Allow GPIO example built with Linux v6.10+

Since the commit dbcedec ("gpiolib: legacy: Remove unused
gpio_request_array() and gpio_free_array()"), these functions had no
users in kernel and were subsequently removed to simplify the library.

These functions have been removed from GPIO examples for Linux
v6.10+ to ensure compatibility across all kernel versions.

Testing detail:

- Tested on Raspberry Pi 5B with Raspberry Pi OS (Debian 12, Linux
  version 6.12.1-v8-16k+)

- Verified the GPIO examples compile and load successfully

- Verified GPIO17 interrupt turns on the LED (GPIO4)

- Verified GPIO18 interrupt turns off the LED (GPIO4)

Resolves: #285

examples/bh_threaded.c

@@ -13,6 +13,11 @@
 #include <linux/gpio.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 10, 0)
+#define NO_GPIO_REQUEST_ARRAY
+#endif
 
 static int button_irqs[] = { -1, -1 };
 
@@ -50,29 +55,53 @@ static int __init bottomhalf_init(void)
 
     pr_info("%s\n", __func__);
 
-    /* register LED gpios */
+/* register LED gpios */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    ret = gpio_request(leds[0].gpio, leds[0].label);
+#else
     ret = gpio_request_array(leds, ARRAY_SIZE(leds));
+#endif
 
     if (ret) {
         pr_err("Unable to request GPIOs for LEDs: %d\n", ret);
         return ret;
     }
 
-    /* register BUTTON gpios */
+/* register BUTTON gpios */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    ret = gpio_request(buttons[0].gpio, buttons[0].label);
+
+    if (ret) {
+        pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
+        goto fail1;
+    }
+
+    ret = gpio_request(buttons[1].gpio, buttons[1].label);
+
+    if (ret) {
+        pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
+        goto fail2;
+    }
+#else
     ret = gpio_request_array(buttons, ARRAY_SIZE(buttons));
 
     if (ret) {
         pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
         goto fail1;
     }
+#endif
 
     pr_info("Current button1 value: %d\n", gpio_get_value(buttons[0].gpio));
 
     ret = gpio_to_irq(buttons[0].gpio);
 
     if (ret < 0) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     button_irqs[0] = ret;
@@ -86,14 +115,22 @@ static int __init bottomhalf_init(void)
 
     if (ret) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     ret = gpio_to_irq(buttons[1].gpio);
 
     if (ret < 0) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     button_irqs[1] = ret;
@@ -107,12 +144,29 @@ static int __init bottomhalf_init(void)
 
     if (ret) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail4;
+#else
         goto fail3;
+#endif
     }
 
     return 0;
 
 /* cleanup what has been setup so far */
+#ifdef NO_GPIO_REQUEST_ARRAY
+fail4:
+    free_irq(button_irqs[0], NULL);
+
+fail3:
+    gpio_free(buttons[1].gpio);
+
+fail2:
+    gpio_free(buttons[0].gpio);
+
+fail1:
+    gpio_free(leds[0].gpio);
+#else
 fail3:
     free_irq(button_irqs[0], NULL);
 
@@ -121,27 +175,37 @@ static int __init bottomhalf_init(void)
 
 fail1:
     gpio_free_array(leds, ARRAY_SIZE(leds));
+#endif
 
     return ret;
 }
 
 static void __exit bottomhalf_exit(void)
 {
-    int i;
-
     pr_info("%s\n", __func__);
 
     /* free irqs */
     free_irq(button_irqs[0], NULL);
     free_irq(button_irqs[1], NULL);
 
-    /* turn all LEDs off */
+/* turn all LEDs off */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    gpio_set_value(leds[0].gpio, 0);
+#else
+    int i;
     for (i = 0; i < ARRAY_SIZE(leds); i++)
         gpio_set_value(leds[i].gpio, 0);
-
-    /* unregister */
+#endif
+
+/* unregister */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    gpio_free(leds[0].gpio);
+    gpio_free(buttons[0].gpio);
+    gpio_free(buttons[1].gpio);
+#else
     gpio_free_array(leds, ARRAY_SIZE(leds));
     gpio_free_array(buttons, ARRAY_SIZE(buttons));
+#endif
 }
 
 module_init(bottomhalf_init);

examples/bottomhalf.c

@@ -14,6 +14,11 @@
 #include <linux/module.h>
 #include <linux/printk.h>
 #include <linux/init.h>
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 10, 0)
+#define NO_GPIO_REQUEST_ARRAY
+#endif
 
