Re: [PATCH v4 01/20] PM / devfreq: exynos: Add generic exynos bus frequency driver

[Chanwoo Choi <cw00.choi@samsung.com>]

Hi,

On 2015년 12월 15일 12:41, Krzysztof Kozlowski wrote:
> On 14.12.2015 15:38, Chanwoo Choi wrote:
>> This patch adds the generic exynos bus frequency driver for AMBA AXI bus
>> of sub-blocks in exynos SoC with DEVFREQ framework. The Samsung Exynos SoC
>> have the common architecture for bus between DRAM and sub-blocks in SoC.
>> This driver can support the generic bus frequency driver for Exynos SoCs.
>>
>> In devicetree, Each bus block has a bus clock, regulator, operation-point
>> and devfreq-event devices which measure the utilization of each bus block.
>>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> [linux.amoon: Tested on Odroid U3]
>> Tested-by: Anand Moon <linux.amoon@gmail.com>
>> ---
>>  drivers/devfreq/Kconfig             |  15 ++
>>  drivers/devfreq/Makefile            |   1 +
>>  drivers/devfreq/exynos/Makefile     |   1 +
>>  drivers/devfreq/exynos/exynos-bus.c | 449 ++++++++++++++++++++++++++++++++++++
>>  4 files changed, 466 insertions(+)
>>  create mode 100644 drivers/devfreq/exynos/exynos-bus.c
>>
>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
>> index 64281bb2f650..55ec774f794c 100644
>> --- a/drivers/devfreq/Kconfig
>> +++ b/drivers/devfreq/Kconfig
>> @@ -66,6 +66,21 @@ config DEVFREQ_GOV_USERSPACE
>>  
>>  comment "DEVFREQ Drivers"
>>  
>> +config ARM_EXYNOS_BUS_DEVFREQ
>> +	bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
>> +	depends on ARCH_EXYNOS
>> +	select DEVFREQ_GOV_SIMPLE_ONDEMAND
>> +	select DEVFREQ_EVENT_EXYNOS_PPMU
>> +	select PM_DEVFREQ_EVENT
>> +	select PM_OPP
>> +	help
>> +	  This adds the common DEVFREQ driver for Exynos Memory bus. Exynos
>> +	  Memory bus has one more group of memory bus (e.g, MIF and INT block).
>> +	  Each memory bus group could contain many memoby bus block. It reads
>> +	  PPMU counters of memory controllers by using DEVFREQ-event device
>> +	  and adjusts the operating frequencies and voltages with OPP support.
>> +	  This does not yet operate with optimal voltages.
>> +
>>  config ARM_EXYNOS4_BUS_DEVFREQ
>>  	bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
>>  	depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
>> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
>> index 5134f9ee983d..375ebbb4fcfb 100644
>> --- a/drivers/devfreq/Makefile
>> +++ b/drivers/devfreq/Makefile
>> @@ -6,6 +6,7 @@ obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
>>  obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
>>  
>>  # DEVFREQ Drivers
>> +obj-$(CONFIG_ARCH_EXYNOS)		+= exynos/
> 
> Why limiting it to ARCH_EXYNOS? Are there real dependencies on exynos
> mach code? Or on ARM code?

There is no dependency.

> 
> If not, then this probably should be obj-y to allow compile testing.
> Particular objects would be selected by ARM_EXYNOS_BUS_DEVFREQ.

OK. I'll alter it as obj-y.

Best Regards,
Chanwoo Choi