Re: [PATCH V2 3/7] driver/core: cpu: initialize opp table

From: Sudeep Holla
Date: Wed May 21 2014 - 13:26:31 EST




On 21/05/14 12:10, Viresh Kumar wrote:
All drivers expecting CPU's OPPs from device tree initialize OPP table using
of_init_opp_table() and there is nothing driver specific in that. They all do it
in the same way adding to code redundancy.

It would be better if we can get rid of code redundancy by initializing CPU OPPs
from core code for all CPUs that have a "operating-points" property defined in
their node.

This patch initializes OPPs as soon as CPU device is registered in
register_cpu().

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
Cc: Kukjin Kim <kgene.kim@xxxxxxxxxxx>
Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/base/cpu.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 006b1bc..853e99e 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -16,6 +16,7 @@
#include <linux/acpi.h>
#include <linux/of.h>
#include <linux/cpufeature.h>
+#include <linux/pm_opp.h>

#include "base.h"

@@ -322,6 +323,25 @@ static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
}
#endif

+#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
+static inline void of_init_cpu_opp_table(struct cpu *cpu)
+{
+ int error;
+
+ /* Initialize CPU's OPP table */
+ error = of_init_opp_table(&cpu->dev);
+ if (!error)
+ dev_info(&cpu->dev, "%s: created OPP table for cpu: %d\n",
+ __func__, cpu->dev.id);
+ /* Print error only if there is an issue with OPP table */
+ else if (error != -ENOSYS && error != -ENODEV)
+ dev_err(&cpu->dev, "%s: failed to init OPP table for cpu%d, err: %d\n",
+ __func__, cpu->dev.id, error);
+}
+#else
+static inline void of_init_cpu_opp_table(struct cpu *cpu) {}

Sorry I missed this earlier, main idea of this wrapper is not to have any
config dependency and hide error handling details for non-DT platforms. Since
of_init_opp_table has dummy implementation, you really don't need this dummy
implementation again here.

Regards,
Sudeep

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