[PATCH v7 02/10] dmaengine: Actions: get rid of bit fields from dma descriptor

[PATCH v7 02/10] dmaengine: Actions: get rid of bit fields from dma descriptor

[Amit Singh Tomar]

At the moment, Driver uses bit fields to describe registers of the DMA
descriptor structure that makes it less portable and maintainable, and
Andre suugested(and even sketched important bits for it) to make use of
array to describe this DMA descriptors instead. It gives the flexibility
while extending support for other platform such as Actions S700.

This commit removes the "owl_dma_lli_hw" (that includes bit-fields) and
uses array to describe DMA descriptor.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Suggested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
---
Changes since v6:
	* No change.
Changes since v5:
        * Added Mani's Reviewed-by: tag.
Changes since v4:
        * Reordered it from 01/10 to 02/10.
Changes since v3:
        * Added description for enum fields.
        * Restored the old comment.
        * Added detailed comment about, the way FLEN
          and FCNT values are filled.
Changes since v2:
        * No change.
Changes since v1:
        * Defined macro for frame count value.
        * Introduced llc_hw_flen() from patch 2/9.
        * Removed the unnecessary line break.
Changes since rfc:
        * No change.
---
 drivers/dma/owl-dma.c | 98 +++++++++++++++++++++++++++++----------------------
 1 file changed, 56 insertions(+), 42 deletions(-)

diff --git a/drivers/dma/owl-dma.c b/drivers/dma/owl-dma.c
index 66ef70b00ec0..948d1bead860 100644
--- a/drivers/dma/owl-dma.c
+++ b/drivers/dma/owl-dma.c
@@ -120,30 +120,33 @@
 #define BIT_FIELD(val, width, shift, newshift)	\
 		((((val) >> (shift)) & ((BIT(width)) - 1)) << (newshift))
 
+/* Frame count value is fixed as 1 */
+#define FCNT_VAL				0x1
+
 /**
- * struct owl_dma_lli_hw - Hardware link list for dma transfer
- * @next_lli: physical address of the next link list
- * @saddr: source physical address
- * @daddr: destination physical address
- * @flen: frame length
- * @fcnt: frame count
- * @src_stride: source stride
- * @dst_stride: destination stride
- * @ctrla: dma_mode and linklist ctrl config
- * @ctrlb: interrupt config
- * @const_num: data for constant fill
+ * owl_dmadesc_offsets - Describe DMA descriptor, hardware link
+ * list for dma transfer
+ * @OWL_DMADESC_NEXT_LLI: physical address of the next link list
+ * @OWL_DMADESC_SADDR: source physical address
+ * @OWL_DMADESC_DADDR: destination physical address
+ * @OWL_DMADESC_FLEN: frame length
+ * @OWL_DMADESC_SRC_STRIDE: source stride
+ * @OWL_DMADESC_DST_STRIDE: destination stride
+ * @OWL_DMADESC_CTRLA: dma_mode and linklist ctrl config
+ * @OWL_DMADESC_CTRLB: interrupt config
+ * @OWL_DMADESC_CONST_NUM: data for constant fill
  */
-struct owl_dma_lli_hw {
-	u32	next_lli;
-	u32	saddr;
-	u32	daddr;
-	u32	flen:20;
-	u32	fcnt:12;
-	u32	src_stride;
-	u32	dst_stride;
-	u32	ctrla;
-	u32	ctrlb;
-	u32	const_num;
+enum owl_dmadesc_offsets {
+	OWL_DMADESC_NEXT_LLI = 0,
+	OWL_DMADESC_SADDR,
+	OWL_DMADESC_DADDR,
+	OWL_DMADESC_FLEN,
+	OWL_DMADESC_SRC_STRIDE,
+	OWL_DMADESC_DST_STRIDE,
+	OWL_DMADESC_CTRLA,
+	OWL_DMADESC_CTRLB,
+	OWL_DMADESC_CONST_NUM,
+	OWL_DMADESC_SIZE
 };
 
 /**
@@ -153,7 +156,7 @@ struct owl_dma_lli_hw {
  * @node: node for txd's lli_list
  */
 struct owl_dma_lli {
-	struct  owl_dma_lli_hw	hw;
+	u32			hw[OWL_DMADESC_SIZE];
 	dma_addr_t		phys;
 	struct list_head	node;
 };
@@ -318,6 +321,11 @@ static inline u32 llc_hw_ctrlb(u32 int_ctl)
 	return ctl;
 }
 
