Add support for CST716/CST718S touch sensor used in P8

src/CMakeLists.txt

@@ -652,6 +652,7 @@ set(INCLUDE_FILES
         components/timer/Timer.h
         components/alarm/AlarmController.h
         drivers/Cst816s.h
+        drivers/Cst816s_registers.h
         FreeRTOS/portmacro.h
         FreeRTOS/portmacro_cmsis.h
         displayapp/LittleVgl.h
@@ -794,23 +795,28 @@ add_definitions(-DTARGET_DEVICE_NAME="${TARGET_DEVICE}")
 if(TARGET_DEVICE STREQUAL "PINETIME")
   add_definitions(-DDRIVER_PINMAP_PINETIME)
   add_definitions(-DCLOCK_CONFIG_LF_SRC=1) # XTAL
+  add_definitions(-DDRIVER_TOUCH_DYNAMIC)
 elseif(TARGET_DEVICE STREQUAL "MOY_TFK5") # P8a
   add_definitions(-DDRIVER_PINMAP_P8)
   add_definitions(-DCLOCK_CONFIG_LF_SRC=1) # XTAL
+  add_definitions(-DDRIVER_TOUCH_GESTURE)
 elseif(TARGET_DEVICE STREQUAL "MOY_TIN5") # P8a variant 2
   add_definitions(-DDRIVER_PINMAP_P8)
   add_definitions(-DCLOCK_CONFIG_LF_SRC=1) # XTAL
+  add_definitions(-DDRIVER_TOUCH_GESTURE)
 elseif(TARGET_DEVICE STREQUAL "MOY_TON5") # P8b
   add_definitions(-DDRIVER_PINMAP_P8)
   add_definitions(-DCLOCK_CONFIG_LF_SRC=0) # RC
   add_definitions(-DMYNEWT_VAL_BLE_LL_SCA=500)
   add_definitions(-DCLOCK_CONFIG_LF_CAL_ENABLED=1)
+  add_definitions(-DDRIVER_TOUCH_REPORT)
 elseif(TARGET_DEVICE STREQUAL "MOY_UNK") # P8b mirrored
   add_definitions(-DDRIVER_PINMAP_P8)
   add_definitions(-DCLOCK_CONFIG_LF_SRC=0) # RC
   add_definitions(-DMYNEWT_VAL_BLE_LL_SCA=500)
   add_definitions(-DCLOCK_CONFIG_LF_CAL_ENABLED=1)
   add_definitions(-DDRIVER_DISPLAY_MIRROR)
+  add_definitions(-DDRIVER_TOUCH_REPORT)
 else()
   message(FATAL_ERROR "Invalid TARGET_DEVICE")
 endif()

src/displayapp/LittleVgl.cpp

@@ -260,11 +260,23 @@ void LittleVgl::CancelTap() {
   }
 }
 
+void LittleVgl::SetNewTap(int16_t x, int16_t y) {
+  touchPoint = {x, y};
+  tapped = true;
+  simulate_tap_release = true;
+}
+
 bool LittleVgl::GetTouchPadInfo(lv_indev_data_t* ptr) {
   ptr->point.x = touchPoint.x;
   ptr->point.y = touchPoint.y;
   if (tapped) {
     ptr->state = LV_INDEV_STATE_PR;
+    if (simulate_tap_release) {
+      // If a tap consists of only a single event, enqueue a synthetic release state update
+      tapped = false;
+      simulate_tap_release = false;
+      return true;
+    }
   } else {
     ptr->state = LV_INDEV_STATE_REL;
   }

src/displayapp/LittleVgl.h

@@ -26,6 +26,7 @@ namespace Pinetime {
       void SetFullRefresh(FullRefreshDirections direction);
       void SetNewTouchPoint(int16_t x, int16_t y, bool contact);
       void CancelTap();
+      void SetNewTap(int16_t x, int16_t y);
 
       bool GetFullRefresh() {
         bool returnValue = fullRefresh;
@@ -65,6 +66,7 @@ namespace Pinetime {
       lv_point_t touchPoint = {};
       bool tapped = false;
       bool isCancelled = false;
+      bool simulate_tap_release = false;
     };
   }
 }

src/drivers/Cst816s.cpp

@@ -1,130 +1,107 @@
 #include "drivers/Cst816s.h"
+#include "drivers/PinMap.h"
 #include <FreeRTOS.h>
 #include <legacy/nrf_drv_gpiote.h>
 #include <nrfx_log.h>
 #include <task.h>
-#include "drivers/PinMap.h"
 
 using namespace Pinetime::Drivers;
 
