crypto: inside-secure - fix clock resource by adding a register clock

On Armada 7K/8K we need to explicitly enable the register clock. This
clock is optional because not all the SoCs using this IP need it but at
least for Armada 7K/8K it is actually mandatory.

The binding documentation is updated accordingly.

Signed-off-by: Gregory CLEMENT <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

Documentation/devicetree/bindings/crypto/inside-secure-safexcel.txt

···
 - interrupt-names: Should be "ring0", "ring1", "ring2", "ring3", "eip", "mem".
 
 Optional properties:
-- clocks: Reference to the crypto engine clock.
+- clocks: Reference to the crypto engine clocks, the second clock is
+          needed for the Armada 7K/8K SoCs.
+- clock-names: mandatory if there is a second clock, in this case the
+               name must be "core" for the first clock and "reg" for
+               the second one.
 
 Example:
 

drivers/crypto/inside-secure/safexcel.c

···
 		}
 	}
 
+	priv->reg_clk = devm_clk_get(&pdev->dev, "reg");
+	ret = PTR_ERR_OR_ZERO(priv->reg_clk);
+	/* The clock isn't mandatory */
+	if  (ret != -ENOENT) {
+		if (ret)
+			goto err_core_clk;
+
+		ret = clk_prepare_enable(priv->reg_clk);
+		if (ret) {
+			dev_err(dev, "unable to enable reg clk (%d)\n", ret);
+			goto err_core_clk;
+		}
+	}
+
 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
 	if (ret)
-		goto err_clk;
+		goto err_reg_clk;
 
 	priv->context_pool = dmam_pool_create("safexcel-context", dev,
 					      sizeof(struct safexcel_context_record),
 					      1, 0);
 	if (!priv->context_pool) {
 		ret = -ENOMEM;
-		goto err_clk;
+		goto err_reg_clk;
 	}
 
 	safexcel_configure(priv);
···
 						     &priv->ring[i].cdr,
 						     &priv->ring[i].rdr);
 		if (ret)
-			goto err_clk;
+			goto err_reg_clk;
 
 		ring_irq = devm_kzalloc(dev, sizeof(*ring_irq), GFP_KERNEL);
 		if (!ring_irq) {
 			ret = -ENOMEM;
-			goto err_clk;
+			goto err_reg_clk;
 		}
 
 		ring_irq->priv = priv;
···
 						ring_irq);
 		if (irq < 0) {
 			ret = irq;
-			goto err_clk;
+			goto err_reg_clk;
 		}
 
 		priv->ring[i].work_data.priv = priv;
···
 		priv->ring[i].workqueue = create_singlethread_workqueue(wq_name);
 		if (!priv->ring[i].workqueue) {
 			ret = -ENOMEM;
-			goto err_clk;
+			goto err_reg_clk;
 		}
 
 		priv->ring[i].requests = 0;
···
 	ret = safexcel_hw_init(priv);
 	if (ret) {
 		dev_err(dev, "EIP h/w init failed (%d)\n", ret);
-		goto err_clk;
+		goto err_reg_clk;
 	}
 
 	ret = safexcel_register_algorithms(priv);
 	if (ret) {
 		dev_err(dev, "Failed to register algorithms (%d)\n", ret);
-		goto err_clk;
+		goto err_reg_clk;
 	}
 
 	return 0;
 
-err_clk:
+err_reg_clk:
+	clk_disable_unprepare(priv->reg_clk);
+err_core_clk:
 	clk_disable_unprepare(priv->clk);
 	return ret;
 }

drivers/crypto/inside-secure/safexcel.h

···
 	void __iomem *base;
 	struct device *dev;
 	struct clk *clk;
+	struct clk *reg_clk;
 	struct safexcel_config config;
 
 	enum safexcel_eip_version version;