crypto: qcom-rng - Enable clock in hwrng case

commit 0fd97bb upstream.

Fix qcom-rng.c to enable the clock before accessing the hardware.

Fixes: f29cd5b ("crypto: qcom-rng - Add hw_random interface support")
Cc: stable@vger.kernel.org
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Eric Biggers

drivers/crypto/qcom-rng.c

@@ -113,13 +113,27 @@ static int qcom_rng_seed(struct crypto_rng *tfm, const u8 *seed,
 	return 0;
 }
 
+static int qcom_hwrng_init(struct hwrng *hwrng)
+{
+	struct qcom_rng *qrng = container_of(hwrng, struct qcom_rng, hwrng);
+
+	return clk_prepare_enable(qrng->clk);
+}
+
 static int qcom_hwrng_read(struct hwrng *hwrng, void *data, size_t max, bool wait)
 {
 	struct qcom_rng *qrng = container_of(hwrng, struct qcom_rng, hwrng);
 
 	return qcom_rng_read(qrng, data, max);
 }
 
+static void qcom_hwrng_cleanup(struct hwrng *hwrng)
+{
+	struct qcom_rng *qrng = container_of(hwrng, struct qcom_rng, hwrng);
+
+	clk_disable_unprepare(qrng->clk);
+}
+
 static int qcom_rng_enable(struct qcom_rng *rng)
 {
 	u32 val;
@@ -208,7 +222,9 @@ static int qcom_rng_probe(struct platform_device *pdev)
 
 	if (rng->match_data->hwrng_support) {
 		rng->hwrng.name = "qcom_hwrng";
+		rng->hwrng.init = qcom_hwrng_init;
 		rng->hwrng.read = qcom_hwrng_read;
+		rng->hwrng.cleanup = qcom_hwrng_cleanup;
 		rng->hwrng.quality = QCOM_TRNG_QUALITY;
 		ret = devm_hwrng_register(&pdev->dev, &rng->hwrng);
 		if (ret) {