From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755507AbaCNHOn (ORCPT ); Fri, 14 Mar 2014 03:14:43 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:29490 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755302AbaCNHOk (ORCPT ); Fri, 14 Mar 2014 03:14:40 -0400 X-AuditID: cbfee690-b7f266d00000287c-c2-5322ac5ded0c Message-id: <5322AC5D.9070200@samsung.com> Date: Fri, 14 Mar 2014 16:14:37 +0900 From: Chanwoo Choi User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-version: 1.0 To: Mark Rutland Cc: "myungjoo.ham@samsung.com" , "kyungmin.park@samsung.com" , "rafael.j.wysocki@intel.com" , "nm@ti.com" , "b.zolnierkie@samsaung.com" , Pawel Moll , "swarren@wwwdotorg.org" , "ijc+devicetree@hellion.org.uk" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-samsung-soc@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-doc@vger.kernel.org" Subject: Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12 References: <1394698649-20996-1-git-send-email-cw00.choi@samsung.com> <1394698649-20996-9-git-send-email-cw00.choi@samsung.com> <20140313175308.GE25870@e106331-lin.cambridge.arm.com> In-reply-to: <20140313175308.GE25870@e106331-lin.cambridge.arm.com> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrIIsWRmVeSWpSXmKPExsWyRsSkRDd2jVKwwffjUhYdPb9ZLOYfOcdq ce7VSkaLs01v2C0Wti1hsbi8aw6bxefeI4wWM87vY7JYev0ik8XtxhVsFm9+nGWymDB9LYvF 4xVv2S1eHWxjceDzWDNvDaPHyuVf2DwW73nJ5PFz+XZ2j74tqxg9jt/YzuTxeZOcx8a5oQEc UVw2Kak5mWWpRfp2CVwZ7/dKFHTLVhy428rawPhIvIuRk0NCwESi4ddKRghbTOLCvfVsXYxc HEICSxklZi9dyQRT9Ovub1aIxCJGiQUTpkE5rxglprfPYQWp4hXQkujf/4EZxGYRUJU4dPYn WDcbUHz/ixtsILaoQJjEyulXWCDqBSV+TL4HZosIqEv07PrCAjKUWeAuq8TiOWvAEsIC0RKX Jt+GumkXo8Tzjw1gGzgFnCXm370EVsQsoCOxv3UaG4QtL7F5zVtmkAYJgakcEp0f5rNDnCQg 8W3yIaAGDqCErMSmA8wQv0lKHFxxg2UCo9gsJEfNQjJ2FpKxCxiZVzGKphYkFxQnpReZ6BUn 5haX5qXrJefnbmIERvfpf88m7GC8d8D6EGMy0MqJzFKiyfnA5JBXEm9obGZkYWpiamxkbmlG mrCSOK/ao6QgIYH0xJLU7NTUgtSi+KLSnNTiQ4xMHJxSDYxVV7RuJ8pM/TbrITvrNMkjv/5u PuZ2oHuGSc7hsIfGm1ken88++CC86k+TsFhsbull/dPxs28fu+C9YaZoeYvVB3dBQZdLt7K6 z8uphohJe8xs6fa8WLrxWe6Vz3694WHT/t96f+ZfDv/RlZstgkvsD+1M07qY8l51V5RJ1wr1 aRKCGWxpW+2VWIozEg21mIuKEwFQebVBBAMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrHKsWRmVeSWpSXmKPExsVy+t9jAd3YNUrBBvseCVh09PxmsZh/5Byr xblXKxktzja9YbdY2LaExeLyrjlsFp97jzBazDi/j8li6fWLTBa3G1ewWbz5cZbJYsL0tSwW j1e8Zbd4dbCNxYHPY828NYweK5d/YfNYvOclk8fP5dvZPfq2rGL0OH5jO5PH501yHhvnhgZw RDUw2mSkJqakFimk5iXnp2TmpdsqeQfHO8ebmhkY6hpaWpgrKeQl5qbaKrn4BOi6ZeYAHa6k UJaYUwoUCkgsLlbSt8M0ITTETdcCpjFC1zckCK7HyAANJKxhzHi/V6KgW7biwN1W1gbGR+Jd jJwcEgImEr/u/maFsMUkLtxbz9bFyMUhJLCIUWLBhGmsEM4rRonp7XPAqngFtCT6939gBrFZ BFQlDp39yQRiswHF97+4wQZiiwqESaycfoUFol5Q4sfke2C2iIC6RM+uLywgQ5kF7rJKLJ6z BiwhLBAtcWnybajVuxglnn9sANvAKeAsMf/uJbAiZgEdif2t09ggbHmJzWveMk9gFJiFZMks JGWzkJQtYGRexSiaWpBcUJyUnmukV5yYW1yal66XnJ+7iRGcOp5J72Bc1WBxiFGAg1GJh3fG UcVgIdbEsuLK3EOMEhzMSiK8DPOUgoV4UxIrq1KL8uOLSnNSiw8xJgPDYCKzlGhyPjCt5ZXE GxqbmBlZGpkbWhgZm5MmrCTOe7DVOlBIID2xJDU7NbUgtQhmCxMHp1QD46oXeTqrNWRSDDNe nWoJ4Nf0/fRMJpBNbfHRQ0mxB6TzVbtmnRGwMXE50/PnxvU3PszcR3RXswZwOn+fcOD00kUJ K/Y8maI9Ky2IteWybdjfqWZf1i846Vv9zkeHT3eLXMRzf/9ZjDYn15Tz/00tb5jK4/+af1f/ ruX8Ow9NYjhSWvwhTaRKX4mlOCPRUIu5qDgRAK/wk09hAwAA DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: > On Thu, Mar 13, 2014 at 08:17:29AM +0000, Chanwoo Choi wrote: >> This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface >> and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU >> counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides >> PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization >> and then busfreq driver adjusts dynamically the operating frequency/voltage >> by using DEVFREQ Subsystem. >> >> Signed-off-by: Chanwoo Choi >> --- >> .../devicetree/bindings/devfreq/exynos4_bus.txt | 49 ++++++++++++++++++++++ >> 1 file changed, 49 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> new file mode 100644 >> index 0000000..2a83fcc >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> @@ -0,0 +1,49 @@ >> + >> +Exynos4210/4x12 busfreq driver >> +----------------------------- >> + >> +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage >> +scaling according to PPMU counters of memory controllers >> + >> +Required properties: >> +- compatible : should contain Exynos4 SoC type as follwoing: >> + - "samsung,exynos4x12-busfreq" for Exynos4x12 >> + - "samsung,exynos4210-busfreq" for Exynos4210 > > Is there a device called "busfreq"? What device does this binding > describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). > >> +- reg : offset and length of the ppmudmc0/1 >> + - PPMU (Performance Profiling Monitoring Units) > > You seem to require a particular order here. It would be good to be > explicit about it. OK, I'll modify it as following: the offset and length of the PPMU_DMC0 / PPMU_DMC1 PPMU_DMC0/PPMU_DMC1 show memory buy utilization to exynos4_bus driver. > >> + : It is to profile performance event of DMC(Dynamic Memory >> + Controller) So, exynos4_bus.c can check memory bus utilization >> + by using PPMU of Exynos4 SoC. > > This is superfluous, and Linux-specific. The binding document shouldn't > need to refer to drivers. I'll remove this description. > >> +- clocks : clock number of ppmudmc0/1 >> +- clock-names : clock name of ppmudmc0/1 > > Are these two clocks, or one clock with a slash in the name? > > Please list each name separately. I'll expalin clocks as following: "ppmudmc0", "ppmudmc1" > >> +- vdd_int-supply: regulator for interface block of Exynos4 >> + >> +Optional properties: >> +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc >> +- regs-name : register name of ppmudmc0/1 > > This is completely nonstandard. Did you mean reg-names? I'll remove it about 'regs-name'. > > Please be explicit about the names you expect. Write them in full, > quoted, and describe the relationship to the reg property. > >> + >> +All the required listed above must be defined under code busfreq with devfreq > > I'm having some difficulty figuring out what exactly this is intended to > mean. I'll add detailed opeation method and role of exynos4_busfreq driver. Thanks, Chanwoo Choi