portable/chipidea: configure LPC USB0 AHB bursts

3 files changed, 22 insertions, 0 deletions

diff --git a/src/portable/chipidea/ci_hs/ci_hs_lpc18_43.h b/src/portable/chipidea/ci_hs/ci_hs_lpc18_43.h
index f2061bd7a..dec3a34b1 100644
--- a/src/portable/chipidea/ci_hs/ci_hs_lpc18_43.h
+++ b/src/portable/chipidea/ci_hs/ci_hs_lpc18_43.h
@@ -34,4 +34,18 @@ static const ci_hs_controller_t _ci_controller[] =
 #define CI_HCD_INT_ENABLE(_p)   NVIC_EnableIRQ ((IRQn_Type)_ci_controller[_p].irqnum)
 #define CI_HCD_INT_DISABLE(_p)  NVIC_DisableIRQ((IRQn_Type)_ci_controller[_p].irqnum)
 
+enum {
+  CI_HS_LPC18_43_SBUSCFG_OFFSET        = 0x90u,
+  CI_HS_LPC18_43_AHBBRST_INCR16_UNSPEC = 0x07u,
+};
+
+TU_ATTR_ALWAYS_INLINE static inline void ci_hs_lpc18_43_set_ahb_burst(uint8_t rhport) {
+  // USB0 SBUSCFG is at offset 0x90. NXP recommends AHBBRST=0x7:
+  // INCR16 with non-multiple transfers decomposed into smaller unspecified bursts.
+  if (rhport == 0) {
+    volatile uint32_t *sbuscfg = (volatile uint32_t *)(_ci_controller[rhport].reg_base + CI_HS_LPC18_43_SBUSCFG_OFFSET);
+    *sbuscfg = CI_HS_LPC18_43_AHBBRST_INCR16_UNSPEC;
+  }
+}
+
 #endif
diff --git a/src/portable/chipidea/ci_hs/dcd_ci_hs.c b/src/portable/chipidea/ci_hs/dcd_ci_hs.c
index fa98d6882..32c701bfa 100644
--- a/src/portable/chipidea/ci_hs/dcd_ci_hs.c
+++ b/src/portable/chipidea/ci_hs/dcd_ci_hs.c
@@ -237,6 +237,10 @@ bool dcd_init(uint8_t rhport, const tusb_rhport_init_t *rh_init) {
   usbmode |= USBMODE_CM_DEVICE;
   dcd_reg->USBMODE = usbmode;
 
+  #if TU_CHECK_MCU(OPT_MCU_LPC18XX, OPT_MCU_LPC43XX)
+  ci_hs_lpc18_43_set_ahb_burst(rhport);
+  #endif
+
   #ifdef CFG_TUD_CI_HS_VBUS_CHARGE
   dcd_reg->OTGSC = OTGSC_VBUS_CHARGE | OTGSC_OTG_TERMINATION;
   #else
diff --git a/src/portable/chipidea/ci_hs/hcd_ci_hs.c b/src/portable/chipidea/ci_hs/hcd_ci_hs.c
index 3cb69acfa..c94ce810f 100644
--- a/src/portable/chipidea/ci_hs/hcd_ci_hs.c
+++ b/src/portable/chipidea/ci_hs/hcd_ci_hs.c
@@ -82,6 +82,10 @@ bool hcd_init(uint8_t rhport, const tusb_rhport_init_t *rh_init) {
   hcd_reg->USBMODE = USBMODE_CM_HOST;
   #endif
 
+  #if TU_CHECK_MCU(OPT_MCU_LPC18XX, OPT_MCU_LPC43XX)
+  ci_hs_lpc18_43_set_ahb_burst(rhport);
+  #endif
+
   #if !TUH_OPT_HIGH_SPEED
   hcd_reg->PORTSC1 |= PORTSC1_FORCE_FULL_SPEED;
   #endif