[PATCH v5 0/3] spi: airoha: add support of en7523 SoC (for 6.19)

[PATCH v5 0/3] spi: airoha: add support of en7523 SoC (for 6.19)

[Mikhail Kshevetskiy]

Airoha EN7523 snfi controller almost identical to AN7581 one, so the same
driver can be used. The only known difference appears in the very specific
boot conditions, when attached serial console force EN7523 SoC boots
in undocumented (reserved) mode. In this mode dma reading of the flash
works incorrectly.

This patch series:
 * add support of EN7523 SoC
 * add spinand node to en7523 dts (so spinand flash finally becomes usable)
 * updates dt-bindings to mark driver as compatible with en7523
 * disable dma usage to prevent possible data damage if booting in
   reserved mode was detected.

This patch series was a part of a bigger series:

  https://lore.kernel.org/lkml/20251012121707.2296160-1-mikhail.kshevetskiy@iopsys.eu/

All patches of the bigger series (except these patches) was already accepted
to linux-next.

Changes v2:
 * small improvement proposed by Lorenzo Bianconi

Changes v3:
 * split multi-line print on a series of single line prints as suggested by
   Mark Brown

Changes v4:
 * improve description of Airoha en7523 SoC specific issue that may
   lead to flash data damaging.
 * add fixes tag

Changes v5:
 * replace 'boot pin' with 'bootstrap pin'
 * do not use caps in some cases
 * always set dma mask (even if dma will not be used et all)

Mikhail Kshevetskiy (3):
  spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was
    short to GND
  dt-bindings: spi: airoha: add compatible for EN7523
  arm: dts: airoha: en7523: add SNAND node

 .../bindings/spi/airoha,en7581-snand.yaml     |  7 ++++-
 arch/arm/boot/dts/airoha/en7523.dtsi          | 20 ++++++++++++++
 drivers/spi/spi-airoha-snfi.c                 | 26 ++++++++++++++++++-
 3 files changed, 51 insertions(+), 2 deletions(-)

-- 
2.51.0

[PATCH v5 1/3] spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was short to GND

[Mikhail Kshevetskiy]

Airoha EN7523 specific bug
--------------------------
We found that some serial console may pull TX line to GROUND during board
boot time. Airoha uses TX line as one of its bootstrap pins. On the EN7523
SoC this may lead to booting in RESERVED boot mode.

It was found that some flashes operates incorrectly in RESERVED mode.
Micron and Skyhigh flashes are definitely affected by the issue,
Winbond flashes are not affected.

Details:
--------
DMA reading of odd pages on affected flashes operates incorrectly. Page
reading offset (start of the page) on hardware level is replaced by 0x10.
Thus results in incorrect data reading. As result OS loading becomes
impossible.

Usage of UBI make things even worse. On attaching, UBI will detects
corruptions (because of wrong reading of odd pages) and will try to
recover. For recovering UBI will erase and write 'damaged' blocks with
a valid information. This will destroy all UBI data.

Non-DMA reading is OK.

This patch detects booting in reserved mode, turn off DMA and print big
fat warning.

Fixes: a403997c12019 ("spi: airoha: add SPI-NAND Flash controller driver")
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/spi/spi-airoha-snfi.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-airoha-snfi.c b/drivers/spi/spi-airoha-snfi.c
index 8408aee9c06e..1b91ed07d046 100644
--- a/drivers/spi/spi-airoha-snfi.c
+++ b/drivers/spi/spi-airoha-snfi.c
@@ -1013,6 +1013,11 @@ static const struct spi_controller_mem_ops airoha_snand_mem_ops = {
 	.dirmap_write = airoha_snand_dirmap_write,
 };
 
