[FL-3316] Settings: add contrast adjustment (#2737)

Co-authored-by: hedger <hedger@users.noreply.github.com>

lib/toolbox/value_index.c

@@ -1,5 +1,18 @@
 #include "value_index.h"
 
+uint8_t value_index_int32(const int32_t value, const int32_t values[], uint8_t values_count) {
+    int64_t last_value = INT64_MIN;
+    uint8_t index = 0;
+    for(uint8_t i = 0; i < values_count; i++) {
+        if((value >= last_value) && (value <= values[i])) {
+            index = i;
+            break;
+        }
+        last_value = values[i];
+    }
+    return index;
+}
+
 uint8_t value_index_uint32(const uint32_t value, const uint32_t values[], uint8_t values_count) {
     int64_t last_value = INT64_MIN;
     uint8_t index = 0;

lib/toolbox/value_index.h

@@ -7,6 +7,19 @@
 extern "C" {
 #endif
 
+/** Get the index of a int32_t array element which is closest to the given value.
+ *
+ * Returned index corresponds to the first element found.
+ * If no suitable elements were found, the function returns 0.
+ *
+ * @param   value           value to be searched.
+ * @param   values          pointer to the array to perform the search in.
+ * @param   values_count    array size.
+ *
+ * @return value's index.
+ */
+uint8_t value_index_int32(const int32_t value, const int32_t values[], uint8_t values_count);
+
 /** Get the index of a uint32_t array element which is closest to the given value.
  *
  * Returned index corresponds to the first element found.

lib/u8g2/u8g2_glue.c

@@ -2,6 +2,9 @@
 
 #include <furi_hal.h>
 
+#define CONTRAST_ERC 32
+#define CONTRAST_MGG 31
+
 uint8_t u8g2_gpio_and_delay_stm32(u8x8_t* u8x8, uint8_t msg, uint8_t arg_int, void* arg_ptr) {
     UNUSED(u8x8);
     UNUSED(arg_ptr);
@@ -207,6 +210,19 @@ void u8x8_d_st756x_init(u8x8_t* u8x8, uint8_t contrast, uint8_t regulation_ratio
     u8x8_cad_EndTransfer(u8x8);
 }
 
+void u8x8_d_st756x_set_contrast(u8x8_t* u8x8, int8_t contrast_offset) {
+    uint8_t contrast = (furi_hal_version_get_hw_display() == FuriHalVersionDisplayMgg) ?
+                           CONTRAST_MGG :
+                           CONTRAST_ERC;
+    contrast += contrast_offset;
+    contrast = contrast & 0b00111111;
+
+    u8x8_cad_StartTransfer(u8x8);
+    u8x8_cad_SendCmd(u8x8, ST756X_CMD_SET_EV);
+    u8x8_cad_SendArg(u8x8, contrast);
+    u8x8_cad_EndTransfer(u8x8);
+}
+
 uint8_t u8x8_d_st756x_flipper(u8x8_t* u8x8, uint8_t msg, uint8_t arg_int, void* arg_ptr) {
     /* call common procedure first and handle messages there */
     if(u8x8_d_st756x_common(u8x8, msg, arg_int, arg_ptr) == 0) {
@@ -225,7 +241,7 @@ uint8_t u8x8_d_st756x_flipper(u8x8_t* u8x8, uint8_t msg, uint8_t arg_int, void*
                  * RR = 10 / ((1 - (63 - 32) / 162) * 2.1) ~= 5.88 is 6 (0b110)
                  * Bias = 1/9 (false)
                  */
-                u8x8_d_st756x_init(u8x8, 31, 0b110, false);
+                u8x8_d_st756x_init(u8x8, CONTRAST_MGG, 0b110, false);
             } else {
                 /* ERC v1(ST7565) and v2(ST7567)
                  * EV = 33
@@ -233,7 +249,7 @@ uint8_t u8x8_d_st756x_flipper(u8x8_t* u8x8, uint8_t msg, uint8_t arg_int, void*
                  * RR = 9.3 / ((1 - (63 - 32) / 162) * 2.1) ~= 5.47 is 5.5 (0b101)
                  * Bias = 1/9 (false)
                  */
-                u8x8_d_st756x_init(u8x8, 32, 0b101, false);
+                u8x8_d_st756x_init(u8x8, CONTRAST_ERC, 0b101, false);
             }
             break;
         case U8X8_MSG_DISPLAY_SET_FLIP_MODE:

lib/u8g2/u8g2_glue.h

@@ -14,3 +14,5 @@ void u8g2_Setup_st756x_flipper(
     u8x8_msg_cb gpio_and_delay_cb);
 
 void u8x8_d_st756x_init(u8x8_t* u8x8, uint8_t contrast, uint8_t regulation_ratio, bool bias);
+
+void u8x8_d_st756x_set_contrast(u8x8_t* u8x8, int8_t contrast_offset);