path: root/drivers/cpufreq/kirkwood-cpufreq.c
diff options
authorMike Turquette <mturquette@linaro.org>2014-08-18 17:30:29 +0200
committerMike Turquette <mturquette@linaro.org>2014-09-02 15:02:54 -0700
commit105299381d8720a3afd4252689ae8551f49944be (patch)
tree4978320975b50e6960af612cbeaab04bb48e549b /drivers/cpufreq/kirkwood-cpufreq.c
parente8e8a9b0d86c093b208789fd71501c91a919ffdb (diff)
cpufreq: kirkwood: use the powersave multiplexer
The powersave clock acts like a multiplexer for the cpu, selecting either the clock signal derived from the cpu pll or from the ddr clock. This patch changes powersave from a gate clock to a mux clock to better reflect this behavior. This is a cleaner approach whereby the frequency of the cpu always matches the rate of powersave_clk. The cpufreq driver for the kirkwood platform no longer must parse this behavior out of various calls to clk_enable and clk_disable, but can instead simply select the parent cpu it wants when changing rate. Likewise when requesting the cpu rate we need only query powersave_clk's rate through the usual call to clk_get_rate. The new clock data and corresponding changes to the cpufreq driver are combined into this single commit to avoid a git bisect issue where this cpufreq driver fails to work properly between the commit that updates the kirkwood clock driver and the commit that changes how the cpufreq driver uses that clock. Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/cpufreq/kirkwood-cpufreq.c')
1 files changed, 5 insertions, 9 deletions
diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
index 37a480680cd0..7906d4acfe40 100644
--- a/drivers/cpufreq/kirkwood-cpufreq.c
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -12,7 +12,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/clk.h>
-#include <linux/clk-provider.h>
#include <linux/cpufreq.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
@@ -39,8 +38,7 @@ static struct priv
* - cpu clk
* - ddr clk
- * The frequencies are set at runtime before registering this *
- * table.
+ * The frequencies are set at runtime before registering this table.
static struct cpufreq_frequency_table kirkwood_freq_table[] = {
{0, STATE_CPU_FREQ, 0}, /* CPU uses cpuclk */
@@ -50,9 +48,7 @@ static struct cpufreq_frequency_table kirkwood_freq_table[] = {
static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu)
- if (__clk_is_enabled(priv.powersave_clk))
- return kirkwood_freq_table[1].frequency;
- return kirkwood_freq_table[0].frequency;
+ return clk_get_rate(priv.powersave_clk) / 1000;
static int kirkwood_cpufreq_target(struct cpufreq_policy *policy,
@@ -70,10 +66,10 @@ static int kirkwood_cpufreq_target(struct cpufreq_policy *policy,
switch (state) {
- clk_disable(priv.powersave_clk);
+ clk_set_parent(priv.powersave_clk, priv.cpu_clk);
- clk_enable(priv.powersave_clk);
+ clk_set_parent(priv.powersave_clk, priv.ddr_clk);
@@ -150,7 +146,7 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
err = PTR_ERR(priv.powersave_clk);
goto out_ddr;
- clk_prepare(priv.powersave_clk);
+ clk_prepare_enable(priv.powersave_clk);
np = NULL;