From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="WNZPdabE" Received: from mail-yw1-x112f.google.com (mail-yw1-x112f.google.com [IPv6:2607:f8b0:4864:20::112f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00445199 for ; Wed, 22 Nov 2023 11:01:43 -0800 (PST) Received: by mail-yw1-x112f.google.com with SMTP id 00721157ae682-5cc66213a34so954767b3.1 for ; Wed, 22 Nov 2023 11:01:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1700679703; x=1701284503; darn=vger.kernel.org; h=cc:to:subject:message-id:date:thread-index:mime-version:in-reply-to :references:from:from:to:cc:subject:date:message-id:reply-to; bh=azifW+C+eMZxvuKwHdUrv98tgfUY1yL1OzzBzI5a5XI=; b=WNZPdabEKe11u/O6D+mpvyN/JFIEimZWG7WNuN1QHjpHIRQYqMA5oQmttU8QoDY6+m hhq4H6jgME2awxdXLmxfXIfu0LmMvJLKlN5BnzfnfwJf5CQ8LPqGQYqd7r6QhBFXY1N2 aePS2J8Jr1Oic6d6Few6QCzwBktVQ2DQpGw/Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700679703; x=1701284503; h=cc:to:subject:message-id:date:thread-index:mime-version:in-reply-to :references:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=azifW+C+eMZxvuKwHdUrv98tgfUY1yL1OzzBzI5a5XI=; b=D5bGTnAY3FGsM6HCUZfGQjAwvsPpEKOACMyK3VOsKJNPz8tPtLggVXozMzGS5mu3ma fLiTP6InWoZpfNOsogB1xX7zM59iatp9Ix7GHqTUzgiOwqjdWLVHT5nNJhGE0YJK7niE X10YlaUTYKTYGRTFcAvj19TYLAkDWNfLLfsEHFhFKGaehCoFB3E3XeUtQuE8f1wCZxX/ i70zijEnST3haftzco9AORZPqYD7TZNVsgof+2NzflCOrWaVd495qg2/QVY3/fr6EOvo UTdx0yivWpMnXd5nfoBi+cM7Q+BTJ06cfK9EthrC9HOxLgS/Ykd1+JA4SskKQdzgg5iW pxQw== X-Gm-Message-State: AOJu0YzkE5mbPj5ot2FdcykweQqhvaDhlMDf/yXnmsiUDeZ4ny9j5Wlh 2NxHaFBifRe6ub47hWMG6Qy9Csma4LEVpKlRMABPiw== X-Google-Smtp-Source: AGHT+IFq+Al4Dzg5Y2u0cdp+jh8sUSUDkzP14I6q9BxpXanOkbPlcwQQzFGz1DepV1Ebcdlw90cmJmHKWMaNvjX9OUY= X-Received: by 2002:a0d:d94d:0:b0:5ca:95ac:453b with SMTP id b74-20020a0dd94d000000b005ca95ac453bmr3402612ywe.2.1700679703165; Wed, 22 Nov 2023 11:01:43 -0800 (PST) From: William Zhang References: <20231122144208.21114-1-zajec5@gmail.com> <66c4b54b-7631-484a-9f7d-31542284e620@linaro.org> <08fcb328-fe4b-40c7-a01e-8a0b527b1c71@gmail.com> <758114a7-0b18-44e8-b3d8-b5aabd244279@linaro.org> <57a77c9d-684e-4f5e-977a-4586e15f7c3e@gmail.com> <141deca9-6017-4e3f-a237-8dacc67662de@linaro.org> <03ad42c0-1648-43e1-bbd0-9ed02bdf4073@gmail.com> <525384ca-f84e-471c-bc82-0029db6ccb77@linaro.org> In-Reply-To: <525384ca-f84e-471c-bc82-0029db6ccb77@linaro.