crypto: omap-aes - PIO mode: platform data for OMAP4/AM437x and trigger

We initialize the scatter gather walk lists needed for PIO mode and avoid all
DMA paths such as mapping/unmapping buffers by checking for the pio_only flag.
Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-aes.c

@@ -169,6 +169,7 @@ struct omap_aes_dev {
 	struct dma_chan		*dma_lch_out;
 	int			in_sg_len;
 	int			out_sg_len;
+	int			pio_only;
 	const struct omap_aes_pdata	*pdata;
 };
 
@@ -408,6 +409,16 @@ static int omap_aes_crypt_dma(struct crypto_tfm *tfm,
 	struct dma_slave_config cfg;
 	int ret;
 
+	if (dd->pio_only) {
+		scatterwalk_start(&dd->in_walk, dd->in_sg);
+		scatterwalk_start(&dd->out_walk, dd->out_sg);
+
+		/* Enable DATAIN interrupt and let it take
+		   care of the rest */
+		omap_aes_write(dd, AES_REG_IRQ_ENABLE(dd), 0x2);
+		return 0;
+	}
+
 	dma_sync_sg_for_device(dd->dev, dd->in_sg, in_sg_len, DMA_TO_DEVICE);
 
 	memset(&cfg, 0, sizeof(cfg));
@@ -477,21 +488,25 @@ static int omap_aes_crypt_dma_start(struct omap_aes_dev *dd)
 
 	pr_debug("total: %d\n", dd->total);
 
-	err = dma_map_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
+	if (!dd->pio_only) {
+		err = dma_map_sg(dd->dev, dd->in_sg, dd->in_sg_len,
+				 DMA_TO_DEVICE);
 		if (!err) {
 			dev_err(dd->dev, "dma_map_sg() error\n");
 			return -EINVAL;
 		}
 
-	err = dma_map_sg(dd->dev, dd->out_sg, dd->out_sg_len, DMA_FROM_DEVICE);
+		err = dma_map_sg(dd->dev, dd->out_sg, dd->out_sg_len,
+				 DMA_FROM_DEVICE);
 		if (!err) {
 			dev_err(dd->dev, "dma_map_sg() error\n");
 			return -EINVAL;
 		}
+	}
 
 	err = omap_aes_crypt_dma(tfm, dd->in_sg, dd->out_sg, dd->in_sg_len,
 				 dd->out_sg_len);
-	if (err) {
+	if (err && !dd->pio_only) {
 		dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
 		dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len,
 			     DMA_FROM_DEVICE);
@@ -594,9 +609,11 @@ static void omap_aes_done_task(unsigned long data)
 
 	pr_debug("enter done_task\n");
 
-	dma_sync_sg_for_cpu(dd->dev, dd->in_sg, dd->in_sg_len, DMA_FROM_DEVICE);
-
+	if (!dd->pio_only) {
+		dma_sync_sg_for_device(dd->dev, dd->out_sg, dd->out_sg_len,
+				       DMA_FROM_DEVICE);
 		omap_aes_crypt_dma_stop(dd);
+	}
 	omap_aes_finish_req(dd, 0);
 	omap_aes_handle_queue(dd, NULL);