[PATCH v3 0/9] STM32 DMA3 updates for STM32MP25

[PATCH v3 0/9] STM32 DMA3 updates for STM32MP25

[Amelie Delaunay]

The HW version of STM32 DMA3 inside STM32MP25 requires some tunings to
meet the needs of the interconnect. This series adds the linked list
refactoring feature to have optimal performance when addressing the
memory, and it adds the use of two new bits in the third cell specifying
the DMA transfer requirements:
- bit[16] to prevent packing/unpacking mode to avoid bytes loss in case
of interrupting an ongoing transfer (e.g. UART RX),
- bit[17] to prevent linked-list refactoring because some peripherals
(e.g. FMC ECC) require a one-shot transfer, they trigger the DMA only
once.
It also adds platform data to clamp the burst length on AXI port,
especially when it is interconnected to AXI3 bus, such as on STM32MP25.
Finally this series also contains STM32MP25 device tree updates, to add
DMA support on SPI, I2C, UART and apply the tunings introduced.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v3:
- Refine commit description of patch 4 about preventing
  additionnal transfers, as per Rob's suggestion.
- Link to v2: https://lore.kernel.org/r/20241015-dma3-mp25-updates-v2-0-b63e21556ec8@foss.st.com

Changes in v2:
- Reword commit title/message/content of patch 4 about preventing
  additionnal transfers, as per Rob's suggestion
- Rework AXI maximum burst length management using SoC specific
  compatible, as pointed out by Rob
- Drop former patches 6 and 8, which are no longer relevant
- Link to v1: https://lore.kernel.org/r/20241010-dma3-mp25-updates-v1-0-adf0633981ea@foss.st.com

---
Amelie Delaunay (9):
      dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode
      dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration
      dmaengine: stm32-dma3: refactor HW linked-list to optimize memory accesses
      dt-bindings: dma: stm32-dma3: prevent additional transfers
      dmaengine: stm32-dma3: prevent LL refactoring thanks to DT configuration
      dmaengine: stm32-dma3: clamp AXI burst using match data
      arm64: dts: st: add DMA support on U(S)ART instances of stm32mp25
      arm64: dts: st: add DMA support on I2C instances of stm32mp25
      arm64: dts: st: add DMA support on SPI instances of stm32mp25

 .../bindings/dma/stm32/st,stm32-dma3.yaml          |   6 ++
 arch/arm64/boot/dts/st/stm32mp251.dtsi             |  75 +++++++++++++
 arch/arm64/boot/dts/st/stm32mp257f-ev1.dts         |   2 +
 drivers/dma/stm32/stm32-dma3.c                     | 119 +++++++++++++++++----
 4 files changed, 182 insertions(+), 20 deletions(-)
---
base-commit: 76355c25e4f71ee4667ebaadd9faf8ec29d18f23
change-id: 20241015-dma3-mp25-updates-d7f26753b0dd

Best regards,
-- 
Amelie Delaunay <amelie.delaunay@foss.st.com>

[PATCH v3 1/9] dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode

[Amelie Delaunay]

When source data width/burst and destination data width/burst are
different, data are packed or unpacked in DMA3 channel FIFO.
Data are pushed out from DMA3 channel FIFO when the destination burst
length (= data width * burst) is reached.
If the channel is stopped before the transfer end, and if some bytes are
packed/unpacked in the DMA3 channel FIFO, these bytes are lost.
Indeed, DMA3 channel FIFO has no flush capability, only reset.
To avoid potential bytes lost, pack/unpack must be prevented by setting
memory data width/burst equal to peripheral data width/burst.
Memory accesses will be penalized. But it is the only way to avoid bytes
lost.

Some devices (e.g. cyclic RX like UART) need this, so add the possibility
to prevent pack/unpack feature, by setting bit 16 of the 'DMA transfer
requirements' bit mask.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
index 7fdc44b2e6467928622a5bb25d9e0c74bb1790ae..5484848735f8ac3d2050104bbab1d986e82ba6a7 100644
--- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
+++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
@@ -96,6 +96,9 @@ properties:
                including the update of the LLI if any
           0x3: at channel level, the transfer complete event is generated at the
                end of the last LLI
+        -bit 16: Prevent packing/unpacking mode
+          0x0: pack/unpack enabled when source data width/burst != destination data width/burst
+          0x1: memory data width/burst forced to peripheral data width/burst to prevent pack/unpack
 
 required:
   - compatible

-- 
2.25.1

[PATCH v3 2/9] dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration

[Amelie Delaunay]

When source data width/burst and destination data width/burst are
different, data are packed or unpacked in DMA3 channel FIFO, using
CxTR1.PAM.
Data are pushed out from DMA3 channel FIFO when the destination burst
length (= data width * burst) is reached.
If the transfer is stopped before CxBR1.BNDT = 0, and if some bytes are
packed/unpacked in the DMA3 channel FIFO, these bytes are lost.
Indeed, DMA3 channel FIFO has no flush capability, only reset.
To avoid potential bytes lost, pack/unpack must be prevented by setting
memory data width/burst equal to peripheral data width/burst.
Memory accesses will be penalized. But it is the only way to avoid bytes
lost.

