openwrt/target/linux/bcm27xx/patches-6.6/950-1211-gpiolib-Override-gpiochip-numbers-with-DT-aliases.patch

From 53b9d9bbb57e292c6b332a2fb9899003586e17ca Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Thu, 2 May 2024 16:17:02 +0100
Subject: [PATCH 1211/1215] gpiolib: Override gpiochip numbers with DT aliases

In the same way that other subsystems support the setting of device
id numbers from Device Tree aliases, allow gpiochip numbers to be
derived from "gpiochip<n>" aliases.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
 drivers/gpio/gpiolib.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -110,6 +110,7 @@ static int gpiochip_irqchip_init_valid_m
 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
 
 static bool gpiolib_initialized;
+static int first_dynamic_gpiochip_num = -1;
 
 static inline void desc_set_label(struct gpio_desc *d, const char *label)
 {
@@ -745,6 +746,7 @@ int gpiochip_add_data_with_key(struct gp
 	unsigned int i;
 	int base = 0;
 	int ret = 0;
+	int id;
 
 	/*
 	 * First: allocate and populate the internal stat container, and
@@ -769,7 +771,16 @@ int gpiochip_add_data_with_key(struct gp
 	else if (gc->parent)
 		device_set_node(&gdev->dev, dev_fwnode(gc->parent));
 
-	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
+	if (first_dynamic_gpiochip_num < 0) {
+		id = of_alias_get_highest_id("gpiochip");
+		first_dynamic_gpiochip_num = (id >= 0) ? (id + 1) : 0;
+	}
+
+	id = of_alias_get_id(gdev->dev.of_node, "gpiochip");
+	if (id < 0)
+		id = first_dynamic_gpiochip_num;
+
+	gdev->id = ida_alloc_range(&gpio_ida, id, ~0, GFP_KERNEL);
 	if (gdev->id < 0) {
 		ret = gdev->id;
 		goto err_free_gdev;