From mboxrd@z Thu Jan 1 00:00:00 1970 From: atish.patra@wdc.com (Atish Patra) Date: Tue, 16 Oct 2018 15:20:34 -0700 Subject: [RFC 1/4] pwm: sifive: Add DT documentation for SiFive PWM Controller. In-Reply-To: <20181016220437.GB31973@mithrandir> References: <1539111085-25502-1-git-send-email-atish.patra@wdc.com> <1539111085-25502-2-git-send-email-atish.patra@wdc.com> <20181010134926.GD21134@ulmo> <25758ab9-eb36-741b-6264-42412b3ddd8e@wdc.com> <20181016110142.GC8852@ulmo> <6e108e3c-15c1-b13b-ac3e-60c5eb209c7b@sifive.com> <20181016220437.GB31973@mithrandir> Message-ID: <7fc1168d-a840-032a-c0a9-2a610127c484@wdc.com> To: linux-riscv@lists.infradead.org List-Id: linux-riscv.lists.infradead.org On 10/16/18 3:04 PM, Thierry Reding wrote: > On Tue, Oct 16, 2018 at 10:31:42AM -0700, Paul Walmsley wrote: >> >> On 10/16/18 4:01 AM, Thierry Reding wrote: >>> On Mon, Oct 15, 2018 at 03:57:35PM -0700, Atish Patra wrote: >>>> On 10/10/18 6:49 AM, Thierry Reding wrote: >>>>> On Tue, Oct 09, 2018 at 11:51:22AM -0700, Atish Patra wrote: >>>>>> +Required properties: >>>>>> +- compatible: should be one of >>>>>> + "sifive,fu540-c000-pwm0","sifive,pwm0". >>>>> What's the '0' in here? A version number? >>>>> >>>> I think yes. Since fu540 is the first Linux capable RISC-V core, SiFive Guys >>>> decided mark it as version 0. >>>> >>>> @Wesly: Please correct me if I am wrong. >>> It seems fairly superfluous to me to have a version number in additon to >>> the fu540-c000, which already seems to be the core plus some sort of >>> part number. Do you really expect there to be any changes in the SoC >>> that would require a different compatible string at this point? If the >>> SoC has taped out, how will you ever get a different version of the PWM >>> IP in it? >>> >>> I would expect any improvements or changes to the PWM IP to show up in a >>> different SoC generation, at which point it would be something like >>> "sifive,fu640-c000" maybe, or perhaps "sifive,fu540-d000", or whatever >>> the numbering is. >> >> >> The "0" suffix refers to a revision number for the underlying PWM IP block. >> >> It's certainly important to keep that version number on the "sifive,pwm0" >> compatible string that doesn't have the chip name associated with it. > > Isn't the hardware identified by "sifive,pwm0" and "sifive,fu540-c000" > effectively identical? Yes. Is there a need to have two compatible strings > that refer to the exact same hardware? > The DT in the hardware has only sifive,pwm0. I have added "sifive,fu540-c000" as that was concluded as the correct compatible string from platform level interrupt controller patch(PLIC) discussion. (http://lists.infradead.org/pipermail/linux-riscv/2018-August/001135.html) "sifive,pwm0" is required to until all the Unleashed SoC gets an updated firmware with correct compatible string "sifive,fu540-c000". I agree this is a mess. But we have to carry it until all every DT(corresponding to