Prevent pack/unpack feature can be activated by setting bit 16 of DMA3
Transfer requirements bitfield (tr_conf) in device tree.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 drivers/dma/stm32/stm32-dma3.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index b9470f783f98940a99addaeef6d0a8bc07b5c54b..f793eecd2c27ca17cedd5cabbaa1b1beca202039 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -221,6 +221,7 @@ enum stm32_dma3_port_data_width {
 #define STM32_DMA3_DT_BREQ		BIT(8) /* CTR2_BREQ */
 #define STM32_DMA3_DT_PFREQ		BIT(9) /* CTR2_PFREQ */
 #define STM32_DMA3_DT_TCEM		GENMASK(13, 12) /* CTR2_TCEM */
+#define STM32_DMA3_DT_NOPACK		BIT(16) /* CTR1_PAM */
 
 /* struct stm32_dma3_chan .config_set bitfield */
 #define STM32_DMA3_CFG_SET_DT		BIT(0)
@@ -622,6 +623,10 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		/* Set source (memory) data width and burst */
 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
 		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst);
+		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf)) {
+			sdw = ddw;
+			sbl_max = dbl_max;
+		}
 
 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
@@ -652,6 +657,11 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		/* Set destination (memory) data width and burst */
 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
 		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst);
+		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf) ||
+		    ((_ctr2 & CTR2_PFREQ) && ddw > sdw)) { /* Packing to wider ddw not supported */
+			ddw = sdw;
+			dbl_max = sbl_max;
+		}
 
 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);

-- 
2.25.1

[PATCH v3 3/9] dmaengine: stm32-dma3: refactor HW linked-list to optimize memory accesses

[Amelie Delaunay]

Current behavior splits the buffer/sg in n * STM32_DMA3_MAX_BLOCK_SIZE + 1
for the remainder without optimization.

New behavior splits the buffer/sg in n * STM32_DMA3_MAX_BLOCK_SIZE + 1 for
(x * chan->max_burst) + 1 for the remainder.
Depending on channel FIFO size, optimal double-word (word if only 8-byte
FIFO size) bursts can be programmed before managing the very last remainder
with lower data width.
In case of _prep_slave_sg, and depending on the channel Transfer Complete
event configuration, the user is warned about the refactored linked-list,
not having the same items count than the initial sg_list. This warning is
shown only if the configuration is successful.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 drivers/dma/stm32/stm32-dma3.c | 40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index f793eecd2c27ca17cedd5cabbaa1b1beca202039..1d961f5935f935e3855467318cdcde6e6173e43c 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -1126,6 +1126,25 @@ static void stm32_dma3_free_chan_resources(struct dma_chan *c)
 	chan->config_set = 0;
 }
 
+static u32 stm32_dma3_get_ll_count(struct stm32_dma3_chan *chan, size_t len)
+{
+	u32 count;
+
+	count = len / STM32_DMA3_MAX_BLOCK_SIZE;
+	len -= (len / STM32_DMA3_MAX_BLOCK_SIZE) * STM32_DMA3_MAX_BLOCK_SIZE;
+
+	if (len >= chan->max_burst) {
+		count += 1; /* len < STM32_DMA3_MAX_BLOCK_SIZE here, so it fits in one item */
+		len -= (len / chan->max_burst) * chan->max_burst;
+	}
+
+	/* Unaligned remainder fits in one extra item */
+	if (len > 0)
+		count += 1;
+
+	return count;
+}
+
 static void stm32_dma3_init_chan_config_for_memcpy(struct stm32_dma3_chan *chan,
 						   dma_addr_t dst, dma_addr_t src)
 {
@@ -1161,7 +1180,7 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_cha
 	size_t next_size, offset;
 	u32 count, i, ctr1, ctr2;
 
-	count = DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE);
+	count = stm32_dma3_get_ll_count(chan, len);
 
 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
 	if (!swdesc)
@@ -1177,6 +1196,9 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_cha
 		remaining = len - offset;
 		next_size = min_t(size_t, remaining, STM32_DMA3_MAX_BLOCK_SIZE);
 
+		if (next_size < STM32_DMA3_MAX_BLOCK_SIZE && next_size >= chan->max_burst)
+			next_size = chan->max_burst * (remaining / chan->max_burst);
+
 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
 					      src + offset, dst + offset, next_size);
 		if (ret)
@@ -1215,12 +1237,9 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan
 	u32 i, j, count, ctr1, ctr2;
 	int ret;
 
-	count = sg_len;
-	for_each_sg(sgl, sg, sg_len, i) {
-		len = sg_dma_len(sg);
-		if (len > STM32_DMA3_MAX_BLOCK_SIZE)
-			count += DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE) - 1;
-	}
+	count = 0;
+	for_each_sg(sgl, sg, sg_len, i)
+		count += stm32_dma3_get_ll_count(chan, sg_dma_len(sg));
 
 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
 	if (!swdesc)
@@ -1237,6 +1256,9 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan
 		do {
 			size_t chunk = min_t(size_t, len, STM32_DMA3_MAX_BLOCK_SIZE);
 
+			if (chunk < STM32_DMA3_MAX_BLOCK_SIZE && chunk >= chan->max_burst)
+				chunk = chan->max_burst * (len / chan->max_burst);
+
 			if (dir == DMA_MEM_TO_DEV) {
 				src = sg_addr;
 				dst = dev_addr;
@@ -1269,6 +1291,10 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan
 		} while (len);
 	}
 
