From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.majewski@samsung.com (Lukasz Majewski) Date: Tue, 17 Dec 2013 10:09:56 +0100 Subject: [PATCH 3/3] cpufreq: exynos: Add exynos5420 cpufreq driver In-Reply-To: References: <1386323284-15646-1-git-send-email-arun.kk@samsung.com> <1386323284-15646-4-git-send-email-arun.kk@samsung.com> <20131217090005.1e04ff7b@amdc2363> Message-ID: <20131217100956.6fa5b7e6@amdc2363> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Arun, > Hi Lukasz, > > On Tue, Dec 17, 2013 at 1:30 PM, Lukasz Majewski > wrote: > > Hi Viresh, > > > >> On 6 December 2013 15:18, Arun Kumar K wrote: > >> > From: "Arjun.K.V" > >> > > >> > The patch adds cpufreq driver for exynos5420. > >> > > >> > Signed-off-by: Arjun.K.V > >> > Signed-off-by: Andrew Bresticker > >> > Signed-off-by: Arun Kumar K > >> > --- > >> > drivers/cpufreq/Kconfig.arm | 11 ++ > >> > drivers/cpufreq/Makefile | 1 + > >> > drivers/cpufreq/exynos-cpufreq.c | 2 + > >> > drivers/cpufreq/exynos-cpufreq.h | 8 + > >> > drivers/cpufreq/exynos5420-cpufreq.c | 346 > >> > ++++++++++++++++++++++++++++++++++ 5 files changed, 368 > >> > insertions(+) create mode 100644 > >> > drivers/cpufreq/exynos5420-cpufreq.c > >> > >> Hmm.. That's the second big LITTLE SoC after TC2.. > >> And we already have a generic enough driver for all big LITTLE > >> platforms: arm_big_little.c > >> > >> Please use that with a glue clk and regulator driver if required. > >> We don't want to get any new driver for big LITTLE unless there is > >> a real limitation. > >> > >> Also, the generic big LITTLE driver supports IKS (In Kernel > >> Switcher) which may or maynot be used by Exynos. > >> > >> @Lukasz: We can't use cpu0 driver here as we have multiple clusters > >> here A7 and A15, and so there are two clock domains instead of one. > >> That's why we have written big LITTLE driver. > > > > When I first looked into the patch - it was almost identical to the > > exynos4210-cpufreq.c or exynos4x12-cpufreq.c files. > > > > Also I didn't spot the code characteristic to IKS. It seems like the > > code in this file is not aware if it runs on A7 or A15. > > > > This initial version was only for A15s and I was planning for an > incremental patch for A7s along with common code for the same. Now > that is not needed with the generic implementation in place. Ok. I see. > > Regards > Arun -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group