crypto: atmel-aes - add support for Device Tree

Add support for Device Tree and use of the DMA DT API to
get the needed channels.
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>

1 files changed, 94 insertions, 49 deletions

diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index c1efd910d97b..d7c9e317423c 100644
--- a/drivers/crypto/atmel-aes.c
+++ b/drivers/crypto/atmel-aes.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>
@@ -39,6 +40,7 @@
 #include <crypto/hash.h>
 #include <crypto/internal/hash.h>
 #include <linux/platform_data/crypto-atmel.h>
+#include <dt-bindings/dma/at91.h>
 #include "atmel-aes-regs.h"
 
 #define CFB8_BLOCK_SIZE         1
@@ -747,59 +749,50 @@ static int atmel_aes_dma_init(struct atmel_aes_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_aes_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 +
+                AES_IDATAR(0);
+        dd->dma_lch_in.dma_conf.src_maxburst = dd->caps.max_burst_size;
+        dd->dma_lch_in.dma_conf.src_addr_width =
+                DMA_SLAVE_BUSWIDTH_4_BYTES;
+        dd->dma_lch_in.dma_conf.dst_maxburst = dd->caps.max_burst_size;
+        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_aes_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 +
+                AES_ODATAR(0);
+        dd->dma_lch_out.dma_conf.src_maxburst = dd->caps.max_burst_size;
+        dd->dma_lch_out.dma_conf.src_addr_width =
+                DMA_SLAVE_BUSWIDTH_4_BYTES;
+        dd->dma_lch_out.dma_conf.dst_maxburst = dd->caps.max_burst_size;
+        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_aes_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 +
-                        AES_IDATAR(0);
-                dd->dma_lch_in.dma_conf.src_maxburst = dd->caps.max_burst_size;
-                dd->dma_lch_in.dma_conf.src_addr_width =
-                        DMA_SLAVE_BUSWIDTH_4_BYTES;
-                dd->dma_lch_in.dma_conf.dst_maxburst = dd->caps.max_burst_size;
-                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_aes_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 +
-                        AES_ODATAR(0);
-                dd->dma_lch_out.dma_conf.src_maxburst = dd->caps.max_burst_size;
-                dd->dma_lch_out.dma_conf.src_addr_width =
-                        DMA_SLAVE_BUSWIDTH_4_BYTES;
-                dd->dma_lch_out.dma_conf.dst_maxburst = dd->caps.max_burst_size;
-                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;
 }
 
@@ -1261,6 +1254,47 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd)
         }
 }
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_aes_dt_ids[] = {
+        { .compatible = "atmel,at91sam9g46-aes" },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, atmel_aes_dt_ids);
+
+static struct crypto_platform_data *atmel_aes_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
+static inline struct crypto_platform_data *atmel_aes_of_init(struct platform_device *pdev)
+{
+        return ERR_PTR(-EINVAL);
+}
+#endif
+
 static int atmel_aes_probe(struct platform_device *pdev)
 {
         struct atmel_aes_dev *aes_dd;
@@ -1272,6 +1306,14 @@ static int atmel_aes_probe(struct platform_device *pdev)
 
         pdata = pdev->dev.platform_data;
         if (!pdata) {
+                pdata = atmel_aes_of_init(pdev);
+                if (IS_ERR(pdata)) {
+                        err = PTR_ERR(pdata);
+                        goto aes_dd_err;
+                }
+        }
+
+        if (!pdata->dma_slave) {
                 err = -ENXIO;
                 goto aes_dd_err;
         }
@@ -1358,7 +1400,9 @@ static int atmel_aes_probe(struct platform_device *pdev)
         if (err)
                 goto err_algs;
 
-        dev_info(dev, "Atmel AES\n");
+        dev_info(dev, "Atmel AES - Using %s, %s for DMA transfers\n",
+                        dma_chan_name(aes_dd->dma_lch_in.chan),
+                        dma_chan_name(aes_dd->dma_lch_out.chan));
 
         return 0;
 
@@ -1424,6 +1468,7 @@ static struct platform_driver atmel_aes_driver = {
         .driver         = {
                 .name   = "atmel_aes",
                 .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(atmel_aes_dt_ids),
         },
 };