each driver) is finalized. I guess SiFive will release a firmware update that contains all the updated DT once that is done. We can get rid of all the redundant compatible strings at that time. Regards, Atish >> As to whether there could ever be a FU540-C000 part with different IP block >> versions on it: FU540-C000 is ultimately a marketing name.? While >> theoretically we shouldn't have another "FU540-C000" chip with different >> peripheral IP block versions on it, I don't think any engineer can guarantee >> that it won't happen. > > I would argue that if at some point there was indeed a chip with the > same name but a different IP block version in it, we can figure out what > to call it. Sure there are no guarantees, but it's still fairly unlikely > in my opinion, so I personally wouldn't worry about this up front. > > Anyway, I don't feel strongly either way, I'm just pointing out that > this is somewhat unusual. If you want to keep it, feel free to. > > Thierry > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D33E8C5ACC6 for ; Tue, 16 Oct 2018 22:20:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A0DD22148E for ; Tue, 16 Oct 2018 22:20:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="rx10t38Y"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="lu+mW7bR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0DD22148E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=wdc.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JP/GPmDQgYErDP21OnDxMQM2J3bm9OtDYTwVwqWavCI=; b=rx10t38YNdMnmiZuD+o6L7mRy MOFOBSZf9PbrIhGwJ8g+u9pkk3P81Db2nZZMa1zuKyO4YYc9v5i1kkBl33dTKLFBsohOcuAazD9KX yRjNvNdWDk4OmdOxxx+uO1du0v/RKYZ8E732I0zME/BSYHKWEw+6/wbujt5nZdh1V/yfq2f9+pEKP NlYwg0zpg09aXHxLwAGWdC6bcxWZ3dPa147Bpl7fK3vpLQGoSFO69iNQrx7mgNLBI4U7AJvy8hlAx Xb2Rqz63UQ61LjrrSWaTxokHAH4ZNBtomfoP5HeI8uJyHLS8BV8iTb7s2djT13wd/XEnIW5BOKjGx r3cGQOwXQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gCXhr-0006um-MB; Tue, 16 Oct 2018 22:20:51 +0000 Received: from esa5.hgst.iphmx.com ([216.71.153.144]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gCXhn-0006tA-O2 for linux-riscv@lists.infradead.org; Tue, 16 Oct 2018 22:20:49 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1539728448; x=1571264448; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=a2fG+05X3DwXT0k2mb0bZPF86aHlYDiKC30d3quRiTA=; b=lu+mW7bR66BFxqYA9W9+JWD+q+xq9JQFjlzGsRgb8O92X1QR51imPFwu z9cqewzncKuSYXC0JKl0fxFP1K6jYmN6TbaL6Pwj2IX/SUmCfZj6XakO0 XDT22PQnehNCvuSF3+Q3iA6tHJvRRJ2Rx3tpWHJ/0TBmG3qnjvwcVDi5/ YKis0yooE8epNdYJc+JfyS1NngirvnNTmlPhD6CKsuSljoIzd2kdCdpcq C3nRELqbTCKF43edHx2qxRF8/eEzO69No/a+Y3Z2VqoCIdCC8ztAYcA5K pEmXAKId3s/FdnIgEg4+2gtW6vjgOP6lppiFElQE/C1ee9yLa3h/OFctM A==; X-IronPort-AV: E=Sophos;i="5.54,389,1534780800"; d="scan'208";a="93188008" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 17 Oct 2018 06:20:36 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP; 16 Oct 2018 15:05:41 -0700 Received: from