Re: [PATCH v7 8/8] PCI: imx: Add the imx8mm pcie support
From: Krzysztof Wilczyński <hidden>
Date: 2021-12-16 16:51:57
Also in:
linux-arm-kernel, linux-pci, linux-phy, lkml
Hi Richard, Apologies for a very late review! Especially since Lorenzo already took patches as per: https://lore.kernel.org/linux-pci/163965080404.20006.5241609551643501749.b4-ty@arm.com/ (local) However, perhaps it's not too late. [...]
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@@ -446,6 +452,13 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) break; case IMX7D: break; + case IMX8MM: + ret = clk_prepare_enable(imx6_pcie->pcie_aux); + if (ret) { + dev_err(dev, "unable to enable pcie_aux clock\n"); + break; + } + break;
You can drop the inner break, it wouldn't do much here, unless this was intended to be a return?
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@@ -538,6 +559,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) case IMX8MQ: reset_control_deassert(imx6_pcie->pciephy_reset); break; + case IMX8MM: + if (phy_init(imx6_pcie->phy) != 0) + dev_err(dev, "Waiting for PHY ready timeout!\n"); + break;
If the above, you can keep the same style as used throughout the file already, so it would just simply be: if (phy_init(imx6_pcie->phy)) Also, a nitpick: to be consistent with other such messages here, the error message would be all lower-case letters. [...]
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@@ -614,6 +639,8 @@ static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie) static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie) { switch (imx6_pcie->drvdata->variant) { + case IMX8MM: + break; case IMX8MQ:
Would it warrant a comment that adds a note there to this single bare break? Perhaps this version is not support, lack this particular functionality, etc. [...]
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@@ -1089,10 +1122,39 @@ static int imx6_pcie_probe(struct platform_device *pdev) dev_err(dev, "Failed to get PCIE APPS reset control\n"); return PTR_ERR(imx6_pcie->apps_reset); } + break; + case IMX8MM: + imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux"); + if (IS_ERR(imx6_pcie->pcie_aux)) + return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_aux), + "pcie_aux clock source missing or invalid\n"); + imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev, + "apps"); + if (IS_ERR(imx6_pcie->apps_reset)) { + dev_err(dev, "Failed to get PCIE APPS reset control\n"); + return PTR_ERR(imx6_pcie->apps_reset); + } + + imx6_pcie->phy = devm_phy_get(dev, "pcie-phy"); + if (IS_ERR(imx6_pcie->phy)) { + if (PTR_ERR(imx6_pcie->phy) == -EPROBE_DEFER) + return -EPROBE_DEFER; + dev_err(dev, "Failed to get PCIE PHY\n"); + return PTR_ERR(imx6_pcie->phy); + }
A question about handling of the -EPROBE_DEFER above: why not to use the dev_err_probe() helper similarly to the code above and below? Would there be something different preventing the use of dev_err_probe() here too?
break;
default:
break;
}
+ /* Don't fetch the pcie_phy clock, if it has abstract PHY driver */
+ if (imx6_pcie->phy == NULL) {
+ imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
+ if (IS_ERR(imx6_pcie->pcie_phy))
+ return dev_err_probe(dev, PTR_ERR(imx6_pcie->pcie_phy),
+ "pcie_phy clock source missing or invalid\n");
+ }Thank you for another amazing patch! Krzysztof