RE: [PATCH 1/3] PCI: imx: encapsulate the clock enable into one standalone function

-----Original Message-----
From: Lucas Stach <l.stach@pengutronix.de>
Sent: Wednesday, September 8, 2021 4:48 PM
To: Richard Zhu <hongxing.zhu@nxp.com>; bhelgaas@google.com;
lorenzo.pieralisi@arm.com
Cc: linux-pci@vger.kernel.org; dl-linux-imx <redacted>;
linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
kernel@pengutronix.de
Subject: Re: [PATCH 1/3] PCI: imx: encapsulate the clock enable into one
standalone function

Am Mittwoch, dem 08.09.2021 um 14:59 +0800 schrieb Richard Zhu:

quoted

No function changes, just encapsulate the i.MX PCIe clocks enable
operations into one standalone function

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 82
+++++++++++++++++----------
 1 file changed, 51 insertions(+), 31 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c

b/drivers/pci/controller/dwc/pci-imx6.c
index 80fc98acf097..0264432e4c4a 100644

--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c

@@ -143,6 +143,8 @@ struct imx6_pcie {
 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN		BIT(5)
 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN		BIT(3)

+static int imx6_pcie_clk_enable(struct imx6_pcie *imx6_pcie);
+

I don't think this is strictly needed. Can you just move the placement of the
new imx6_pcie_clk_enable function in the file, such that we can avoid the
forward declaration?

[Richard Zhu] Thanks for your quickly review.
Okay, would move the placement to avoid he forward declaration.

quoted

 static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool
exp_val)  {
 	struct dw_pcie *pci = imx6_pcie->pci; @@ -498,33 +500,12 @@ static
void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 		}
 	}

-	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie_phy clock\n");
-		goto err_pcie_phy;
-	}
-
-	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
+	ret = imx6_pcie_clk_enable(imx6_pcie);
 	if (ret) {
-		dev_err(dev, "unable to enable pcie_bus clock\n");
-		goto err_pcie_bus;
+		dev_err(dev, "unable to enable pcie clocks\n");
+		goto err_clks;
 	}

-	ret = clk_prepare_enable(imx6_pcie->pcie);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie clock\n");
-		goto err_pcie;
-	}
-
-	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie ref clock\n");
-		goto err_ref_clk;
-	}
-
-	/* allow the clocks to stabilize */
-	usleep_range(200, 500);
-
 	/* Some boards don't have PCIe reset GPIO. */
 	if (gpio_is_valid(imx6_pcie->reset_gpio)) {
 		gpio_set_value_cansleep(imx6_pcie->reset_gpio,

@@ -578,13 +559,7 @@ static void imx6_pcie_deassert_core_reset(struct

imx6_pcie *imx6_pcie)

 	return;

-err_ref_clk:
-	clk_disable_unprepare(imx6_pcie->pcie);
-err_pcie:
-	clk_disable_unprepare(imx6_pcie->pcie_bus);
-err_pcie_bus:
-	clk_disable_unprepare(imx6_pcie->pcie_phy);
-err_pcie_phy:
+err_clks:
 	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
 		ret = regulator_disable(imx6_pcie->vpcie);
 		if (ret)

@@ -914,6 +889,51 @@ static void imx6_pcie_pm_turnoff(struct

imx6_pcie *imx6_pcie)

quoted

 	usleep_range(1000, 10000);
 }

+static int imx6_pcie_clk_enable(struct imx6_pcie *imx6_pcie) {
+	struct dw_pcie *pci = imx6_pcie->pci;
+	struct device *dev = pci->dev;
+	int ret;
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie_phy clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie_bus clock\n");
+		goto err_pcie_bus;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie clock\n");
+		goto err_pcie;
+	}
+
+	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie ref clock\n");
+		goto err_ref_clk;
+	}
+
+	/* allow the clocks to stabilize */
+	usleep_range(200, 500);
+	return 0;
+
+err_ref_clk:
+	clk_disable_unprepare(imx6_pcie->pcie);
+err_pcie:
+	clk_disable_unprepare(imx6_pcie->pcie_bus);
+err_pcie_bus:
+	clk_disable_unprepare(imx6_pcie->pcie_phy);
+
+	return ret;
+

Superfluous newline.

[Richard Zhu]Got that. Blank line would be removed later.
Thanks.

Regards,
Lucas

quoted

+}
+
 static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)  {
 	clk_disable_unprepare(imx6_pcie->pcie);

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