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Commit 7a281284 authored by Colin Cross's avatar Colin Cross
Browse files

ARM: tegra: cpufreq: Adjust memory frequency with cpu frequency 



Adjusts the minimum memory frequency when the cpu frequency
changes.  The values are currently hardcoded to a reasonable
default.  If memory frequency scaling is not enabled this
patch will have no effect.

Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarColin Cross <ccross@android.com>
parent 6d296828

arch/arm/mach-tegra/cpu-tegra.c

+21 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ static struct cpufreq_frequency_table freq_table[] = { 
#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);
@@ -83,6 +84,17 @@ static int tegra_update_cpu_speed(unsigned long 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);
@@ -173,6 +185,13 @@ 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);
@@ -195,6 +214,8 @@ static int tegra_cpu_init(struct cpufreq_policy *policy) 
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;

}