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQK9bTY6ZNvRLeNx0V/T0NyVybBU8QIOFjQkAvZlpgcAqcBEXgKIk+t/ApViaRsB0ifyqgNQwaPUAiS6KKoClnwQ0QEbvXvJrhHf24A= Date: Wed, 22 Nov 2023 11:01:40 -0800 Message-ID: Subject: RE: [PATCH V2 1/2] dt-bindings: serial: add Broadcom's BCMBCA family High Speed UART To: Krzysztof Kozlowski , =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , Florian Fainelli , Anand Gore , Kursad Oney , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Greg Kroah-Hartman , Jiri Slaby , Andre Przywara , Alexandre TORGUE , Neil Armstrong , linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="00000000000099b16f060ac259bb" --00000000000099b16f060ac259bb Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > -----Original Message----- > From: Krzysztof Kozlowski > Sent: Wednesday, November 22, 2023 10:46 AM > To: William Zhang ; Rafa=C5=82 Mi=C5=82ecki > ; Florian Fainelli ; > Anand Gore ; Kursad Oney > ; Rob Herring ; > Krzysztof Kozlowski ; Conor Dooley > > Cc: Greg Kroah-Hartman ; Jiri Slaby > ; Andre Przywara ; > Alexandre TORGUE ; Neil Armstrong > ; linux-serial@vger.kernel.org; > devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; bcm- > kernel-feedback-list@broadcom.com; Rafa=C5=82 Mi=C5=82ecki > Subject: Re: [PATCH V2 1/2] dt-bindings: serial: add Broadcom's BCMBCA > family High Speed UART > > On 22/11/2023 19:39, William Zhang wrote: > > Hi, > > > > On 11/22/2023 07:52 AM, Rafa=C5=82 Mi=C5=82ecki wrote: > >> On 22.11.2023 16:50, Krzysztof Kozlowski wrote: > >>> On 22/11/2023 16:49, Rafa=C5=82 Mi=C5=82ecki wrote: > >>>>>> For example a year ago I added binding for BCMBCA SoC timer > without > >>>>>> actual driver, see e112f2de151b ("dt-bindings: timer: Add > Broadcom's > >>>>>> BCMBCA timers"). > >>>>>> > >>>>>> I'm not sure if we're going to agree on this, but personally I lik= e > >>>>>> describing hardware as much as I can. So it's well documented / > >>>>>> understood and people may eventually write drivers for it. Maybe > it's > >>>>>> partially because I come from Broadcom's world that isn't well > known > >>>>>> for upstream efforts in general. > >>>>> > >>>>> The problem is that "brcm,bcmbca-hs-uart" is not describing > >>>>> hardware. It > >>>>> is saying that all these devices have similar (compatible) > >>>>> programming > >>>>> model, so the OS can use just one compatible. This goes away from > pure > >>>>> hardware description into interpretation. > >>>>> > > It is the same hardware IP block used in bcmbca SoCs. To me, it > > perfectly