tcl: Add default hooks for STM32F4x

Set up PLL and increase clock at reset init.

Change-Id: I611bc6fb7c0c5afd8ed3f4ad8e64f3c7b981d31c
Signed-off-by: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Reviewed-on: http://openocd.zylin.com/2609


Tested-by: jenkins
Reviewed-by: Rémi PRUD'HOMME <prudhomme.remi@gmail.com>
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

tcl/target/stm32f4x.cfg

@@ -92,6 +92,7 @@ if {![using_hla]} {
 }
 
 $_TARGETNAME configure -event examine-end {
+	# Enable debug during low power modes (uses more power)
 	# DBGMCU_CR |= DBG_STANDBY | DBG_STOP | DBG_SLEEP
 	mmw 0xE0042004 0x00000007 0
 
@@ -106,3 +107,16 @@ $_TARGETNAME configure -event trace-config {
 	# assignment
 	mmw 0xE0042004 0x00000020 0
 }
+
+$_TARGETNAME configure -event reset-init {
+	# Configure PLL to boost clock to HSI x 4 (64 MHz)
+	mww 0x40023804 0x08012008   ;# RCC_PLLCFGR 16 Mhz /8 (M) * 128 (N) /4(P)
+	mww 0x40023C00 0x00000102   ;# FLASH_ACR = PRFTBE | 2(Latency)
+	mmw 0x40023800 0x01000000 0 ;# RCC_CR |= PLLON
+	sleep 10                    ;# Wait for PLL to lock
+	mmw 0x40023808 0x00001000 0 ;# RCC_CFGR |= RCC_CFGR_PPRE1_DIV2
+	mmw 0x40023808 0x00000002 0 ;# RCC_CFGR |= RCC_CFGR_SW_PLL
+
+	# Boost JTAG frequency
+	adapter_khz 8000
+}