From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932828AbcETDaj (ORCPT ); Thu, 19 May 2016 23:30:39 -0400 Received: from nasmtp01.atmel.com ([192.199.1.245]:21080 "EHLO ussmtp01.atmel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932276AbcETDai (ORCPT ); Thu, 19 May 2016 23:30:38 -0400 Subject: Re: [PATCH v2 2/2] [media] atmel-isc: DT binding for Image Sensor Controller driver To: Rob Herring References: <1463557590-29318-1-git-send-email-songjun.wu@atmel.com> <1463557590-29318-3-git-send-email-songjun.wu@atmel.com> <20160518230522.GA3198@rob-hp-laptop> CC: , , , , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , , From: "Wu, Songjun" Organization: ATMEL Message-ID: Date: Fri, 20 May 2016 11:30:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <20160518230522.GA3198@rob-hp-laptop> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, Thank you for your comments. On 5/19/2016 07:05, Rob Herring wrote: > On Wed, May 18, 2016 at 03:46:29PM +0800, Songjun Wu wrote: >> DT binding documentation for ISC driver. >> >> Signed-off-by: Songjun Wu >> --- >> >> Changes in v2: >> - Remove the unit address of the endpoint. >> - Add the unit address to the clock node. >> - Avoid using underscores in node names. >> - Drop the "0x" in the unit address of the i2c node. >> - Modify the description of "atmel,sensor-preferred". >> - Add the description for the ISC internal clock. >> >> .../devicetree/bindings/media/atmel-isc.txt | 100 +++++++++++++++++++++ >> 1 file changed, 100 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/media/atmel-isc.txt >> >> diff --git a/Documentation/devicetree/bindings/media/atmel-isc.txt b/Documentation/devicetree/bindings/media/atmel-isc.txt >> new file mode 100644 >> index 0000000..9e65395 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/media/atmel-isc.txt >> @@ -0,0 +1,100 @@ >> +Atmel Image Sensor Controller (ISC) >> +---------------------------------------------- >> + >> +Required properties for ISC: >> +- compatible >> + Must be "atmel,sama5d2-isc" >> +- reg >> + Physical base address and length of the registers set for the device; >> +- interrupts >> + Should contain IRQ line for the ISC; >> +- clocks >> + List of clock specifiers, corresponding to entries in >> + the clock-names property; >> + Please refer to clock-bindings.txt. >> +- clock-names >> + Required elements: "hclock", "ispck". >> +- pinctrl-names, pinctrl-0 >> + Please refer to pinctrl-bindings.txt. >> +- clk-in-isc >> + ISC internal clock node, it includes two clock nodes, >> + isc-ispck and isc-mck. > > And you need to describe each of these nodes and the properties they > have. But more on this below... > Should I move the description of clock node below to here? >> +- atmel,sensor-preferred >> + ISC may convert the raw format to the specified format when the sensor >> + outputs the raw format, and the sensor may output the specified format >> + directly. If sensor is preferred to output the specified format >> + directly, the value should be 1 (1-preferred, 0-not). >> + The default value is 1. > > I don't think this belongs in DT. It sounds more like a configuration > and userspace decision. It is still not clear what you mean by > "specified format". > Accept, I will remove this. >> + >> +ISC supports a single port node with parallel bus. It should contain one >> +'port' child node with child 'endpoint' node. Please refer to the bindings >> +defined in Documentation/devicetree/bindings/media/video-interfaces.txt. >> + >> +Required properties for the ISC internal clocks: >> +- #address-cells >> + should be 1 (reg is used to encode clk id). >> +- #size-cells >> + should be 0 (reg is used to encode clk id). >> +- name >> + device tree node describing a ISC internal clock. >> + * #clock-cells: from common clock binding; should be set to 0. >> + * reg: clock id, there are two values, >> + <0> is ISP clock, <1> is master clock. >> + * clocks: shall be the isc internal clock source phandles. >> + e.g. clocks = <&isc_clk>, <&iscck>, <&isc_gclk>; >> + >> +Example: >> +isc: isc@f0008000 { >> + compatible = "atmel,sama5d2-isc"; >> + reg = <0xf0008000 0x4000>; >> + interrupts = <46 IRQ_TYPE_LEVEL_HIGH 5>; >> + clocks = <&isc_clk>, <&isc_ispck>; >> + clock-names = "hclock", "ispck"; >> + atmel,sensor-preferred = <1>; >> + >> + port { >> + #address-cells = <1>; >> + #size-cells = <0>; >> + >> + isc_0: endpoint { >> + remote-endpoint = <&ov7740_0>; >> + hsync-active = <1>; >> + vsync-active = <0>; >> + pclk-sample = <1>; >> + }; >> + }; >> + >> + clk-in-isc { > > Is this really separate from the rest of the isc block. It would be > much more simple to define all the input clocks at the parent and then > reference these 2 clocks with <&isc 0> and <&isc 1>. > Yes, it's separate from the rest of isc block. It will register two clocks, one is used in ISC internal processor, the other will provide the clock to the sensor outside. I think it's better that the parent clock is included in node 'clk-in-isc' node. I will try to optimize this node. >> + #address-cells = <1>; >> + #size-cells = <0>; >> + >> + isc_ispck: isc-ispck@0 { > > These would need a compatible string otherwise. > >> + #clock-cells = <0>; >> + reg = <0>; > > Are 0 and 1 meaningful in terms of the hardware description? > Yes, It's meaningful. The register field is different, 0 and 1 can distinguish the different clock. >> + clocks = <&isc_clk>, <&iscck>; >> + }; >> + >> + isc_mck: isc-mck@1 { >> + #clock-cells = <0>; >> + reg = <1>; >> + clocks = <&isc_clk>, <&iscck>, <&isc_gclk>; >> + }; >> + }; >> +};