For Exynos4 and Exynos5 SoCs from Samsung the i2c clock is based
on a fixed 66 MHz peripheral clock, and therefore is completely
independent of the cpu frequency.
Thus, registering for a CPU freq notifier is very wasteful.
This patch modifes the code such that, i2c bus registers to
cpu_freq_transition only if CONFIG_CPU_FREQ_S3C24XX is enabled.
This change should save a bunch of cpufreq transitions calls
which does not apply to exynos SoCs.
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx>
---
Changes since v2:
None, Rebased on for-next of linux-i2c git repo.
Changes since v1:
Use CONFIG_CPU_FREQ_S3C24XX instead of (CONFIG_CPU_FREQ & !CONFIG_EXYNOS)
As commented by Tomasz
drivers/i2c/busses/i2c-s3c2410.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index bf8fb94..fa51dff 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -123,7 +123,7 @@ struct s3c24xx_i2c {
struct s3c2410_platform_i2c *pdata;
int gpios[2];
struct pinctrl *pctrl;
-#ifdef CONFIG_CPU_FREQ
+#if defined(CONFIG_CPU_FREQ_S3C24XX)
struct notifier_block freq_transition;
#endif
};
@@ -843,7 +843,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
return 0;
}
-#ifdef CONFIG_CPU_FREQ
+#if defined(CONFIG_CPU_FREQ_S3C24XX)
#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition)
--
1.7.10.4
--
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