[PATCH] crypto: atmel-aes - add support for Device Tree
Nicolas Ferre
nicolas.ferre at atmel.com
Mon Oct 14 12:35:33 EDT 2013
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 at atmel.com>
---
.../devicetree/bindings/crypto/atmel-crypto.txt | 23 ++++
drivers/crypto/atmel-aes.c | 143 ++++++++++++++-------
2 files changed, 117 insertions(+), 49 deletions(-)
create mode 100644 Documentation/devicetree/bindings/crypto/atmel-crypto.txt
diff --git a/Documentation/devicetree/bindings/crypto/atmel-crypto.txt b/Documentation/devicetree/bindings/crypto/atmel-crypto.txt
new file mode 100644
index 0000000..d273f0b
--- /dev/null
+++ b/Documentation/devicetree/bindings/crypto/atmel-crypto.txt
@@ -0,0 +1,23 @@
+* Atmel HW cryptographic accelerators
+
+These are the HW cryptographic accelerators found on some Atmel products.
+
+* Advanced Encryption Standard (AES)
+
+Required properties:
+- compatible : Should be "atmel,at91sam9g46-aes".
+- reg: Should contain AES registers location and length.
+- interrupts: Should contain the IRQ line for the AES.
+- 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:
+aes at f8038000 {
+ compatible = "atmel,at91sam9g46-aes";
+ reg = <0xf8038000 0x100>;
+ interrupts = <43 4 0>;
+ dmas = <&dma1 2 18>,
+ <&dma1 2 19>;
+ dma-names = "tx", "rx";
diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index c1efd91..d7c9e31 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),
},
};
--
1.8.2.2
More information about the linux-arm-kernel
mailing list