#
# Copyright (C)   2010-2011   by Karl Kurbjun
# Copyright (C)   2009-2011   by Øyvind Harboe
# Copyright (C)   2009        by David Brownell
# Copyright (C)   2009        by Magnus Lundin
#
# TI AM/DM37x
#  http://www.ti.com/litv/pdf/sprugn4b
#
# This script is based on the AM3517 initialization.  It should be considered
# preliminary since it needs more complete testing and only the basic
# operations work.
#

###############################################################################
# User modifiable parameters
###############################################################################

# This script uses the variable CHIPTYPE to determine whether this is an AM35x
# or DM37x target. If CHIPTYPE is not set it will error out.
if { [info exists CHIPTYPE] } {

   if { [info exists CHIPNAME] } {
      set _CHIPNAME $CHIPNAME
   } else {
      set _CHIPNAME $CHIPTYPE
   }

   switch $CHIPTYPE {
      dm37x {
         # Primary TAP: ICEpick-C (JTAG route controller) and boundary scan
         set _JRC_TAPID "-expected-id 0x2b89102f -expected-id 0x1b89102f -expected-id 0x0b89102f"
      }
      am35x {
         # Primary TAP: ICEpick-C (JTAG route controller) and boundary scan
         set _JRC_TAPID "-expected-id 0x0b7ae02f"
      }
      default {
         error "ERROR: CHIPTYPE was set, but it was not set to a valid value.  Acceptable values are \"dm37x\" or \"am35x\"."
      }
   }
} else {
  error "ERROR: CHIPTYPE was not defined. Please set CHIPTYPE to \"am35x\" for the AM35x or \"dm37x\" for the DM37x series in the board configuration."
}

# Run the adapter at the fastest acceptable speed with the slowest possible
# core clock.
adapter_khz 10

###############################################################################
# JTAG setup
# The OpenOCD commands are described in the TAP Declaration section
#  http://openocd.berlios.de/doc/html/TAP-Declaration.html
###############################################################################

# The AM/DM37x has an ICEpick module in it like many of TI's other devices. More
#  can be read about this module in sprugn4b under chapter 27:  "Debug and
#  Emulation".  The module is used to route the JTAG chain to the various
#  subsystems in the chip.
source [find target/icepick.cfg]

# The TAP order should be described from the TDO connection in OpenOCD to the
#  TDI pin.  The OpenOCD FAQ describes this in more detail:
#  http://openocd.berlios.de/doc/html/FAQ.html

# From SPRUGN4B CH27 the available secondary TAPs are in this order from TDO:
#
#  Device   |  TAP number
#  ---------|------------
#  DAP      |  3
#  Sequencer|  2   Note: The sequencer is an ARM968
#  DSP      |  1
#  D2D      |  0
#
# Right now the only secondary tap enabled is the DAP so the rest are left
# undescribed.

######
# Start of Chain Description
# The Secondary TAPs all have enable functions defined for use with the ICEpick
# Only the DAP is enabled.  The AM37xx does not have the Sequencer or DSP but
# the TAP numbers for ICEpick do not change.
#
# TODO: A disable function should also be added.
######

# Secondary TAP: DAP is closest to the TDO output
# The TAP enable event also needs to be described
jtag newtap $_CHIPNAME dap -irlen 4 -ircapture 0x1 -irmask 0xf -disable
jtag configure $_CHIPNAME.dap -event tap-enable \
   "icepick_c_tapenable $_CHIPNAME.jrc 3"

# These taps are only present in the DM37x series.
if { $CHIPTYPE == "dm37x" } {
   # Secondary TAP: Sequencer (ARM968) it is not in the chain by default
   # The ICEpick can be used to enable it in the chain.
   jtag newtap $_CHIPNAME arm2 -irlen 4 -ircapture 0x1 -irmask 0x0f -disable
   jtag configure $_CHIPNAME.arm2 -event tap-enable \
      "icepick_c_tapenable $_CHIPNAME.jrc 2"

   # Secondary TAP: C64x+ DSP - it is not in the chain by default (-disable)
   # The ICEpick can be used to enable it in the chain.
   jtag newtap $_CHIPNAME dsp -irlen 38 -ircapture 0x25 -irmask 0x3f -disable
   jtag configure $_CHIPNAME.dsp -event tap-enable \
      "icepick_c_tapenable $_CHIPNAME.jrc 1"
}

# Secondary TAP: D2D it is not in the chain by default (-disable)
# The ICEpick can be used to enable it in the chain.
# This IRLEN is probably incorrect - not sure where the documentation is.
jtag newtap $_CHIPNAME d2d -irlen 4 -ircapture 0x1 -irmask 0x0f -disable
jtag configure $_CHIPNAME.d2d -event tap-enable \
   "icepick_c_tapenable $_CHIPNAME.jrc 0"

# Primary TAP: ICEpick - it is closest to TDI so last in the chain
eval "jtag newtap $_CHIPNAME jrc -irlen 6 -ircapture 0x1 -irmask 0x3f $_JRC_TAPID"

######
# End of Chain Description
######

######
# Start JTAG TAP events
######

# some TCK tycles are required to activate the DEBUG power domain
jtag configure $_CHIPNAME.jrc -event post-reset "runtest 100"

# Enable the DAP TAP
jtag configure $_CHIPNAME.jrc -event setup "jtag tapenable $_CHIPNAME.dap"

######
# End JTAG TAP events
######

###############################################################################
# Target Setup:
# This section is described in the OpenOCD documentation under CPU Configuration
#  http://openocd.berlios.de/doc/html/CPU-Configuration.html
###############################################################################

# Create the CPU target to be used with GDB:  Cortex-A8, using DAP
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME cortex_a8 -chain-position $_CHIPNAME.dap

# The DM37x has 64K of SRAM starting at address 0x4020_0000.  Allow the first
# 16K to be used as a scratchpad for OpenOCD.

$_TARGETNAME configure -work-area-phys 0x40200000 -work-area-size 0x4000

######
# Start Target Reset Event Setup:
######

# Set the JTAG clock down to 10 kHz to be sure that it will work with the
#  slowest possible core clock (16.8MHz/2 = 8.4MHz). It is OK to speed up
#  *after* PLL and clock tree setup.

$_TARGETNAME configure -event "reset-start" { adapter_khz 10 }

# Describe the reset assert process for openocd - this is asserted with the
# ICEPick
$_TARGETNAME configure -event "reset-assert" {

   global _CHIPNAME

   # assert warm system reset through ICEPick
   icepick_c_wreset $_CHIPNAME.jrc
}

# After the reset is asserted we need to re-initialize debugging and speed up
# the JTAG clock.

$_TARGETNAME configure -event reset-assert-post {

   global _TARGETNAME
   amdm37x_dbginit $_TARGETNAME
   adapter_khz 1000
}

$_TARGETNAME configure -event gdb-attach {

   global _TARGETNAME
   amdm37x_dbginit $_TARGETNAME

   echo "Halting target"
   halt
}

######
# End Target Reset Event Setup:
######

###############################################################################
# Target Functions
# Add any functions needed for the target here
###############################################################################

# Run this to enable invasive debugging.  This is run automatically in the
# reset sequence.
proc amdm37x_dbginit {target} {
   # General Cortex A8 debug initialisation
   cortex_a8 dbginit

   # Enable DBGEN signal.  This signal is described in the ARM v7 TRM, but
   # access to the signal appears to be implementation specific.  TI does not
   # describe this register much except a quick line that states DBGEM (sic) is
   # at this address and this bit.
   $target mww phys 0x5401d030 0x00002000
}

