summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/cpu-tegra.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-tegra/cpu-tegra.c')
-rw-r--r--arch/arm/mach-tegra/cpu-tegra.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/arch/arm/mach-tegra/cpu-tegra.c b/arch/arm/mach-tegra/cpu-tegra.c
index ceb52db1e2f1..627bf0f4262e 100644
--- a/arch/arm/mach-tegra/cpu-tegra.c
+++ b/arch/arm/mach-tegra/cpu-tegra.c
@@ -49,6 +49,8 @@ static struct cpufreq_frequency_table freq_table[] = {
#define NUM_CPUS 2
static struct clk *cpu_clk;
+static struct clk *pll_x_clk;
+static struct clk *pll_p_clk;
static struct clk *emc_clk;
static unsigned long target_cpu_speed[NUM_CPUS];
@@ -71,6 +73,42 @@ static unsigned int tegra_getspeed(unsigned int cpu)
return rate;
}
+static int tegra_cpu_clk_set_rate(unsigned long rate)
+{
+ int ret;
+
+ /*
+ * Take an extra reference to the main pll so it doesn't turn
+ * off when we move the cpu off of it
+ */
+ clk_prepare_enable(pll_x_clk);
+
+ ret = clk_set_parent(cpu_clk, pll_p_clk);
+ if (ret) {
+ pr_err("Failed to switch cpu to clock pll_p\n");
+ goto out;
+ }
+
+ if (rate == clk_get_rate(pll_p_clk))
+ goto out;
+
+ ret = clk_set_rate(pll_x_clk, rate);
+ if (ret) {
+ pr_err("Failed to change pll_x to %lu\n", rate);
+ goto out;
+ }
+
+ ret = clk_set_parent(cpu_clk, pll_x_clk);
+ if (ret) {
+ pr_err("Failed to switch cpu to clock pll_x\n");
+ goto out;
+ }
+
+out:
+ clk_disable_unprepare(pll_x_clk);
+ return ret;
+}
+
static int tegra_update_cpu_speed(unsigned long rate)
{
int ret = 0;
@@ -101,7 +139,7 @@ static int tegra_update_cpu_speed(unsigned long rate)
freqs.old, freqs.new);
#endif
- ret = clk_set_rate(cpu_clk, freqs.new * 1000);
+ ret = tegra_cpu_clk_set_rate(freqs.new * 1000);
if (ret) {
pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n",
freqs.new);
@@ -183,6 +221,14 @@ static int tegra_cpu_init(struct cpufreq_policy *policy)
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
+ pll_x_clk = clk_get_sys(NULL, "pll_x");
+ if (IS_ERR(pll_x_clk))
+ return PTR_ERR(pll_x_clk);
+
+ pll_p_clk = clk_get_sys(NULL, "pll_p");
+ if (IS_ERR(pll_p_clk))
+ return PTR_ERR(pll_p_clk);
+
emc_clk = clk_get_sys("cpu", "emc");
if (IS_ERR(emc_clk)) {
clk_put(cpu_clk);