+	if (count != sg_len && chan->tcem != CTR2_TCEM_CHANNEL)
+		dev_warn(chan2dev(chan), "Linked-list refactored, %d items instead of %d\n",
+			 count, sg_len);
+
 	/* Enable Error interrupts */
 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
 	/* Enable Transfer state interrupts */

-- 
2.25.1

[PATCH v3 4/9] dt-bindings: dma: stm32-dma3: prevent additional transfers

[Amelie Delaunay]

Some devices require a single transfer. For example, reading FMC ECC status
registers does not support multiple transfers.
Add the possibility to prevent additional transfers, by setting bit 17 of
the 'DMA transfer requirements' bit mask.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v3:
- Refine commit description as per Rob's suggestion.
Changes in v2:
- Reword commit title/message/content as per Rob's suggestion.
---
 Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
index 5484848735f8ac3d2050104bbab1d986e82ba6a7..36f9fe860eb990e6caccedd31460ee6993772a35 100644
--- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
+++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
@@ -99,6 +99,9 @@ properties:
         -bit 16: Prevent packing/unpacking mode
           0x0: pack/unpack enabled when source data width/burst != destination data width/burst
           0x1: memory data width/burst forced to peripheral data width/burst to prevent pack/unpack
+        -bit 17: Prevent additional transfers due to linked-list refactoring
+          0x0: don't prevent additional transfers for optimal performance
+          0x1: prevent additional transfer to accommodate user constraints such as single transfer
 
 required:
   - compatible

-- 
2.25.1

[PATCH v3 5/9] dmaengine: stm32-dma3: prevent LL refactoring thanks to DT configuration

[Amelie Delaunay]

stm32-dma3 driver refactors the linked-list in order to address the memory
with the highest possible data width.
It means that it can introduce up to 2 linked-list items. One with a
transfer length multiple of channel maximum burst length and so with the
highest possible data width. And an extra one with the latest bytes, with
lower data width.
Some devices (e.g. FMC ECC) don't support having several transfers instead
of only one.
So add the possibility to prevent linked-list refactoring, when bit 17 of
the 'DMA transfer requirements' bit mask is set in device tree.
When NOPACK feature is used (bit 16 pf the 'DMA transfer requirements' bit
mask in device tree), linked-list refactoring can be avoided, since the
memory data width and burst will be aligned with the device ones.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 drivers/dma/stm32/stm32-dma3.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index 1d961f5935f935e3855467318cdcde6e6173e43c..fc874fec729df733fd8a6b4362fe1a937e9443c7 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -222,6 +222,7 @@ enum stm32_dma3_port_data_width {
 #define STM32_DMA3_DT_PFREQ		BIT(9) /* CTR2_PFREQ */
 #define STM32_DMA3_DT_TCEM		GENMASK(13, 12) /* CTR2_TCEM */
 #define STM32_DMA3_DT_NOPACK		BIT(16) /* CTR1_PAM */
+#define STM32_DMA3_DT_NOREFACT		BIT(17)
 
 /* struct stm32_dma3_chan .config_set bitfield */
 #define STM32_DMA3_CFG_SET_DT		BIT(0)
@@ -1126,10 +1127,13 @@ static void stm32_dma3_free_chan_resources(struct dma_chan *c)
 	chan->config_set = 0;
 }
 
-static u32 stm32_dma3_get_ll_count(struct stm32_dma3_chan *chan, size_t len)
+static u32 stm32_dma3_get_ll_count(struct stm32_dma3_chan *chan, size_t len, bool prevent_refactor)
 {
 	u32 count;
 
+	if (prevent_refactor)
+		return DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE);
+
 	count = len / STM32_DMA3_MAX_BLOCK_SIZE;
 	len -= (len / STM32_DMA3_MAX_BLOCK_SIZE) * STM32_DMA3_MAX_BLOCK_SIZE;
 
@@ -1179,8 +1183,10 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_cha
 	struct stm32_dma3_swdesc *swdesc;
 	size_t next_size, offset;
 	u32 count, i, ctr1, ctr2;
+	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
+				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
 
-	count = stm32_dma3_get_ll_count(chan, len);
+	count = stm32_dma3_get_ll_count(chan, len, prevent_refactor);
 
 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
 	if (!swdesc)
@@ -1196,7 +1202,8 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_cha
 		remaining = len - offset;
 		next_size = min_t(size_t, remaining, STM32_DMA3_MAX_BLOCK_SIZE);
 
-		if (next_size < STM32_DMA3_MAX_BLOCK_SIZE && next_size >= chan->max_burst)
+		if (!prevent_refactor &&
+		    (next_size < STM32_DMA3_MAX_BLOCK_SIZE && next_size >= chan->max_burst))
 			next_size = chan->max_burst * (remaining / chan->max_burst);
 
 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
@@ -1235,11 +1242,13 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan
 	size_t len;
 	dma_addr_t sg_addr, dev_addr, src, dst;
 	u32 i, j, count, ctr1, ctr2;
+	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
+				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
 	int ret;
 
 	count = 0;
 	for_each_sg(sgl, sg, sg_len, i)
-		count += stm32_dma3_get_ll_count(chan, sg_dma_len(sg));
+		count += stm32_dma3_get_ll_count(chan, sg_dma_len(sg), prevent_refactor);
 
 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
 	if (!swdesc)
@@ -1256,7 +1265,8 @@ static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan
 		do {
 			size_t chunk = min_t(size_t, len, STM32_DMA3_MAX_BLOCK_SIZE);
 
