[PATCH net-next v2 05/10] net: ftgmac100: Convert using devm_clk_get_enabled() in ftgmac100_setup_clk()

[Li Zetao]

Use devm_clk_get_enabled() instead of devm_clk_get() +
clk_prepare_enable(), which can make the clk consistent with the device
life cycle and reduce the risk of unreleased clk resources. Since the
device framework has automatically released the clk resource, there is
no need to execute clk_disable_unprepare(clk) on the error path, drop
the cleanup_clk label, and the original error process can return directly.

It turns out that checking the return value of clk_prepare_enable is a bit
counter-intuitive. Here use PTR_ERR_OR_ZERO to make it more intuitive.

Signed-off-by: Li Zetao <lizetao1 at huawei.com>
---
v1 -> v2: Optimize return value checking and add commit information for easy
understanding
v1:
https://lore.kernel.org/all/20240831021334.1907921-6-lizetao1@huawei.com/

 drivers/net/ethernet/faraday/ftgmac100.c | 26 +++++-------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index f3cc14cc757d..f2911507d7b8 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1767,13 +1767,10 @@ static int ftgmac100_setup_clk(struct ftgmac100 *priv)
 	struct clk *clk;
 	int rc;
 
-	clk = devm_clk_get(priv->dev, NULL /* MACCLK */);
+	clk = devm_clk_get_enabled(priv->dev, NULL /* MACCLK */);
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 	priv->clk = clk;
-	rc = clk_prepare_enable(priv->clk);
-	if (rc)
-		return rc;
 
 	/* Aspeed specifies a 100MHz clock is required for up to
 	 * 1000Mbit link speeds. As NCSI is limited to 100Mbit, 25MHz
@@ -1782,21 +1779,14 @@ static int ftgmac100_setup_clk(struct ftgmac100 *priv)
 	rc = clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ :
 			  FTGMAC_100MHZ);
 	if (rc)
-		goto cleanup_clk;
+		return rc;
 
 	/* RCLK is for RMII, typically used for NCSI. Optional because it's not
 	 * necessary if it's the AST2400 MAC, or the MAC is configured for
 	 * RGMII, or the controller is not an ASPEED-based controller.
 	 */
-	priv->rclk = devm_clk_get_optional(priv->dev, "RCLK");
-	rc = clk_prepare_enable(priv->rclk);
-	if (!rc)
-		return 0;
-
-cleanup_clk:
-	clk_disable_unprepare(priv->clk);
-
-	return rc;
+	priv->rclk = devm_clk_get_optional_enabled(priv->dev, "RCLK");
+	return PTR_ERR_OR_ZERO(priv->rclk);
 }
 
 static bool ftgmac100_has_child_node(struct device_node *np, const char *name)
@@ -2020,16 +2010,13 @@ static int ftgmac100_probe(struct platform_device *pdev)
 	err = register_netdev(netdev);
 	if (err) {
 		dev_err(&pdev->dev, "Failed to register netdev\n");
-		goto err_register_netdev;
+		goto err_phy_connect;
 	}
 
 	netdev_info(netdev, "irq %d, mapped at %p\n", netdev->irq, priv->base);
 
 	return 0;
 
-err_register_netdev:
-	clk_disable_unprepare(priv->rclk);
-	clk_disable_unprepare(priv->clk);
 err_phy_connect:
 	ftgmac100_phy_disconnect(netdev);
 err_ncsi_dev:
@@ -2058,9 +2045,6 @@ static void ftgmac100_remove(struct platform_device *pdev)
 		ncsi_unregister_dev(priv->ndev);
 	unregister_netdev(netdev);
 
-	clk_disable_unprepare(priv->rclk);
-	clk_disable_unprepare(priv->clk);
-
 	/* There's a small chance the reset task will have been re-queued,
 	 * during stop, make sure it's gone before we free the structure.
 	 */
-- 
2.34.1