describe the hardware IP block and it does not need fallback > > because there is no fallback. We did that for SPI controller although > > it has two revisions of that IP block so we have brcm,bcmbca-hsspi-v1.0 > > and 1.1 > > > >>>>> Rob already commented on such non-SoC compatibles multiple times. > I do > >>>>> not see any reason here to not use specific compatible as fallback. > >>>> > > Sorry I missed Rob's comments. If we have any new rule or notes about > > this, I would like to check it out. > > > >>>> Do I get it right we should rather have some base specific compatibl= e > >>>> like: "brcm,bcm63138-hs-uart" and then if anything use fallback to i= t > >>>> like: "brcm,bcm4908-hs-uart", "brcm,bcm63138-hs-uart"; ? > >>> > >>> Yes, or the other way around, depends which is probably the oldest. > > If we absolutely can not use bcmbca-hs-uart, I would suggest to use > > We can, but I am surprised that you want without any driver. What's the > point of generic compatible? > I agree we should have the driver along with the dts. But it looks it depends on the bandwidth of Rafal. > > bcm63xx-hs-uart to be more soc specific and in fact the oldest SoC have > > What is xx? Wildcard? I mean... ehhh... > Bcm63 series of SoC (DSL broadband chip, part of the bcmbca family) and it is the oldest chip for such IP. bcm63xx has been used in many ip block's compatible string for long time in the upstream kernel. > Best regards, > Krzysztof --00000000000099b16f060ac259bb Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIQcAYJKoZIhvcNAQcCoIIQYTCCEF0CAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg gg3HMIIFDTCCA/WgAwIBAgIQeEqpED+lv77edQixNJMdADANBgkqhkiG9w0BAQsFADBMMSAwHgYD VQQLExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSMzETMBEGA1UEChMKR2xvYmFsU2lnbjETMBEGA1UE AxMKR2xvYmFsU2lnbjAeFw0yMDA5MTYwMDAwMDBaFw0yODA5MTYwMDAwMDBaMFsxCzAJBgNVBAYT AkJFMRkwFwYDVQQKExBHbG9iYWxTaWduIG52LXNhMTEwLwYDVQQDEyhHbG9iYWxTaWduIEdDQyBS MyBQZXJzb25hbFNpZ24gMiBDQSAyMDIwMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA vbCmXCcsbZ/a0fRIQMBxp4gJnnyeneFYpEtNydrZZ+GeKSMdHiDgXD1UnRSIudKo+moQ6YlCOu4t rVWO/EiXfYnK7zeop26ry1RpKtogB7/O115zultAz64ydQYLe+a1e/czkALg3sgTcOOcFZTXk38e aqsXsipoX1vsNurqPtnC27TWsA7pk4uKXscFjkeUE8JZu9BDKaswZygxBOPBQBwrA5+20Wxlk6k1 e6EKaaNaNZUy30q3ArEf30ZDpXyfCtiXnupjSK8WU2cK4qsEtj09JS4+mhi0CTCrCnXAzum3tgcH cHRg0prcSzzEUDQWoFxyuqwiwhHu3sPQNmFOMwIDAQABo4IB2jCCAdYwDgYDVR0PAQH/BAQDAgGG