-			if (chunk < STM32_DMA3_MAX_BLOCK_SIZE && chunk >= chan->max_burst)
+			if (!prevent_refactor &&
+			    (chunk < STM32_DMA3_MAX_BLOCK_SIZE && chunk >= chan->max_burst))
 				chunk = chan->max_burst * (len / chan->max_burst);
 
 			if (dir == DMA_MEM_TO_DEV) {

-- 
2.25.1

[PATCH v3 6/9] dmaengine: stm32-dma3: clamp AXI burst using match data

[Amelie Delaunay]

STM32 DMA3 can be interconnected with AXI3 or AXI4 busses. In case it is
interconnected with AXI3, the maximum burst length supported by AXI3
protocol is 16 beats, which is lower than the maximum burst length
supported by STM32 DMA3. So the programmed burst has to be shortened when
AXI port is used.
Introduce struct stm32_dma3_pdata to specify the specific configurations
(e.g. AXI maximum burst length) required by the SoC, so implied by the SoC
specific compatible.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v2:
- Rework AXI maximum burst length management using SoC specific compatible
  instead of st,axi-max-burst-len DT property, as pointed out by Rob.
---
 drivers/dma/stm32/stm32-dma3.c | 59 ++++++++++++++++++++++++++++++++----------
 1 file changed, 46 insertions(+), 13 deletions(-)

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index fc874fec729df733fd8a6b4362fe1a937e9443c7..0c6c4258b19561c94f1c68f26ade16b82660ebe6 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -230,6 +230,8 @@ enum stm32_dma3_port_data_width {
 #define STM32_DMA3_CFG_SET_BOTH		(STM32_DMA3_CFG_SET_DT | STM32_DMA3_CFG_SET_DMA)
 
 #define STM32_DMA3_MAX_BLOCK_SIZE	ALIGN_DOWN(CBR1_BNDT, 64)
+#define STM32_DMA3_MAX_BURST_LEN	(1 + min_t(u32, FIELD_MAX(CTR1_SBL_1), \
+							FIELD_MAX(CTR1_DBL_1)))
 #define port_is_ahb(maxdw)		({ typeof(maxdw) (_maxdw) = (maxdw); \
 					   ((_maxdw) != DW_INVALID) && ((_maxdw) == DW_32); })
 #define port_is_axi(maxdw)		({ typeof(maxdw) (_maxdw) = (maxdw); \
@@ -295,6 +297,10 @@ struct stm32_dma3_chan {
 	u32 dma_status;
 };
 
+struct stm32_dma3_pdata {
+	u32 axi_max_burst_len;
+};
+
 struct stm32_dma3_ddata {
 	struct dma_device dma_dev;
 	void __iomem *base;
@@ -303,6 +309,7 @@ struct stm32_dma3_ddata {
 	u32 dma_channels;
 	u32 dma_requests;
 	enum stm32_dma3_port_data_width ports_max_dw[2];
+	u32 axi_max_burst_len;
 };
 
 static inline struct stm32_dma3_ddata *to_stm32_dma3_ddata(struct stm32_dma3_chan *chan)
@@ -535,7 +542,8 @@ static enum dma_slave_buswidth stm32_dma3_get_max_dw(u32 chan_max_burst,
 	return 1 << __ffs(len | addr | max_dw);
 }
 
-static u32 stm32_dma3_get_max_burst(u32 len, enum dma_slave_buswidth dw, u32 chan_max_burst)
+static u32 stm32_dma3_get_max_burst(u32 len, enum dma_slave_buswidth dw,
+				    u32 chan_max_burst, u32 bus_max_burst)
 {
 	u32 max_burst = chan_max_burst ? chan_max_burst / dw : 1;
 
@@ -546,8 +554,9 @@ static u32 stm32_dma3_get_max_burst(u32 len, enum dma_slave_buswidth dw, u32 cha
 	/*
 	 * HW doesn't modify the burst if burst size <= half of the fifo size.
 	 * If len is not a multiple of burst size, last burst is shortened by HW.
+	 * Take care of maximum burst supported on interconnect bus.
 	 */
-	return max_burst;
+	return min_t(u32, max_burst, bus_max_burst);
 }
 
 static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transfer_direction dir,
@@ -556,6 +565,7 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 {
 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
 	struct dma_device dma_device = ddata->dma_dev;
+	u32 src_max_burst = STM32_DMA3_MAX_BURST_LEN, dst_max_burst = STM32_DMA3_MAX_BURST_LEN;
 	u32 sdw, ddw, sbl_max, dbl_max, tcem, init_dw, init_bl_max;
 	u32 _ctr1 = 0, _ctr2 = 0;
 	u32 ch_conf = chan->dt_config.ch_conf;
@@ -596,10 +606,14 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		_ctr1 |= CTR1_SINC;
 	if (sap)
 		_ctr1 |= CTR1_SAP;
+	if (port_is_axi(sap_max_dw)) /* AXI - apply axi maximum burst limitation */
+		src_max_burst = ddata->axi_max_burst_len;
 	if (FIELD_GET(STM32_DMA3_DT_DINC, tr_conf))
 		_ctr1 |= CTR1_DINC;
 	if (dap)
 		_ctr1 |= CTR1_DAP;
+	if (port_is_axi(dap_max_dw)) /* AXI - apply axi maximum burst limitation */
+		dst_max_burst = ddata->axi_max_burst_len;
 
