From 20a71428fcb438f4959dae5e7211f46fa352b9a8 Mon Sep 17 00:00:00 2001
From: Alex Demenchuk <alexander.demenchuk@gmail.com>
Date: Thu, 31 May 2018 10:47:05 -0400
Subject: [PATCH 1/3] Add all protocol SUPPORT macros to CFLAGS to allow
 selective disabling

---
 extras/ssd1306/component.mk | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/extras/ssd1306/component.mk b/extras/ssd1306/component.mk
index f12a292..9e1708a 100644
--- a/extras/ssd1306/component.mk
+++ b/extras/ssd1306/component.mk
@@ -1,17 +1,19 @@
 # Component makefile for extras/ssd1306
 
 # expected anyone using ssd1306 driver includes it as 'ssd1306/ssd1306.h'
-INC_DIRS += $(ssd1306_ROOT)..
+INC_DIRS += $(ROOT)extras
 
 # I2C support is on by default
-SSD1306_I2C_SUPPORT ?= 1
+SSD1306_I2C_SUPPORT   ?= 1
 # SPI4 support is on by default
-SSD1306_SPI4_SUPPORT ?= 1
+SSD1306_SPI4_SUPPORT  ?= 1
+# SPI3 support is on by default
+SSD1306_SPI3_SUPPORT  ?= 1
 
 # args for passing into compile rule generation
 ssd1306_SRC_DIR = $(ssd1306_ROOT)
 
-ssd1306_CFLAGS = -DSSD1306_I2C_SUPPORT=${SSD1306_I2C_SUPPORT} -DSSD1306_SPI4_SUPPORT=${SSD1306_SPI4_SUPPORT} $(CFLAGS)
+ssd1306_CFLAGS = -DSSD1306_I2C_SUPPORT=${SSD1306_I2C_SUPPORT} -DSSD1306_SPI4_SUPPORT=${SSD1306_SPI4_SUPPORT} -DSSD1306_SPI3_SUPPORT=${SSD1306_SPI3_SUPPORT} $(CFLAGS)
 
 
-$(eval $(call component_compile_rules,ssd1306))
+$(eval $(call component_compile_rules,ssd1306))
\ No newline at end of file

From c5a78b4c6f6f56fac588307d7eb4541fb4abeb71 Mon Sep 17 00:00:00 2001
From: Alex Demenchuk <alexander.demenchuk@gmail.com>
Date: Thu, 31 May 2018 10:54:56 -0400
Subject: [PATCH 2/3] Clean up device descriptor struct

---
 extras/ssd1306/ssd1306.h | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/extras/ssd1306/ssd1306.h b/extras/ssd1306/ssd1306.h
index 86abaab..6e0e577 100644
--- a/extras/ssd1306/ssd1306.h
+++ b/extras/ssd1306/ssd1306.h
@@ -66,15 +66,12 @@ typedef struct
 {
     ssd1306_protocol_t protocol;
     ssd1306_screen_t screen;
-    union
-    {
 #if (SSD1306_I2C_SUPPORT)
-        i2c_dev_t i2c_dev;         //!< I2C devuce descriptor, used by SSD1306_PROTO_I2C
+    i2c_dev_t i2c_dev;            //!< I2C device descriptor, used by SSD1306_PROTO_I2C
 #endif
 #if (SSD1306_SPI4_SUPPORT) || (SSD1306_SPI3_SUPPORT)
-        uint8_t cs_pin;            //!< Chip Select GPIO pin, used by SSD1306_PROTO_SPI3, SSD1306_PROTO_SPI4
+    uint8_t cs_pin;               //!< Chip Select GPIO pin, used by SSD1306_PROTO_SPI3, SSD1306_PROTO_SPI4
 #endif
-    };
 #if (SSD1306_SPI4_SUPPORT)
     uint8_t dc_pin;               //!< Data/Command GPIO pin, used by SSD1306_PROTO_SPI4
 #endif

From ecd060c27b940c1eba22be22a560b12c5e2136bd Mon Sep 17 00:00:00 2001
From: Alex Demenchuk <alexander.demenchuk@gmail.com>
Date: Thu, 31 May 2018 11:00:16 -0400
Subject: [PATCH 3/3] Pack device descriptor enums to shrink the struct

---
 extras/ssd1306/ssd1306.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/extras/ssd1306/ssd1306.h b/extras/ssd1306/ssd1306.h
index 6e0e577..0f0fe1a 100644
--- a/extras/ssd1306/ssd1306.h
+++ b/extras/ssd1306/ssd1306.h
@@ -64,8 +64,10 @@ typedef enum
  */
 typedef struct
 {
-    ssd1306_protocol_t protocol;
-    ssd1306_screen_t screen;
+    struct {
+        uint8_t protocol : 4;     //!< I/O protocol
+        uint8_t screen : 4;       //!< Screen type
+    };
 #if (SSD1306_I2C_SUPPORT)
     i2c_dev_t i2c_dev;            //!< I2C device descriptor, used by SSD1306_PROTO_I2C
 #endif