-/* References :
+/*
+ * References :
  * This implementation is based on this article :
  * https://medium.com/@ly.lee/building-a-rust-driver-for-pinetimes-touch-controller-cbc1a5d5d3e9 Touch panel datasheet (weird chinese
  * translation) : https://wiki.pine64.org/images/5/51/CST816S%E6%95%B0%E6%8D%AE%E6%89%8B%E5%86%8CV1.1.en.pdf
  *
- * TODO : we need a complete datasheet and protocol reference!
+ * TODO: We need a complete datasheet and protocol reference!
+ * For register desciptions, see Cst816s_registers.h. Information was collected from various chinese datasheets and documents.
  * */
 
 Cst816S::Cst816S(TwiMaster& twiMaster, uint8_t twiAddress) : twiMaster {twiMaster}, twiAddress {twiAddress} {
 }
 
 bool Cst816S::Init() {
+  // Reset the touch driver
   nrf_gpio_cfg_output(PinMap::Cst816sReset);
   nrf_gpio_pin_clear(PinMap::Cst816sReset);
-  vTaskDelay(5);
+  vTaskDelay(10);
   nrf_gpio_pin_set(PinMap::Cst816sReset);
   vTaskDelay(50);
 
-  // Wake the touchpanel up
-  uint8_t dummy;
-  twiMaster.Read(twiAddress, 0x15, &dummy, 1);
-  vTaskDelay(5);
-  twiMaster.Read(twiAddress, 0xa7, &dummy, 1);
-  vTaskDelay(5);
-
-  // TODO This function check that the device IDs from the controller are equal to the ones
-  // we expect. However, it seems to return false positive (probably in case of communication issue).
-  // Also, it seems that some users have pinetimes that works correctly but that report different device IDs
-  // Until we know more about this, we'll just read the IDs but not take any action in case they are not 'valid'
-  CheckDeviceIds();
-
-  /*
-  [2] EnConLR - Continuous operation can slide around
-  [1] EnConUD - Slide up and down to enable continuous operation
-  [0] EnDClick - Enable Double-click action
-  */
-  static constexpr uint8_t motionMask = 0b00000101;
-  twiMaster.Write(twiAddress, 0xEC, &motionMask, 1);
-
-  /*
-  [7] EnTest - Interrupt pin to test, enable automatic periodic issued after a low pulse.
-  [6] EnTouch - When a touch is detected, a periodic pulsed Low.
-  [5] EnChange - Upon detecting a touch state changes, pulsed Low.
-  [4] EnMotion - When the detected gesture is pulsed Low.
-  [0] OnceWLP - Press gesture only issue a pulse signal is low.
-  */
-  static constexpr uint8_t irqCtl = 0b01110000;
-  twiMaster.Write(twiAddress, 0xFA, &irqCtl, 1);
+  // Chip ID is suspected to be dependent on embedded firmware and factory configuration,
+  // and not (just) on hardware type and revision.
+  if (twiMaster.Read(twiAddress, CHIP_ID, &chipId, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
+    chipId = 0xFF;
+  }
+  // Vendor / project ID and firmware version can vary between devices.
+  if (twiMaster.Read(twiAddress, PROJ_ID, &vendorId, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
+    vendorId = 0xFF;
+  }
+  if (twiMaster.Read(twiAddress, FW_VERSION, &fwVersion, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
+    fwVersion = 0xFF;
+  }
+
+  // These configuration settings will be ignored by chips which were
+  // fused / pre-configured in the factory (GESTURE and REPORT settings).
+  // This mainly applies to CST716, however there may be CST816S with static configurations as well.
+  // The other, freely configureable ones (DYNAMIC), are configured in reporting mode here.
+
+  // Configure motion behaviour
+  static constexpr uint8_t motionMask = MOTION_MASK_EN_DCLICK | MOTION_MASK_EN_CON_UD | MOTION_MASK_EN_CON_LR;
+  twiMaster.Write(twiAddress, MOTION_MASK, &motionMask, 1);
+
+  // Configure interrupt generating events
+  static constexpr uint8_t irqCtl = IRQ_CTL_EN_MOTION | IRQ_CTL_EN_CHANGE | IRQ_CTL_EN_TOUCH;
+  twiMaster.Write(twiAddress, IRQ_CTL, &irqCtl, 1);
 
