gpio: htc-egpio: allocate irq with the main struct

Use a flexible array member to combinwe allocations.

Add __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260309225204.44789-1-rosenp@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: neheb

drivers/gpio/gpio-htc-egpio.c

@@ -46,8 +46,8 @@ struct egpio_info {
 	uint              chained_irq;
 
 	/* egpio info */
-	struct egpio_chip *chip;
 	int               nchips;
+	struct egpio_chip chip[] __counted_by(nchips);
 };
 
 static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
@@ -270,10 +270,12 @@ static int __init egpio_probe(struct platform_device *pdev)
 	int               i;
 
 	/* Initialize ei data structure. */
-	ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
+	ei = devm_kzalloc(&pdev->dev, struct_size(ei, chip, pdata->num_chips), GFP_KERNEL);
 	if (!ei)
 		return -ENOMEM;
 
+	ei->nchips = pdata->num_chips;
+
 	spin_lock_init(&ei->lock);
 
 	/* Find chained irq */
@@ -302,13 +304,6 @@ static int __init egpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ei);
 
-	ei->nchips = pdata->num_chips;
-	ei->chip = devm_kcalloc(&pdev->dev,
-				ei->nchips, sizeof(struct egpio_chip),
-				GFP_KERNEL);
-	if (!ei->chip)
-		return -ENOMEM;
-
 	for (i = 0; i < ei->nchips; i++) {
 		ei->chip[i].reg_start = pdata->chip[i].reg_start;
 		ei->chip[i].cached_values = pdata->chip[i].initial_values;