[PATCH v2] staging: axis-fifo: refactor device tree parsing

[Gustavo Piaz da Silva <gustavopiazdasilva2102@gmail.com>]

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.

Also change has_rx_fifo and has_tx_fifo types from int to u32 in struct axis_fifo to avoid pointer type mismatch warnings, as of_property_read_u32 expects u32 pointers.

This change reduces the verbosity of the probe function and consolidates error logging for missing properties.

Signed-off-by: Gustavo Piaz da Silva <gustavopiazdasilva2102@gmail.com>
---
Changes in v2:
 - Changed has_rx_fifo and has_tx_fifo to u32 in struct axis_fifo to avoid casting.
 - Removed goto logic in axis_fifo_parse_dt() to simplify error handling.
 - Reverted unrelated changes in axis_fifo_remove().
 - Wrapped commit message to 72 characters.
 drivers/staging/axis-fifo/axis-fifo.c | 79 +++++++++------------------
 1 file changed, 26 insertions(+), 53 deletions(-)

diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
index 509d620d6ce7..f46cd211d359 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 */
@@ -482,68 +482,41 @@ 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