From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanley Chu Subject: Re: [PATCH v3 5/7] dt-bindings: scsi: ufs: Add document for ufs-mediatek Date: Thu, 14 Mar 2019 11:45:45 +0800 Message-ID: <1552535145.30977.61.camel@mtkswgap22> References: <1551252192-535-1-git-send-email-stanley.chu@mediatek.com> <1551252192-535-7-git-send-email-stanley.chu@mediatek.com> <20190312133113.GA8956@bogus> <1552444909.30977.39.camel@mtkswgap22> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+glpam-linux-mediatek=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Rob Herring Cc: "mark.rutland-5wv7dgnIgG8@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "martin.petersen-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org" , "subhashj-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org" , Chun-Hung Wu =?UTF-8?Q?=28=E5=B7=AB=E9=A7=BF=E5=AE=8F=29?= , Kuohong Wang =?UTF-8?Q?=28=E7=8E=8B=E5=9C=8B=E9=B4=BB=29?= , Peter Wang =?UTF-8?Q?=28=E7=8E=8B=E4=BF=A1=E5=8F=8B=29?= , "kishon-l0cyMroinI0@public.gmane.org" , "avri.altman-Sjgp3cTcYWE@public.gmane.org" , "linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "liwei213-hv44wF8Li93QT0dZR+AlfA@public.gmane.org" , "alim.akhtar-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org" , Chunfeng Yun =?UTF-8?Q?=28=E4=BA=91=E6=98=A5=E5=B3=B0=29?= pe List-Id: devicetree@vger.kernel.org Hi Rob, On Thu, 2019-03-14 at 03:48 +0800, Rob Herring wrote: > On Tue, Mar 12, 2019 at 9:41 PM Stanley Chu wrote: > > > > Hi Rob, > > > > On Tue, 2019-03-12 at 21:31 +0800, Rob Herring wrote: > > > On Wed, Feb 27, 2019 at 03:23:10PM +0800, Stanley Chu wrote: > > > > Add UFS and UFS PHY node document for Mediatek SoC chips. > > > > > > > > Signed-off-by: Stanley Chu > > > > --- > > > > .../devicetree/bindings/ufs/ufs-mediatek.txt | 47 +++++++++++++++++++ > > > > 1 file changed, 47 insertions(+) > > > > create mode 100644 Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > > > > > > diff --git a/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > > new file mode 100644 > > > > index 000000000000..5fc985928b3e > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > > @@ -0,0 +1,47 @@ > > > > +* Mediatek Universal Flash Storage (UFS) Host Controller > > > > + > > > > +UFS nodes are defined to describe on-chip UFS hardware macro. > > > > +Each UFS Host Controller should have its own node. > > > > + > > > > +To bind UFS PHY with UFS host controller, the controller node should > > > > +contain a phandle reference to UFS M-PHY node. > > > > + > > > > +Required properties for UFS nodes: > > > > +- compatible : Compatible list, contains the following controller: > > > > + "mediatek,ufshci" > > > > > > Needs an SoC specific compatible string. > > > > Will add. > > > > > > > > > +- reg : Address and length of the UFS register set. > > > > +- interrupt-parent : Interrupt device. > > > > > > Drop this. It is implied or may be in a parent node. > > > > Will remove it. > > > > > > > > > +- phys : phandle to m-phy. > > > > +- clocks : List of phandle and clock specifier pairs. > > > > +- clock-names : List of clock input name strings sorted in the same > > > > + order as the clocks property. "ufs-clk" is mandatory. > > > > +- freq-table-hz : Array of operating frequencies stored in the same > > > > + order as the clocks property. If this property is not > > > > + defined or a value in the array is "0" then it is assumed > > > > + that the frequency is set by the parent clock or a > > > > + fixed rate clock source. > > > > +- vcc-supply : Power to the UFS device. > > > > +- vcc-fixed-regulator: Specify that vcc-supply is a fixed regulator. > > > > > > Why is this needed? The driver could query the voltage range of the > > > regulator or you could check the regulator node. > > > > Both ufshcd-pltfrm.txt and ufshcd-pltfrm.c driver allow > > > > - -fixed-regulator : boolean property specifying that > > -supply is a fixed regulator. > > > > Our vcc does not require further initializatio, so is it OK here or > > shall we also modify both ufshcd-pltfrm dt-bindings document and ufs > > driver to avoid using it ? > > There are no users of that property in tree and doesn't look like > adding it was ever reviewed. We have standard ways to handle this and > don't need a custom property. Got it and thanks. I am planning to drop VCC related first in this series and add it back by another patch accompanied with VCC/ICC logic fix in UFS common driver which beyond the scope of this series. > > Rob Thanks, Stanley.