From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Daney Subject: Re: [PATCH 1/2] of/phylib: Use device tree properties to initialize Marvell PHYs. Date: Wed, 17 Nov 2010 16:01:19 -0800 Message-ID: <4CE46CCF.4080707@caviumnetworks.com> References: <1290038071-13296-1-git-send-email-ddaney@caviumnetworks.com> <1290038071-13296-2-git-send-email-ddaney@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Cyril Chemparathy , Arnaud Patard To: David Daney Return-path: In-Reply-To: <1290038071-13296-2-git-send-email-ddaney-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: netdev.vger.kernel.org On 11/17/2010 03:54 PM, David Daney wrote: > Some aspects of PHY initialization are board dependent, things like > indicator LED connections and some clocking modes cannot be determined > by probing. The dev_flags element of struct phy_device can be used to > control these things if an appropriate value can be passed from the > Ethernet driver. We run into problems however if the PHY connections > are specified by the device tree. There is no way for the Ethernet > driver to know what flags it should pass. > > If we are using the device tree, the struct phy_device will be > populated with the device tree node corresponding to the PHY, and we > can extract extra configuration information from there. > > The next question is what should the format of that information be? > It is highly device specific, and the device tree representation > should not be tied to any arbitrary kernel defined constants. A > straight forward representation is just to specify the exact bits that > should be set using the "marvell,reg-init" property: > > phy5: ethernet-phy@5 { > reg =<5>; > device_type = "ethernet-phy"; > marvell,reg-init = > <0x00030010 0x5777>, /* Reg 3,16<- 0x5777 */ > <0x00030011 0x00aa>, /* Reg 3,17<- 0x00aa */ > <0x00030012 0x4105>, /* Reg 3,18<- 0x4105 */ > <0x00030013 0x0060>; /* Reg 3,19<- 0x0060 */ > <0x00020015 0x00300000>; /* clear bits 4..5 of Reg 2,21 */ Well, of course these mask bits are reversed. That last line should really be: <0x00020015 0xffcf0000>; /* clear bits 4..5 of Reg 2,21 */ > }; > > The Marvell PHYs have a page select register at register 22 (0x16), we > can specify any register by its page and register number. These are > encoded in the high and low parts of the first word. The second word > contains a mask and value to be ORed in its high and low parts. > property, the PHY initialization is unchanged. [...] David Daney