cpufreq: introduce cpufreq_generic_get() routine

CPUFreq drivers that use clock frameworks interface,i.e. clk_get_rate(),
to get CPUs clk rate, have similar sort of code used in most of them.

This patch adds a generic ->get() which will do the same thing for them.
All those drivers are required to now is to set .get to cpufreq_generic_get()
and set their clk pointer in policy->clk during ->init().

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/unicore2-cpufreq.c b/drivers/cpufreq/unicore2-cpufreq.c
index 86f6cfe..36cc330 100644
--- a/drivers/cpufreq/unicore2-cpufreq.c
+++ b/drivers/cpufreq/unicore2-cpufreq.c
@@ -11,6 +11,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/init.h>
@@ -33,28 +34,18 @@
 	return 0;
 }
 
-static unsigned int ucv2_getspeed(unsigned int cpu)
-{
-	struct clk *mclk = clk_get(NULL, "MAIN_CLK");
-
-	if (cpu)
-		return 0;
-	return clk_get_rate(mclk)/1000;
-}
-
 static int ucv2_target(struct cpufreq_policy *policy,
 			 unsigned int target_freq,
 			 unsigned int relation)
 {
 	struct cpufreq_freqs freqs;
-	struct clk *mclk = clk_get(NULL, "MAIN_CLK");
 	int ret;
 
 	freqs.old = policy->cur;
 	freqs.new = target_freq;
 
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-	ret = clk_set_rate(mclk, target_freq * 1000);
+	ret = clk_set_rate(policy->mclk, target_freq * 1000);
 	cpufreq_notify_post_transition(policy, &freqs, ret);
 
 	return ret;
@@ -64,9 +55,13 @@
 {
 	if (policy->cpu != 0)
 		return -EINVAL;
+
 	policy->min = policy->cpuinfo.min_freq = 250000;
 	policy->max = policy->cpuinfo.max_freq = 1000000;
 	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	policy->clk = clk_get(NULL, "MAIN_CLK");
+	if (IS_ERR(policy->clk))
+		return PTR_ERR(policy->clk);
 	return 0;
 }
 
@@ -74,7 +69,7 @@
 	.flags		= CPUFREQ_STICKY,
 	.verify		= ucv2_verify_speed,
 	.target		= ucv2_target,
-	.get		= ucv2_getspeed,
+	.get		= cpufreq_generic_get,
 	.init		= ucv2_cpu_init,
 	.name		= "UniCore-II",
 };