+static const struct spi_controller_mem_ops airoha_snand_nodma_mem_ops = {
+	.supports_op = airoha_snand_supports_op,
+	.exec_op = airoha_snand_exec_op,
+};
+
 static int airoha_snand_setup(struct spi_device *spi)
 {
 	struct airoha_snand_ctrl *as_ctrl;
@@ -1057,7 +1062,9 @@ static int airoha_snand_probe(struct platform_device *pdev)
 	struct airoha_snand_ctrl *as_ctrl;
 	struct device *dev = &pdev->dev;
 	struct spi_controller *ctrl;
+	bool dma_enable = true;
 	void __iomem *base;
+	u32 sfc_strap;
 	int err;
 
 	ctrl = devm_spi_alloc_host(dev, sizeof(*as_ctrl));
@@ -1092,12 +1099,29 @@ static int airoha_snand_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(as_ctrl->spi_clk),
 				     "unable to get spi clk\n");
 
+	if (device_is_compatible(dev, "airoha,en7523-snand")) {
+		err = regmap_read(as_ctrl->regmap_ctrl,
+				  REG_SPI_CTRL_SFC_STRAP, &sfc_strap);
+		if (err)
+			return err;
+
+		if (!(sfc_strap & 0x04)) {
+			dma_enable = false;
+			dev_warn(dev, "Detected booting in RESERVED mode (UART_TXD was short to GND).\n");
+			dev_warn(dev, "This mode is known for incorrect DMA reading of some flashes.\n");
+			dev_warn(dev, "Usage of DMA for flash operations will be disabled to prevent data\n");
+			dev_warn(dev, "damage. Unplug your serial console and power cycle the board\n");
+			dev_warn(dev, "to boot with full performance.\n");
+		}
+	}
+
 	err = dma_set_mask(as_ctrl->dev, DMA_BIT_MASK(32));
 	if (err)
 		return err;
 
 	ctrl->num_chipselect = 2;
-	ctrl->mem_ops = &airoha_snand_mem_ops;
+	ctrl->mem_ops = dma_enable ? &airoha_snand_mem_ops
+				   : &airoha_snand_nodma_mem_ops;
 	ctrl->bits_per_word_mask = SPI_BPW_MASK(8);
 	ctrl->mode_bits = SPI_RX_DUAL;
 	ctrl->setup = airoha_snand_setup;
-- 
2.51.0

[PATCH v5 2/3] dt-bindings: spi: airoha: add compatible for EN7523

[Mikhail Kshevetskiy]

Add dt-bindings documentation of SPI NAND controller
for Airoha EN7523 SoC platform.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../devicetree/bindings/spi/airoha,en7581-snand.yaml       | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/spi/airoha,en7581-snand.yaml b/Documentation/devicetree/bindings/spi/airoha,en7581-snand.yaml
index b820c5613dcc..855aa08995b9 100644
--- a/Documentation/devicetree/bindings/spi/airoha,en7581-snand.yaml
+++ b/Documentation/devicetree/bindings/spi/airoha,en7581-snand.yaml
@@ -14,7 +14,12 @@ allOf:
 
 properties:
   compatible:
-    const: airoha,en7581-snand
+    oneOf:
+      - const: airoha,en7581-snand
+      - items:
+          - enum:
+              - airoha,en7523-snand
+          - const: airoha,en7581-snand
 
   reg:
     items:
-- 
2.51.0

[PATCH v5 3/3] arm: dts: airoha: en7523: add SNAND node

[Mikhail Kshevetskiy]

Add SNAND node to enable support of attached SPI-NAND on the EN7523 SoC.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 arch/arm/boot/dts/airoha/en7523.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/airoha/en7523.dtsi b/arch/arm/boot/dts/airoha/en7523.dtsi
index b523a868c4ad..31191b8d1430 100644
--- a/arch/arm/boot/dts/airoha/en7523.dtsi
+++ b/arch/arm/boot/dts/airoha/en7523.dtsi
@@ -203,4 +203,24 @@ pcie_intc1: interrupt-controller {
 			#interrupt-cells = <1>;
 		};
 	};
+
+	spi_ctrl: spi@1fa10000 {
+		compatible = "airoha,en7523-snand", "airoha,en7581-snand";
+		reg = <0x1fa10000 0x140>,
+		      <0x1fa11000 0x160>;
+
+		clocks = <&scu EN7523_CLK_SPI>;
+		clock-names = "spi";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		nand: nand@0 {
+			compatible = "spi-nand";
+			reg = <0>;
+			spi-max-frequency = <50000000>;
+			spi-tx-bus-width = <1>;
+			spi-rx-bus-width = <2>;
+		};
+	};
 };
-- 
2.51.0