c02v91rdhtd5.sdcorp.global.sandisk.com (HELO [10.111.73.114]) ([10.111.73.114]) by uls-op-cesaip02.wdc.com with ESMTP; 16 Oct 2018 15:20:34 -0700 Subject: Re: [RFC 1/4] pwm: sifive: Add DT documentation for SiFive PWM Controller. To: Thierry Reding , Paul Walmsley References: <1539111085-25502-1-git-send-email-atish.patra@wdc.com> <1539111085-25502-2-git-send-email-atish.patra@wdc.com> <20181010134926.GD21134@ulmo> <25758ab9-eb36-741b-6264-42412b3ddd8e@wdc.com> <20181016110142.GC8852@ulmo> <6e108e3c-15c1-b13b-ac3e-60c5eb209c7b@sifive.com> <20181016220437.GB31973@mithrandir> From: Atish Patra Message-ID: <7fc1168d-a840-032a-c0a9-2a610127c484@wdc.com> Date: Tue, 16 Oct 2018 15:20:34 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181016220437.GB31973@mithrandir> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181016_152047_899415_66652085 X-CRM114-Status: GOOD ( 21.54 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, Wesley Terpstra , linus.walleij@linaro.org, palmer@sifive.com, linux-kernel@vger.kernel.org, hch@infradead.org, linux-gpio@vger.kernel.org, Rob Herring , linux-riscv@lists.infradead.org Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org Message-ID: <20181016222034.MaZhvaPAgTEYJU1wEeZQcA-Uht4OsELlN5P_WOpXqmc@z> T24gMTAvMTYvMTggMzowNCBQTSwgVGhpZXJyeSBSZWRpbmcgd3JvdGU6Cj4gT24gVHVlLCBPY3Qg MTYsIDIwMTggYXQgMTA6MzE6NDJBTSAtMDcwMCwgUGF1bCBXYWxtc2xleSB3cm90ZToKPj4KPj4g T24gMTAvMTYvMTggNDowMSBBTSwgVGhpZXJyeSBSZWRpbmcgd3JvdGU6Cj4+PiBPbiBNb24sIE9j dCAxNSwgMjAxOCBhdCAwMzo1NzozNVBNIC0wNzAwLCBBdGlzaCBQYXRyYSB3cm90ZToKPj4+PiBP biAxMC8xMC8xOCA2OjQ5IEFNLCBUaGllcnJ5IFJlZGluZyB3cm90ZToKPj4+Pj4gT24gVHVlLCBP Y3QgMDksIDIwMTggYXQgMTE6NTE6MjJBTSAtMDcwMCwgQXRpc2ggUGF0cmEgd3JvdGU6Cj4+Pj4+ PiArUmVxdWlyZWQgcHJvcGVydGllczoKPj4+Pj4+ICstIGNvbXBhdGlibGU6IHNob3VsZCBiZSBv bmUgb2YKPj4+Pj4+ICsJInNpZml2ZSxmdTU0MC1jMDAwLXB3bTAiLCJzaWZpdmUscHdtMCIuCj4+ Pj4+IFdoYXQncyB0aGUgJzAnIGluIGhlcmU/IEEgdmVyc2lvbiBudW1iZXI/Cj4+Pj4+Cj4+Pj4g SSB0aGluayB5ZXMuIFNpbmNlIGZ1NTQwIGlzIHRoZSBmaXJzdCBMaW51eCBjYXBhYmxlIFJJU0Mt ViBjb3JlLCBTaUZpdmUgR3V5cwo+Pj4+IGRlY2lkZWQgbWFyayBpdCBhcyB2ZXJzaW9uIDAuCj4+ Pj4KPj4+PiBAV2VzbHk6IFBsZWFzZSBjb3JyZWN0IG1lIGlmIEkgYW0gd3JvbmcuCj4+PiBJdCBz ZWVtcyBmYWlybHkgc3VwZXJmbHVvdXMgdG8gbWUgdG8gaGF2ZSBhIHZlcnNpb24gbnVtYmVyIGlu IGFkZGl0b24gdG8KPj4+IHRoZSBmdTU0MC1jMDAwLCB3aGljaCBhbHJlYWR5IHNlZW1zIHRvIGJl IHRoZSBjb3JlIHBsdXMgc29tZSBzb3J0IG9mCj4+PiBwYXJ0IG51bWJlci4gRG8geW91IHJlYWxs eSBleHBlY3QgdGhlcmUgdG8gYmUgYW55IGNoYW5nZXMgaW4gdGhlIFNvQwo+Pj4gdGhhdCB3b3Vs ZCByZXF1aXJlIGEgZGlmZmVyZW50IGNvbXBhdGlibGUgc3RyaW5nIGF0IHRoaXMgcG9pbnQ/IElm IHRoZQo+Pj4gU29DIGhhcyB0YXBlZCBvdXQsIGhvdyB3aWxsIHlvdSBldmVyIGdldCBhIGRpZmZl cmVudCB2ZXJzaW9uIG9mIHRoZSBQV00KPj4+IElQIGluIGl0Pwo+Pj4KPj4+IEkgd291bGQgZXhw ZWN0IGFueSBpbXByb3ZlbWVudHMgb3IgY2hhbmdlcyB0byB0aGUgUFdNIElQIHRvIHNob3cgdXAg aW4gYQo+Pj4gZGlmZmVyZW50IFNvQyBnZW5lcmF0aW9uLCBhdCB3aGljaCBwb2ludCBpdCB3b3Vs ZCBiZSBzb21ldGhpbmcgbGlrZQo+Pj4gInNpZml2ZSxmdTY0MC1jMDAwIiBtYXliZSwgb3IgcGVy