drivers/st77xx: implement initialization

drivers/include/st77xx.h

@@ -53,6 +53,273 @@
 extern "C" {
 #endif
 
+/**
+ * @brief ST7735 Customized Configuration Enable
+ *
+ * Define CONFIG_ST7735_CUSTOM_CONFIG=1 to use customized voltage
+ * configurations. Otherwise ST7735 is using reset defaults.
+ */
+#ifndef CONFIG_ST7735_CUSTOM_CONFIG
+#define CONFIG_ST7735_CUSTOM_CONFIG     0
+#endif
+
+/**
+ * @brief ST7735 AVDD voltage (in millivolts)
+ *
+ * A default voltage of 4.9V is used for AVDD.
+ * Valid values must be in the range of 4500 (4.5V) to 5100 (5.1V)
+ * in steps of 100.
+ */
+#ifndef CONFIG_ST7735_AVDD
+#define CONFIG_ST7735_AVDD             4900
+#endif
+
+/**
+ * @brief ST7735 GVDD voltage (in millivolts)
+ *
+ * A default voltage of 4.6V is used for GVDD (gamma reference positive voltage).
+ * Valid values must be in the range of 3150 (3.15V) to 4700 (4.7V)
+ * in steps of 50.
+ */
+#ifndef CONFIG_ST7735_GVDD
+#define CONFIG_ST7735_GVDD             4600
+#endif
+
+/**
+ * @brief ST7735 GVL voltage (in millivolts)
+ *
+ * A default voltage of -4.6V is used for GVCL (gamma reference negative voltage).
+ * Valid values must be in the range of -4700 (-4.7V) to -3150 (-3.15V)
+ * in steps of 50.
+ */
+#ifndef CONFIG_ST7735_GVCL
+#define CONFIG_ST7735_GVCL             -4600
+#endif
+
+/**
+ * @brief ST7735 VCOM voltage (in millivolts)
+ *
+ * A default voltage of -0.425V is used for VCOM. VCOM needs to be adjusted
+ * to match the capacitance and performance specifications of the TFT panel
+ * to maximize contrast and minimize flickering.
+ * Valid values must be in the range of -2000 (-2.0V) to -425 (-0.425V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7735_VCOM
+#define CONFIG_ST7735_VCOM              -775
+#endif
+
+/**
+ * @brief ST7735 VGH voltage (in millivolts)
+ *
+ * A default voltage of 14.7V is used for VGH, the high voltage for gate drivers.
+ * Valid values must be in the range of 10000 (10V) to 15000 (15V) and
+ * in the range of (2 * AVDD + 2.1V) and (3 * AVDD + 2.4 V).
+ */
+#ifndef CONFIG_ST7735_VGH
+#define CONFIG_ST7735_VGH               14700
+#endif
+
+/**
+ * @brief ST7735 VGL voltage (in millivolts)
+ *
+ * A default voltage of -10V is used for VGL, the low voltage for gate drivers.
+ * Valid values must be in the range of -13000 (-13V) to -7500 (-7.5V)
+ * in steps of 2500.
+ */
+#ifndef CONFIG_ST7735_VGL
+#define CONFIG_ST7735_VGL               -10000
+#endif
+
+/**
+ * @brief ST7789 Customized Configuration Enable
+ *
+ * Define CONFIG_ST7789_CUSTOM_CONFIG=1 to use customized voltage
+ * configurations. Otherwise ST7735 is using reset defaults.
+ */
+#ifndef CONFIG_ST7789_CUSTOM_CONFIG
+#define CONFIG_ST7789_CUSTOM_CONFIG     0
+#endif
+
+/**
+ * @brief ST7789 AVDD voltage (in millivolts)
+ *
+ * A default voltage of 6.8V is used for AVDD.
+ * Valid values must be in the range of 6400 (6.4V) to 6800 (6.8V)
+ * in steps of 100.
+ */
+#ifndef CONFIG_ST7789_AVDD
+#define CONFIG_ST7789_AVDD              6800
+#endif
+
+/**
+ * @brief ST7789 AVCL voltage (in millivolts)
+ *
+ * A default voltage of -4.8V is used for AVCL.
+ * Valid values must be in the range of -5000 (-5.0V) to -4400 (-4.4V)
+ * in steps of 100.
+ */
+#ifndef CONFIG_ST7789_AVCL
+#define CONFIG_ST7789_AVCL              -4800
+#endif
+
+/**
+ * @brief ST7789 VCOM voltage (in millivolts)
+ *
+ * A default voltage of 0.9V is used for VCOM. VCOM needs to be adjusted
+ * to match the capacitance and performance specifications of the TFT panel
+ * to maximize contrast and minimize flickering. VCOM is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET + (0.5 * VDV)
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET - (0.5 * VDV)
+ *
+ * Valid values must be in the range of 100 (0.1V) to 1675 (1.675V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7789_VCOM
