dmaengine: Actions: Add support for S700 DMA engine

DMA controller present on S700 SoC is compatible with the one on S900
(as most of registers are same), but it has different DMA descriptor
structure where registers "fcnt" and "ctrlb" uses different encoding.

For instance, on S900 "fcnt" starts at offset 0x0c and uses upper 12
bits whereas on S700, it starts at offset 0x1c and uses lower 12 bits.

This commit adds support for DMA controller present on S700.

Signed-off-by: Amit Singh Tomar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: Atomar25

drivers/dma/owl-dma.c

@@ -149,6 +149,11 @@ enum owl_dmadesc_offsets {
 	OWL_DMADESC_SIZE
 };
 
+enum owl_dma_id {
+	S900_DMA,
+	S700_DMA,
+};
+
 /**
  * struct owl_dma_lli - Link list for dma transfer
  * @hw: hardware link list
@@ -213,6 +218,7 @@ struct owl_dma_vchan {
  * @pchans: array of data for the physical channels
  * @nr_vchans: the number of physical channels
  * @vchans: array of data for the physical channels
+ * @devid: device id based on OWL SoC
  */
 struct owl_dma {
 	struct dma_device	dma;
@@ -227,6 +233,7 @@ struct owl_dma {
 
 	unsigned int		nr_vchans;
 	struct owl_dma_vchan	*vchans;
+	enum owl_dma_id		devid;
 };
 
 static void pchan_update(struct owl_dma_pchan *pchan, u32 reg,
@@ -316,6 +323,10 @@ static inline u32 llc_hw_ctrlb(u32 int_ctl)
 {
 	u32 ctl;
 
+	/*
+	 * Irrespective of the SoC, ctrlb value starts filling from
+	 * bit 18.
+	 */
 	ctl = BIT_FIELD(int_ctl, 7, 0, 18);
 
 	return ctl;
@@ -372,6 +383,7 @@ static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
 				  struct dma_slave_config *sconfig,
 				  bool is_cyclic)
 {
+	struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
 	u32 mode, ctrlb;
 
 	mode = OWL_DMA_MODE_PW(0);
@@ -427,14 +439,26 @@ static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
 	lli->hw[OWL_DMADESC_DADDR] = dst;
 	lli->hw[OWL_DMADESC_SRC_STRIDE] = 0;
 	lli->hw[OWL_DMADESC_DST_STRIDE] = 0;
-	/*
-	 * Word starts from offset 0xC is shared between frame length
-	 * (max frame length is 1MB) and frame count, where first 20
-	 * bits are for frame length and rest of 12 bits are for frame
-	 * count.
-	 */
-	lli->hw[OWL_DMADESC_FLEN] = len | FCNT_VAL << 20;
-	lli->hw[OWL_DMADESC_CTRLB] = ctrlb;
+
+	if (od->devid == S700_DMA) {
+		/* Max frame length is 1MB */
+		lli->hw[OWL_DMADESC_FLEN] = len;
+		/*
+		 * On S700, word starts from offset 0x1C is shared between
+		 * frame count and ctrlb, where first 12 bits are for frame
+		 * count and rest of 20 bits are for ctrlb.
+		 */
+		lli->hw[OWL_DMADESC_CTRLB] = FCNT_VAL | ctrlb;
+	} else {
+		/*
+		 * On S900, word starts from offset 0xC is shared between
+		 * frame length (max frame length is 1MB) and frame count,
+		 * where first 20 bits are for frame length and rest of
+		 * 12 bits are for frame count.
+		 */
+		lli->hw[OWL_DMADESC_FLEN] = len | FCNT_VAL << 20;
+		lli->hw[OWL_DMADESC_CTRLB] = ctrlb;
+	}
 
 	return 0;
 }
@@ -596,7 +620,7 @@ static irqreturn_t owl_dma_interrupt(int irq, void *dev_id)
 
 		global_irq_pending = dma_readl(od, OWL_DMA_IRQ_PD0);
 
-		if (chan_irq_pending && !(global_irq_pending & BIT(i)))	{
+		if (chan_irq_pending && !(global_irq_pending & BIT(i))) {
 			dev_dbg(od->dma.dev,
 				"global and channel IRQ pending match err\n");
 
@@ -1054,6 +1078,13 @@ static struct dma_chan *owl_dma_of_xlate(struct of_phandle_args *dma_spec,
 	return chan;
 }
 
+static const struct of_device_id owl_dma_match[] = {
+	{ .compatible = "actions,s900-dma", .data = (void *)S900_DMA,},
+	{ .compatible = "actions,s700-dma", .data = (void *)S700_DMA,},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, owl_dma_match);
+
 static int owl_dma_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1083,6 +1114,8 @@ static int owl_dma_probe(struct platform_device *pdev)
 	dev_info(&pdev->dev, "dma-channels %d, dma-requests %d\n",
 		 nr_channels, nr_requests);
 
+	od->devid = (enum owl_dma_id)of_device_get_match_data(&pdev->dev);
+
 	od->nr_pchans = nr_channels;
 	od->nr_vchans = nr_requests;
 
@@ -1215,12 +1248,6 @@ static int owl_dma_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id owl_dma_match[] = {
-	{ .compatible = "actions,s900-dma", },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, owl_dma_match);
-
 static struct platform_driver owl_dma_driver = {
 	.probe	= owl_dma_probe,
 	.remove	= owl_dma_remove,