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.fe...@atmel.com>
---
 .../devicetree/bindings/crypto/atmel-crypto.txt    | 22 +++++
 drivers/crypto/atmel-sha.c                         | 99 ++++++++++++++++------
 2 files changed, 97 insertions(+), 24 deletions(-)

diff --git a/Documentation/devicetree/bindings/crypto/atmel-crypto.txt 
b/Documentation/devicetree/bindings/crypto/atmel-crypto.txt
index 9a24fd9..f2aab3d 100644
--- a/Documentation/devicetree/bindings/crypto/atmel-crypto.txt
+++ b/Documentation/devicetree/bindings/crypto/atmel-crypto.txt
@@ -44,3 +44,25 @@ tdes@f803c000 {
               <&dma1 2 21>;
        dma-names = "tx", "rx";
 };
+
+* Secure Hash Algorithm (SHA)
+
+Required properties:
+- compatible : Should be "atmel,at91sam9g46-sha".
+- reg: Should contain SHA registers location and length.
+- interrupts: Should contain the IRQ line for the SHA.
+
+Optional properties:
+- dmas: One 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. Only one "tx" string needed.
+
+Example:
+sha@f8034000 {
+       compatible = "atmel,at91sam9g46-sha";
+       reg = <0xf8034000 0x100>;
+       interrupts = <42 4 0>;
+       dmas = <&dma1 2 17>;
+       dma-names = "tx";
+};
diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
index eaed8bf..ecfdf72 100644
--- a/drivers/crypto/atmel-sha.c
+++ b/drivers/crypto/atmel-sha.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>
@@ -1263,32 +1264,29 @@ static int atmel_sha_dma_init(struct atmel_sha_dev *dd,
        int err = -ENOMEM;
        dma_cap_mask_t mask_in;
 
-       if (pdata && pdata->dma_slave->rxdata.dma_dev) {
-               /* Try to grab DMA channel */
-               dma_cap_zero(mask_in);
-               dma_cap_set(DMA_SLAVE, mask_in);
+       /* Try to grab DMA channel */
+       dma_cap_zero(mask_in);
+       dma_cap_set(DMA_SLAVE, mask_in);
 
-               dd->dma_lch_in.chan = dma_request_channel(mask_in,
-                               atmel_sha_filter, &pdata->dma_slave->rxdata);
-
-               if (!dd->dma_lch_in.chan)
-                       return err;
-
-               dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
-               dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
-                       SHA_REG_DIN(0);
-               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;
-
-               return 0;
+       dd->dma_lch_in.chan = dma_request_slave_channel_compat(mask_in,
+                       atmel_sha_filter, &pdata->dma_slave->rxdata, dd->dev, 
"tx");
+       if (!dd->dma_lch_in.chan) {
+               dev_warn(dd->dev, "no DMA channel available\n");
+               return err;
        }
 
-       return -ENODEV;
+       dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
+       dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
+               SHA_REG_DIN(0);
+       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;
+
+       return 0;
 }
 
 static void atmel_sha_dma_cleanup(struct atmel_sha_dev *dd)
@@ -1326,6 +1324,48 @@ static void atmel_sha_get_cap(struct atmel_sha_dev *dd)
        }
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_sha_dt_ids[] = {
+       { .compatible = "atmel,at91sam9g46-sha" },
+       { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_sha_dt_ids);
+
+static struct crypto_platform_data *atmel_sha_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_sha_of_init(struct 
platform_device *dev)
+{
+       return ERR_PTR(-EINVAL);
+}
+#endif
+
 static int atmel_sha_probe(struct platform_device *pdev)
 {
        struct atmel_sha_dev *sha_dd;
@@ -1402,13 +1442,23 @@ static int atmel_sha_probe(struct platform_device *pdev)
        if (sha_dd->caps.has_dma) {
                pdata = pdev->dev.platform_data;
                if (!pdata) {
-                       dev_err(&pdev->dev, "platform data not available\n");
+                       pdata = atmel_sha_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_sha_dma_init(sha_dd, pdata);
                if (err)
                        goto err_sha_dma;
+
+               dev_info(dev, "using %s for DMA transfers\n",
+                               dma_chan_name(sha_dd->dma_lch_in.chan));
        }
 
        spin_lock(&atmel_sha.lock);
@@ -1483,6 +1533,7 @@ static struct platform_driver atmel_sha_driver = {
        .driver         = {
                .name   = "atmel_sha",
                .owner  = THIS_MODULE,
+               .of_match_table = of_match_ptr(atmel_sha_dt_ids),
        },
 };
 
-- 
1.8.2.2

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