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From:   Manish Narani <manish.narani@xilinx.com>
To:     <anurag.kumar.vulisha@xilinx.com>,
        <laurent.pinchart@ideasonboard.com>, <kishon@ti.com>,
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CC:     <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        Manish Narani <manish.narani@xilinx.com>
Subject: [PATCH] phy: zynqmp: Handle the clock enable/disable properly
Date:   Tue, 9 Mar 2021 00:19:16 +0530
Message-ID: <1615229356-26237-1-git-send-email-manish.narani@xilinx.com>
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The current driver is not handling the clock enable/disable operations
properly. The clocks need to be handled correctly by enabling or
disabling at appropriate places. This patch adds code to handle the
same.

Signed-off-by: Manish Narani <manish.narani@xilinx.com>
---
 drivers/phy/xilinx/phy-zynqmp.c | 40 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index 2b65f84..0ec534e 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -219,6 +219,7 @@ struct xpsgtr_dev {
 	struct mutex gtr_mutex; /* mutex for locking */
 	struct xpsgtr_phy phys[NUM_LANES];
 	const struct xpsgtr_ssc *refclk_sscs[NUM_LANES];
+	struct clk *clk[NUM_LANES];
 	bool tx_term_fix;
 	unsigned int saved_icm_cfg0;
 	unsigned int saved_icm_cfg1;
@@ -818,11 +819,15 @@ static struct phy *xpsgtr_xlate(struct device *dev,
 static int __maybe_unused xpsgtr_suspend(struct device *dev)
 {
 	struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
+	int i;
 
 	/* Save the snapshot ICM_CFG registers. */
 	gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
 	gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
 
+	for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
+		clk_disable(gtr_dev->clk[i]);
+
 	return 0;
 }
 
@@ -832,6 +837,13 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
 	unsigned int icm_cfg0, icm_cfg1;
 	unsigned int i;
 	bool skip_phy_init;
+	int err;
+
+	for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) {
+		err = clk_enable(gtr_dev->clk[i]);
+		if (err)
+			return err;
+	}
 
 	icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
 	icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
@@ -865,6 +877,7 @@ static const struct dev_pm_ops xpsgtr_pm_ops = {
 static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
 {
 	unsigned int refclk;
+	int ret;
 
 	for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->refclk_sscs); ++refclk) {
 		unsigned long rate;
@@ -882,6 +895,12 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
 		if (!clk)
 			continue;
 
+		gtr_dev->clk[refclk] = clk;
+
+		ret = clk_prepare_enable(gtr_dev->clk[refclk]);
+		if (ret)
+			return ret;
+
 		/*
 		 * Get the spread spectrum (SSC) settings for the reference
 		 * clock rate.
@@ -899,11 +918,17 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
 			dev_err(gtr_dev->dev,
 				"Invalid rate %lu for reference clock %u\n",
 				rate, refclk);
-			return -EINVAL;
+			goto err_clk_put;
 		}
 	}
 
 	return 0;
+
+err_clk_put:
+	for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->clk); refclk++)
+		clk_disable_unprepare(gtr_dev->clk[refclk]);
+
+	return -EINVAL;
 }
 
 static int xpsgtr_probe(struct platform_device *pdev)
@@ -913,6 +938,7 @@ static int xpsgtr_probe(struct platform_device *pdev)
 	struct phy_provider *provider;
 	unsigned int port;
 	int ret;
+	int i;
 
 	gtr_dev = devm_kzalloc(&pdev->dev, sizeof(*gtr_dev), GFP_KERNEL);
 	if (!gtr_dev)
@@ -951,7 +977,8 @@ static int xpsgtr_probe(struct platform_device *pdev)
 		phy = devm_phy_create(&pdev->dev, np, &xpsgtr_phyops);
 		if (IS_ERR(phy)) {
 			dev_err(&pdev->dev, "failed to create PHY\n");
-			return PTR_ERR(phy);
+			ret = PTR_ERR(phy);
+			goto err_clk_put;
 		}
 
 		gtr_phy->phy = phy;
@@ -962,9 +989,16 @@ static int xpsgtr_probe(struct platform_device *pdev)
 	provider = devm_of_phy_provider_register(&pdev->dev, xpsgtr_xlate);
 	if (IS_ERR(provider)) {
 		dev_err(&pdev->dev, "registering provider failed\n");
-		return PTR_ERR(provider);
+		ret = PTR_ERR(provider);
+		goto err_clk_put;
 	}
 	return 0;
+
+err_clk_put:
+	for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
+		clk_disable_unprepare(gtr_dev->clk[i]);
+
+	return ret;
 }
 
 static const struct of_device_id xpsgtr_of_match[] = {
-- 
2.1.1