[PATCH v3 0/2] staging: axis-fifo: refactor and cleanup

[PATCH v3 0/2] staging: axis-fifo: refactor and cleanup

[Gustavo Piaz da Silva]

This series cleans up the axis-fifo driver probe function logic.

Patch 1 aligns the struct types with the OF API to avoid potential mismatches.
Patch 2 refactors the parsing logic to be less verbose and removes goto usage.

Changes in v3:
 - Split into two patches as requested.
 - Dropped the "fixes warning" claim from Patch 1, focusing on type correctness.
 - Link to v2: https://lore.kernel.org/linux-staging/20260131140517.29771-1-gustavopiazdasilva2102@gmail.com/

Gustavo Piaz da Silva (2):
  staging: axis-fifo: align fifo depth types with OF API
  staging: axis-fifo: refactor device tree parsing

 drivers/staging/axis-fifo/axis-fifo.c | 80 +++++++++------------------
 1 file changed, 27 insertions(+), 53 deletions(-)

-- 
2.52.0

[PATCH v3 1/2] staging: axis-fifo: align fifo depth types with OF API

[Gustavo Piaz da Silva]

Change has_rx_fifo and has_tx_fifo types from int to u32 in struct

axis_fifo.

The of_property_read_u32() function expects a u32 pointer. While the

current code might work, aligning the types avoids potential mixed-type

issues and clarifies the data structure.

Signed-off-by: Gustavo Piaz da Silva <gustavopiazdasilva2102@gmail.com>
---
 drivers/staging/axis-fifo/axis-fifo.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
index 509d620d6ce7..7bc7bf191250 100644
--- a/drivers/staging/axis-fifo/axis-fifo.c
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -121,8 +121,8 @@ struct axis_fifo {
 
 	unsigned int rx_fifo_depth; /* max words in the receive fifo */
 	unsigned int tx_fifo_depth; /* max words in the transmit fifo */
-	int has_rx_fifo; /* whether the IP has the rx fifo enabled */
-	int has_tx_fifo; /* whether the IP has the tx fifo enabled */
+	u32 has_rx_fifo; /* whether the IP has the rx fifo enabled */
+	u32 has_tx_fifo; /* whether the IP has the tx fifo enabled */
 
 	wait_queue_head_t read_queue; /* wait queue for asynchronos read */
 	struct mutex read_lock; /* lock for reading */
-- 
2.52.0

[PATCH v3 2/2] staging: axis-fifo: refactor device tree parsing

[Gustavo Piaz da Silva]

Refactor the device tree parsing logic in axis_fifo_probe() to reduce

code duplication and improve readability.

Create a helper function axis_fifo_get_u32() to handle property reading

and error checking, replacing repetitive of_property_read_u32() calls.

This eliminates the goto logic for error handling in the probe path and

consolidates error logging.

Signed-off-by: Gustavo Piaz da Silva <gustavopiazdasilva2102@gmail.com>
---
 drivers/staging/axis-fifo/axis-fifo.c | 76 +++++++++------------------
 1 file changed, 25 insertions(+), 51 deletions(-)

diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
index 7bc7bf191250..1e3059ec4fbd 100644
--- a/drivers/staging/axis-fifo/axis-fifo.c
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -482,68 +482,42 @@ static void axis_fifo_debugfs_init(struct axis_fifo *fifo)
 			    &axis_fifo_debugfs_regs_fops);
 }
 
-static int axis_fifo_parse_dt(struct axis_fifo *fifo)
+
+static int axis_fifo_get_u32(struct axis_fifo *fifo, const char *prop, u32 *val)
 {
-	int ret;
-	unsigned int value;
-	struct device_node *node = fifo->dt_device->of_node;
+	int ret = of_property_read_u32(fifo->dt_device->of_node, prop, val);
 
-	ret = of_property_read_u32(node, "xlnx,axi-str-rxd-tdata-width",
-				   &value);
 	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,axi-str-rxd-tdata-width property\n");
-		goto end;
-	} else if (value != 32) {
-		dev_err(fifo->dt_device, "xlnx,axi-str-rxd-tdata-width only supports 32 bits\n");
-		ret = -EIO;
-		goto end;
+		dev_err(fifo->dt_device, "missing %s property\n", prop);
+		return ret;
 	}
+	return 0;
+}
 
-	ret = of_property_read_u32(node, "xlnx,axi-str-txd-tdata-width",
-				   &value);
-	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,axi-str-txd-tdata-width property\n");
-		goto end;
-	} else if (value != 32) {
-		dev_err(fifo->dt_device, "xlnx,axi-str-txd-tdata-width only supports 32 bits\n");
-		ret = -EIO;
-		goto end;
-	}
+static int axis_fifo_parse_dt(struct axis_fifo *fifo)
+{
+	u32 width;
 
-	ret = of_property_read_u32(node, "xlnx,rx-fifo-depth",
-				   &fifo->rx_fifo_depth);
-	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,rx-fifo-depth property\n");
-		ret = -EIO;
-		goto end;
+	if (axis_fifo_get_u32(fifo, "xlnx,axi-str-rxd-tdata-width", &width) || width != 32) {
+		dev_err(fifo->dt_device, "tdata-width only supports 32 bits\n");
+		return -EIO;
 	}
-
-	ret = of_property_read_u32(node, "xlnx,tx-fifo-depth",
-				   &fifo->tx_fifo_depth);
-	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,tx-fifo-depth property\n");
-		ret = -EIO;
-		goto end;
+	if (axis_fifo_get_u32(fifo, "xlnx,axi-str-txd-tdata-width", &width) || width != 32) {
+		dev_err(fifo->dt_device, "tdata-width only supports 32 bits\n");
+		return -EIO;
 	}
 