+#define CONFIG_ST7789_VCOM              900
+#endif
+
+/**
+ * @brief ST7789 VCOM voltage offset (in millivolts)
+ *
+ * A default voltage of 0V is used for VCOM voltage offset (VCOM_OFFSET).
+ * VCOM_OFFSET is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET + (0.5 * VDV)
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET - (0.5 * VDV)
+ *
+ * Valid values must be in the range of -800 (-0.8V) to 775 (0.775V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7789_VCOM_OFFSET
+#define CONFIG_ST7789_VCOM_OFFSET       0
+#endif
+
+/**
+ * @brief ST7789 VDV voltage (in millivolts)
+ *
+ * A default voltage of 0V is used for VDV. VDV is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET + (0.5 * VDV)
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET - (0.5 * VDV)
+ *
+ * Valid values must be in the range of -800 (-0.8V) to 775 (0.775V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7789_VDV
+#define CONFIG_ST7789_VDV               0
+#endif
+
+/**
+ * @brief ST7789 VRH voltage (in millivolts)
+ *
+ * A default voltage of 4.1V is used for VRH. VRH is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET + (0.5 * VDV)
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET - (0.5 * VDV)
+ *
+ * Valid values must be in the range of 3350 (3.35V) to 5500 (5.5V)
+ * in steps of 50.
+ */
+#ifndef CONFIG_ST7789_VRH
+#define CONFIG_ST7789_VRH               4100
+#endif
+
+/**
+ * @brief ST7796 Customized Configuration Enable
+ *
+ * Define CONFIG_ST7796_CUSTOM_CONFIG=1 to use customized voltage
+ * configurations. Otherwise ST7735 is using reset defaults.
+ */
+#ifndef CONFIG_ST7796_CUSTOM_CONFIG
+#define CONFIG_ST7796_CUSTOM_CONFIG     0
+#endif
+
+/**
+ * @brief ST7796 AVDD voltage (in millivolts)
+ *
+ * A default voltage of 6.6V is used for AVDD.
+ * Valid values must be in the range of 6200 (6.2V) to 6800 (6.8V)
+ * in steps of 100.
+ */
+#ifndef CONFIG_ST7796_AVDD
+#define CONFIG_ST7796_AVDD              6600
+#endif
+
+/**
+ * @brief ST7796 AVCL voltage (in millivolts)
+ *
+ * A default voltage of -4.4V is used for AVCL.
+ * Valid values must be in the range of -5000 (-5.0V) to -4400 (-4.4V)
+ * in steps of 100.
+ */
+#ifndef CONFIG_ST7796_AVCL
+#define CONFIG_ST7796_AVCL              -4400
+#endif
+
+/**
+ * @brief ST7796 VCOM voltage (in millivolts)
+ *
+ * A default voltage of 1.0V is used for VCOM. VCOM needs to be adjusted
+ * to match the capacitance and performance specifications of the TFT panel
+ * to maximize contrast and minimize flickering. VCOM is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET
+ *
+ * Valid values must be in the range of 100 (0.1V) to 1875 (1.875V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7796_VCOM
+#define CONFIG_ST7796_VCOM              1000
+#endif
+
+/**
+ * @brief ST7796 VCOM voltage offset (in millivolts)
+ *
+ * A default voltage of 0V is used for VCOM voltage offset (VCOM_OFFSET).
+ * VCOM_OFFSET is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET
+ *
+ * Valid values must be in the range of -800 (-0.8V) to 775 (0.775V)
+ * in steps of 25.
+ */
+#ifndef CONFIG_ST7796_VCOM_OFFSET
+#define CONFIG_ST7796_VCOM_OFFSET       0
+#endif
+
+/**
+ * @brief ST7796 VRH voltage (in millivolts)
+ *
+ * A default voltage of 4.1V is used for VRH. VRH is used to derive
+ * the GVDD (gamma reference positive voltage) and
+ * the GVCL (gamma reference negative voltage) as follows:
+ *
+ *     GDDV = +VRH + VCOM + VCOM_OFFSET
+ *     GVCL = -VRH + VCOM + VCOM_OFFSET
+ *
+ * Valid values must be in the range of 3350 (3.35V) to 5500 (5.5V)
+ * in steps of 50.
+ */
+#ifndef CONFIG_ST7796_VRH
+#define CONFIG_ST7796_VRH               4100
+#endif
+
 /**
  * @name    ST77xx display rotation modes
  * @{

