From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 3C8817E22E for ; Thu, 12 Apr 2018 02:11:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751961AbeDLCL0 (ORCPT ); Wed, 11 Apr 2018 22:11:26 -0400 Received: from mga17.intel.com ([192.55.52.151]:10837 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751734AbeDLCLZ (ORCPT ); Wed, 11 Apr 2018 22:11:25 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Apr 2018 19:11:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,439,1517904000"; d="scan'208";a="36571536" Received: from ifreitas-mobl.amr.corp.intel.com (HELO [10.254.104.117]) ([10.254.104.117]) by fmsmga002.fm.intel.com with ESMTP; 11 Apr 2018 19:11:22 -0700 Subject: Re: [PATCH v3 04/10] Documentations: dt-bindings: Add a document of PECI adapter driver for Aspeed AST24xx/25xx SoCs To: Joel Stanley , Rob Herring , linux-aspeed@lists.ozlabs.org, Ryan Chen Cc: Alan Cox , Andrew Jeffery , Andrew Lunn , Andy Shevchenko , Arnd Bergmann , Benjamin Herrenschmidt , Fengguang Wu , Greg KH , Guenter Roeck , Haiyue Wang , James Feist , Jason M Biils , Jean Delvare , Julia Cartwright , Miguel Ojeda , Milton Miller II , Pavel Machek , Randy Dunlap , Stef van Os , Sumeet R Pawnikar , Vernon Mauery , Linux Kernel Mailing List , linux-doc@vger.kernel.org, devicetree , linux-hwmon@vger.kernel.org, Linux ARM , OpenBMC Maillist References: <20180410183212.16787-1-jae.hyun.yoo@linux.intel.com> <20180410183212.16787-5-jae.hyun.yoo@linux.intel.com> From: Jae Hyun Yoo Message-ID: <2c5f7636-169c-f58f-1c45-2e9950be72f3@linux.intel.com> Date: Wed, 11 Apr 2018 19:11:22 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi Joel, On 4/11/2018 4:52 AM, Joel Stanley wrote: > On 11 April 2018 at 04:02, Jae Hyun Yoo wrote: >> This commit adds a dt-bindings document of PECI adapter driver for Aspeed > > We try to capitalise ASPEED. > Got it. Will capitalize all Aspeed words. >> AST24xx/25xx SoCs. >> --- >> .../devicetree/bindings/peci/peci-aspeed.txt | 60 ++++++++++++++++++++++ >> 1 file changed, 60 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/peci/peci-aspeed.txt >> >> diff --git a/Documentation/devicetree/bindings/peci/peci-aspeed.txt b/Documentation/devicetree/bindings/peci/peci-aspeed.txt >> new file mode 100644 >> index 000000000000..4598bb8c20fa >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/peci/peci-aspeed.txt >> @@ -0,0 +1,60 @@ >> +Device tree configuration for PECI buses on the AST24XX and AST25XX SoCs. >> + >> +Required properties: >> +- compatible : Should be "aspeed,ast2400-peci" or "aspeed,ast2500-peci" >> + - aspeed,ast2400-peci: Aspeed AST2400 family PECI >> + controller >> + - aspeed,ast2500-peci: Aspeed AST2500 family PECI >> + controller >> +- reg : Should contain PECI controller registers location and >> + length. >> +- #address-cells : Should be <1>. >> +- #size-cells : Should be <0>. >> +- interrupts : Should contain PECI controller interrupt. >> +- clocks : Should contain clock source for PECI controller. >> + Should reference clkin. > > Are you sure that this is driven by clkin? Most peripherals on the > Aspeed are attached to the apb, so should reference that clock. > According to the datasheet, PECI controller module is attached to apb but its clock source is the 24MHz external clock. >> +- clock_frequency : Should contain the operation frequency of PECI controller >> + in units of Hz. >> + 187500 ~ 24000000 > > Can you explain why you need both the parent clock and this frequency > to be specified? > Based on this setting, driver code makes clock divisor value to set operation clock of PECI controller which is adjustable. >> + >> +Optional properties: >> +- msg-timing-nego : Message timing negotiation period. This value will > > Perhaps msg-timing-period? Or just msg-timing? > Will use msg-timing instead. >> + determine the period of message timing negotiation to be >> + issued by PECI controller. The unit of the programmed >> + value is four times of PECI clock period. >> + 0 ~ 255 (default: 1) >> +- addr-timing-nego : Address timing negotiation period. This value will >> + determine the period of address timing negotiation to be >> + issued by PECI controller. The unit of the programmed >> + value is four times of PECI clock period. >> + 0 ~ 255 (default: 1) >> +- rd-sampling-point : Read sampling point selection. The whole period of a bit >> + time will be divided into 16 time frames. This value will >> + determine the time frame in which the controller will >> + sample PECI signal for data read back. Usually in the >> + middle of a bit time is the best. >> + 0 ~ 15 (default: 8) >> +- cmd_timeout_ms : Command timeout in units of ms. >> + 1 ~ 60000 (default: 1000) >> + >> +Example: >> + peci: peci@1e78b000 { >> + compatible = "simple-bus"; >> + #address-cells = <1>; >> + #size-cells = <1>; >> + ranges = <0x0 0x1e78b000 0x60>; >> + >> + peci0: peci-bus@0 { >> + compatible = "aspeed,ast2500-peci"; >> + reg = <0x0 0x60>; >> + #address-cells = <1>; >> + #size-cells = <0>; >> + interrupts = <15>; >> + clocks = <&clk_clkin>; >> + clock-frequency = <24000000>; >> + msg-timing-nego = <1>; >> + addr-timing-nego = <1>; >> + rd-sampling-point = <8>; >> + cmd-timeout-ms = <1000>; >> + }; >> + }; >> -- >> 2.16.2 >> -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html