target/stm32f7x: Clear stuck HSE clock with CSS

[fw/openocd] / tcl / target / stm32f7x.cfg

diff --git a/tcl/target/stm32f7x.cfg b/tcl/target/stm32f7x.cfg
index 16624670116e69e467314f0a321e23fd0cc9b6fa..562de30f6a1eb23e4f968351f733e93c591ea7a9 100755 (executable)
--- a/tcl/target/stm32f7x.cfg
+++ b/tcl/target/stm32f7x.cfg
@@ -36,22 +36,14 @@ if { [info exists CPUTAPID] } {
 }
 
 swj_newdap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf -expected-id $_CPUTAPID
-
-if { [info exists BSTAPID] } {
-   set _BSTAPID $BSTAPID
-} else {
-  # See STM Document RM0385
-  # Section 40.6.1
-  # STM32F75xxG
-  set _BSTAPID1 0x06449071
-}
+dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu
 
 if {[using_jtag]} {
- swj_newdap $_CHIPNAME bs -irlen 5 -expected-id $_BSTAPID1
+   jtag newtap $_CHIPNAME bs -irlen 5
 }
 
 set _TARGETNAME $_CHIPNAME.cpu
-target create $_TARGETNAME cortex_m -endian $_ENDIAN -chain-position $_TARGETNAME
+target create $_TARGETNAME cortex_m -endian $_ENDIAN -dap $_CHIPNAME.dap
 
 $_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
 
@@ -90,3 +82,66 @@ $_TARGETNAME configure -event trace-config {
        # assignment
        mmw 0xE0042004 0x00000020 0
 }
+
+$_TARGETNAME configure -event reset-init {
+       # If the HSE was previously enabled and the external clock source
+       # disappeared, RCC_CR.HSERDY can get stuck at 1 and the PLL cannot be
+       # properly switched back to HSI. This situation persists even over a system
+       # reset, including a pin reset via SRST. However, activating the clock
+       # security system will detect the problem and clear HSERDY to 0, which in
+       # turn allows the PLL to switch back to HSI properly. Since we just came
+       # out of reset, HSEON should be 0. If HSERDY is 1, then this situation must
+       # have happened; in that case, activate the clock security system to clear
+       # HSERDY.
+       if {[mrw 0x40023800] & 0x00020000} {
+               mmw 0x40023800 0x00090000 0 ;# RCC_CR = CSSON | HSEON
+               sleep 10                    ;# Wait for CSS to fire, if it wants to
+               mmw 0x40023800 0 0x00090000 ;# RCC_CR &= ~CSSON & ~HSEON
+               mww 0x4002380C 0x00800000   ;# RCC_CIR = CSSC
+               sleep 1                     ;# Wait for CSSF to clear
+       }
+
+       # If the clock security system fired, it will pend an NMI. A pending NMI
+       # will cause a bad time for any subsequent executing code, such as a
+       # programming algorithm.
+       if {[mrw 0xE000ED04] & 0x80000000} {
+               # ICSR.NMIPENDSET reads as 1. Need to clear it. A pending NMI can’t be
+               # cleared by any normal means (such as ICSR or NVIC). It can only be
+               # cleared by entering the NMI handler or by resetting the processor.
+               echo "[target current]: Clock security system generated NMI. Clearing."
+
+               # Keep the old DEMCR value.
+               set old [mrw 0xE000EDFC]
+
+               # Enable vector catch on reset.
+               mww 0xE000EDFC 0x01000001
+
+               # Issue local reset via AIRCR.
+               mww 0xE000ED0C 0x05FA0001
+
+               # Restore old DEMCR value.
+               mww 0xE000EDFC $old
+       }
+
+       # Configure PLL to boost clock to HSI x 10 (160 MHz)
+       mww 0x40023804 0x08002808   ;# RCC_PLLCFGR 16 Mhz /10 (M) * 128 (N) /2(P)
+       mww 0x40023C00 0x00000107   ;# FLASH_ACR = PRFTBE | 7(Latency)
+       mmw 0x40023800 0x01000000 0 ;# RCC_CR |= PLLON
+       sleep 10                    ;# Wait for PLL to lock
+       mww 0x40023808 0x00009400   ;# RCC_CFGR_PPRE1 = 5(div 4), PPRE2 = 4(div 2)
+       mmw 0x40023808 0x00000002 0 ;# RCC_CFGR |= RCC_CFGR_SW_PLL
+
+       # Boost SWD frequency
+       # Do not boost JTAG frequency and slow down JTAG memory access or flash write algo
+       # suffers from DAP WAITs
+       if {[using_jtag]} {
+               [[target current] cget -dap] memaccess 16
+       } {
+               adapter_khz 8000
+       }
+}
+
+$_TARGETNAME configure -event reset-start {
+       # Reduce speed since CPU speed will slow down to 16MHz with the reset
+       adapter_khz 2000
+}