From b5e73204e85ae656ae7b1d2ef4b2d196c61a7713 Mon Sep 17 00:00:00 2001
From: Peter Johanson <peter@peterjohanson.com>
Date: Sun, 5 Jun 2022 05:56:45 +0000
Subject: [PATCH] fix(drivers): Avoid build failures for GPIO driver

* Avoid defining the ZMK GPIO drivers lib if none of the drivers  are
  selected.
---
 app/drivers/CMakeLists.txt        | 2 +-
 app/drivers/gpio/Kconfig          | 3 +++
 app/drivers/gpio/Kconfig.595      | 1 +
 app/drivers/gpio/Kconfig.mcp23017 | 1 +
 4 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/app/drivers/CMakeLists.txt b/app/drivers/CMakeLists.txt
index c58ada48..44d69ac3 100644
--- a/app/drivers/CMakeLists.txt
+++ b/app/drivers/CMakeLists.txt
@@ -1,7 +1,7 @@
 # Copyright (c) 2020 The ZMK Contributors
 # SPDX-License-Identifier: MIT
 
-add_subdirectory(gpio)
+add_subdirectory_ifdef(CONFIG_ZMK_DRIVERS_GPIO gpio)
 add_subdirectory(kscan)
 add_subdirectory(sensor)
 add_subdirectory(display)
diff --git a/app/drivers/gpio/Kconfig b/app/drivers/gpio/Kconfig
index 336d60b9..e6f8bfb8 100644
--- a/app/drivers/gpio/Kconfig
+++ b/app/drivers/gpio/Kconfig
@@ -1,2 +1,5 @@
+menuconfig ZMK_DRIVERS_GPIO
+    bool "GPIO"
+
 rsource "Kconfig.mcp23017"
 rsource "Kconfig.595"
\ No newline at end of file
diff --git a/app/drivers/gpio/Kconfig.595 b/app/drivers/gpio/Kconfig.595
index b863adcb..f43e807b 100644
--- a/app/drivers/gpio/Kconfig.595
+++ b/app/drivers/gpio/Kconfig.595
@@ -10,6 +10,7 @@ menuconfig GPIO_595
 	default $(dt_compat_enabled,$(DT_COMPAT_ZMK_GPIO_595))
 	depends on SPI
 	select HAS_DTS_GPIO
+	select ZMK_DRIVERS_GPIO
 	help
 	  Enable driver for 595 shift register chip using SPI.
 
diff --git a/app/drivers/gpio/Kconfig.mcp23017 b/app/drivers/gpio/Kconfig.mcp23017
index 4953b924..049ca82e 100644
--- a/app/drivers/gpio/Kconfig.mcp23017
+++ b/app/drivers/gpio/Kconfig.mcp23017
@@ -7,6 +7,7 @@ menuconfig GPIO_MCP23017
 	bool "MCP23017 I2C-based GPIO chip"
 	depends on I2C
 	select HAS_DTS_GPIO
+	select ZMK_DRIVERS_GPIO
 	help
 	  Enable driver for MCP23017 I2C-based GPIO chip.