 	_ctr2 |= FIELD_PREP(CTR2_REQSEL, chan->dt_config.req_line) & ~CTR2_SWREQ;
 	if (FIELD_GET(STM32_DMA3_DT_BREQ, tr_conf))
@@ -619,11 +633,12 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		/* Set destination (device) data width and burst */
 		ddw = min_t(u32, ddw, stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw,
 							    len, dst_addr));
-		dbl_max = min_t(u32, dbl_max, stm32_dma3_get_max_burst(len, ddw, chan->max_burst));
+		dbl_max = min_t(u32, dbl_max, stm32_dma3_get_max_burst(len, ddw, chan->max_burst,
+								       dst_max_burst));
 
 		/* Set source (memory) data width and burst */
 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
-		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst);
+		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf)) {
 			sdw = ddw;
 			sbl_max = dbl_max;
@@ -653,11 +668,12 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		/* Set source (device) data width and burst */
 		sdw = min_t(u32, sdw, stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw,
 							    len, src_addr));
-		sbl_max = min_t(u32, sbl_max, stm32_dma3_get_max_burst(len, sdw, chan->max_burst));
+		sbl_max = min_t(u32, sbl_max, stm32_dma3_get_max_burst(len, sdw, chan->max_burst,
+								       src_max_burst));
 
 		/* Set destination (memory) data width and burst */
 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
-		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst);
+		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf) ||
 		    ((_ctr2 & CTR2_PFREQ) && ddw > sdw)) { /* Packing to wider ddw not supported */
 			ddw = sdw;
@@ -689,22 +705,24 @@ static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transf
 		init_dw = sdw;
 		init_bl_max = sbl_max;
 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
-		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst);
+		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
 			sdw = min_t(u32, init_dw, sdw);
-			sbl_max = min_t(u32, init_bl_max,
-					stm32_dma3_get_max_burst(len, sdw, chan->max_burst));
+			sbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, sdw,
+										   chan->max_burst,
+										   src_max_burst));
 		}
 
 		/* Set destination (memory) data width and burst */
 		init_dw = ddw;
 		init_bl_max = dbl_max;
 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
-		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst);
+		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
 			ddw = min_t(u32, init_dw, ddw);
-			dbl_max = min_t(u32, init_bl_max,
-					stm32_dma3_get_max_burst(len, ddw, chan->max_burst));
+			dbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, ddw,
+										   chan->max_burst,
+										   dst_max_burst));
 		}
 
 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
@@ -1647,8 +1665,12 @@ static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
 	return chan_reserved;
 }
 
+static struct stm32_dma3_pdata stm32mp25_pdata = {
+	.axi_max_burst_len = 16,
+};
+
 static const struct of_device_id stm32_dma3_of_match[] = {
-	{ .compatible = "st,stm32mp25-dma3", },
+	{ .compatible = "st,stm32mp25-dma3", .data = &stm32mp25_pdata, },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, stm32_dma3_of_match);
@@ -1656,6 +1678,7 @@ MODULE_DEVICE_TABLE(of, stm32_dma3_of_match);
 static int stm32_dma3_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
+	const struct stm32_dma3_pdata *pdata;
 	struct stm32_dma3_ddata *ddata;
 	struct reset_control *reset;
 	struct stm32_dma3_chan *chan;
@@ -1750,6 +1773,16 @@ static int stm32_dma3_probe(struct platform_device *pdev)
 	else /* Dual master ports */
 		ddata->ports_max_dw[1] = FIELD_GET(G_M1_DATA_WIDTH_ENC, hwcfgr);
 
+	/* axi_max_burst_len is optional, if not defined, use STM32_DMA3_MAX_BURST_LEN  */
+	ddata->axi_max_burst_len = STM32_DMA3_MAX_BURST_LEN;
+	pdata = device_get_match_data(&pdev->dev);
+	if (pdata && pdata->axi_max_burst_len) {
+		ddata->axi_max_burst_len = min_t(u32, pdata->axi_max_burst_len,
+						 STM32_DMA3_MAX_BURST_LEN);
+		dev_dbg(&pdev->dev, "Burst is limited to %u beats through AXI port\n",
+			ddata->axi_max_burst_len);
+	}
+
 	ddata->chans = devm_kcalloc(&pdev->dev, ddata->dma_channels, sizeof(*ddata->chans),
 				    GFP_KERNEL);
 	if (!ddata->chans) {

-- 
2.25.1

[PATCH v3 7/9] arm64: dts: st: add DMA support on U(S)ART instances of stm32mp25

[Amelie Delaunay]

