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From: =?utf-8?q?Th=C3=A9o_Lebrun?= <theo.lebrun@bootlin.com>
Date: Wed, 28 Feb 2024 12:28:21 +0100
Subject: [PATCH v2 23/30] gpio: nomadik: handle variadic GPIO count
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Message-Id: <20240228-mbly-gpio-v2-23-3ba757474006@bootlin.com>
References: <20240228-mbly-gpio-v2-0-3ba757474006@bootlin.com>
In-Reply-To: <20240228-mbly-gpio-v2-0-3ba757474006@bootlin.com>
To: Linus Walleij <linus.walleij@linaro.org>, 
 Bartosz Golaszewski <brgl@bgdev.pl>, Rob Herring <robh+dt@kernel.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
 Conor Dooley <conor+dt@kernel.org>, Philipp Zabel <p.zabel@pengutronix.de>, 
 Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, 
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
 linux-mips@vger.kernel.org, Gregory CLEMENT <gregory.clement@bootlin.com>, 
 Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>, 
 Thomas Petazzoni <thomas.petazzoni@bootlin.com>, 
 Tawfik Bayouk <tawfik.bayouk@mobileye.com>, 
 =?utf-8?q?Th=C3=A9o_Lebrun?= <theo.lebrun@bootlin.com>

Read the "ngpios" property to determine the number of GPIOs for a bank.
If not available, fallback to NMK_GPIO_PER_CHIP ie 32 ie the current
behavior.

The IP block always supports 32 GPIOs, but platforms can expose a lesser
amount. The Mobileye EyeQ5 is in this case; one bank is 29 GPIOs and
the other is 23.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 drivers/gpio/gpio-nomadik.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-nomadik.c b/drivers/gpio/gpio-nomadik.c
index ca5c28965224..19394dc7e34a 100644
--- a/drivers/gpio/gpio-nomadik.c
+++ b/drivers/gpio/gpio-nomadik.c
@@ -488,7 +488,7 @@ struct nmk_gpio_chip *nmk_gpio_populate_chip(struct device_node *np,
 	struct gpio_chip *chip;
 	struct clk *clk;
 	void __iomem *base;
-	u32 id;
+	u32 id, ngpio;
 
 	gpio_dev = bus_find_device_by_of_node(&platform_bus_type, np);
 	if (!gpio_dev) {
@@ -518,10 +518,15 @@ struct nmk_gpio_chip *nmk_gpio_populate_chip(struct device_node *np,
 		return ERR_PTR(-ENOMEM);
 	}
 
+	if (device_property_read_u32(gpio_dev, "ngpios", &ngpio)) {
+		ngpio = NMK_GPIO_PER_CHIP;
+		dev_dbg(&pdev->dev, "populate: using default ngpio (%d)\n", ngpio);
+	}
+
 	nmk_chip->bank = id;
 	chip = &nmk_chip->chip;
 	chip->base = -1;
-	chip->ngpio = NMK_GPIO_PER_CHIP;
+	chip->ngpio = ngpio;
 	chip->label = dev_name(gpio_dev);
 	chip->parent = gpio_dev;
 

-- 
2.44.0