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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 5F484CA9EB0 for ; Sun, 3 Nov 2019 17:32:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D9AE2084D for ; Sun, 3 Nov 2019 17:32:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572802352; bh=UzLLL1Ca+sjdIQykVRqTI78sHlr2eCUpPuADKt3IhL0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=URKhFQNNtppaOM6AGfQOKz3cL97B2WwkaG9oJezVdk5xIEbHbL8Jg7BeXDvb/efzC EvF0+/PEhaUeqsLGDmtnPlu0+UW9dH9IIW7b2KS8L08WPfUPJHn/dwb6GqEGwa5UV/ F7Iqei2+UTQieA7K3kN9Pk6DH4WV9RhJP1V4nzr8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbfKCRcb (ORCPT ); Sun, 3 Nov 2019 12:32:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:56842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727488AbfKCRcb (ORCPT ); Sun, 3 Nov 2019 12:32:31 -0500 Received: from localhost (lfbn-1-10718-76.w90-89.abo.wanadoo.fr [90.89.68.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E6A782080F; Sun, 3 Nov 2019 17:32:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572802350; bh=UzLLL1Ca+sjdIQykVRqTI78sHlr2eCUpPuADKt3IhL0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A1fyaYe43+mDax1rBL8Mn178Q81As7bkN3B8ZbBrGbLDS82jKqipE6imQiPJYGnlz M+9e1IPNj3aLpjH6GHNqG9sApJmYWFEOAuYOM6PybzHSwjH+lDSQ+ENzyJ1mXiZ7us nslC1hLxRXdLoLVYm6Ma8hr3egT4FlCHajlZSJHU= Date: Sun, 3 Nov 2019 18:32:27 +0100 From: Maxime Ripard To: Jagan Teki Cc: Mark Rutland , devicetree , David Airlie , linux-sunxi , dri-devel , linux-kernel , Chen-Yu Tsai , Rob Herring , Michael Trimarchi , linux-amarula , linux-arm-kernel , Icenowy Zheng Subject: Re: [PATCH v11 4/7] drm/sun4i: dsi: Handle bus clock explicitly Message-ID: <20191103173227.GF7001@gilmour> References: <20191025175625.8011-1-jagan@amarulasolutions.com> <20191025175625.8011-5-jagan@amarulasolutions.com> <20191028153427.pc3tnoz2d23filhx@hendrix> <20191029085401.gvqpwmmpyml75vis@hendrix> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dFWYt1i2NyOo1oI9" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --dFWYt1i2NyOo1oI9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Nov 01, 2019 at 07:42:55PM +0530, Jagan Teki wrote: > Hi Maxime, > > On Tue, Oct 29, 2019 at 2:24 PM Maxime Ripard wrote: > > > > On Tue, Oct 29, 2019 at 04:03:56AM +0530, Jagan Teki wrote: > > > > > explicit handling of common clock would require since the A64 > > > > > doesn't need to mention the clock-names explicitly in dts since it > > > > > support only one bus clock. > > > > > > > > > > Also pass clk_id NULL instead "bus" to regmap clock init function > > > > > since the single clock variants no need to mention clock-names > > > > > explicitly. > > > > > > > > You don't need explicit clock handling. Passing NULL as the argument > > > > in regmap_init_mmio_clk will make it use the first clock, which is the > > > > bus clock. > > > > > > Indeed I tried that, since NULL clk_id wouldn't enable the bus clock > > > during regmap_mmio_gen_context code, passing NULL triggering vblank > > > timeout. > > > > There's a bunch of users of NULL in tree, so finding out why NULL > > doesn't work is the way forward. > > I'd have looked the some of the users before checking the code as > well. As I said passing NULL clk_id to devm_regmap_init_mmio_clk => > __devm_regmap_init_mmio_clk would return before processing the clock. > > Here is the code snippet on the tree just to make sure I'm on the same > page or not. > > static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev, > const char *clk_id, > void __iomem *regs, > const struct regmap_config *config) > { > ----------------------- > -------------- > if (clk_id == NULL) > return ctx; > > ctx->clk = clk_get(dev, clk_id); > if (IS_ERR(ctx->clk)) { > ret = PTR_ERR(ctx->clk); > goto err_free; > } > > ret = clk_prepare(ctx->clk); > if (ret < 0) { > clk_put(ctx->clk); > goto err_free; > } > ------------- > --------------- > } > > Yes, I did check on the driver in the tree before committing explicit > clock handle, which make similar requirements like us in [1]. this > imx2 wdt driver is handling the explicit clock as well. I'm sure this > driver is updated as I have seen few changes related to this driver in > ML. I guess we have two ways to go at this then. Either we remove the return, but it might have a few side-effects, or we call clk_get with NULL or bus depending on the case, and then call regmap_mmio_attach_clk. Maxime --dFWYt1i2NyOo1oI9 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXb8PKwAKCRDj7w1vZxhR xRo6AQC7cJgPCdmPtwa3+DvnOiO0l+RhF95zulrMO4b+JAewRgEA74E3tqth973g U2/28LW5VnoPT0M0gUDV7UgvhyVeGQA= =PgiZ -----END PGP SIGNATURE----- --dFWYt1i2NyOo1oI9--