Add dmas and dma-names properties in u(s)art nodes of stm32mp251.dtsi to
enable DMA support.
RX channel requires to prevent pack/unpack feature of DMA to avoid losing
bytes when interrupting RX transfer, as it uses a cyclic buffer.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 arch/arm64/boot/dts/st/stm32mp251.dtsi     | 27 +++++++++++++++++++++++++++
 arch/arm64/boot/dts/st/stm32mp257f-ev1.dts |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/arch/arm64/boot/dts/st/stm32mp251.dtsi b/arch/arm64/boot/dts/st/stm32mp251.dtsi
index 1167cf63d7e87aaa15c5c1ed70a9f6511fd818d4..9035fc7ba4857ca98a1a86246d7d0250196b2a13 100644
--- a/arch/arm64/boot/dts/st/stm32mp251.dtsi
+++ b/arch/arm64/boot/dts/st/stm32mp251.dtsi
@@ -266,6 +266,9 @@ usart2: serial@400e0000 {
 				reg = <0x400e0000 0x400>;
 				interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_USART2>;
+				dmas = <&hpdma 11 0x20 0x10012>,
+				       <&hpdma 12 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 32>;
 				status = "disabled";
 			};
@@ -275,6 +278,9 @@ usart3: serial@400f0000 {
 				reg = <0x400f0000 0x400>;
 				interrupts = <GIC_SPI 116 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_USART3>;
+				dmas = <&hpdma 13 0x20 0x10012>,
+				       <&hpdma 14 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 33>;
 				status = "disabled";
 			};
@@ -284,6 +290,9 @@ uart4: serial@40100000 {
 				reg = <0x40100000 0x400>;
 				interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_UART4>;
+				dmas = <&hpdma 15 0x20 0x10012>,
+				       <&hpdma 16 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 34>;
 				status = "disabled";
 			};
@@ -293,6 +302,9 @@ uart5: serial@40110000 {
 				reg = <0x40110000 0x400>;
 				interrupts = <GIC_SPI 127 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_UART5>;
+				dmas = <&hpdma 17 0x20 0x10012>,
+				       <&hpdma 18 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 35>;
 				status = "disabled";
 			};
@@ -393,6 +405,9 @@ usart6: serial@40220000 {
 				reg = <0x40220000 0x400>;
 				interrupts = <GIC_SPI 136 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_USART6>;
+				dmas = <&hpdma 19 0x20 0x10012>,
+				       <&hpdma 20 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 36>;
 				status = "disabled";
 			};
@@ -438,6 +453,9 @@ uart9: serial@402c0000 {
 				reg = <0x402c0000 0x400>;
 				interrupts = <GIC_SPI 150 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_UART9>;
+				dmas = <&hpdma 25 0x20 0x10012>,
+				       <&hpdma 26 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 39>;
 				status = "disabled";
 			};
@@ -447,6 +465,9 @@ usart1: serial@40330000 {
 				reg = <0x40330000 0x400>;
 				interrupts = <GIC_SPI 114 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_USART1>;
+				dmas = <&hpdma 9 0x20 0x10012>,
+				       <&hpdma 10 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 31>;
 				status = "disabled";
 			};
@@ -480,6 +501,9 @@ uart7: serial@40370000 {
 				reg = <0x40370000 0x400>;
 				interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_UART7>;
+				dmas = <&hpdma 21 0x20 0x10012>,
+				       <&hpdma 22 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 37>;
 				status = "disabled";
 			};
@@ -489,6 +513,9 @@ uart8: serial@40380000 {
 				reg = <0x40380000 0x400>;
 				interrupts = <GIC_SPI 149 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_UART8>;
+				dmas = <&hpdma 23 0x20 0x10012>,
+				       <&hpdma 24 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 38>;
 				status = "disabled";
 			};
diff --git a/arch/arm64/boot/dts/st/stm32mp257f-ev1.dts b/arch/arm64/boot/dts/st/stm32mp257f-ev1.dts
index 214191a8322b81e7ae453503863b4465d9b625e0..d468dcbe849680de812a0ddd593f30cbf507f645 100644
--- a/arch/arm64/boot/dts/st/stm32mp257f-ev1.dts
+++ b/arch/arm64/boot/dts/st/stm32mp257f-ev1.dts
@@ -157,6 +157,8 @@ &usart2 {
 	pinctrl-0 = <&usart2_pins_a>;
 	pinctrl-1 = <&usart2_idle_pins_a>;
 	pinctrl-2 = <&usart2_sleep_pins_a>;
+	/delete-property/dmas;
+	/delete-property/dma-names;
 	status = "okay";
 };
 

-- 
2.25.1

[PATCH v3 8/9] arm64: dts: st: add DMA support on I2C instances of stm32mp25

[Amelie Delaunay]