MGAGA1UdJQRZMFcGCCsGAQUFBwMCBggrBgEFBQcDBAYKKwYBBAGCNxQCAgYKKwYBBAGCNwoDBAYJ KwYBBAGCNxUGBgorBgEEAYI3CgMMBggrBgEFBQcDBwYIKwYBBQUHAxEwEgYDVR0TAQH/BAgwBgEB /wIBADAdBgNVHQ4EFgQUljPR5lgXWzR1ioFWZNW+SN6hj88wHwYDVR0jBBgwFoAUj/BLf6guRSSu TVD6Y5qL3uLdG7wwegYIKwYBBQUHAQEEbjBsMC0GCCsGAQUFBzABhiFodHRwOi8vb2NzcC5nbG9i YWxzaWduLmNvbS9yb290cjMwOwYIKwYBBQUHMAKGL2h0dHA6Ly9zZWN1cmUuZ2xvYmFsc2lnbi5j b20vY2FjZXJ0L3Jvb3QtcjMuY3J0MDYGA1UdHwQvMC0wK6ApoCeGJWh0dHA6Ly9jcmwuZ2xvYmFs c2lnbi5jb20vcm9vdC1yMy5jcmwwWgYDVR0gBFMwUTALBgkrBgEEAaAyASgwQgYKKwYBBAGgMgEo CjA0MDIGCCsGAQUFBwIBFiZodHRwczovL3d3dy5nbG9iYWxzaWduLmNvbS9yZXBvc2l0b3J5LzAN BgkqhkiG9w0BAQsFAAOCAQEAdAXk/XCnDeAOd9nNEUvWPxblOQ/5o/q6OIeTYvoEvUUi2qHUOtbf jBGdTptFsXXe4RgjVF9b6DuizgYfy+cILmvi5hfk3Iq8MAZsgtW+A/otQsJvK2wRatLE61RbzkX8 9/OXEZ1zT7t/q2RiJqzpvV8NChxIj+P7WTtepPm9AIj0Keue+gS2qvzAZAY34ZZeRHgA7g5O4TPJ /oTd+4rgiU++wLDlcZYd/slFkaT3xg4qWDepEMjT4T1qFOQIL+ijUArYS4owpPg9NISTKa1qqKWJ jFoyms0d0GwOniIIbBvhI2MJ7BSY9MYtWVT5jJO3tsVHwj4cp92CSFuGwunFMzCCA18wggJHoAMC AQICCwQAAAAAASFYUwiiMA0GCSqGSIb3DQEBCwUAMEwxIDAeBgNVBAsTF0dsb2JhbFNpZ24gUm9v dCBDQSAtIFIzMRMwEQYDVQQKEwpHbG9iYWxTaWduMRMwEQYDVQQDEwpHbG9iYWxTaWduMB4XDTA5 MDMxODEwMDAwMFoXDTI5MDMxODEwMDAwMFowTDEgMB4GA1UECxMXR2xvYmFsU2lnbiBSb290IENB IC0gUjMxEzARBgNVBAoTCkdsb2JhbFNpZ24xEzARBgNVBAMTCkdsb2JhbFNpZ24wggEiMA0GCSqG SIb3DQEBAQUAA4IBDwAwggEKAoIBAQDMJXaQeQZ4Ihb1wIO2hMoonv0FdhHFrYhy/EYCQ8eyip0E XyTLLkvhYIJG4VKrDIFHcGzdZNHr9SyjD4I9DCuul9e2FIYQebs7E4B3jAjhSdJqYi8fXvqWaN+J J5U4nwbXPsnLJlkNc96wyOkmDoMVxu9bi9IEYMpJpij2aTv2y8gokeWdimFXN6x0FNx04Druci8u nPvQu7/1PQDhBjPogiuuU6Y6FnOM3UEOIDrAtKeh6bJPkC4yYOlXy7kEkmho5TgmYHWyn3f/kRTv riBJ/K1AFUjRAjFhGV64l++td7dkmnq/X8ET75ti+w1s4FRpFqkD2m7pg5NxdsZphYIXAgMBAAGj QjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBSP8Et/qC5FJK5N UPpjmove4t0bvDANBgkqhkiG9w0BAQsFAAOCAQEAS0DbwFCq/sgM7/eWVEVJu5YACUGssxOGhigH M8pr5nS5ugAtrqQK0/Xx8Q+Kv3NnSoPHRHt44K9ubG8DKY4zOUXDjuS5V2yq/BKW7FPGLeQkbLmU Y/vcU2hnVj6DuM81IcPJaP7O2sJTqsyQiunwXUaMld16WCgaLx3ezQA3QY/tRG3XUyiXfvNnBB4V 14qWtNPeTCekTBtzc3b0F5nCH3oO4y0IrQocLP88q1UOD5F+NuvDV0m+4S4tfGCLw0FREyOdzvcy a5QBqJnnLDMfOjsl0oZAzjsshnjJYS8Uuu7bVW/fhO4FCU29KNhyztNiUGUe65KXgzHZs7XKR1g/ XzCCBU8wggQ3oAMCAQICDDG6HZcbcVdEvVYk4TANBgkqhkiG9w0BAQsFADBbMQswCQYDVQQGEwJC RTEZMBcGA1UEChMQR2xvYmFsU2lnbiBudi1zYTExMC8GA1UEAxMoR2xvYmFsU2lnbiBHQ0MgUjMg UGVyc29uYWxTaWduIDIgQ0EgMjAyMDAeFw0yMjA5MTAxMTMxNDVaFw0yNTA5MTAxMTMxNDVaMIGQ MQswCQYDVQQGEwJJTjESMBAGA1UECBMJS2FybmF0YWthMRIwEAYDVQQHEwlCYW5nYWxvcmUxFjAU