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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 82453C433F5 for ; Thu, 9 Sep 2021 18:08:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 651016115A for ; Thu, 9 Sep 2021 18:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242417AbhIISJd (ORCPT ); Thu, 9 Sep 2021 14:09:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:54084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231431AbhIISJa (ORCPT ); Thu, 9 Sep 2021 14:09:30 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5804C610C9; Thu, 9 Sep 2021 18:08:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631210897; bh=rUgjo8lIkjG8VTsPFFj78gVWqfDjqFx80l5ivn3DkcU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=fC933vyE/cBcM4YcmOg+DgH13xy31FrmuVVX3jvutEhRRXmQylLC+HDHkFxCH7XHw 5h8YbLstZ39heKg7+wKr90HLgqQkkl5O250x3VsWMY3ijIrzPi3VWy+zaXamYODfnR SsItmcEZ+pMqc29dWZU2ET3FXmu3rFz1KY+2e7YpxPQqEcNoUXnE0O8ykO7MhplXh/ tA1OYUykv8MWwiAqGzZfa8ZLp0hHRUdbdEIAcEE9HHWzXIN2m+N41jgSRlzqQOGBEz IsaOLE51CpdzB8Ku96fVHDZUqKJ+DPhiBYnpreSDx3opM9uqsNSj2F809nvNtb6e4r tdcZ2ZYlUd50Q== Date: Thu, 9 Sep 2021 13:08:15 -0500 From: Bjorn Helgaas To: Prasad Malisetty Cc: Rob Herring , Stephen Boyd , agross@kernel.org, bhelgaas@google.com, bjorn.andersson@linaro.org, lorenzo.pieralisi@arm.com, svarbanov@mm-sol.com, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, dianders@chromium.org, mka@chromium.org, vbadigan@codeaurora.org, sallenki@codeaurora.org, manivannan.sadhasivam@linaro.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v5 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280 Message-ID: <20210909180815.GA997402@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5fae4f586edfde4f615a8ea6a309fbff@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, Sep 09, 2021 at 11:21:22PM +0530, Prasad Malisetty wrote: > On 2021-08-31 21:07, Bjorn Helgaas wrote: > > On Tue, Aug 31, 2021 at 12:07:30PM +0530, Prasad Malisetty wrote: > > > On 2021-08-26 18:07, Rob Herring wrote: > > > > On Thu, Aug 26, 2021 at 2:22 AM Prasad Malisetty > > > > wrote: > > > > > > > > > > On 2021-08-26 02:55, Bjorn Helgaas wrote: > > > > > > [+cc linux-pci; patches to drivers/pci/ should always be cc'd there] > > > > > > > > > > > > On Wed, Aug 25, 2021 at 07:30:09PM +0000, Stephen Boyd wrote: > > > > > >> Quoting Prasad Malisetty (2021-08-24 01:10:48) > > > > > >> > On 2021-08-17 22:56, Prasad Malisetty wrote: > > > > > >> > > On 2021-08-10 09:38, Prasad Malisetty wrote: > > > > > >> > >> On the SC7280, By default the clock source for pcie_1_pipe is > > > > > >> > >> TCXO for gdsc enable. But after the PHY is initialized, the clock > > > > > >> > >> source must be switched to gcc_pcie_1_pipe_clk from TCXO. > > > > > >> > >> > > > > > >> > >> Signed-off-by: Prasad Malisetty > > > > > >> > >> --- > > > > > >> > >> drivers/pci/controller/dwc/pcie-qcom.c | 18 ++++++++++++++++++ > > > > > >> > >> 1 file changed, 18 insertions(+) > > > > > >> > >> > > > > > >> > >> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c > > > > > >> > >> b/drivers/pci/controller/dwc/pcie-qcom.c > > > > > >> > >> index 8a7a300..39e3b21 100644 > > > > > >> > >> --- a/drivers/pci/controller/dwc/pcie-qcom.c > > > > > >> > >> +++ b/drivers/pci/controller/dwc/pcie-qcom.c > > > > > >> > >> @@ -166,6 +166,8 @@ struct qcom_pcie_resources_2_7_0 { > > > > > >> > >> struct regulator_bulk_data supplies[2]; > > > > > >> > >> struct reset_control *pci_reset; > > > > > >> > >> struct clk *pipe_clk; > > > > > >> > >> + struct clk *gcc_pcie_1_pipe_clk_src; > > > > > >> > >> + struct clk *phy_pipe_clk; > > > > > >> > >> }; > > > > > >> > >> > > > > > >> > >> union qcom_pcie_resources { > > > > > >> > >> @@ -1167,6 +1169,16 @@ static int qcom_pcie_get_resources_2_7_0(struct > > > > > >> > >> qcom_pcie *pcie) > > > > > >> > >> if (ret < 0) > > > > > >> > >> return ret; > > > > > >> > >> > > > > > >> > >> + if (of_device_is_compatible(dev->of_node, "qcom,pcie-sc7280")) { > > > > > >> > >> + res->gcc_pcie_1_pipe_clk_src = devm_clk_get(dev, "pipe_mux"); > > > > > >> > >> + if (IS_ERR(res->gcc_pcie_1_pipe_clk_src)) > > > > > >> > >> + return PTR_ERR(res->gcc_pcie_1_pipe_clk_src); > > > > > >> > >> + > > > > > >> > >> + res->phy_pipe_clk = devm_clk_get(dev, "phy_pipe"); > > > > > >> > >> + if (IS_ERR(res->phy_pipe_clk)) > > > > > >> > >> + return PTR_ERR(res->phy_pipe_clk); > > > > > >> > >> + } > > > > > >> > > > > > > > >> > > I would like to check is there any other better > > > > > >> > > approach instead of compatible method here as well or > > > > > >> > > is it fine to use compatible method. > > > > > >> > > > > > >> I'd prefer the compatible method. If nobody is responding > > > > > >> then it's best to just resend the patches with the > > > > > >> approach you prefer instead of waiting for someone to > > > > > >> respond to a review comment. > > > > > > > > > > > > I'm missing some context here, so I'm not exactly sure > > > > > > what your question is, Prasad, but IMO drivers generally > > > > > > should not need to use of_device_is_compatible() if > > > > > > they've already called of_device_get_match_data() (as > > > > > > qcom_pcie_probe() has). > > > > > > > > > > > > of_device_is_compatible() does basically the same work of > > > > > > looking for a match in qcom_pcie_match[] that > > > > > > of_device_get_match_data() does, so it seems pointless to > > > > > > repeat it. > > > > > > > > +1 > > > > > > > > > > I am a little confused because while [1] adds "qcom,pcie-sc7280" to > > > > > > qcom,pcie.txt, I don't see a patch that adds it to qcom_pcie_match[]. > > > > > > > > Either that's missing or there's a fallback to 8250 that's not > > > > documented. > > > > > > > > > I agree on your point, but the main reason is to use compatible in > > > > > get_resources_2_7_0 is same hardware version. For SM8250 & SC7280 > > > > > platforms, the hw version is same. Since we can't have a separate ops > > > > > for SC7280, we are using compatible method in get_resources_2_7_0 to > > > > > differentiate SM8250 and SC7280. > > > > > > > > Then fix the match data to be not just ops, but ops and the flag you > > > > need here. > > > > > > This difference is not universal across all the platforms but > > > instead this is specific to SC7280. Hence it make sense to use > > > compatible other than going for a flag. > > > > There's no reason your qcom_pcie_match[].data pointers need to be > > strictly based on the hardware version. > > > > You can do something like what pcie-brcmstb.c does, e.g., > > > > struct pcie_cfg_data { > > struct qcom_pcie_ops *ops; > > unsigned int pipe_mux:1; > > }; > > > > static const struct pcie_cfg_data sm8250_cfg = { > > .ops = &ops_1_9_0, > > }; > > > > static const struct pcie_cfg_data sc7280_cfg = { > > .ops = &ops_1_9_0, > > .pipe_mux = 1, > > }; > > > > static const struct of_device_id qcom_pcie_match[] = { > > { .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg }, > > { .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg }, > > }; > > I have one quick query, If we use above approach, we should change platform > data reading in PCIe probe to differentiate remaining platforms right. > expect SM8250 and SC7280 all other platforms are using same qcom_pcie_ops > structure pointer as data. Yes. of_device_get_match_data() must return the same type of pointer (in the example above, "struct pcie_cfg_data *") for all platforms. So you would have to add a struct for each of them, and each struct would contain the ops pointer (&ops_1_0_0, &ops_2_1_0, etc). Thanks for working on this! Bjorn