-	ret = of_property_read_u32(node, "xlnx,use-rx-data",
-				   &fifo->has_rx_fifo);
-	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,use-rx-data property\n");
-		ret = -EIO;
-		goto end;
-	}
+	if (axis_fifo_get_u32(fifo, "xlnx,rx-fifo-depth", &fifo->rx_fifo_depth))
+		return -EIO;
+	if (axis_fifo_get_u32(fifo, "xlnx,tx-fifo-depth", &fifo->tx_fifo_depth))
+		return -EIO;
 
-	ret = of_property_read_u32(node, "xlnx,use-tx-data",
-				   &fifo->has_tx_fifo);
-	if (ret) {
-		dev_err(fifo->dt_device, "missing xlnx,use-tx-data property\n");
-		ret = -EIO;
-		goto end;
-	}
+	if (axis_fifo_get_u32(fifo, "xlnx,use-rx-data", &fifo->has_rx_fifo))
+		return -EIO;
+	if (axis_fifo_get_u32(fifo, "xlnx,use-tx-data", &fifo->has_tx_fifo))
+		return -EIO;
 
-end:
-	return ret;
+	return 0;
 }
 
 static int axis_fifo_probe(struct platform_device *pdev)
-- 
2.52.0

Re: [PATCH v3 2/2] staging: axis-fifo: refactor device tree parsing

[Dan Carpenter]

On Sat, Jan 31, 2026 at 03:27:32PM -0300, Gustavo Piaz da Silva wrote:
> Refactor the device tree parsing logic in axis_fifo_probe() to reduce
> 
> code duplication and improve readability.
> 
> Create a helper function axis_fifo_get_u32() to handle property reading
> 
> and error checking, replacing repetitive of_property_read_u32() calls.
> 
> This eliminates the goto logic for error handling in the probe path and
> 
> consolidates error logging.
> 

Delete the extra blank lines.

> Signed-off-by: Gustavo Piaz da Silva <gustavopiazdasilva2102@gmail.com>
> ---

No changelog explaining what changed vs v2.

>  drivers/staging/axis-fifo/axis-fifo.c | 76 +++++++++------------------
>  1 file changed, 25 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
> index 7bc7bf191250..1e3059ec4fbd 100644
> --- a/drivers/staging/axis-fifo/axis-fifo.c
> +++ b/drivers/staging/axis-fifo/axis-fifo.c
> @@ -482,68 +482,42 @@ static void axis_fifo_debugfs_init(struct axis_fifo *fifo)
>  			    &axis_fifo_debugfs_regs_fops);
>  }
>  
> -static int axis_fifo_parse_dt(struct axis_fifo *fifo)
> +
> +static int axis_fifo_get_u32(struct axis_fifo *fifo, const char *prop, u32 *val)
>  {
> -	int ret;
> -	unsigned int value;
> -	struct device_node *node = fifo->dt_device->of_node;
> +	int ret = of_property_read_u32(fifo->dt_device->of_node, prop, val);
>  
> -	ret = of_property_read_u32(node, "xlnx,axi-str-rxd-tdata-width",
> -				   &value);
>  	if (ret) {
> -		dev_err(fifo->dt_device, "missing xlnx,axi-str-rxd-tdata-width property\n");
> -		goto end;
> -	} else if (value != 32) {
> -		dev_err(fifo->dt_device, "xlnx,axi-str-rxd-tdata-width only supports 32 bits\n");
> -		ret = -EIO;
> -		goto end;
> +		dev_err(fifo->dt_device, "missing %s property\n", prop);
> +		return ret;
>  	}
> +	return 0;
> +}
>  
> -	ret = of_property_read_u32(node, "xlnx,axi-str-txd-tdata-width",
> -				   &value);
> -	if (ret) {
> -		dev_err(fifo->dt_device, "missing xlnx,axi-str-txd-tdata-width property\n");
> -		goto end;
> -	} else if (value != 32) {
> -		dev_err(fifo->dt_device, "xlnx,axi-str-txd-tdata-width only supports 32 bits\n");
> -		ret = -EIO;
> -		goto end;
> -	}
> +static int axis_fifo_parse_dt(struct axis_fifo *fifo)
> +{
> +	u32 width;
>  
> -	ret = of_property_read_u32(node, "xlnx,rx-fifo-depth",
> -				   &fifo->rx_fifo_depth);
> -	if (ret) {
> -		dev_err(fifo->dt_device, "missing xlnx,rx-fifo-depth property\n");
> -		ret = -EIO;
> -		goto end;
> +	if (axis_fifo_get_u32(fifo, "xlnx,axi-str-rxd-tdata-width", &width) || width != 32) {
> +		dev_err(fifo->dt_device, "tdata-width only supports 32 bits\n");

Better to put "rx" in the error message

> +		return -EIO;
>  	}
> -
> -	ret = of_property_read_u32(node, "xlnx,tx-fifo-depth",
> -				   &fifo->tx_fifo_depth);
> -	if (ret) {
> -		dev_err(fifo->dt_device, "missing xlnx,tx-fifo-depth property\n");
> -		ret = -EIO;
> -		goto end;
> +	if (axis_fifo_get_u32(fifo, "xlnx,axi-str-txd-tdata-width", &width) || width != 32) {
> +		dev_err(fifo->dt_device, "tdata-width only supports 32 bits\n");

and "tx" here.

regards,
dan carpenter

> +		return -EIO;
>  	}