+static u32 llc_hw_flen(struct owl_dma_lli *lli)
+{
+	return lli->hw[OWL_DMADESC_FLEN] & GENMASK(19, 0);
+}
+
 static void owl_dma_free_lli(struct owl_dma *od,
 			     struct owl_dma_lli *lli)
 {
@@ -349,8 +357,9 @@ static struct owl_dma_lli *owl_dma_add_lli(struct owl_dma_txd *txd,
 		list_add_tail(&next->node, &txd->lli_list);
 
 	if (prev) {
-		prev->hw.next_lli = next->phys;
-		prev->hw.ctrla |= llc_hw_ctrla(OWL_DMA_MODE_LME, 0);
+		prev->hw[OWL_DMADESC_NEXT_LLI] = next->phys;
+		prev->hw[OWL_DMADESC_CTRLA] |=
+					llc_hw_ctrla(OWL_DMA_MODE_LME, 0);
 	}
 
 	return next;
@@ -363,8 +372,7 @@ static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
 				  struct dma_slave_config *sconfig,
 				  bool is_cyclic)
 {
-	struct owl_dma_lli_hw *hw = &lli->hw;
-	u32 mode;
+	u32 mode, ctrlb;
 
 	mode = OWL_DMA_MODE_PW(0);
 
@@ -405,22 +413,28 @@ static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
 		return -EINVAL;
 	}
 
-	hw->next_lli = 0; /* One link list by default */
-	hw->saddr = src;
-	hw->daddr = dst;
-
-	hw->fcnt = 1; /* Frame count fixed as 1 */
-	hw->flen = len; /* Max frame length is 1MB */
-	hw->src_stride = 0;
-	hw->dst_stride = 0;
-	hw->ctrla = llc_hw_ctrla(mode,
-				 OWL_DMA_LLC_SAV_LOAD_NEXT |
-				 OWL_DMA_LLC_DAV_LOAD_NEXT);
+	lli->hw[OWL_DMADESC_CTRLA] = llc_hw_ctrla(mode,
+						  OWL_DMA_LLC_SAV_LOAD_NEXT |
+						  OWL_DMA_LLC_DAV_LOAD_NEXT);
 
 	if (is_cyclic)
-		hw->ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_BLOCK);
+		ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_BLOCK);
 	else
-		hw->ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK);
+		ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK);
+
+	lli->hw[OWL_DMADESC_NEXT_LLI] = 0; /* One link list by default */
+	lli->hw[OWL_DMADESC_SADDR] = src;
+	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;
 
 	return 0;
 }
@@ -752,7 +766,7 @@ static u32 owl_dma_getbytes_chan(struct owl_dma_vchan *vchan)
 			/* Start from the next active node */
 			if (lli->phys == next_lli_phy) {
 				list_for_each_entry(lli, &txd->lli_list, node)
-					bytes += lli->hw.flen;
+					bytes += llc_hw_flen(lli);
 				break;
 			}
 		}
@@ -783,7 +797,7 @@ static enum dma_status owl_dma_tx_status(struct dma_chan *chan,
 	if (vd) {
 		txd = to_owl_txd(&vd->tx);
 		list_for_each_entry(lli, &txd->lli_list, node)
-			bytes += lli->hw.flen;
+			bytes += llc_hw_flen(lli);
 	} else {
 		bytes = owl_dma_getbytes_chan(vchan);
 	}
-- 
2.7.4

Re: [PATCH v7 02/10] dmaengine: Actions: get rid of bit fields from dma descriptor

[Vinod Koul]

On 19-07-20, 23:11, Amit Singh Tomar wrote:
> At the moment, Driver uses bit fields to describe registers of the DMA
> descriptor structure that makes it less portable and maintainable, and
> Andre suugested(and even sketched important bits for it) to make use of
> array to describe this DMA descriptors instead. It gives the flexibility
> while extending support for other platform such as Actions S700.
> 
> This commit removes the "owl_dma_lli_hw" (that includes bit-fields) and
> uses array to describe DMA descriptor.

Applied, thanks

-- 
~Vinod

[PATCH v7 03/10] dmaengine: Actions: Add support for S700 DMA engine

[Amit Singh Tomar]

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 <amittomer25@gmail.com>
---
Changes since v6:
	* NO change.
Changes since v5:
        * No change.
Changes since v4:
        * Reordered it from 02/10 to 03/10.
        * Used of_device_get_match_data() instead of
          of_match_device().
        * Removed the uintptr_t used for typecast.
Changes since v3:
        * Added description for enum fields.
        * Restored the old comment.
        * Added detailed comment about, the way FLEN
          and FCNT values are filled.
Changes since v2:
        * No change.
Changes since v1:
        * Defined macro for frame count value.
        * Introduced llc_hw_flen() from patch 2/9.
        * Removed the unnecessary line break.
Changes since rfc:
        * No change.
---
 drivers/dma/owl-dma.c | 57 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 42 insertions(+), 15 deletions(-)

diff --git a/drivers/dma/owl-dma.c b/drivers/dma/owl-dma.c
index 948d1bead860..331c8d8b10a3 100644
--- a/drivers/dma/owl-dma.c
+++ b/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,
-- 
2.7.4

Re: [PATCH v7 03/10] dmaengine: Actions: Add support for S700 DMA engine

[Vinod Koul]

On 19-07-20, 23:12, Amit Singh Tomar wrote:
> 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.

Applied, thanks

-- 
~Vinod