From 6d8677a78ab4973ff498ec2fe8ea40a1cde230a1 Mon Sep 17 00:00:00 2001
From: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>
Date: Fri, 17 Sep 2021 11:41:58 +0200
Subject: [PATCH] dcd_da146xx: Add VBUS handling

DA146xx are Bluetooth devices that may be battery
powered and when not connected to USB host there
is no need for USB peripheral to be running.

This change allows to enable USB peripheral when
VBUS is present otherwise USB is down reducing
power consumption.

tud_vsub_changed() function must be called
whenever VBUS change was detected.
For bus-powered devices this function should be called
at startup since VBUS must be present while device
is working.
---
 src/portable/dialog/da146xx/dcd_da146xx.c | 65 +++++++++++++++++------
 1 file changed, 50 insertions(+), 15 deletions(-)

diff --git a/src/portable/dialog/da146xx/dcd_da146xx.c b/src/portable/dialog/da146xx/dcd_da146xx.c
index 7b0d8f86c..112cdb502 100644
--- a/src/portable/dialog/da146xx/dcd_da146xx.c
+++ b/src/portable/dialog/da146xx/dcd_da146xx.c
@@ -217,6 +217,7 @@ typedef struct {
 static struct
 {
   bool vbus_present;
+  bool init_called;
   bool in_reset;
   xfer_ctl_t xfer_status[EP_MAX][2];
   // Endpoints that use DMA, one for each direction
@@ -224,6 +225,7 @@ static struct
 } _dcd =
 {
   .vbus_present = false,
+  .init_called = false,
   .xfer_status =
   {
     { { .regs = EP_REGS(USB_EPC0_REG) }, { .regs = EP_REGS(USB_EPC0_REG) } },
@@ -735,19 +737,13 @@ static void handle_ep0_nak(void)
  *------------------------------------------------------------------*/
 void dcd_init(uint8_t rhport)
 {
-  USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk;
-  USB->USB_NFSR_REG = 0;
-  USB->USB_FAR_REG = 0x80;
-  USB->USB_NFSR_REG = NFSR_NODE_RESET;
-  USB->USB_TXMSK_REG = 0;
-  USB->USB_RXMSK_REG = 0;
+  (void) rhport;
 
-  USB->USB_MAMSK_REG = USB_USB_MAMSK_REG_USB_M_INTR_Msk |
-                       USB_USB_MAMSK_REG_USB_M_ALT_Msk |
-                       USB_USB_MAMSK_REG_USB_M_WARN_Msk;
-  USB->USB_ALTMSK_REG = USB_USB_ALTMSK_REG_USB_M_RESET_Msk;
-
-  dcd_connect(rhport);
+  _dcd.init_called = true;
+  if (_dcd.vbus_present)
+  {
+    dcd_connect(rhport);
+  }
 }
 
 void dcd_int_enable(uint8_t rhport)
@@ -783,10 +779,25 @@ void dcd_connect(uint8_t rhport)
 {
   (void)rhport;
 
-  REG_SET_BIT(USB_MCTRL_REG, USB_NAT);
+  if (GET_BIT(USB->USB_MCTRL_REG, USB_USB_MCTRL_REG_USB_NAT) == 0)
+  {
+    USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk;
+    USB->USB_NFSR_REG = 0;
+    USB->USB_FAR_REG = 0x80;
+    USB->USB_NFSR_REG = NFSR_NODE_RESET;
+    USB->USB_TXMSK_REG = 0;
+    USB->USB_RXMSK_REG = 0;
 
-  // Select chosen DMA to be triggered by USB.
-  DMA->DMA_REQ_MUX_REG = (DMA->DMA_REQ_MUX_REG & ~DA146XX_DMA_USB_MUX_MASK) | DA146XX_DMA_USB_MUX;
+    USB->USB_MAMSK_REG = USB_USB_MAMSK_REG_USB_M_INTR_Msk |
+                         USB_USB_MAMSK_REG_USB_M_ALT_Msk |
+                         USB_USB_MAMSK_REG_USB_M_WARN_Msk;
+    USB->USB_ALTMSK_REG = USB_USB_ALTMSK_REG_USB_M_RESET_Msk;
+
+    REG_SET_BIT(USB_MCTRL_REG, USB_NAT);
+
+    // Select chosen DMA to be triggered by USB.
+    DMA->DMA_REQ_MUX_REG = (DMA->DMA_REQ_MUX_REG & ~DA146XX_DMA_USB_MUX_MASK) | DA146XX_DMA_USB_MUX;
+  }
 }
 
 void dcd_disconnect(uint8_t rhport)
@@ -796,6 +807,30 @@ void dcd_disconnect(uint8_t rhport)
   REG_CLR_BIT(USB_MCTRL_REG, USB_NAT);
 }
 
+TU_ATTR_ALWAYS_INLINE static inline bool is_in_isr(void)
+{
+  return (SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk) != 0;
+}
+
+void tusb_vbus_changed(bool present)
+{
+  if (present && !_dcd.vbus_present)
+  {
+    _dcd.vbus_present = true;
+    // If power event happened before USB started, delay dcd_connect
+    // until dcd_init is called.
+    if (_dcd.init_called)
+    {
+      dcd_connect(0);
+    }
+  }
+  else if (!present && _dcd.vbus_present)
+  {
+    _dcd.vbus_present = false;
+    USB->USB_MCTRL_REG = 0;
+    dcd_event_bus_signal(0, DCD_EVENT_UNPLUGGED, is_in_isr());
+  }
+}
 
 /*------------------------------------------------------------------*/
 /* DCD Endpoint port