[f5121] Xiaomi Redmi 5 Plus (vince) compatibility fixes

inifiles/60-f5121.ini

@@ -18,3 +18,15 @@ BlueDirectory=/sys/class/leds/blue
 #RedMaxBrightnessFile=/sys/class/leds/red/max_brightness
 #RedBlinkFile=/sys/class/leds/red/blink
 # ... and similarly for Green and Blue.
+
+# Optional max_brightness override
+# At least in Sony Xperia X / f5121 max_brightness files do not
+# contain true maximum brightness. Additionally the values that
+# are present by default are such that they cause led color
+# representation to be skewed. In such cases these configuration
+# entries can be used for overriding max_brightness content for
+# all / select channels.
+#MaxBrightnessOverride=255
+#RedMaxBrightnessOverride=255
+#GreenMaxBrightnessOverride=255
+#BlueMaxBrightnessOverride=255

inifiles/60-vince.ini

@@ -0,0 +1,8 @@
+[LEDConfigHybris]
+
+# Vince is compatible with f5121 backend
+BackEnd=f5121
+
+RedDirectory=/sys/class/leds/red
+GreenDirectory=/sys/class/leds/red
+BlueDirectory=/sys/class/leds/red

sysfs-led-f5121.c

@@ -53,6 +53,7 @@ typedef struct
     const char *max_brightness;
     const char *brightness;
     const char *blink;
+    const char *max_brightness_override;
 } led_paths_f5121_t;
 
 typedef struct
@@ -127,17 +128,24 @@ led_channel_f5121_probe(led_channel_f5121_t *self,
     if( !sysfsval_open_rw(self->cached_blink, path->blink) )
         goto cleanup;
 
-    if( !sysfsval_open_ro(self->cached_max_brightness, path->max_brightness) )
+    if( !sysfsval_open_rw(self->cached_max_brightness, path->max_brightness) )
         goto cleanup;
 
-    /* The 'max_brightness' seems to be dynamic. Make an attempt
-     * to set it to an artificially high value and assume that kernel
-     * side will cap the value to the true maximum... */
-#if 0 // TODO: make a QUIRK out of this
-    sysfsval_set(self->cached_max_brightness, 255);
-#endif
+    /* If MaxBrightnessOverride has been configured, it will be used
+     * instead of content of max_brightness file.
+     */
+
+    int max_brightness_override = 0;
+    if( path->max_brightness_override )
+        max_brightness_override = strtol(path->max_brightness_override, NULL, 0);
+    if( max_brightness_override > 0 )
+        sysfsval_set(self->cached_max_brightness, max_brightness_override);
+
     sysfsval_refresh(self->cached_max_brightness);
 
+    mce_log(LOG_DEBUG, "%s: effective = %d", path->max_brightness,
+            sysfsval_get(self->cached_max_brightness));
+
     if( sysfsval_get(self->cached_max_brightness) <= 0 )
         goto cleanup;
 
@@ -259,16 +267,19 @@ led_control_f5121_static_probe(led_channel_f5121_t *channel)
                 .max_brightness = "/sys/class/leds/led:rgb_red/max_brightness",
                 .brightness     = "/sys/class/leds/led:rgb_red/brightness",
                 .blink          = "/sys/class/leds/led:rgb_red/blink",
+                .max_brightness_override = "255",
             },
             {
                 .max_brightness = "/sys/class/leds/led:rgb_green/max_brightness",
                 .brightness     = "/sys/class/leds/led:rgb_green/brightness",
                 .blink          = "/sys/class/leds/led:rgb_green/blink",
+                .max_brightness_override = "255",
             },
             {
                 .max_brightness = "/sys/class/leds/led:rgb_blue/max_brightness",
                 .brightness     = "/sys/class/leds/led:rgb_blue/brightness",
                 .blink          = "/sys/class/leds/led:rgb_blue/blink",
+                .max_brightness_override = "255",
             },
         },
         {
@@ -313,6 +324,9 @@ led_control_f5121_dynamic_probe(led_channel_f5121_t *channel)
     OBJCONF_FILE(led_paths_f5121_t, brightness,      Brightness),
     OBJCONF_FILE(led_paths_f5121_t, max_brightness,  MaxBrightness),
     OBJCONF_FILE(led_paths_f5121_t, blink,           Blink),
+
+    OBJCONF_STRING(led_paths_f5121_t, max_brightness_override, MaxBrightnessOverride, NULL),
+
     OBJCONF_STOP
   };
 

sysfs-val.c

@@ -42,6 +42,7 @@ struct sysfsval_t
     char *sv_path;
     int   sv_file;
     int   sv_curr;
+    int   sv_mode;
 };
 
 /* ========================================================================= *
@@ -77,6 +78,7 @@ sysfsval_ctor(sysfsval_t *self)
     self->sv_path = 0;
     self->sv_file = -1;
     self->sv_curr = -1;
+    self->sv_mode = O_RDONLY;
 }
 
 /** Release all dynamically allocated resources used by sysfsval_t object
@@ -171,6 +173,8 @@ sysfsval_open_ex(sysfsval_t *self, const char *path, mode_t mode)
 
     mce_log(LOG_DEBUG, "%s: opened", sysfsval_path(self));
 
+    self->sv_mode = mode;
+
     /* Note: Current value is not fetched by default */
 
     ack = true;
@@ -189,6 +193,8 @@ sysfsval_open_ex(sysfsval_t *self, const char *path, mode_t mode)
 void
 sysfsval_close(sysfsval_t *self)
 {
+    self->sv_mode = O_RDONLY;
+
     if( self->sv_file != -1 ) {
         mce_log(LOG_DEBUG, "%s: closed", sysfsval_path(self));
         close(self->sv_file), self->sv_file = -1;
@@ -242,6 +248,9 @@ sysfsval_set(sysfsval_t *self, int value)
     if( prev == self->sv_curr )
         goto EXIT;
 
+    if( self->sv_mode == O_RDONLY )
+        goto EXIT;
+
     /* If file is closed: assume it was optional and do not
      * spam journal with transitions related to it */
     if( self->sv_file == -1 )