drivers/lcd/include/lcd_internal.h

@@ -51,6 +51,9 @@ extern "C" {
 #define LCD_CMD_MADCTL          0x36    /**< Memory data access control */
 #define LCD_CMD_IDMOFF          0x38    /**< Idle Mode OFF */
 #define LCD_CMD_IDMON           0x39    /**< Idle Mode ON */
+#define LCD_CMD_TEOFF           0x34    /**< Tearing Effect Line Off */
+#define LCD_CMD_TEON            0x35    /**< Tearing Effect Line On */
+#define LCD_CMD_COLMOD          0x3A    /**< Interface Pixel Format Set */
 #define LCD_CMD_PIXSET          0x3A    /**< COLMOD: Pixel Format Set */
 #define LCD_CMD_WRDISBV         0x51    /**< Write Display Brightness */
 #define LCD_CMD_WRCTRLD         0x53    /**< Write Control Display */

drivers/lcd/lcd.c

@@ -184,12 +184,9 @@ int lcd_init(lcd_t *dev, const lcd_params_t *params)
     }
     ztimer_sleep(ZTIMER_MSEC, 120);
 
-    if (dev->driver->init) {
-        return dev->driver->init(dev, params);
-    }
-    else {
-        return -ENOTSUP;
-    }
+    /* controller-specific init function has to be defined */
+    assert(dev->driver->init);
+    return dev->driver->init(dev, params);
 }
 
 void lcd_write_cmd(const lcd_t *dev, uint8_t cmd, const uint8_t *data,

drivers/st77xx/Kconfig.st7735

@@ -13,4 +13,72 @@ config MODULE_ST7735
     help
         ST7735 display controller is used
 
+if MODULE_ST7735
+
+menuconfig ST7735_CUSTOM_CONFIG
+    bool "ST7735 Custom Configuration"
+    help
+        Enable if customized configuration of voltages are needed. Otherwise
+        reset default values are used.
+
+if ST7735_CUSTOM_CONFIG
+
+config ST7735_AVDD
+    int "AVDD voltage (in millivolts)"
+    default 4900
+    range 4500 5100
+    help
+        Configure the AVDD voltage for analog circuits in millivolts.
+        Valid values must be in the range of 4500 (4.5V) to 5100 (5.1V)
+        in steps of 100.
+
+config ST7735_GVDD
+    int "GVDD voltage (in millivolts)"
+    default 4600
+    range 3150 4700
+    help
+        Configure the GVDD voltage, the gamma reference positive voltage.
+        Valid values must be in the range of 3150 (3.15V) to 4700 (4.7V)
+        in steps of 50.
+
+config ST7735_GVCL
+    int "GVCL voltage (in millivolts)"
+    default -4600
+    range -4700 -3150
+    help
+        Configure the GVCL voltage, the gamma reference negative voltage.
+        Valid values must be in the range of -4700 (-4.7V) to -3150 (-3.15V)
+        in steps of 50.
+
+config ST7735_VCOM
+    int "VCOM voltage (in millivolts)"
+    default -775
+    range -2000 -425
+    help
+        Configure the VCOM voltage. VCOM needs to be adjusted to match the
+        capacitance and performance specifications of the TFT panel to
+        maximize contrast and minimize flickering.
+        Valid values must be in the range of -2000 (-2.0V) to -425 (-0.425V)
+        in steps of 25.
+
+config ST7735_VGH
+    int "VGH voltage (in millivolts)"
+    default 14700
+    range 10000 15000
+    help
+        Configure the high voltage for gate drivers in millivolts.
+        Valid values must be in the range of 10000 (10V) to 15000 (15V) and
+        in the range of (2 * AVDD + 2.1V) and (3 * AVDD + 2.4 V).
+
+config ST7735_VGL
+    int "VGL voltage (in millivolts)"
+    default -10000
+    range -13000 -7500
+    help
+        Configure the low voltage for gate drivers in millivolts.
+        Valid values must be in the range of -13000 (-13V) to -7500 (-7.5V)
+        in steps of 2500.
+
+endif # ST7735_CUSTOM_CONFIG
+endif # MODULE_ST7735
 endif # MODULE_ST77XX