From owner-freebsd-drivers@freebsd.org Fri Aug 17 06:18:36 2018 Return-Path: Delivered-To: freebsd-drivers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E4AB31083E44; Fri, 17 Aug 2018 06:18:35 +0000 (UTC) (envelope-from rajfbsd@gmail.com) Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 679268EA07; Fri, 17 Aug 2018 06:18:35 +0000 (UTC) (envelope-from rajfbsd@gmail.com) Received: by mail-wr1-x42c.google.com with SMTP id j5-v6so6086563wrr.8; Thu, 16 Aug 2018 23:18:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=5dqRCMPnNFB09uviXnmOpx7P68onljhWdSmjsNcWZRc=; b=lISGijaVQ4AlLmMNLPByM+Yy6I5A6S/Dh9r2EIAVlkvNKA4MWq2kVdLtMQX5vCvH7a Vi3HOSA+OKvXOeSVDlxxFqOwuWYYBYteFs7+FpNymZtCn9/2e80O58NS4iBwKv4+mCI3 r2ZeAsS1kT2wybHivdVGNw/3n4DWhEW/u5wnhrmEBjoNAGkpErc8fL1XCQjcWD2/JXyX ZkA31mm/fvhJlorpM0Oj/WwiQ0hKkyOXC1GX0ylvFe/3zgXhMXSgDvrF+7pt2ruIB7UQ 5KKkmdTKdQOs/x2VprQ9Nv65fxjdYHpGV/8m7hADVxTT5lZ5FW/7JAdu2YZkqiA3lkbY u1cA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=5dqRCMPnNFB09uviXnmOpx7P68onljhWdSmjsNcWZRc=; b=CUG642HcZyuqA2NEsUI3h7gpZEvtnxD6g+aA61OG1xlhnlUj/pDxmaAbXeflZnoXWj zN5y2Z2Y1sCUwDPTAl9skLo/IkQtXHbdyXWJj4/u0bTHlaOYbkXTwCq92MwodppKLiek AcAcBO+JrQQOU6ltpbXWXPpLnQnVbODeXnviDbKfelWgoYUC7h5fKg+/zAqeJMweyymK ceXRtj6uJqiOzCDuFfgEB3A/Pdy98jXkN4Tvq7irWaLgGAEbTkNuvFvZEov6ChjBMGN8 w9rE9QzmT+RNNqfS7bVQpC9qzwy1OkV+q09kZdLvc4awN1nwkJRPa6OTHfYGRgIszMED B+vA== X-Gm-Message-State: AOUpUlHwM98yJefybOMP+J53qGNj+HUJN9Zoe3lJWQSPJWqw9KfIJYtJ /GbBWTFxuZAUjPh35AFUDW0IkUmUCbvN30xfUalfaEQA X-Google-Smtp-Source: AA+uWPzVshDq4a84y0uKMgW1nT7phFlyaZUk/pBOUuoZtZcuQuUaigybXXdrXli1sb99WmQ7PDWAhcq8kurJb0kpS0Y= X-Received: by 2002:adf:9086:: with SMTP id i6-v6mr22343959wri.271.1534486714186; Thu, 16 Aug 2018 23:18:34 -0700 (PDT) MIME-Version: 1.0 From: Rajesh Kumar Date: Fri, 17 Aug 2018 11:48:22 +0530 Message-ID: Subject: Need a clarification regarding I2C bus frequency in FreeBSD To: freebsd-drivers@freebsd.org, freebsd-hackers@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.27 X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Aug 2018 06:18:36 -0000 Hi, I am trying to use the I2C designware controller driver available in FreeBSD (ig4_iic.c) in our boards. Is there a clean way, I can set the I2C bus frequency from the controller driver itself, rather than using device hints, FDT, tunables etc., Something like, if the driver is loaded for our boards (identified using the PCI or ACPI ID's), then the frequency of the I2C bus needs to be hardcoded from driver itself. This is to avoid additional configs from the config file. I tried adding a new interface "iicbus_set_frequency" (in line with iicbus_get_frequency) and tried calling that from the ig4 driver after the "iicbus" child is added. But, iicbus instance is created only after ig4 driver is loaded. So, calling iicbus_set_frequency after child addition leads to system panic (as there is no iicbus softc at this point). Let me know if you need any details. Thanks, Rajesh.