diff options
| author | Colin Cross <ccross@android.com> | 2010-11-22 18:54:36 -0800 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2011-02-21 00:16:46 -0800 |
| commit | 7a281284125fe8704ea16fd1ca243971b7c0a105 (patch) | |
| tree | 4c3e2e7fbad7844b52e7682dcd91bdbd9ef8ad7f /arch/arm | |
| parent | 6d2968284f63efa1d1849165f9e3a80402509212 (diff) | |
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: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-tegra/cpu-tegra.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/cpu-tegra.c b/arch/arm/mach-tegra/cpu-tegra.c index f02ba603ceb..0e1016a827a 100644 --- a/arch/arm/mach-tegra/cpu-tegra.c +++ b/arch/arm/mach-tegra/cpu-tegra.c @@ -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; } |