crypto: omap-aes - Switch to PIO mode during probe

In cases where requesting for DMA channels fails for some reason, or channel
numbers are not provided in DT or platform data, we switch to PIO-only mode
also checking if platform provides IRQ numbers and interrupt register offsets
in DT and platform data. All dma-only paths are avoided in this mode.
Signed-off-by: NJoel Fernandes <joelf@ti.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-aes.c

@@ -1075,7 +1075,7 @@ static int omap_aes_probe(struct platform_device *pdev)
 	struct omap_aes_dev *dd;
 	struct crypto_alg *algp;
 	struct resource res;
-	int err = -ENOMEM, i, j;
+	int err = -ENOMEM, i, j, irq = -1;
 	u32 reg;
 
 	dd = kzalloc(sizeof(struct omap_aes_dev), GFP_KERNEL);
@@ -1118,8 +1118,23 @@ static int omap_aes_probe(struct platform_device *pdev)
 	tasklet_init(&dd->queue_task, omap_aes_queue_task, (unsigned long)dd);
 
 	err = omap_aes_dma_init(dd);
-	if (err)
-		goto err_dma;
+	if (err && AES_REG_IRQ_STATUS(dd) && AES_REG_IRQ_ENABLE(dd)) {
+		dd->pio_only = 1;
+
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0) {
+			dev_err(dev, "can't get IRQ resource\n");
+			goto err_irq;
+		}
+
+		err = request_irq(irq, omap_aes_irq, 0,
+				dev_name(dev), dd);
+		if (err) {
+			dev_err(dev, "Unable to grab omap-aes IRQ\n");
+			goto err_irq;
+		}
+	}
+
 
 	INIT_LIST_HEAD(&dd->list);
 	spin_lock(&list_lock);
@@ -1147,8 +1162,11 @@ static int omap_aes_probe(struct platform_device *pdev)
 		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)
 			crypto_unregister_alg(
 					&dd->pdata->algs_info[i].algs_list[j]);
-	omap_aes_dma_cleanup(dd);
-err_dma:
+	if (dd->pio_only)
+		free_irq(irq, dd);
+	else
+		omap_aes_dma_cleanup(dd);
+err_irq:
 	tasklet_kill(&dd->done_task);
 	tasklet_kill(&dd->queue_task);
 	pm_runtime_disable(dev);