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

[PATCH 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. The was no any activity around remaining patches for a long
time, so it's time to send them again.

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                 | 40 ++++++++++++++++---
 3 files changed, 61 insertions(+), 6 deletions(-)

-- 
2.51.0

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

[Mikhail Kshevetskiy]

We found that some serial console may pull TX line to GROUND during board
boot time. Airoha uses TX line as one of it's BOOT pins. This will 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. Usage of UBI make things even
worse. Any attempt to access UBI leads to ubi damaging. As result OS loading
becomes impossible.

Non-DMA reading is OK.

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

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
---
 drivers/spi/spi-airoha-snfi.c | 40 ++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-airoha-snfi.c b/drivers/spi/spi-airoha-snfi.c
index 8408aee9c06e..0e84a9addfa5 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;
@@ -1058,7 +1063,8 @@ static int airoha_snand_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct spi_controller *ctrl;
 	void __iomem *base;
-	int err;
+	int err, dma_enabled;
+	u32 sfc_strap;
 
 	ctrl = devm_spi_alloc_host(dev, sizeof(*as_ctrl));
 	if (!ctrl)
@@ -1092,12 +1098,36 @@ 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");
 
-	err = dma_set_mask(as_ctrl->dev, DMA_BIT_MASK(32));
-	if (err)
-		return err;
+	dma_enabled = 1;
+	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_enabled = 0;
+			dev_warn(dev,
+				"=== WARNING ======================================================\n"
+				"Detected booting in RESERVED mode (UART_TXD was short to GND).\n"
+				"This mode is known for incorrect DMA reading of some flashes.\n"
+				"Usage of DMA for flash operations will be disabled to prevent data\n"
+				"damage. Unplug your serial console and power cycle the board\n"
+				"to boot with full performance.\n"
+				"==================================================================\n");
+		}
+	}
+
+	if (dma_enabled) {
+		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_enabled ?
+				&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

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

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 3870 bytes --]

> We found that some serial console may pull TX line to GROUND during board
> boot time. Airoha uses TX line as one of it's BOOT pins. This will 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. Usage of UBI make things even
> worse. Any attempt to access UBI leads to ubi damaging. As result OS loading
> becomes impossible.
> 
> Non-DMA reading is OK.
> 
> This patch detects booting in reserved mode, turn off DMA and print big
> fat warning.
> 
> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
> ---
>  drivers/spi/spi-airoha-snfi.c | 40 ++++++++++++++++++++++++++++++-----
>  1 file changed, 35 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-airoha-snfi.c b/drivers/spi/spi-airoha-snfi.c
> index 8408aee9c06e..0e84a9addfa5 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;
> @@ -1058,7 +1063,8 @@ static int airoha_snand_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct spi_controller *ctrl;
>  	void __iomem *base;
> -	int err;
> +	int err, dma_enabled;

here you can use bool for dma_enable:

	bool dma_enable = true;

> +	u32 sfc_strap;
>  
>  	ctrl = devm_spi_alloc_host(dev, sizeof(*as_ctrl));
>  	if (!ctrl)
> @@ -1092,12 +1098,36 @@ 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");
>  
> -	err = dma_set_mask(as_ctrl->dev, DMA_BIT_MASK(32));
> -	if (err)
> -		return err;
> +	dma_enabled = 1;
> +	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_enabled = 0;

			dma_enable = false;

> +			dev_warn(dev,
> +				"=== WARNING ======================================================\n"

you do not need to add "WARNING here".

> +				"Detected booting in RESERVED mode (UART_TXD was short to GND).\n"
> +				"This mode is known for incorrect DMA reading of some flashes.\n"
> +				"Usage of DMA for flash operations will be disabled to prevent data\n"
> +				"damage. Unplug your serial console and power cycle the board\n"
> +				"to boot with full performance.\n"
> +				"==================================================================\n");
> +		}
> +	}
> +
> +	if (dma_enabled) {
> +		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_enabled ?
> +				&airoha_snand_mem_ops :
> +				&airoha_snand_nodma_mem_ops;

nit: no need to add a new-line here:

	ctrl->mem_ops = dma_enabled ? &airoha_snand_mem_ops
				    : &airoha_snand_nodma_mem_ops;


Regards,
Lorenzo

>  	ctrl->bits_per_word_mask = SPI_BPW_MASK(8);
>  	ctrl->mode_bits = SPI_RX_DUAL;
>  	ctrl->setup = airoha_snand_setup;
> -- 
> 2.51.0
> 

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[PATCH 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 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