   return true;
 }
 
 Cst816S::TouchInfos Cst816S::GetTouchInfo() {
-  Cst816S::TouchInfos info;
-  uint8_t touchData[7];
-
-  auto ret = twiMaster.Read(twiAddress, 0, touchData, sizeof(touchData));
-  if (ret != TwiMaster::ErrorCodes::NoError) {
-    info.isValid = false;
-    return info;
+  // Some chips fail to wake up even though the reset pin has been toggled.
+  // They only provide an I2C communication window after a touch interrupt,
+  // so the first touch interrupt is used to force initialisation.
+  if (firstEvent) {
+    Init();
+    firstEvent = false;
+    // The data registers should now be reset, so this touch event will be detected as invalid.
   }
 
-  // This can only be 0 or 1
-  uint8_t nbTouchPoints = touchData[touchPointNumIndex] & 0x0f;
-  uint8_t xHigh = touchData[touchXHighIndex] & 0x0f;
-  uint8_t xLow = touchData[touchXLowIndex];
-  uint16_t x = (xHigh << 8) | xLow;
-  uint8_t yHigh = touchData[touchYHighIndex] & 0x0f;
-  uint8_t yLow = touchData[touchYLowIndex];
-  uint16_t y = (yHigh << 8) | yLow;
-  Gestures gesture = static_cast<Gestures>(touchData[gestureIndex]);
-
-  // Validity check
-  if (x >= maxX || y >= maxY ||
-      (gesture != Gestures::None && gesture != Gestures::SlideDown && gesture != Gestures::SlideUp && gesture != Gestures::SlideLeft &&
-       gesture != Gestures::SlideRight && gesture != Gestures::SingleTap && gesture != Gestures::DoubleTap &&
-       gesture != Gestures::LongPress)) {
-    info.isValid = false;
+  // Read gesture metadata and first touch point coordinate block
+  Cst816S::TouchInfos info;
+  uint8_t touchData[P1_Y_POS_L + 1];
+  auto ret = twiMaster.Read(twiAddress, 0x00, touchData, sizeof(touchData));
+  if (ret != TwiMaster::ErrorCodes::NoError)
     return info;
-  }
 
-  info.x = x;
-  info.y = y;
-  info.touching = (nbTouchPoints > 0);
-  info.gesture = gesture;
-  info.isValid = true;
+  // Assemble 12 bit point coordinates from lower 8 bits and higher 4 bits
+  info.x = ((touchData[P1_X_POS_H] & POS_H_POS_MASK) << 8) | touchData[P1_X_POS_L];
+  info.y = ((touchData[P1_Y_POS_H] & POS_H_POS_MASK) << 8) | touchData[P1_Y_POS_L];
+  // Evaluate number of touch points
+  info.touching = (touchData[TD_STATUS] & TD_STATUS_MASK) > 0;
+  // Decode gesture ID
+  info.gesture = static_cast<Gestures>(touchData[GESTURE_ID]);
+
+  // Validity check, verify value ranges
+  info.isValid = (info.x < maxX && info.y < maxY &&
+                  (info.gesture == Gestures::None || info.gesture == Gestures::SlideDown || info.gesture == Gestures::SlideUp ||
+                   info.gesture == Gestures::SlideLeft || info.gesture == Gestures::SlideRight || info.gesture == Gestures::SingleTap ||
+                   info.gesture == Gestures::DoubleTap || info.gesture == Gestures::LongPress));
+
   return info;
 }
 
