linux-kernel - [PATCH v3 2/4] gpio: sifive: Look up IRQs only once during probe

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Date:   Mon, 24 Jul 2023 17:40:40 -0700
From:   Samuel Holland <samuel.holland@...ive.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Andy Shevchenko <andy@...nel.org>
Cc:     Emil Renner Berthing <emil.renner.berthing@...onical.com>,
        Rob Herring <robh+dt@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        Samuel Holland <samuel.holland@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-riscv@...ts.infradead.org
Subject: [PATCH v3 2/4] gpio: sifive: Look up IRQs only once during probe

of_irq_count(), or eqivalently platform_irq_count(), simply looks up
successively-numbered IRQs until that fails. Since this driver needs to
look up each IRQ anyway to get its virq number, use that existing loop
to count the IRQs at the same time.

The check against SIFIVE_GPIO_MAX functioned as a bounds check for
chip->irq_number. That is now handled by the loop condition.

Signed-off-by: Samuel Holland <samuel.holland@...ive.com>
---

Changes in v3:
 - Mention the SIFIVE_GPIO_MAX check in the commit message

Changes in v2:
 - New patch for v2

 drivers/gpio/gpio-sifive.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/gpio-sifive.c b/drivers/gpio/gpio-sifive.c
index db480cd7271a..e96829ac731d 100644
--- a/drivers/gpio/gpio-sifive.c
+++ b/drivers/gpio/gpio-sifive.c
@@ -186,7 +186,7 @@ static int sifive_gpio_probe(struct platform_device *pdev)
 	struct irq_domain *parent;
 	struct gpio_irq_chip *girq;
 	struct sifive_gpio *chip;
-	int ret, ngpio, i;
+	int ret, ngpio;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
@@ -203,13 +203,6 @@ static int sifive_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(chip->regs))
 		return PTR_ERR(chip->regs);
 
-	ngpio = of_irq_count(node);
-	if (ngpio > SIFIVE_GPIO_MAX) {
-		dev_err(dev, "Too many GPIO interrupts (max=%d)\n",
-			SIFIVE_GPIO_MAX);
-		return -ENXIO;
-	}
-
 	irq_parent = of_irq_find_parent(node);
 	if (!irq_parent) {
 		dev_err(dev, "no IRQ parent node\n");
@@ -222,11 +215,11 @@ static int sifive_gpio_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	for (i = 0; i < ngpio; i++) {
-		ret = platform_get_irq(pdev, i);
+	for (ngpio = 0; ngpio < SIFIVE_GPIO_MAX; ngpio++) {
+		ret = platform_get_irq_optional(pdev, ngpio);
 		if (ret < 0)
-			return ret;
-		chip->irq_number[i] = ret;
+			break;
+		chip->irq_number[ngpio] = ret;
 	}
 
 	ret = bgpio_init(&chip->gc, dev, 4,
-- 
2.40.1