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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43B23C54E94 for ; Wed, 25 Jan 2023 21:38:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236113AbjAYViX (ORCPT ); Wed, 25 Jan 2023 16:38:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236476AbjAYViW (ORCPT ); Wed, 25 Jan 2023 16:38:22 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A9372ED42; Wed, 25 Jan 2023 13:38:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E2778615AD; Wed, 25 Jan 2023 21:38:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CB93C433D2; Wed, 25 Jan 2023 21:38:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674682696; bh=bmq9nscR0EgSU6fvc32oRHpBhN1RRimmYW62O6DIiZE=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=Qe+JY92dmT+G+YKxGHzlrcnkItmlqhnSMBDUvzjxW06cgIUVYEGnhYXFGw7/AoGvR TwCcuYuiobaRRtXKBT8/rq2by9cOLucsgqX7myHZ8TQuX7fbykQvTNSjpivrE+0DY4 cubxeHMZI/n2DlTvQ6GSP12tK8C6Rh3OGDFq5ahugpaiyNfknHWCXZj8+ZIktbZ/Tn pWBluZI+C0wwUDTik2qP42U/QY2iyRqDOVQ4CZCd3i27aTraNI5z8F/6DEaq/m0etz NoX6PJ7NQWOts1il55m2JiMF3zq9x0Wy2LOzYCo4ouNixzdhpx/+DO2YA6mRYr22J1 lmbqL1N9+R2TQ== Message-ID: <7055af43f4a8894ac34e53c5847fb3de.sboyd@kernel.org> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20230118132254.2356209-8-dmitry.baryshkov@linaro.org> References: <20230118132254.2356209-1-dmitry.baryshkov@linaro.org> <20230118132254.2356209-8-dmitry.baryshkov@linaro.org> Subject: Re: [PATCH v4 7/7] clk: qcom: add the driver for the MSM8996 APCS clocks From: Stephen Boyd Cc: linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org To: Andy Gross , Bjorn Andersson , Dmitry Baryshkov , Jassi Brar , Konrad Dybcio , Krzysztof Kozlowski , Michael Turquette , Rob Herring , Taniya Das Date: Wed, 25 Jan 2023 13:38:14 -0800 User-Agent: alot/0.10 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Quoting Dmitry Baryshkov (2023-01-18 05:22:54) > diff --git a/drivers/clk/qcom/apcs-msm8996.c b/drivers/clk/qcom/apcs-msm8= 996.c > new file mode 100644 > index 000000000000..7e46ea8ed444 > --- /dev/null > +++ b/drivers/clk/qcom/apcs-msm8996.c > @@ -0,0 +1,76 @@ [...] > + > +static int qcom_apcs_msm8996_clk_probe(struct platform_device *pdev) > +{ > + struct device *dev =3D &pdev->dev; > + struct device *parent =3D dev->parent; > + struct regmap *regmap; > + struct clk_hw *hw; > + unsigned int val; > + int ret =3D -ENODEV; > + > + regmap =3D dev_get_regmap(parent, NULL); > + if (!regmap) { > + dev_err(dev, "failed to get regmap: %d\n", ret); > + return ret; > + } > + > + regmap_read(regmap, APCS_AUX_OFFSET, &val); > + regmap_update_bits(regmap, APCS_AUX_OFFSET, APCS_AUX_DIV_MASK, > + FIELD_PREP(APCS_AUX_DIV_MASK, APCS_AUX_DIV_2)); > + > + /* Hardware mandated delay */ Delay for what? Setting the divider? What if the register value didn't change at all? Can you skip the delay in that case? > + udelay(5); > + > + /* > + * Register the clock as fixed rate instead of being a child of g= pll0 > + * to let the driver register probe as early as possible. The function doesn't block or return EPROBE_DEFER if the clk is orphaned when registered. Why is this necessary? Are you getting defered by the fw_devlink logic thinking it needs to defer probe of this driver until gpll0 provider probes? We should fix fw_devlink to not do that. Maybe if the node is a clk provider (#clock-cells exists) then we don't wait for clocks property to be provided, because the clk core already handles that itself. > + */ > + hw =3D devm_clk_hw_register_fixed_rate(dev, "sys_apcs_aux", NULL,= 0, 300000000);