FURTHER_CPUFREQ);
-		if (ret < 0)
-			return NOTIFY_BAD;
-		return NOTIFY_OK;
+		ret = cpufreq_driver_target(policy, limit_avg_freq, DISABLE_FURTHER_CPUFREQ | CPUFREQ_RELATION_L);
+		if (ret < 0) {
+			ret = NOTIFY_BAD;
+			goto out;
+		}
+		ret = NOTIFY_OK;
+		break;
 	case PM_POST_RESTORE:
 	case PM_POST_SUSPEND:
-		cpufreq_driver_target(cpufreq_cpu_get(0), SLEEP_FREQ,
-				ENABLE_FURTHER_CPUFREQ);
-		return NOTIFY_OK;
+		cpufreq_driver_target(policy, limit_avg_freq, ENABLE_FURTHER_CPUFREQ | CPUFREQ_RELATION_L);
+		ret = NOTIFY_OK;
+		break;
 	}
-	return NOTIFY_DONE;
+out:
+	cpufreq_cpu_put(policy);
+	return ret;
 }
 
 static struct notifier_block rk29_cpufreq_pm_notifier = {