Add dmas and dma-names properties in i2c nodes of stm32mp251.dtsi to
enable DMA support.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 arch/arm64/boot/dts/st/stm32mp251.dtsi | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm64/boot/dts/st/stm32mp251.dtsi b/arch/arm64/boot/dts/st/stm32mp251.dtsi
index 9035fc7ba4857ca98a1a86246d7d0250196b2a13..e166e2f1f1400faf7fb56ed07c5779c26cf80cdd 100644
--- a/arch/arm64/boot/dts/st/stm32mp251.dtsi
+++ b/arch/arm64/boot/dts/st/stm32mp251.dtsi
@@ -318,6 +318,9 @@ i2c1: i2c@40120000 {
 				resets = <&rcc I2C1_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 27 0x20 0x3012>,
+				       <&hpdma 28 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 41>;
 				status = "disabled";
 			};
@@ -331,6 +334,9 @@ i2c2: i2c@40130000 {
 				resets = <&rcc I2C2_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 30 0x20 0x3012>,
+				       <&hpdma 31 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 42>;
 				status = "disabled";
 			};
@@ -344,6 +350,9 @@ i2c3: i2c@40140000 {
 				resets = <&rcc I2C3_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 33 0x20 0x3012>,
+				       <&hpdma 34 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 43>;
 				status = "disabled";
 			};
@@ -357,6 +366,9 @@ i2c4: i2c@40150000 {
 				resets = <&rcc I2C4_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 36 0x20 0x3012>,
+				       <&hpdma 37 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 44>;
 				status = "disabled";
 			};
@@ -370,6 +382,9 @@ i2c5: i2c@40160000 {
 				resets = <&rcc I2C5_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 39 0x20 0x3012>,
+				       <&hpdma 40 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 45>;
 				status = "disabled";
 			};
@@ -383,6 +398,9 @@ i2c6: i2c@40170000 {
 				resets = <&rcc I2C6_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 42 0x20 0x3012>,
+				       <&hpdma 43 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 46>;
 				status = "disabled";
 			};
@@ -396,6 +414,9 @@ i2c7: i2c@40180000 {
 				resets = <&rcc I2C7_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 45 0x20 0x3012>,
+				       <&hpdma 46 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 47>;
 				status = "disabled";
 			};
@@ -541,6 +562,9 @@ i2c8: i2c@46040000 {
 				resets = <&rcc I2C8_R>;
 				#address-cells = <1>;
 				#size-cells = <0>;
+				dmas = <&hpdma 168 0x20 0x3012>,
+				       <&hpdma 169 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 48>;
 				status = "disabled";
 			};

-- 
2.25.1

[PATCH v3 9/9] arm64: dts: st: add DMA support on SPI instances of stm32mp25

[Amelie Delaunay]

Add dmas and dma-names properties in spi nodes of stm32mp251.dtsi to
enable DMA support.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 arch/arm64/boot/dts/st/stm32mp251.dtsi | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm64/boot/dts/st/stm32mp251.dtsi b/arch/arm64/boot/dts/st/stm32mp251.dtsi
index e166e2f1f1400faf7fb56ed07c5779c26cf80cdd..ed1d778ab441be3ebf2e53dea9fef484d41ab31a 100644
--- a/arch/arm64/boot/dts/st/stm32mp251.dtsi
+++ b/arch/arm64/boot/dts/st/stm32mp251.dtsi
@@ -245,6 +245,9 @@ spi2: spi@400b0000 {
 				interrupts = <GIC_SPI 113 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI2>;
 				resets = <&rcc SPI2_R>;
+				dmas = <&hpdma 51 0x20 0x3012>,
+				       <&hpdma 52 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 23>;
 				status = "disabled";
 			};
@@ -257,6 +260,9 @@ spi3: spi@400c0000 {
 				interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI3>;
 				resets = <&rcc SPI3_R>;
+				dmas = <&hpdma 53 0x20 0x3012>,
+				       <&hpdma 54 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 24>;
 				status = "disabled";
 			};
@@ -441,6 +447,9 @@ spi1: spi@40230000 {
 				interrupts = <GIC_SPI 112 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI1>;
 				resets = <&rcc SPI1_R>;
+				dmas = <&hpdma 49 0x20 0x3012>,
+				       <&hpdma 50 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 22>;
 				status = "disabled";
 			};
@@ -453,6 +462,9 @@ spi4: spi@40240000 {
 				interrupts = <GIC_SPI 152 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI4>;
 				resets = <&rcc SPI4_R>;
+				dmas = <&hpdma 55 0x20 0x3012>,
+				       <&hpdma 56 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 25>;
 				status = "disabled";
 			};
@@ -465,6 +477,9 @@ spi5: spi@40280000 {
 				interrupts = <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI5>;
 				resets = <&rcc SPI5_R>;
+				dmas = <&hpdma 57 0x20 0x3012>,
+				       <&hpdma 58 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 26>;
 				status = "disabled";
 			};
@@ -501,6 +516,9 @@ spi6: spi@40350000 {
 				interrupts = <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI6>;
 				resets = <&rcc SPI6_R>;
+				dmas = <&hpdma 59 0x20 0x3012>,
+				       <&hpdma 60 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 27>;
 				status = "disabled";
 			};
@@ -513,6 +531,9 @@ spi7: spi@40360000 {
 				interrupts = <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI7>;
 				resets = <&rcc SPI7_R>;
+				dmas = <&hpdma 61 0x20 0x3012>,
+				       <&hpdma 62 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 28>;
 				status = "disabled";
 			};
@@ -549,6 +570,9 @@ spi8: spi@46020000 {
 				interrupts = <GIC_SPI 156 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&rcc CK_KER_SPI8>;
 				resets = <&rcc SPI8_R>;
+				dmas = <&hpdma 171 0x20 0x3012>,
+				       <&hpdma 172 0x20 0x3021>;
+				dma-names = "rx", "tx";
 				access-controllers = <&rifsc 29>;
 				status = "disabled";
 			};

-- 
2.25.1

Re: [PATCH v3 4/9] dt-bindings: dma: stm32-dma3: prevent additional transfers

[Rob Herring (Arm)]

On Wed, 16 Oct 2024 14:39:56 +0200, Amelie Delaunay wrote:
> Some devices require a single transfer. For example, reading FMC ECC status
> registers does not support multiple transfers.
> Add the possibility to prevent additional transfers, by setting bit 17 of
> the 'DMA transfer requirements' bit mask.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
> ---
> Changes in v3:
> - Refine commit description as per Rob's suggestion.
> Changes in v2:
> - Reword commit title/message/content as per Rob's suggestion.
> ---
>  Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