aGFwcyAic2lmaXZlLGZ1NTQwLWQwMDAiLCBvciB3aGF0ZXZlcgo+Pj4gdGhlIG51bWJlcmluZyBp cy4KPj4KPj4KPj4gVGhlICIwIiBzdWZmaXggcmVmZXJzIHRvIGEgcmV2aXNpb24gbnVtYmVyIGZv ciB0aGUgdW5kZXJseWluZyBQV00gSVAgYmxvY2suCj4+Cj4+IEl0J3MgY2VydGFpbmx5IGltcG9y dGFudCB0byBrZWVwIHRoYXQgdmVyc2lvbiBudW1iZXIgb24gdGhlICJzaWZpdmUscHdtMCIKPj4g Y29tcGF0aWJsZSBzdHJpbmcgdGhhdCBkb2Vzbid0IGhhdmUgdGhlIGNoaXAgbmFtZSBhc3NvY2lh dGVkIHdpdGggaXQuCj4gCj4gSXNuJ3QgdGhlIGhhcmR3YXJlIGlkZW50aWZpZWQgYnkgInNpZml2 ZSxwd20wIiBhbmQgInNpZml2ZSxmdTU0MC1jMDAwIgo+IGVmZmVjdGl2ZWx5IGlkZW50aWNhbD8g CgpZZXMuCgpJcyB0aGVyZSBhIG5lZWQgdG8gaGF2ZSB0d28gY29tcGF0aWJsZSBzdHJpbmdzCj4g dGhhdCByZWZlciB0byB0aGUgZXhhY3Qgc2FtZSBoYXJkd2FyZT8KPiAKClRoZSBEVCBpbiB0aGUg aGFyZHdhcmUgaGFzIG9ubHkgc2lmaXZlLHB3bTAuIEkgaGF2ZSBhZGRlZCAKInNpZml2ZSxmdTU0 MC1jMDAwIiBhcyB0aGF0IHdhcyBjb25jbHVkZWQgYXMgdGhlIGNvcnJlY3QgY29tcGF0aWJsZSAK c3RyaW5nIGZyb20gcGxhdGZvcm0gbGV2ZWwgaW50ZXJydXB0IGNvbnRyb2xsZXIgcGF0Y2goUExJ QykgZGlzY3Vzc2lvbi4KCihodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9waXBlcm1haWwvbGlu dXgtcmlzY3YvMjAxOC1BdWd1c3QvMDAxMTM1Lmh0bWwpCgoic2lmaXZlLHB3bTAiIGlzIHJlcXVp cmVkIHRvIHVudGlsIGFsbCB0aGUgVW5sZWFzaGVkIFNvQyBnZXRzIGFuIHVwZGF0ZWQgCmZpcm13 YXJlIHdpdGggY29ycmVjdCBjb21wYXRpYmxlIHN0cmluZyAic2lmaXZlLGZ1NTQwLWMwMDAiLiBJ IGFncmVlIAp0aGlzIGlzIGEgbWVzcy4gQnV0IHdlIGhhdmUgdG8gY2FycnkgaXQgdW50aWwgYWxs IGV2ZXJ5IERUKGNvcnJlc3BvbmRpbmcgCnRvIGVhY2ggZHJpdmVyKSBpcyBmaW5hbGl6ZWQuIEkg Z3Vlc3MgU2lGaXZlIHdpbGwgcmVsZWFzZSBhIGZpcm13YXJlIAp1cGRhdGUgdGhhdCBjb250YWlu cyBhbGwgdGhlIHVwZGF0ZWQgRFQgb25jZSB0aGF0IGlzIGRvbmUuIFdlIGNhbiBnZXQgCnJpZCBv ZiBhbGwgdGhlIHJlZHVuZGFudCBjb21wYXRpYmxlIHN0cmluZ3MgYXQgdGhhdCB0aW1lLgoKUmVn YXJkcywKQXRpc2gKPj4gQXMgdG8gd2hldGhlciB0aGVyZSBjb3VsZCBldmVyIGJlIGEgRlU1NDAt QzAwMCBwYXJ0IHdpdGggZGlmZmVyZW50IElQIGJsb2NrCj4+IHZlcnNpb25zIG9uIGl0OiBGVTU0 MC1DMDAwIGlzIHVsdGltYXRlbHkgYSBtYXJrZXRpbmcgbmFtZS7CoCBXaGlsZQo+PiB0aGVvcmV0 aWNhbGx5IHdlIHNob3VsZG4ndCBoYXZlIGFub3RoZXIgIkZVNTQwLUMwMDAiIGNoaXAgd2l0aCBk aWZmZXJlbnQKPj4gcGVyaXBoZXJhbCBJUCBibG9jayB2ZXJzaW9ucyBvbiBpdCwgSSBkb24ndCB0 aGluayBhbnkgZW5naW5lZXIgY2FuIGd1YXJhbnRlZQo+PiB0aGF0IGl0IHdvbid0IGhhcHBlbi4K PiAKPiBJIHdvdWxkIGFyZ3VlIHRoYXQgaWYgYXQgc29tZSBwb2ludCB0aGVyZSB3YXMgaW5kZWVk IGEgY2hpcCB3aXRoIHRoZQo+IHNhbWUgbmFtZSBidXQgYSBkaWZmZXJlbnQgSVAgYmxvY2sgdmVy c2lvbiBpbiBpdCwgd2UgY2FuIGZpZ3VyZSBvdXQgd2hhdAo+IHRvIGNhbGwgaXQuIFN1cmUgdGhl cmUgYXJlIG5vIGd1YXJhbnRlZXMsIGJ1dCBpdCdzIHN0aWxsIGZhaXJseSB1bmxpa2VseQo+IGlu IG15IG9waW5pb24sIHNvIEkgcGVyc29uYWxseSB3b3VsZG4ndCB3b3JyeSBhYm91dCB0aGlzIHVw IGZyb250Lgo+IAo+IEFueXdheSwgSSBkb24ndCBmZWVsIHN0cm9uZ2x5IGVpdGhlciB3YXksIEkn bSBqdXN0IHBvaW50aW5nIG91dCB0aGF0Cj4gdGhpcyBpcyBzb21ld2hhdCB1bnVzdWFsLiBJZiB5 b3Ugd2FudCB0byBrZWVwIGl0LCBmZWVsIGZyZWUgdG8uCj4gCj4gVGhpZXJyeQo+IAoKCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LXJpc2N2IG1h aWxpbmcgbGlzdApsaW51eC1yaXNjdkBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5p bmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtcmlzY3YK