linux-kernel - [PATCH 2/4] hwrng: cctrng - let devres enable the clock

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Message-Id: <20230719071806.335718-3-martin@kaiser.cx>
Date:   Wed, 19 Jul 2023 09:18:04 +0200
From:   Martin Kaiser <martin@...ser.cx>
To:     Herbert Xu <herbert@...dor.apana.org.au>
Cc:     linux-crypto@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Martin Kaiser <martin@...ser.cx>
Subject: [PATCH 2/4] hwrng: cctrng - let devres enable the clock

Call devm_clk_get_optional_enabled in the cctrng driver. We don't have to
disable and unprepare the clock any more in error paths or in the remove
function.

Signed-off-by: Martin Kaiser <martin@...ser.cx>
---
 drivers/char/hw_random/cctrng.c | 29 +++++------------------------
 1 file changed, 5 insertions(+), 24 deletions(-)

diff --git a/drivers/char/hw_random/cctrng.c b/drivers/char/hw_random/cctrng.c
index 241da7e44675..ac4a2fbc6a0f 100644
--- a/drivers/char/hw_random/cctrng.c
+++ b/drivers/char/hw_random/cctrng.c
@@ -460,30 +460,16 @@ static int cc_trng_clk_init(struct cctrng_drvdata *drvdata)
 {
 	struct clk *clk;
 	struct device *dev = &(drvdata->pdev->dev);
-	int rc = 0;
 
-	clk = devm_clk_get_optional(dev, NULL);
+	clk = devm_clk_get_optional_enabled(dev, NULL);
 	if (IS_ERR(clk))
 		return dev_err_probe(dev, PTR_ERR(clk),
-				     "Error getting clock\n");
+				     "Failed to get or enable the clock\n");
 
 	drvdata->clk = clk;
-
-	rc = clk_prepare_enable(drvdata->clk);
-	if (rc) {
-		dev_err(dev, "Failed to enable clock\n");
-		return rc;
-	}
-
 	return 0;
 }
 
-static void cc_trng_clk_fini(struct cctrng_drvdata *drvdata)
-{
-	clk_disable_unprepare(drvdata->clk);
-}
-
-
 static int cctrng_probe(struct platform_device *pdev)
 {
 	struct cctrng_drvdata *drvdata;
@@ -545,7 +531,7 @@ static int cctrng_probe(struct platform_device *pdev)
 	rc = devm_request_irq(dev, irq, cc_isr, IRQF_SHARED, "cctrng", drvdata);
 	if (rc) {
 		dev_err(dev, "Could not register to interrupt %d\n", irq);
-		goto post_clk_err;
+		return rc;
 	}
 	dev_dbg(dev, "Registered to IRQ: %d\n", irq);
 
@@ -563,14 +549,14 @@ static int cctrng_probe(struct platform_device *pdev)
 	rc = cc_trng_pm_init(drvdata);
 	if (rc) {
 		dev_err(dev, "cc_trng_pm_init failed\n");
-		goto post_clk_err;
+		return rc;
 	}
 
 	/* increment device's usage counter */
 	rc = cc_trng_pm_get(dev);
 	if (rc) {
 		dev_err(dev, "cc_trng_pm_get returned %x\n", rc);
-		goto post_pm_err;
+		return rc;
 	}
 
 	/* set pending_hw to verify that HW won't be triggered from read */
@@ -597,9 +583,6 @@ static int cctrng_probe(struct platform_device *pdev)
 post_pm_err:
 	cc_trng_pm_fini(drvdata);
 
-post_clk_err:
-	cc_trng_clk_fini(drvdata);
-
 	return rc;
 }
 
@@ -612,8 +595,6 @@ static int cctrng_remove(struct platform_device *pdev)
 
 	cc_trng_pm_fini(drvdata);
 
-	cc_trng_clk_fini(drvdata);
-
 	dev_info(dev, "ARM cctrng device terminated\n");
 
 	return 0;
-- 
2.30.2