crypto: atmel-tdes - add support for Device Tree

Add support for Device Tree and use of the DMA DT API to
get the channels if needed.
Documentation is added for these DT nodes.

Initial code by: Nicolas Royer and Eukrea.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Documentation/devicetree/bindings/crypto/atmel-crypto.txt

@@ -21,3 +21,26 @@ aes@f8038000 {
 	dmas = <&dma1 2 18>,
 	       <&dma1 2 19>;
 	dma-names = "tx", "rx";
+
+* Triple Data Encryption Standard (Triple DES)
+
+Required properties:
+- compatible : Should be "atmel,at91sam9g46-tdes".
+- reg: Should contain TDES registers location and length.
+- interrupts: Should contain the IRQ line for the TDES.
+
+Optional properties:
+- dmas: List of two DMA specifiers as described in
+        atmel-dma.txt and dma.txt files.
+- dma-names: Contains one identifier string for each DMA specifier
+             in the dmas property.
+
+Example:
+tdes@f803c000 {
+	compatible = "atmel,at91sam9g46-tdes";
+	reg = <0xf803c000 0x100>;
+	interrupts = <44 4 0>;
+	dmas = <&dma1 2 20>,
+	       <&dma1 2 21>;
+	dma-names = "tx", "rx";
+};

drivers/crypto/atmel-tdes.c

@@ -30,6 +30,7 @@
 #include <linux/irq.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-mapping.h>
+#include <linux/of_device.h>
 #include <linux/delay.h>
 #include <linux/crypto.h>
 #include <linux/cryptohash.h>
@@ -716,59 +717,50 @@ static int atmel_tdes_dma_init(struct atmel_tdes_dev *dd,
 			struct crypto_platform_data *pdata)
 {
 	int err = -ENOMEM;
-	dma_cap_mask_t mask_in, mask_out;
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/* Try to grab 2 DMA channels */
+	dd->dma_lch_in.chan = dma_request_slave_channel_compat(mask,
+			atmel_tdes_filter, &pdata->dma_slave->rxdata, dd->dev, "tx");
+	if (!dd->dma_lch_in.chan)
+		goto err_dma_in;
+
+	dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
+	dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
+		TDES_IDATA1R;
+	dd->dma_lch_in.dma_conf.src_maxburst = 1;
+	dd->dma_lch_in.dma_conf.src_addr_width =
+		DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dd->dma_lch_in.dma_conf.dst_maxburst = 1;
+	dd->dma_lch_in.dma_conf.dst_addr_width =
+		DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dd->dma_lch_in.dma_conf.device_fc = false;
+
+	dd->dma_lch_out.chan = dma_request_slave_channel_compat(mask,
+			atmel_tdes_filter, &pdata->dma_slave->txdata, dd->dev, "rx");
+	if (!dd->dma_lch_out.chan)
+		goto err_dma_out;
+
+	dd->dma_lch_out.dma_conf.direction = DMA_DEV_TO_MEM;
+	dd->dma_lch_out.dma_conf.src_addr = dd->phys_base +
+		TDES_ODATA1R;
+	dd->dma_lch_out.dma_conf.src_maxburst = 1;
+	dd->dma_lch_out.dma_conf.src_addr_width =
+		DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dd->dma_lch_out.dma_conf.dst_maxburst = 1;
+	dd->dma_lch_out.dma_conf.dst_addr_width =
+		DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dd->dma_lch_out.dma_conf.device_fc = false;
 
