Messages in this thread | | | Date | Thu, 26 Aug 2021 12:51:53 +0530 | From | Prasad Malisetty <> | Subject | Re: [PATCH v5 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280 |
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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 <pmaliset@codeaurora.org> >> > >> --- >> > >> 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. > > 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[]. > > Bjorn > Hi Bjorn,
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.
Thanks -Prasad > [1] > https://lore.kernel.org/linux-arm-msm/1628568516-24155-2-git-send-email-pmaliset@codeaurora.org/
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