1 files changed, 84 insertions, 16 deletions

diff --git a/arch/arm/mach-tegra/cpu-tegra.c b/arch/arm/mach-tegra/cpu-tegra.c
index fea5719c7072..0e1016a827ac 100644
--- a/arch/arm/mach-tegra/cpu-tegra.c
+++ b/arch/arm/mach-tegra/cpu-tegra.c
@@ -28,6 +28,7 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/suspend.h>
 
 #include <asm/system.h>
 
@@ -36,21 +37,25 @@
 
 /* Frequency table index must be sequential starting at 0 */
 static struct cpufreq_frequency_table freq_table[] = {
-	{ 0, 312000 },
-	{ 1, 456000 },
-	{ 2, 608000 },
-	{ 3, 760000 },
-	{ 4, 816000 },
-	{ 5, 912000 },
-	{ 6, 1000000 },
-	{ 7, CPUFREQ_TABLE_END },
+	{ 0, 216000 },
+	{ 1, 312000 },
+	{ 2, 456000 },
+	{ 3, 608000 },
+	{ 4, 760000 },
+	{ 5, 816000 },
+	{ 6, 912000 },
+	{ 7, 1000000 },
+	{ 8, CPUFREQ_TABLE_END },
 };
 
 #define NUM_CPUS	2
 
 static struct clk *cpu_clk;
+static struct clk *emc_clk;
 
 static unsigned long target_cpu_speed[NUM_CPUS];
+static DEFINE_MUTEX(tegra_cpu_lock);
+static bool is_suspended;
 
 int tegra_verify_speed(struct cpufreq_policy *policy)
 {
@@ -68,22 +73,28 @@ unsigned int tegra_getspeed(unsigned int cpu)
 	return rate;
 }
 
-static int tegra_update_cpu_speed(void)
+static int tegra_update_cpu_speed(unsigned long rate)
 {
-	int i;
-	unsigned long rate = 0;
 	int ret = 0;
 	struct cpufreq_freqs freqs;
 
-	for_each_online_cpu(i)
-		rate = max(rate, target_cpu_speed[i]);
-
 	freqs.old = tegra_getspeed(0);
 	freqs.new = rate;
 
 	if (freqs.old == freqs.new)
 		return ret;
 
+	/*
+	 * Vote on memory bus frequency based on cpu frequency
+	 * This sets the minimum frequency, display or avp may request higher
+	 */
+	if (rate >= 816000)
+		clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */
+	else if (rate >= 456000)
+		clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */
+	else
+		clk_set_rate(emc_clk, 100000000);  /* emc 50Mhz */
+
 	for_each_online_cpu(freqs.cpu)
 		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 
@@ -92,7 +103,7 @@ static int tegra_update_cpu_speed(void)
 	       freqs.old, freqs.new);
 #endif
 
-	ret = clk_set_rate_cansleep(cpu_clk, freqs.new * 1000);
+	ret = clk_set_rate(cpu_clk, freqs.new * 1000);
 	if (ret) {
 		pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
 			freqs.new);
@@ -105,12 +116,30 @@ static int tegra_update_cpu_speed(void)
 	return 0;
 }
 
+static unsigned long tegra_cpu_highest_speed(void)
+{
+	unsigned long rate = 0;
+	int i;
+
+	for_each_online_cpu(i)
+		rate = max(rate, target_cpu_speed[i]);
+	return rate;
+}
+
 static int tegra_target(struct cpufreq_policy *policy,
 		       unsigned int target_freq,
 		       unsigned int relation)
 {
 	int idx;
 	unsigned int freq;
+	int ret = 0;
+
+	mutex_lock(&tegra_cpu_lock);
+
+	if (is_suspended) {
+		ret = -EBUSY;
+		goto out;
+	}
 
 	cpufreq_frequency_table_target(policy, freq_table, target_freq,
 		relation, &idx);
@@ -119,9 +148,34 @@ static int tegra_target(struct cpufreq_policy *policy,
 
 	target_cpu_speed[policy->cpu] = freq;
 
-	return tegra_update_cpu_speed();
+	ret = tegra_update_cpu_speed(tegra_cpu_highest_speed());
+
+out:
+	mutex_unlock(&tegra_cpu_lock);
+	return ret;
 }
 
+static int tegra_pm_notify(struct notifier_block *nb, unsigned long event,
+	void *dummy)
+{
+	mutex_lock(&tegra_cpu_lock);
+	if (event == PM_SUSPEND_PREPARE) {
+		is_suspended = true;
+		pr_info("Tegra cpufreq suspend: setting frequency to %d kHz\n",
+			freq_table[0].frequency);
+		tegra_update_cpu_speed(freq_table[0].frequency);
+	} else if (event == PM_POST_SUSPEND) {
+		is_suspended = false;
+	}
+	mutex_unlock(&tegra_cpu_lock);
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block tegra_cpu_pm_notifier = {
+	.notifier_call = tegra_pm_notify,
+};
+
 static int tegra_cpu_init(struct cpufreq_policy *policy)
 {
 	if (policy->cpu >= NUM_CPUS)
@@ -131,6 +185,15 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
 	if (IS_ERR(cpu_clk))
 		return PTR_ERR(cpu_clk);
 
+	emc_clk = clk_get_sys("cpu", "emc");
+	if (IS_ERR(emc_clk)) {
+		clk_put(cpu_clk);
+		return PTR_ERR(emc_clk);
+	}
+
+	clk_enable(emc_clk);
+	clk_enable(cpu_clk);
+
 	cpufreq_frequency_table_cpuinfo(policy, freq_table);
 	cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
 	policy->cur = tegra_getspeed(policy->cpu);
@@ -142,12 +205,17 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
 	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 	cpumask_copy(policy->related_cpus, cpu_possible_mask);
 
+	if (policy->cpu == 0)
+		register_pm_notifier(&tegra_cpu_pm_notifier);
+
 	return 0;
 }
 
 static int tegra_cpu_exit(struct cpufreq_policy *policy)
 {
 	cpufreq_frequency_table_cpuinfo(policy, freq_table);
+	clk_disable(emc_clk);
+	clk_put(emc_clk);
 	clk_put(cpu_clk);
 	return 0;
 }