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.nav...@samsung.com> Acked-by: Kyungmin Park <kyungmin.p...@samsung.com> Reviewed-by: Doug Anderson <diand...@chromium.org> --- Changes since v3: As per discussion at https://patchwork.kernel.org/patch/3235091/ Post f023f8dd59 commit we should be using ARM_S3C24XX_CPUFREQ instead of CPU_FREQ_S3C24XX upstrea linux kernel and linuxsamsung already has the commit f023f8dd59. Hence, rebasing the patch. 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..a77ce13 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_ARM_S3C24XX_CPUFREQ) 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_ARM_S3C24XX_CPUFREQ) #define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
