From d745c9fdb9bcd3c30e227e2135ad6cf9de2bd583 Mon Sep 17 00:00:00 2001
From: NIIBE Yutaka <gniibe@fsij.org>
Date: Thu, 16 Nov 2017 12:19:25 +0900
Subject: [PATCH] Only sleep mode can be used for USB suspend on STM32F103.

---
 chopstx-cortex-m.c  | 41 +++++++++++++++++++++--------------------
 mcu/usb-stm32f103.c | 15 ++++++++++++---
 2 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/chopstx-cortex-m.c b/chopstx-cortex-m.c
index e5ebb12..c341179 100644
--- a/chopstx-cortex-m.c
+++ b/chopstx-cortex-m.c
@@ -709,6 +709,7 @@ svc (void)
 }
 #endif
 
+#ifdef MCU_STM32F0 
 struct SCB
 {
   volatile uint32_t CPUID;
@@ -748,27 +749,27 @@ static struct PWR *const PWR = ((struct PWR *)0x40007000);
 void
 chx_sleep_mode (int how)
 {
-  if (how == 0)
-    ;
+  PWR->CR |= PWR_CR_CWUF;
+  PWR->CR &= ~(PWR_CR_PDDS|PWR_CR_LPDS);
+
+  if (how == 0 || how == 1 /* Sleep only (not deepsleep) */)
+    SCB->SCR &= ~SCB_SCR_SLEEPDEEP;
   else
-    {
-      if (how == 1)
-	/* sleep only */
-	SCB->SCR &= ~SCB_SCR_SLEEPDEEP;
-      else
-	{
-	  PWR->CR |= PWR_CR_CWUF;
+    {			   /* Deepsleep */
+      /* how == 2: deepsleep but regulator ON */
+      if (how == 3)
+	PWR->CR |= PWR_CR_LPDS;	/* regulator low-power mode */
+      else if (how == 4)
+	PWR->CR |= PWR_CR_PDDS;	/* Power down: All OFF     */
 
-	  if (how == 2 || how == 3)
-	    {
-	      PWR->CR &= ~PWR_CR_PDDS;
-	      if (how == 3)
-		PWR->CR |= PWR_CR_LPDS;
-	    }
-	  else /* how == 4 */
-	    PWR->CR |= PWR_CR_PDDS;
-
-	  SCB->SCR |= SCB_SCR_SLEEPDEEP;
-	}
+      SCB->SCR |= SCB_SCR_SLEEPDEEP;
     }
 }
+#else
+/* Deepsleep is only useful with RTC, Watch Dog, or WKUP pin.  */
+void
+chx_sleep_mode (int how)
+{
+  (void)how;
+}
+#endif
diff --git a/mcu/usb-stm32f103.c b/mcu/usb-stm32f103.c
index 77ffe55..e5a95d1 100644
--- a/mcu/usb-stm32f103.c
+++ b/mcu/usb-stm32f103.c
@@ -29,7 +29,6 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-#include "mcu/stm32f103.h"
 #include "sys-stm32f103.h"
 #include "usb_lld.h"
 #include "usb_lld_driver.h"
@@ -343,9 +342,19 @@ void usb_lld_init (struct usb_dev *dev, uint8_t feature)
   st103_set_cntr (CNTR_CTRM | CNTR_OVRM | CNTR_ERRM
 		  | CNTR_WKUPM | CNTR_SUSPM | CNTR_RESETM);
 
-  /* Setting of EXTI wakeup event to break sleep on WFE.    */
-  EXTI->RTSR |= (1 << 18);	/* Rising trigger selection */
+#if 0
+/*
+ * Since stop mode makes PLL, HSI & HES oscillators stop, USB clock is
+ * not supplied in stop mode.  Thus, USB wakeup can't occur.
+ *
+ * So, only sleep mode can be supported with USB, which doesn't
+ * require use of EXTI.
+ */
+#include "mcu/stm32f103.h"
+  /* Setting of EXTI wakeup event to break stop mode.       */
   EXTI->EMR  |= (1 << 18);	/* Event mask cleared       */
+  EXTI->RTSR |= (1 << 18);	/* Rising trigger selection */
+#endif
 }
 
 void usb_lld_prepare_shutdown (void)