From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755492AbeEaPbx (ORCPT ); Thu, 31 May 2018 11:31:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:51226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755369AbeEaPbt (ORCPT ); Thu, 31 May 2018 11:31:49 -0400 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 To: Codrin Ciubotariu , Rob Herring From: Stephen Boyd In-Reply-To: Cc: devicetree@vger.kernel.org, Linux-ALSA , Alexandre Belloni , "linux-kernel@vger.kernel.org" , Boris Brezillon , Mark Brown , Cristian.Birsan@microchip.com, linux-clk , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" References: <1527251668-31396-1-git-send-email-codrin.ciubotariu@microchip.com> <1527251668-31396-2-git-send-email-codrin.ciubotariu@microchip.com> <20180531005827.GA17203@rob-hp-laptop> <4f2e6e6a-df3a-b645-093c-b4467b3aa843@microchip.com> Message-ID: <152778070837.144038.4555982304713569160@swboyd.mtv.corp.google.com> User-Agent: alot/0.7 Subject: Re: [PATCH v4 1/7] dt-bindings: clk: at91: add an I2S mux clock Date: Thu, 31 May 2018 08:31:48 -0700 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w4VFVvDj020085 Quoting Rob Herring (2018-05-31 07:20:57) > On Thu, May 31, 2018 at 5:25 AM, Codrin Ciubotariu > wrote: > > On 31.05.2018 03:58, Rob Herring wrote: > >> > >> On Fri, May 25, 2018 at 03:34:22PM +0300, Codrin Ciubotariu wrote: > >>> > >>> The I2S mux clock can be used to select the I2S input clock. The > >>> available parents are the peripheral and the generated clocks. > >>> > >>> Signed-off-by: Codrin Ciubotariu > >>> --- > >>> .../devicetree/bindings/clock/at91-clock.txt | 34 > >>> ++++++++++++++++++++++ > >>> 1 file changed, 34 insertions(+) > >>> > >>> diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt > >>> b/Documentation/devicetree/bindings/clock/at91-clock.txt > >>> index 51c259a..1c46b3c 100644 > >>> --- a/Documentation/devicetree/bindings/clock/at91-clock.txt > >>> +++ b/Documentation/devicetree/bindings/clock/at91-clock.txt > >>> @@ -90,6 +90,8 @@ Required properties: > >>> "atmel,sama5d2-clk-audio-pll-pmc" > >>> at91 audio pll output on AUDIOPLLCLK that feeds the PMC > >>> and can be used by peripheral clock or generic clock > >>> + "atmel,sama5d2-clk-i2s-mux": > >>> + at91 I2S clock source selection > >> > >> > >> Is this boolean or takes some values. If latter, what are valid values? > > > > > > This is the compatible string of the clock driver. > > Ah, now I remember. AT91 uses fine grained clock nodes in DT. Is there > still a plan to fix this? I'm also interested in a plan. > >> > >>> + compatible = "atmel,sama5d2-clk-i2s-mux"; > >>> + #address-cells = <1>; > >>> + #size-cells = <0>; > >> > >> > >> How do you address this block? My guess is you don't because it is just > >> part of some other block and you are just creating this node to > >> instantiate a driver. Just make the node for the actual h/w block a > >> clock provider and define the clock ids (0 and 1). > > > > > > This block is not addressed, but its children are. The register we access in > > this driver is not part of other block. It's a SFR register, accessed > > through syscon and it has nothing to do with the I2S IP (see SAMA5D2 DS, > > page 1256, fig. 44-1: I2SC Block Diagram) that is the consumer of this > > clock. Adding a clock-id property in the I2S node would be just like v3 of > > this series, with the difference that we use clock-id instead of alias id to > > set the clock parent, which is not how you suggested back then. > > I wasn't suggesting a clock-id property, but a clock specifier (i.e. > make #clock-cells 1). > > But AT91 clocks are all a mess, so I don't know what to tell you. > If #clock-cells of 1 works then we should go with that. It's still weird that we need random nodes to add more clks, but I guess that's how it's going to be for each at91 clk driver until it changes to be one big provider node.