linux-kernel - [PATCH v2 2/5] crypto: ccree: better clock handling

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Date:   Thu, 24 May 2018 15:19:07 +0100
From:   Gilad Ben-Yossef <gilad@...yossef.com>
To:     Simon Horman <horms@...ge.net.au>,
        Magnus Damm <magnus.damm@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>
Cc:     Ofir Drang <ofir.drang@....com>, linux-renesas-soc@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-crypto@...r.kernel.org
Subject: [PATCH v2 2/5] crypto: ccree: better clock handling

Use managed clock handling, differentiate between no clock (possibly OK)
and clock init failure (never OK) and correctly handle clock detection
being deferred.

Suggested-by: Geert Uytterhoeven <geert@...ux-m68k.org>
Signed-off-by: Gilad Ben-Yossef <gilad@...yossef.com>
---
 drivers/crypto/ccree/cc_driver.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_driver.c b/drivers/crypto/ccree/cc_driver.c
index 6f93ce7..b266657 100644
--- a/drivers/crypto/ccree/cc_driver.c
+++ b/drivers/crypto/ccree/cc_driver.c
@@ -190,6 +190,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
 	u64 dma_mask;
 	const struct cc_hw_data *hw_rev;
 	const struct of_device_id *dev_id;
+	struct clk *clk;
 	int rc = 0;
 
 	new_drvdata = devm_kzalloc(dev, sizeof(*new_drvdata), GFP_KERNEL);
@@ -219,7 +220,24 @@ static int init_cc_resources(struct platform_device *plat_dev)
 	platform_set_drvdata(plat_dev, new_drvdata);
 	new_drvdata->plat_dev = plat_dev;
 
-	new_drvdata->clk = of_clk_get(np, 0);
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		switch (PTR_ERR(clk)) {
+		/* Clock is optional so this might be fine */
+		case -ENOENT:
+			break;
+
+		/* Clock not available, let's try again soon */
+		case -EPROBE_DEFER:
+			return -EPROBE_DEFER;
+
+		default:
+			dev_err(dev, "Error getting clock: %ld\n",
+				PTR_ERR(clk));
+			return PTR_ERR(clk);
+		}
+	new_drvdata->clk = clk;
+
 	new_drvdata->coherent = of_dma_is_coherent(np);
 
 	/* Get device resources */
-- 
2.7.4