From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: [RFC 1/3] devfreq: dt-bindings: Document Exynos3250 devfreq driver Date: Mon, 08 Dec 2014 10:09:02 +0100 Message-ID: <1418029742.6084.8.camel@AMDC1943> References: <1417797988-29225-1-git-send-email-k.kozlowski@samsung.com> <1417797988-29225-2-git-send-email-k.kozlowski@samsung.com> <20141205165356.GC12849@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-reply-to: <20141205165356.GC12849@leverpostej> Sender: linux-pm-owner@vger.kernel.org To: Mark Rutland Cc: MyungJoo Ham , Kyungmin Park , Kukjin Kim , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , "devicetree@vger.kernel.org" , Russell King , Chanwoo Choi , Marek Szyprowski , Bartlomiej Zolnierkiewicz , Tomasz Figa List-Id: devicetree@vger.kernel.org On pi=C4=85, 2014-12-05 at 16:53 +0000, Mark Rutland wrote: > On Fri, Dec 05, 2014 at 04:46:26PM +0000, Krzysztof Kozlowski wrote: > > Add documentation for bindings used by Exynos3250 devfreq driver. > >=20 > > Signed-off-by: Krzysztof Kozlowski > > --- > > .../bindings/arm/samsung/exynos3250-devfreq.txt | 66 ++++++++++= ++++++++++++ > > 1 file changed, 66 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/arm/samsung/e= xynos3250-devfreq.txt > >=20 > > diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos32= 50-devfreq.txt b/Documentation/devicetree/bindings/arm/samsung/exynos32= 50-devfreq.txt > > new file mode 100644 > > index 000000000000..047955e9e371 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/arm/samsung/exynos3250-devf= req.txt > > @@ -0,0 +1,66 @@ > > +Samsung Exynos3250 devfreq driver >=20 > The binding should describe the hardware, not a particular driver of > that hardware. Please write the binding (and its documentation) with > that in mind, and drop references to the driver and "busfreq". >=20 > With an adequate binding we can probe the device and forward the > information to relevant driver(s) as necessary. OK >=20 > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > + > > +The driver support changing frequencies and voltage for: > > + - memory controller and bus, > > + - peripheral buses (left and right). >=20 >=20 > What do left and right mean in this context? These are names for clock domains associated with buses between memory controller and peripherals. They're called "leftbus" and "rightbus" in documentation. >=20 > > + > > +Memory controller and bus > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D > > +Required properties: > > + - compatible : should be "samsung,exynos3250-busfreq-mif" > > + - reg : two sets (offset and length of the register) for PPMU reg= isters > > + used by this devfreq driver > > + - clock-names : one clock of name "dmc" to manage frequency > > + - clocks : phandle and specifier for clock listed in clock-names = property > > + - vdd_mif-supply : phandle to MIF voltage regulator >=20 > s/_/-/ in property names please. Sure. >=20 > > + > > +Peripheral buses > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > +Required properties: > > + - compatible : should be "samsung,exynos3250-busfreq-int" >=20 > What does "int" mean here? It is the name of power source (VDD_INT) and regulator supplying certai= n power domains in SoC. However I have no clue what engineers meant by this abbreviation. >=20 > > + - reg : two sets (offset and length of the register) for PPMU reg= isters > > + used by this devfreq driver > > + - clock-names : names for PPMU clocks and bus clocks to manage fr= equencies; > > + All following clock names (and corresponding phandles) must be > > + provided: > > + - "ppmu_left", "ppmu_right", > > + - "aclk_400", "aclk_266", "aclk_200", "aclk_160", "aclk_gdl", "ac= lk_gdr", "mfc"; > > + - clocks : phandles and specifiers for clocks listed in clock-nam= es property > > + - vdd_mif-supply : phandle to INT voltage regulator >=20 > s/_/-/ here too. OK Thanks for feedback. Best regards, Krzysztof > Thanks, > Mark. >=20 > > + > > +Example > > +=3D=3D=3D=3D=3D=3D=3D > > + busfreq_mif: busfreq@106A0000 { > > + compatible =3D "samsung,exynos3250-busfreq-mif"; > > + reg =3D <0x106A0000 0x2000>, <0x106B0000 0x2000>; > > + clocks =3D <&cmu_dmc CLK_DIV_DMC>; > > + clock-names =3D "dmc"; > > + vdd_mif-supply =3D <&buck1_reg>; > > + status =3D "okay"; > > + }; > > + > > + busfreq_int: busfreq@116A0000 { > > + compatible =3D "samsung,exynos3250-busfreq-int"; > > + reg =3D <0x116A0000 0x2000>, <0x112A0000 0x2000>; > > + clocks =3D <&cmu CLK_PPMULEFT>, > > + <&cmu CLK_PPMURIGHT>, > > + <&cmu CLK_DIV_ACLK_400_MCUISP>, > > + <&cmu CLK_DIV_ACLK_266>, > > + <&cmu CLK_DIV_ACLK_200>, > > + <&cmu CLK_DIV_ACLK_160>, > > + <&cmu CLK_DIV_GDL>, > > + <&cmu CLK_DIV_GDR>, > > + <&cmu CLK_DIV_MFC>; > > + clock-names =3D "ppmuleft", > > + "ppmuright", > > + "aclk_400", > > + "aclk_266", > > + "aclk_200", > > + "aclk_160", > > + "aclk_gdl", > > + "aclk_gdr", > > + "mfc"; > > + vdd_int-supply =3D <&buck3_reg>; > > + status =3D "okay"; > > + }; > > --=20 > > 1.9.1 > >=20 > > -- > > To unsubscribe from this list: send the line "unsubscribe devicetre= e" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > >=20