Re: (subset) [PATCH v3 0/9] STM32 DMA3 updates for STM32MP25

[Vinod Koul]

On Wed, 16 Oct 2024 14:39:52 +0200, Amelie Delaunay wrote:
> The HW version of STM32 DMA3 inside STM32MP25 requires some tunings to
> meet the needs of the interconnect. This series adds the linked list
> refactoring feature to have optimal performance when addressing the
> memory, and it adds the use of two new bits in the third cell specifying
> the DMA transfer requirements:
> - bit[16] to prevent packing/unpacking mode to avoid bytes loss in case
> of interrupting an ongoing transfer (e.g. UART RX),
> - bit[17] to prevent linked-list refactoring because some peripherals
> (e.g. FMC ECC) require a one-shot transfer, they trigger the DMA only
> once.
> It also adds platform data to clamp the burst length on AXI port,
> especially when it is interconnected to AXI3 bus, such as on STM32MP25.
> Finally this series also contains STM32MP25 device tree updates, to add
> DMA support on SPI, I2C, UART and apply the tunings introduced.
> 
> [...]

Applied, thanks!

[1/9] dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode
      commit: 689f05586e7ea620c8fc1066c067809e52ffc2f3
[2/9] dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration
      commit: 12eb621e1abff65d89aeb4c92a4f3436225971d0
[3/9] dmaengine: stm32-dma3: refactor HW linked-list to optimize memory accesses
      commit: cb467c451163bacad4cbb7540ce7d731946f13f9
[4/9] dt-bindings: dma: stm32-dma3: prevent additional transfers
      commit: e18a9830233e739ae7045700232c53b4cb2e98eb
[5/9] dmaengine: stm32-dma3: prevent LL refactoring thanks to DT configuration
      commit: 2ff0fb9474eefa7149c199fb3f79e54355a6c184
[6/9] dmaengine: stm32-dma3: clamp AXI burst using match data
      commit: e713468e7c104a0598a7ec31ab7ec0bec94a174d

Best regards,
-- 
~Vinod

Re: [PATCH v3 0/9] STM32 DMA3 updates for STM32MP25

[Alexandre TORGUE]

Hi

On 10/16/24 14:39, Amelie Delaunay wrote:
> The HW version of STM32 DMA3 inside STM32MP25 requires some tunings to
> meet the needs of the interconnect. This series adds the linked list
> refactoring feature to have optimal performance when addressing the
> memory, and it adds the use of two new bits in the third cell specifying
> the DMA transfer requirements:
> - bit[16] to prevent packing/unpacking mode to avoid bytes loss in case
> of interrupting an ongoing transfer (e.g. UART RX),
> - bit[17] to prevent linked-list refactoring because some peripherals
> (e.g. FMC ECC) require a one-shot transfer, they trigger the DMA only
> once.
> It also adds platform data to clamp the burst length on AXI port,
> especially when it is interconnected to AXI3 bus, such as on STM32MP25.
> Finally this series also contains STM32MP25 device tree updates, to add
> DMA support on SPI, I2C, UART and apply the tunings introduced.
> 
> Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
> ---
> Changes in v3:
> - Refine commit description of patch 4 about preventing
>    additionnal transfers, as per Rob's suggestion.
> - Link to v2: https://lore.kernel.org/r/20241015-dma3-mp25-updates-v2-0-b63e21556ec8@foss.st.com
> 
> Changes in v2:
> - Reword commit title/message/content of patch 4 about preventing
>    additionnal transfers, as per Rob's suggestion
> - Rework AXI maximum burst length management using SoC specific
>    compatible, as pointed out by Rob
> - Drop former patches 6 and 8, which are no longer relevant
> - Link to v1: https://lore.kernel.org/r/20241010-dma3-mp25-updates-v1-0-adf0633981ea@foss.st.com
> 
> ---
> Amelie Delaunay (9):
>        dt-bindings: dma: stm32-dma3: prevent packing/unpacking mode
>        dmaengine: stm32-dma3: prevent pack/unpack thanks to DT configuration
>        dmaengine: stm32-dma3: refactor HW linked-list to optimize memory accesses
>        dt-bindings: dma: stm32-dma3: prevent additional transfers
>        dmaengine: stm32-dma3: prevent LL refactoring thanks to DT configuration
>        dmaengine: stm32-dma3: clamp AXI burst using match data
>        arm64: dts: st: add DMA support on U(S)ART instances of stm32mp25
>        arm64: dts: st: add DMA support on I2C instances of stm32mp25
>        arm64: dts: st: add DMA support on SPI instances of stm32mp25
> 

Patches [7], [8], and [9] applied on stm32-next.

Thanks
Alex



>   .../bindings/dma/stm32/st,stm32-dma3.yaml          |   6 ++
>   arch/arm64/boot/dts/st/stm32mp251.dtsi             |  75 +++++++++++++
>   arch/arm64/boot/dts/st/stm32mp257f-ev1.dts         |   2 +
>   drivers/dma/stm32/stm32-dma3.c                     | 119 +++++++++++++++++----
>   4 files changed, 182 insertions(+), 20 deletions(-)
> ---
> base-commit: 76355c25e4f71ee4667ebaadd9faf8ec29d18f23
> change-id: 20241015-dma3-mp25-updates-d7f26753b0dd
> 
> Best regards,