cpufreq: instantiate cpufreq-cpu0 as a platform_driver

As multiplatform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully.  For example, when
GENERIC_CPUFREQ_CPU0 is built in the kernel, cpu0_cpufreq_driver_init()
will be called on all the platforms to initialize cpufreq-cpu0 driver.

To eliminate this undesired the effect, the patch changes cpufreq-cpu0
driver to have it instantiated as a platform_driver.  Then it will only
run on platforms that create the platform_device "cpufreq-cpu0".

Along with the change, it also changes cpu_dev to be &pdev->dev,
so that managed functions can start working, and module build gets
supported too.

The highbank-cpufreq driver is also updated accordingly to adapt the
changes on cpufreq-cpu0.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index 53f25e5aa6b7..66e3a71b81a3 100644
--- a/drivers/cpufreq/highbank-cpufreq.c
+++ b/drivers/cpufreq/highbank-cpufreq.c
@@ -20,6 +20,7 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/mailbox.h>
+#include <linux/platform_device.h>
 
 #define HB_CPUFREQ_CHANGE_NOTE  0x80000001
 #define HB_CPUFREQ_IPC_LEN      7
@@ -65,6 +66,7 @@ static struct notifier_block hb_cpufreq_clk_nb = {
 
 static int hb_cpufreq_driver_init(void)
 {
+        struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
         struct device *cpu_dev;
         struct clk *cpu_clk;
         struct device_node *np;
@@ -104,6 +106,9 @@ static int hb_cpufreq_driver_init(void)
                 goto out_put_node;
         }
 
+        /* Instantiate cpufreq-cpu0 */
+        platform_device_register_full(&devinfo);
+
 out_put_node:
         of_node_put(np);
         return ret;