 /* Macro DECLARE_TASKLET_OLD exists for compatibility.
  * See https://lwn.net/Articles/830964/
@@ -70,28 +75,52 @@ static int __init bottomhalf_init(void)
     pr_info("%s\n", __func__);
 
     /* register LED gpios */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    ret = gpio_request(leds[0].gpio, leds[0].label);
+#else
     ret = gpio_request_array(leds, ARRAY_SIZE(leds));
+#endif
 
     if (ret) {
         pr_err("Unable to request GPIOs for LEDs: %d\n", ret);
         return ret;
     }
 
     /* register BUTTON gpios */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    ret = gpio_request(buttons[0].gpio, buttons[0].label);
+
+    if (ret) {
+        pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
+        goto fail1;
+    }
+
+    ret = gpio_request(buttons[1].gpio, buttons[1].label);
+
+    if (ret) {
+        pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
+        goto fail2;
+    }
+#else
     ret = gpio_request_array(buttons, ARRAY_SIZE(buttons));
 
     if (ret) {
         pr_err("Unable to request GPIOs for BUTTONs: %d\n", ret);
         goto fail1;
     }
+#endif
 
     pr_info("Current button1 value: %d\n", gpio_get_value(buttons[0].gpio));
 
     ret = gpio_to_irq(buttons[0].gpio);
 
     if (ret < 0) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     button_irqs[0] = ret;
@@ -104,14 +133,22 @@ static int __init bottomhalf_init(void)
 
     if (ret) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     ret = gpio_to_irq(buttons[1].gpio);
 
     if (ret < 0) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail3;
+#else
         goto fail2;
+#endif
     }
 
     button_irqs[1] = ret;
@@ -124,12 +161,29 @@ static int __init bottomhalf_init(void)
 
     if (ret) {
         pr_err("Unable to request IRQ: %d\n", ret);
+#ifdef NO_GPIO_REQUEST_ARRAY
+        goto fail4;
+#else
         goto fail3;
+#endif
     }
 
     return 0;
 
 /* cleanup what has been setup so far */
+#ifdef NO_GPIO_REQUEST_ARRAY
+fail4:
+    free_irq(button_irqs[0], NULL);
+
+fail3:
+    gpio_free(buttons[1].gpio);
+
+fail2:
+    gpio_free(buttons[0].gpio);
+
+fail1:
+    gpio_free(leds[0].gpio);
+#else
 fail3:
     free_irq(button_irqs[0], NULL);
 
@@ -138,27 +192,37 @@ static int __init bottomhalf_init(void)
 
 fail1:
     gpio_free_array(leds, ARRAY_SIZE(leds));
+#endif
 
     return ret;
 }
 
 static void __exit bottomhalf_exit(void)
 {
-    int i;
-
     pr_info("%s\n", __func__);
 
     /* free irqs */
     free_irq(button_irqs[0], NULL);
     free_irq(button_irqs[1], NULL);
 
     /* turn all LEDs off */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    gpio_set_value(leds[0].gpio, 0);
+#else
+    int i;
     for (i = 0; i < ARRAY_SIZE(leds); i++)
         gpio_set_value(leds[i].gpio, 0);
+#endif
 
     /* unregister */
+#ifdef NO_GPIO_REQUEST_ARRAY
+    gpio_free(leds[0].gpio);
+    gpio_free(buttons[0].gpio);
+    gpio_free(buttons[1].gpio);
+#else
     gpio_free_array(leds, ARRAY_SIZE(leds));
     gpio_free_array(buttons, ARRAY_SIZE(buttons));
+#endif
 }
 
 module_init(bottomhalf_init);