BgNVBAoTDUJyb2FkY29tIEluYy4xFjAUBgNVBAMTDVdpbGxpYW0gWmhhbmcxKTAnBgkqhkiG9w0B CQEWGndpbGxpYW0uemhhbmdAYnJvYWRjb20uY29tMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB CgKCAQEAyKF+RmY29Wvfmfe3L8J4rZNmBIvRmrWKI5td5L0vlpPMCEzUkVhBdL2N9cDP0rPScvWL CX/9cI1a2BUy/6/ZT5j9PhcUn6A3kwKFGukLY2itfKaDrP3ANVJGhBXPVJ6sx55GF41PkiL2EMnY 7LJGNpl9WHYrw8VqtRediPyXq8M6ZWGPZWxygsE6y1pOkEk9qLpvXTb2Epxk2JWcQFZQCDWVULue YDZuuBJwnyCzevMoPtVYPharioL5H3BRnQi8YoTXH7/uRo33dewYFm474yFjwwnt82TFtveVZkVq 6h4WIQ4wTcwFfET8zMkELnGzS5SHCl8sPD+lNxxJ1JDZYwIDAQABo4IB2zCCAdcwDgYDVR0PAQH/ BAQDAgWgMIGjBggrBgEFBQcBAQSBljCBkzBOBggrBgEFBQcwAoZCaHR0cDovL3NlY3VyZS5nbG9i YWxzaWduLmNvbS9jYWNlcnQvZ3NnY2NyM3BlcnNvbmFsc2lnbjJjYTIwMjAuY3J0MEEGCCsGAQUF BzABhjVodHRwOi8vb2NzcC5nbG9iYWxzaWduLmNvbS9nc2djY3IzcGVyc29uYWxzaWduMmNhMjAy MDBNBgNVHSAERjBEMEIGCisGAQQBoDIBKAowNDAyBggrBgEFBQcCARYmaHR0cHM6Ly93d3cuZ2xv YmFsc2lnbi5jb20vcmVwb3NpdG9yeS8wCQYDVR0TBAIwADBJBgNVHR8EQjBAMD6gPKA6hjhodHRw Oi8vY3JsLmdsb2JhbHNpZ24uY29tL2dzZ2NjcjNwZXJzb25hbHNpZ24yY2EyMDIwLmNybDAlBgNV HREEHjAcgRp3aWxsaWFtLnpoYW5nQGJyb2FkY29tLmNvbTATBgNVHSUEDDAKBggrBgEFBQcDBDAf BgNVHSMEGDAWgBSWM9HmWBdbNHWKgVZk1b5I3qGPzzAdBgNVHQ4EFgQUq65GzwZxydFHjjYEU/9h xHhPWlwwDQYJKoZIhvcNAQELBQADggEBAA2hGG3JPAdGPH0ZdohGUCIVjKz+U+EFuIDbS6A/5jqX VhYAxZlzj7tSjUIM7G7IhyfqPC46GKJ/4x+Amz1Z6YxNGy71L68kYD6hIbBcA5AM42QBUufly6Oa /ppSz3WoflVyFFQ5YXniZ+eU+2/cdnYZg4aVUnFjimOF5o3NfMLzOkhQNxbaDjFUfUYD8hKmU6v4 0vUBj8KZ9Gi1LIagLKUREn8jku0lcLsRbnJ5Ey5ScajC/FESPyYWasOW8j8/1EoJksmhbYGKNS6C urb/KlmDGfVrIRYDbL0ckhGQIP5c6L+kSQZ2sHnQK0e0WgIaZYxaPYeY5u0GLCOze+3vyRMxggJt MIICaQIBATBrMFsxCzAJBgNVBAYTAkJFMRkwFwYDVQQKExBHbG9iYWxTaWduIG52LXNhMTEwLwYD VQQDEyhHbG9iYWxTaWduIEdDQyBSMyBQZXJzb25hbFNpZ24gMiBDQSAyMDIwAgwxuh2XG3FXRL1W JOEwDQYJYIZIAWUDBAIBBQCggdQwLwYJKoZIhvcNAQkEMSIEIAzMHcLLBS/YOp7rYgpB0cb1apgh vLvpU3ZzSe9Yp1g4MBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTIz MTEyMjE5MDE0M1owaQYJKoZIhvcNAQkPMVwwWjALBglghkgBZQMEASowCwYJYIZIAWUDBAEWMAsG CWCGSAFlAwQBAjAKBggqhkiG9w0DBzALBgkqhkiG9w0BAQowCwYJKoZIhvcNAQEHMAsGCWCGSAFl AwQCATANBgkqhkiG9w0BAQEFAASCAQAWMHHjsi6OcoZawzpyfxhMZkoTArFCDamT2EyXzYpdFli8 gDqxmBZHX90yPDa60MGhRox7bo1WSmvBlNKf9Z/V4CcI/Inz5W7BOVHKm1uMPQ1mfFnJb77z8it8 6BZRaeiLQR+iAh3Mlo1xB3O7Q5XxNQ0tPyCK4uoofc3wuB9efBSZeerg+FqsZV5IeJPHPeHqQQTo qtDdm8p8y3mck21Sn+U0Fn5+LdBB4RJKxQl/ZohSP8PQIOND7goytEeej5QmORjT1NVJkDYDSRWz p5FFzaUnlVUDNYoNCQ3T+UwXVz5CVwx9L9Pr/JxbGO9OgxJWPRArC3QwmzdoKzeRotsQ --00000000000099b16f060ac259bb--