From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCHv3 1/8] devfreq: exynos: Add generic exynos memory bus frequency driver Date: Tue, 13 Jan 2015 19:29:42 +0900 Message-ID: <54B4F396.3090105@samsung.com> References: <2009992739.970611421140038667.JavaMail.weblogic@epmlwas05d> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <2009992739.970611421140038667.JavaMail.weblogic@epmlwas05d> Sender: linux-samsung-soc-owner@vger.kernel.org To: myungjoo.ham@samsung.com Cc: "kgene@kernel.org" , =?UTF-8?B?67CV6rK966+8?= , "rafael.j.wysocki@intel.com" , "mark.rutland@arm.com" , ABHILASH KESAVAN , "tomasz.figa@gmail.com" , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , "robh+dt@kernel.org" , =?UTF-8?B?64yA7J246riw?= , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" List-Id: linux-pm@vger.kernel.org On 01/13/2015 06:07 PM, MyungJoo Ham wrote: >> >> Dear Myungjoo, >> >> On 01/13/2015 05:42 PM, MyungJoo Ham wrote: >>>> >>>> This patch adds the generic exynos bus frequency driver for memory bus >>>> with DEVFREQ framework. The Samsung Exynos SoCs have the common architecture >>>> for memory bus between DRAM memory and MMC/sub IP in SoC. This driver can >>>> support the memory bus frequency driver for Exynos SoCs. >>>> >>>> Each memory bus block has a clock for memory bus speed and frequency >>>> table which is changed according to the utilization of memory bus on runtime. >>>> And then each memory bus group has the one more memory bus blocks and >>>> OPP table (including frequency and voltage), regulator, devfreq-event >>>> devices. >>>> >>>> There are a little difference about the number of memory bus because each Exynos >>>> SoC have the different sub-IP and different memory bus speed. In spite of this >>>> difference among Exynos SoCs, we can support almost Exynos SoC by adding >>>> unique data of memory bus to devicetree file. >>>> >>>> Cc: Myungjoo Ham >>>> Cc: Kyungmin Park >>>> Cc: Kukjin Kim >>>> Signed-off-by: Chanwoo Choi >>>> --- >>>> drivers/devfreq/Kconfig | 15 + >>>> drivers/devfreq/Makefile | 1 + >>>> drivers/devfreq/exynos-busfreq.c | 589 +++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 605 insertions(+) >>>> create mode 100644 drivers/devfreq/exynos-busfreq.c >>> >>> Exynos drivers are located at drivers/devfreq/exynos/ >>> Please relocate/rename exynos-busfreq.c >> >> OK. I'll move it at drivers/devfreq/exynos directory. >> Do you prefer 'exynos-bus.c' instead of 'exynos-busfreq.c'? >> If you reply, I'll change it. > > exynos-bus looks more pretty :) OK, I'll change the driver name according to your comment. Best Regards, Chanwoo Choi > >> >>> >>> [] >>> >>>> diff --git a/drivers/devfreq/exynos-busfreq.c b/drivers/devfreq/exynos-busfreq.c >>>> new file mode 100644 >>>> index 0000000..b180f43 >>>> --- /dev/null >>>> +++ b/drivers/devfreq/exynos-busfreq.c >>> >>> [] >>> >>>> + >>>> +#define BUS_SATURATION_RATIO 40 >>> >>> In order to be a common driver, this should be tunable. >>> >>> Because .dts is supposed to have hardware configuration only, >>> you may keep a table of { chip-name, saturation ratio} in this >>> driver and look up the saturation ratio based on the chip-name. >> >> OK, I'll add new property for saturation_ratio. >> >> I'll implement to use default saturation_ratio value , >> if dt node don't include saturation_ratio property. > > Yes. I didn't talk with DT maintainers and I do not have much > experience with DT; however, it appears that such values are not > recommended to be in DTS files and this value is determined by > the SoC model number without complications in the driver file. > From mboxrd@z Thu Jan 1 00:00:00 1970 From: cw00.choi@samsung.com (Chanwoo Choi) Date: Tue, 13 Jan 2015 19:29:42 +0900 Subject: [PATCHv3 1/8] devfreq: exynos: Add generic exynos memory bus frequency driver In-Reply-To: <2009992739.970611421140038667.JavaMail.weblogic@epmlwas05d> References: <2009992739.970611421140038667.JavaMail.weblogic@epmlwas05d> Message-ID: <54B4F396.3090105@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/13/2015 06:07 PM, MyungJoo Ham wrote: >> >> Dear Myungjoo, >> >> On 01/13/2015 05:42 PM, MyungJoo Ham wrote: >>>> >>>> This patch adds the generic exynos bus frequency driver for memory bus >>>> with DEVFREQ framework. The Samsung Exynos SoCs have the common architecture >>>> for memory bus between DRAM memory and MMC/sub IP in SoC. This driver can >>>> support the memory bus frequency driver for Exynos SoCs. >>>> >>>> Each memory bus block has a clock for memory bus speed and frequency >>>> table which is changed according to the utilization of memory bus on runtime. >>>> And then each memory bus group has the one more memory bus blocks and >>>> OPP table (including frequency and voltage), regulator, devfreq-event >>>> devices. >>>> >>>> There are a little difference about the number of memory bus because each Exynos >>>> SoC have the different sub-IP and different memory bus speed. In spite of this >>>> difference among Exynos SoCs, we can support almost Exynos SoC by adding >>>> unique data of memory bus to devicetree file. >>>> >>>> Cc: Myungjoo Ham >>>> Cc: Kyungmin Park >>>> Cc: Kukjin Kim >>>> Signed-off-by: Chanwoo Choi >>>> --- >>>> drivers/devfreq/Kconfig | 15 + >>>> drivers/devfreq/Makefile | 1 + >>>> drivers/devfreq/exynos-busfreq.c | 589 +++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 605 insertions(+) >>>> create mode 100644 drivers/devfreq/exynos-busfreq.c >>> >>> Exynos drivers are located at drivers/devfreq/exynos/ >>> Please relocate/rename exynos-busfreq.c >> >> OK. I'll move it at drivers/devfreq/exynos directory. >> Do you prefer 'exynos-bus.c' instead of 'exynos-busfreq.c'? >> If you reply, I'll change it. > > exynos-bus looks more pretty :) OK, I'll change the driver name according to your comment. Best Regards, Chanwoo Choi > >> >>> >>> [] >>> >>>> diff --git a/drivers/devfreq/exynos-busfreq.c b/drivers/devfreq/exynos-busfreq.c >>>> new file mode 100644 >>>> index 0000000..b180f43 >>>> --- /dev/null >>>> +++ b/drivers/devfreq/exynos-busfreq.c >>> >>> [] >>> >>>> + >>>> +#define BUS_SATURATION_RATIO 40 >>> >>> In order to be a common driver, this should be tunable. >>> >>> Because .dts is supposed to have hardware configuration only, >>> you may keep a table of { chip-name, saturation ratio} in this >>> driver and look up the saturation ratio based on the chip-name. >> >> OK, I'll add new property for saturation_ratio. >> >> I'll implement to use default saturation_ratio value , >> if dt node don't include saturation_ratio property. > > Yes. I didn't talk with DT maintainers and I do not have much > experience with DT; however, it appears that such values are not > recommended to be in DTS files and this value is determined by > the SoC model number without complications in the driver file. >