-	if (pdata && pdata->dma_slave->txdata.dma_dev &&
-		pdata->dma_slave->rxdata.dma_dev) {
-
-		/* Try to grab 2 DMA channels */
-		dma_cap_zero(mask_in);
-		dma_cap_set(DMA_SLAVE, mask_in);
-
-		dd->dma_lch_in.chan = dma_request_channel(mask_in,
-				atmel_tdes_filter, &pdata->dma_slave->rxdata);
-
-		if (!dd->dma_lch_in.chan)
-			goto err_dma_in;
-
-		dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
-		dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
-			TDES_IDATA1R;
-		dd->dma_lch_in.dma_conf.src_maxburst = 1;
-		dd->dma_lch_in.dma_conf.src_addr_width =
-			DMA_SLAVE_BUSWIDTH_4_BYTES;
-		dd->dma_lch_in.dma_conf.dst_maxburst = 1;
-		dd->dma_lch_in.dma_conf.dst_addr_width =
-			DMA_SLAVE_BUSWIDTH_4_BYTES;
-		dd->dma_lch_in.dma_conf.device_fc = false;
-
-		dma_cap_zero(mask_out);
-		dma_cap_set(DMA_SLAVE, mask_out);
-		dd->dma_lch_out.chan = dma_request_channel(mask_out,
-				atmel_tdes_filter, &pdata->dma_slave->txdata);
-
-		if (!dd->dma_lch_out.chan)
-			goto err_dma_out;
-
-		dd->dma_lch_out.dma_conf.direction = DMA_DEV_TO_MEM;
-		dd->dma_lch_out.dma_conf.src_addr = dd->phys_base +
-			TDES_ODATA1R;
-		dd->dma_lch_out.dma_conf.src_maxburst = 1;
-		dd->dma_lch_out.dma_conf.src_addr_width =
-			DMA_SLAVE_BUSWIDTH_4_BYTES;
-		dd->dma_lch_out.dma_conf.dst_maxburst = 1;
-		dd->dma_lch_out.dma_conf.dst_addr_width =
-			DMA_SLAVE_BUSWIDTH_4_BYTES;
-		dd->dma_lch_out.dma_conf.device_fc = false;
-
-		return 0;
-	} else {
-		return -ENODEV;
-	}
+	return 0;
 
 err_dma_out:
 	dma_release_channel(dd->dma_lch_in.chan);
 err_dma_in:
+	dev_warn(dd->dev, "no DMA channel available\n");
 	return err;
 }
 
@@ -1317,6 +1309,47 @@ static void atmel_tdes_get_cap(struct atmel_tdes_dev *dd)
 	}
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_tdes_dt_ids[] = {
+	{ .compatible = "atmel,at91sam9g46-tdes" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, atmel_tdes_dt_ids);
+
+static struct crypto_platform_data *atmel_tdes_of_init(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct crypto_platform_data *pdata;
+
+	if (!np) {
+		dev_err(&pdev->dev, "device node not found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(&pdev->dev, "could not allocate memory for pdata\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	pdata->dma_slave = devm_kzalloc(&pdev->dev,
+					sizeof(*(pdata->dma_slave)),
+					GFP_KERNEL);
+	if (!pdata->dma_slave) {
+		dev_err(&pdev->dev, "could not allocate memory for dma_slave\n");
+		devm_kfree(&pdev->dev, pdata);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return pdata;
+}
+#else /* CONFIG_OF */
+static inline struct crypto_platform_data *atmel_tdes_of_init(struct platform_device *pdev)
+{
+	return ERR_PTR(-EINVAL);
+}
+#endif
+
 static int atmel_tdes_probe(struct platform_device *pdev)
 {
 	struct atmel_tdes_dev *tdes_dd;
@@ -1399,13 +1432,24 @@ static int atmel_tdes_probe(struct platform_device *pdev)
 	if (tdes_dd->caps.has_dma) {
 		pdata = pdev->dev.platform_data;
 		if (!pdata) {
-			dev_err(&pdev->dev, "platform data not available\n");
+			pdata = atmel_tdes_of_init(pdev);
+			if (IS_ERR(pdata)) {
+				dev_err(&pdev->dev, "platform data not available\n");
+				err = PTR_ERR(pdata);
+				goto err_pdata;
+			}
+		}
+		if (!pdata->dma_slave) {
 			err = -ENXIO;
 			goto err_pdata;
 		}
 		err = atmel_tdes_dma_init(tdes_dd, pdata);
 		if (err)
 			goto err_tdes_dma;
+
+		dev_info(dev, "using %s, %s for DMA transfers\n",
+				dma_chan_name(tdes_dd->dma_lch_in.chan),
+				dma_chan_name(tdes_dd->dma_lch_out.chan));
 	}
 
 	spin_lock(&atmel_tdes.lock);
@@ -1487,6 +1531,7 @@ static struct platform_driver atmel_tdes_driver = {
 	.driver		= {
 		.name	= "atmel_tdes",
 		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(atmel_tdes_dt_ids),
 	},
 };