Store backlight breathing state in EEPROM (#6105)

* Store backlight breathing state in EEPROM

* Reduce backlight_config.level from 6 bits to 4 (max 15 "on" levels)

* Error out if BACKLIGHT_LEVELS is > 15

* Remove mention of default backlight pin in rules.mk template

* Remove pointless comment

2 files changed, 71 insertions, 3 deletions

diff --git a/tmk_core/common/backlight.c b/tmk_core/common/backlight.c
index 8ddacd98b6..c0e9fb5ee4 100644
--- a/tmk_core/common/backlight.c
+++ b/tmk_core/common/backlight.c
@@ -100,7 +100,7 @@ void backlight_enable(void)
 	backlight_set(backlight_config.level);
 }
 
-/** /brief Disable backlight
+/** \brief Disable backlight
  *
  * FIXME: needs doc
  */
@@ -162,3 +162,56 @@ uint8_t get_backlight_level(void)
 {
     return backlight_config.level;
 }
+
+#ifdef BACKLIGHT_BREATHING
+/** \brief Backlight breathing toggle
+ *
+ * FIXME: needs doc
+ */
+void backlight_toggle_breathing(void)
+{
+    bool breathing = backlight_config.breathing;
+    dprintf("backlight breathing toggle: %u\n", breathing);
+    if (breathing) 
+        backlight_disable_breathing();
+    else
+        backlight_enable_breathing();
+}
+
+/** \brief Enable backlight breathing
+ *
+ * FIXME: needs doc
+ */
+void backlight_enable_breathing(void)
+{
+    if (backlight_config.breathing) return; // do nothing if breathing is already on
+
+    backlight_config.breathing = true;
+    eeconfig_update_backlight(backlight_config.raw);
+    dprintf("backlight breathing enable\n");
+    breathing_enable();
+}
+
+/** \brief Disable backlight breathing
+ *
+ * FIXME: needs doc
+ */
+void backlight_disable_breathing(void)
+{
+    if (!backlight_config.breathing) return; // do nothing if breathing is already off
+
+    backlight_config.breathing = false;
+    eeconfig_update_backlight(backlight_config.raw);
+    dprintf("backlight breathing disable\n");
+    breathing_disable();
+}
+
+/** \brief Get the backlight breathing status
+ *
+ * FIXME: needs doc
+ */
+bool is_backlight_breathing(void)
+{
+    return backlight_config.breathing;
+}
+#endif
diff --git a/tmk_core/common/backlight.h b/tmk_core/common/backlight.h
index 420c9d19ed..cc56fb9af0 100644
--- a/tmk_core/common/backlight.h
+++ b/tmk_core/common/backlight.h
@@ -20,11 +20,18 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdint.h>
 #include <stdbool.h>
 
+#ifndef BACKLIGHT_LEVELS
+  #define BACKLIGHT_LEVELS 3
+#elif BACKLIGHT_LEVELS > 15
+  #error "Maximum value of BACKLIGHT_LEVELS is 15"
+#endif
+
 typedef union {
     uint8_t raw;
     struct {
-        bool    enable :1;
-        uint8_t level  :7;
+        bool    enable    :1;
+        bool    breathing :1;
+        uint8_t level     :4;
     };
 } backlight_config_t;
 
@@ -40,3 +47,11 @@ void backlight_set(uint8_t level);
 void backlight_level(uint8_t level);
 uint8_t get_backlight_level(void);
 
+#ifdef BACKLIGHT_BREATHING
+void backlight_toggle_breathing(void);
+void backlight_enable_breathing(void);
+void backlight_disable_breathing(void);
+bool is_backlight_breathing(void);
+void breathing_enable(void);
+void breathing_disable(void);
+#endif