 void Cst816S::Sleep() {
-  nrf_gpio_pin_clear(PinMap::Cst816sReset);
-  vTaskDelay(5);
-  nrf_gpio_pin_set(PinMap::Cst816sReset);
-  vTaskDelay(50);
-  static constexpr uint8_t sleepValue = 0x03;
-  twiMaster.Write(twiAddress, 0xA5, &sleepValue, 1);
+  // This only controls the CST716, the CST816S will ignore this register.
+  // The CST816S power state is managed using auto-sleep.
+
+  static constexpr uint8_t sleepValue = PWR_MODE_DEEP_SLEEP;
+  twiMaster.Write(twiAddress, PWR_MODE_CST716, &sleepValue, 1);
+
   NRF_LOG_INFO("[TOUCHPANEL] Sleep");
 }
 
 void Cst816S::Wakeup() {
   Init();
   NRF_LOG_INFO("[TOUCHPANEL] Wakeup");
 }
-
-bool Cst816S::CheckDeviceIds() {
-  // There's mixed information about which register contains which information
-  if (twiMaster.Read(twiAddress, 0xA7, &chipId, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
-    chipId = 0xFF;
-    return false;
-  }
-  if (twiMaster.Read(twiAddress, 0xA8, &vendorId, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
-    vendorId = 0xFF;
-    return false;
-  }
-  if (twiMaster.Read(twiAddress, 0xA9, &fwVersion, 1) == TwiMaster::ErrorCodes::TransactionFailed) {
-    fwVersion = 0xFF;
-    return false;
-  }
-
-  return chipId == 0xb4 && vendorId == 0 && fwVersion == 1;
-}

src/drivers/Cst816s.h

@@ -1,20 +1,22 @@
 #pragma once
 
+#include "drivers/Cst816s_registers.h"
 #include "drivers/TwiMaster.h"
 
 namespace Pinetime {
   namespace Drivers {
     class Cst816S {
     public:
       enum class Gestures : uint8_t {
-        None = 0x00,
-        SlideDown = 0x01,
-        SlideUp = 0x02,
-        SlideLeft = 0x03,
-        SlideRight = 0x04,
-        SingleTap = 0x05,
-        DoubleTap = 0x0B,
-        LongPress = 0x0C
+        None = GESTURE_ID_NONE,
+        SlideDown = GESTURE_ID_SLIDE_DOWN,
+        SlideUp = GESTURE_ID_SLIDE_UP,
+        SlideLeft = GESTURE_ID_SLIDE_LEFT,
+        SlideRight = GESTURE_ID_SLIDE_RIGHT,
+        SingleTap = GESTURE_ID_SINGLE_TAP,
+        DoubleTap = GESTURE_ID_DOUBLE_TAP,
+        LongPress = GESTURE_ID_LONG_PRESS,
+        Invalid = 0xFF
       };
 
       struct TouchInfos {
@@ -49,21 +51,6 @@ namespace Pinetime {
       }
 
     private:
-      bool CheckDeviceIds();
-
-      // Unused/Unavailable commented out
-      static constexpr uint8_t gestureIndex = 1;
-      static constexpr uint8_t touchPointNumIndex = 2;
-      // static constexpr uint8_t touchEventIndex = 3;
-      static constexpr uint8_t touchXHighIndex = 3;
-      static constexpr uint8_t touchXLowIndex = 4;
-      // static constexpr uint8_t touchIdIndex = 5;
-      static constexpr uint8_t touchYHighIndex = 5;
-      static constexpr uint8_t touchYLowIndex = 6;
-      // static constexpr uint8_t touchStep = 6;
-      // static constexpr uint8_t touchXYIndex = 7;
-      // static constexpr uint8_t touchMiscIndex = 8;
-
       static constexpr uint8_t maxX = 240;
       static constexpr uint8_t maxY = 240;
 
@@ -73,6 +60,8 @@ namespace Pinetime {
       uint8_t chipId;
       uint8_t vendorId;
       uint8_t fwVersion;
+
+      bool firstEvent = true;
     };
 
   }