Re: [PATCH v5 1/3] spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was short to GND

[Andy Shevchenko]

On Tue, Nov 25, 2025 at 10:16:33PM +0300, Mikhail Kshevetskiy wrote:
> Airoha EN7523 specific bug
> --------------------------
> We found that some serial console may pull TX line to GROUND during board
> boot time. Airoha uses TX line as one of its bootstrap pins. On the EN7523
> SoC this may lead to booting in RESERVED boot mode.
> 
> It was found that some flashes operates incorrectly in RESERVED mode.
> Micron and Skyhigh flashes are definitely affected by the issue,
> Winbond flashes are not affected.
> 
> Details:
> --------
> DMA reading of odd pages on affected flashes operates incorrectly. Page
> reading offset (start of the page) on hardware level is replaced by 0x10.
> Thus results in incorrect data reading. As result OS loading becomes
> impossible.
> 
> Usage of UBI make things even worse. On attaching, UBI will detects
> corruptions (because of wrong reading of odd pages) and will try to
> recover. For recovering UBI will erase and write 'damaged' blocks with
> a valid information. This will destroy all UBI data.
> 
> Non-DMA reading is OK.
> 
> This patch detects booting in reserved mode, turn off DMA and print big
> fat warning.

LGTM now, thanks!
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 1/3] spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was short to GND

[Andy Shevchenko]

On Tue, Nov 25, 2025 at 10:16:33PM +0300, Mikhail Kshevetskiy wrote:

...

> +			dev_warn(dev, "Detected booting in RESERVED mode (UART_TXD was short to GND).\n");
> +			dev_warn(dev, "This mode is known for incorrect DMA reading of some flashes.\n");
> +			dev_warn(dev, "Usage of DMA for flash operations will be disabled to prevent data\n");
> +			dev_warn(dev, "damage. Unplug your serial console and power cycle the board\n");
> +			dev_warn(dev, "to boot with full performance.\n");

One non-critical remark (for the future), the '\n' in the string literals when
we print messages has two meanings:
 - (obviously) new line
 - (seems not so obvious for people) flush the line to the output device

Due to the second property the messages might be interleaved with the other
messages (assuming SMP machine actively doing and printing something), hence
your messages might be split with other and imagine the user who gets in the
middle of the text something like

"Usage of DMA for flash operations will be disabled to prevent data"

The first thought will be "what the heck does this mean?"

TL;DR: place '\n' with a care in the messages to print not only here,
but in general.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 1/3] spi: airoha-snfi: en7523: workaround flash damaging if UART_TXD was short to GND

[Mikhail Kshevetskiy]

On 11/25/25 23:24, Andy Shevchenko wrote:
> On Tue, Nov 25, 2025 at 10:16:33PM +0300, Mikhail Kshevetskiy wrote:
>
> ...
>
>> +			dev_warn(dev, "Detected booting in RESERVED mode (UART_TXD was short to GND).\n");
>> +			dev_warn(dev, "This mode is known for incorrect DMA reading of some flashes.\n");
>> +			dev_warn(dev, "Usage of DMA for flash operations will be disabled to prevent data\n");
>> +			dev_warn(dev, "damage. Unplug your serial console and power cycle the board\n");
>> +			dev_warn(dev, "to boot with full performance.\n");
> One non-critical remark (for the future), the '\n' in the string literals when
> we print messages has two meanings:
>  - (obviously) new line
>  - (seems not so obvious for people) flush the line to the output device
>
> Due to the second property the messages might be interleaved with the other
> messages (assuming SMP machine actively doing and printing something), hence
> your messages might be split with other and imagine the user who gets in the
> middle of the text something like
>
> "Usage of DMA for flash operations will be disabled to prevent data"
>
> The first thought will be "what the heck does this mean?"
>
> TL;DR: place '\n' with a care in the messages to print not only here,
> but in general.

Thanks for the point. I know this '\n' issue, but you give me an idea
about making it better.

>