From cc19c02f860f96299ceccdfcaf1befb308c9fab8 Mon Sep 17 00:00:00 2001 From: hathach Date: Mon, 15 Sep 2025 15:47:06 +0700 Subject: dwc2: wait for ahb idle before core reset --- src/common/tusb_common.h | 4 ++-- src/portable/synopsys/dwc2/dwc2_common.c | 16 +++++++++++----- 2 files changed, 13 insertions(+), 7 deletions(-) (limited to 'src') diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h index 1fb93da11..e35d3e6fe 100644 --- a/src/common/tusb_common.h +++ b/src/common/tusb_common.h @@ -168,8 +168,8 @@ TU_ATTR_ALWAYS_INLINE static inline uint8_t tu_u16_high(uint16_t ui16) { return TU_ATTR_ALWAYS_INLINE static inline uint8_t tu_u16_low (uint16_t ui16) { return TU_U16_LOW(ui16); } //------------- Bits -------------// -TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_bit_set (uint32_t value, uint8_t pos) { return value | TU_BIT(pos); } -TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_bit_clear(uint32_t value, uint8_t pos) { return value & (~TU_BIT(pos)); } +TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_bit_set (uint32_t value, uint8_t pos) { return value | TU_BIT(pos); } +TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_bit_clear(uint32_t value, uint8_t pos) { return value & (~TU_BIT(pos)); } TU_ATTR_ALWAYS_INLINE static inline bool tu_bit_test (uint32_t value, uint8_t pos) { return (value & TU_BIT(pos)) ? true : false; } //------------- Min -------------// diff --git a/src/portable/synopsys/dwc2/dwc2_common.c b/src/portable/synopsys/dwc2/dwc2_common.c index d7d157149..5ff18ab94 100644 --- a/src/portable/synopsys/dwc2/dwc2_common.c +++ b/src/portable/synopsys/dwc2/dwc2_common.c @@ -45,20 +45,26 @@ // //-------------------------------------------------------------------- static void reset_core(dwc2_regs_t* dwc2) { + // The software must check that bit 31 in this register is set to 1 (AHB Master is Idle) before starting any operation + while (!(dwc2->grstctl & GRSTCTL_AHBIDL)) { + } + // load gsnpsid (it is not readable after reset is asserted) - uint32_t gsnpsid = dwc2->gsnpsid; + const uint32_t gsnpsid = dwc2->gsnpsid; // reset core dwc2->grstctl |= GRSTCTL_CSRST; if ((gsnpsid & DWC2_CORE_REV_MASK) < (DWC2_CORE_REV_4_20a & DWC2_CORE_REV_MASK)) { - // prior v4.20a CSRST is self-clearing + // prior v4.20a: CSRST is self-clearing and the core clears this bit after all the necessary logic is reset in + // the core, which can take several clocks, depending on the current state of the core. Once this bit has been + // cleared, the software must wait at least 3 PHY clocks before accessing the PHY domain (synchronization delay). while (dwc2->grstctl & GRSTCTL_CSRST) {} } else { - // From v4.20a CSRST bit is write only, CSRT_DONE (w1c) is introduced for checking. - // CSRST must also be explicitly cleared + // From v4.20a: CSRST bit is write only. The application must clear this bit after checking the bit 29 of this + // register i.e Core Soft Reset Done CSRT_DONE (w1c) while (!(dwc2->grstctl & GRSTCTL_CSRST_DONE)) {} - dwc2->grstctl = (dwc2->grstctl & ~GRSTCTL_CSRST) | GRSTCTL_CSRST_DONE; + dwc2->grstctl = (dwc2->grstctl & ~GRSTCTL_CSRST) | GRSTCTL_CSRST_DONE; } while (!(dwc2->grstctl & GRSTCTL_AHBIDL)) {} // wait for AHB master IDLE -- cgit v1.3.1