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crypto: atmel-tdes - add support for Device Tree
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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>
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Nicolas Ferre committed Dec 12, 2013
1 parent be943c7 commit 84c8976
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Showing 2 changed files with 117 additions and 49 deletions.
23 changes: 23 additions & 0 deletions Documentation/devicetree/bindings/crypto/atmel-crypto.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -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";
};
143 changes: 94 additions & 49 deletions drivers/crypto/atmel-tdes.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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),
},
};

Expand Down

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