bcma: use absolute base for SoC GPIO pins

On some BCM5301x ARM devices, user space still needs to control some
system GPIO pins for which no driver exists. This is a lot easier to do
with a predictable GPIO base.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/bcma/driver_gpio.c

@@ -235,16 +235,17 @@ int bcma_gpio_init(struct bcma_drv_cc *cc)
 	}
 
 	/*
-	 * On MIPS we register GPIO devices (LEDs, buttons) using absolute GPIO
-	 * pin numbers. We don't have Device Tree there and we can't really use
-	 * relative (per chip) numbers.
-	 * So let's use predictable base for BCM47XX and "random" for all other.
+	 * Register SoC GPIO devices with absolute GPIO pin base.
+	 * On MIPS, we don't have Device Tree and we can't use relative (per chip)
+	 * GPIO numbers.
+	 * On some ARM devices, user space may want to access some system GPIO
+	 * pins directly, which is easier to do with a predictable GPIO base.
 	 */
-#if IS_BUILTIN(CONFIG_BCM47XX)
+	if (IS_BUILTIN(CONFIG_BCM47XX) ||
+	    cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
 		chip->base		= bus->num * BCMA_GPIO_MAX_PINS;
-#else
+	else
 		chip->base		= -1;
-#endif
 
 	err = bcma_gpio_irq_domain_init(cc);
 	if (err)