Power optimization - Improve SPI sleep mode

ST7789 driver : replace the constant '26' with a named constant to specify the pin number of the reset pin of the LCD controller.

Author: JF002

src/drivers/PinMap.h

@@ -34,6 +34,7 @@ namespace Pinetime {
     static constexpr uint8_t SpiFlashCsn = 5;
     static constexpr uint8_t SpiLcdCsn = 25;
     static constexpr uint8_t LcdDataCommand = 18;
+    static constexpr uint8_t LcdReset = 26;
 
     static constexpr uint8_t TwiScl = 7;
     static constexpr uint8_t TwiSda = 6;

src/drivers/St7789.cpp

@@ -6,13 +6,13 @@
 
 using namespace Pinetime::Drivers;
 
-St7789::St7789(Spi& spi, uint8_t pinDataCommand) : spi {spi}, pinDataCommand {pinDataCommand} {
+St7789::St7789(Spi& spi, uint8_t pinDataCommand, uint8_t pinReset) : spi {spi}, pinDataCommand {pinDataCommand}, pinReset{pinReset} {
 }
 
 void St7789::Init() {
   nrf_gpio_cfg_output(pinDataCommand);
-  nrf_gpio_cfg_output(26);
-  nrf_gpio_pin_set(26);
+  nrf_gpio_cfg_output(pinReset);
+  nrf_gpio_pin_set(pinReset);
   HardwareReset();
   SoftwareReset();
   SleepOut();
@@ -178,15 +178,15 @@ void St7789::DrawBuffer(uint16_t x, uint16_t y, uint16_t width, uint16_t height,
 }
 
 void St7789::HardwareReset() {
-  nrf_gpio_pin_clear(26);
+  nrf_gpio_pin_clear(pinReset);
   nrf_delay_ms(10);
-  nrf_gpio_pin_set(26);
+  nrf_gpio_pin_set(pinReset);
 }
 
 void St7789::Sleep() {
   SleepIn();
   nrf_gpio_cfg_default(pinDataCommand);
-  nrf_gpio_cfg_default(26);
+  nrf_gpio_cfg_default(pinReset);
   NRF_LOG_INFO("[LCD] Sleep");
 }
 

src/drivers/St7789.h

@@ -8,7 +8,7 @@ namespace Pinetime {
 
     class St7789 {
     public:
-      explicit St7789(Spi& spi, uint8_t pinDataCommand);
+      explicit St7789(Spi& spi, uint8_t pinDataCommand, uint8_t pinReset);
       St7789(const St7789&) = delete;
       St7789& operator=(const St7789&) = delete;
       St7789(St7789&&) = delete;
@@ -29,6 +29,7 @@ namespace Pinetime {
     private:
       Spi& spi;
       uint8_t pinDataCommand;
+      uint8_t pinReset;
       uint8_t verticalScrollingStartAddress = 0;
 
       void HardwareReset();

src/main.cpp

@@ -68,7 +68,7 @@ Pinetime::Drivers::SpiMaster spi {Pinetime::Drivers::SpiMaster::SpiModule::SPI0,
                                    Pinetime::PinMap::SpiMiso}};
 
 Pinetime::Drivers::Spi lcdSpi {spi, Pinetime::PinMap::SpiLcdCsn};
-Pinetime::Drivers::St7789 lcd {lcdSpi, Pinetime::PinMap::LcdDataCommand};
+Pinetime::Drivers::St7789 lcd {lcdSpi, Pinetime::PinMap::LcdDataCommand, Pinetime::PinMap::LcdReset};
 
 Pinetime::Drivers::Spi flashSpi {spi, Pinetime::PinMap::SpiFlashCsn};
 Pinetime::Drivers::SpiNorFlash spiNorFlash {flashSpi};