X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=tcl%2Finterface%2Fraspberrypi-native.cfg;h=2d0547f310d1b70f3f2b3949d77cffa6df3d70ec;hp=6d5c3bfd4936c9eeffb33d3f80a5a3d28cc007c7;hb=HEAD;hpb=3bccc77999175494ceb534c172475e509ff99189

diff --git a/tcl/interface/raspberrypi-native.cfg b/tcl/interface/raspberrypi-native.cfg
index 6d5c3bfd49..7224723d63 100644
--- a/tcl/interface/raspberrypi-native.cfg
+++ b/tcl/interface/raspberrypi-native.cfg
@@ -1,40 +1,71 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-#
-# Config for using Raspberry Pi's expansion header
-#
-# This is best used with a fast enough buffer but also
-# is suitable for direct connection if the target voltage
-# matches RPi's 3.3V and the cable is short enough.
-#
-# Do not forget the GND connection, pin 6 of the expansion header.
-#
+# Config for Raspberry Pi used as a bitbang adapter.
+# https://www.raspberrypi.com/documentation/computers/raspberry-pi.html
+
+# Supports all models with 40-pin or 26-pin GPIO connector up to Raspberry Pi 4 B
+# also supports Raspberry Pi Zero, Zero W and Zero 2 W.
+
+# Adapter speed calibration is computed from cpufreq/scaling_max_freq.
+# Adjusts automatically if CPU is overclocked.
 
 adapter driver bcm2835gpio
 
-bcm2835gpio peripheral_base 0x20000000
+proc read_file { name } {
+	if {[catch {open $name r} fd]} {
+		return ""
+	}
+	set result [read $fd]
+	close $fd
+	return $result
+}
 
-# Transition delay calculation: SPEED_COEFF/khz - SPEED_OFFSET
-# These depend on system clock, calibrated for stock 700MHz
-# bcm2835gpio speed SPEED_COEFF SPEED_OFFSET
-bcm2835gpio speed_coeffs 113714 28
+proc measure_clock {} {
+	set result [exec vcgencmd measure_clock arm]
+	set clock_hz [lindex [split $result "="] 1]
+	expr { $clock_hz / 1000 }
+}
+
+proc get_max_cpu_clock { default } {
+	set clock [read_file /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq]
+	if { $clock > 100000 } {
+		return $clock
+	}
 
-# Each of the JTAG lines need a gpio number set: tck tms tdi tdo
-# Header pin numbers: 23 22 19 21
-bcm2835gpio jtag_nums 11 25 10 9
+	# cpufreq not available. As the last resort try Broadcom's proprietary utility
+	if {![catch measure_clock clock] && $clock > 100000} {
+		return $clock
+	}
 
-# Each of the SWD lines need a gpio number set: swclk swdio
-# Header pin numbers: 23 22
-bcm2835gpio swd_nums 11 25
+	echo "WARNING: Host CPU clock unknown."
+	echo "WARNING: Using the highest possible value $default kHz as a safe default."
+	echo "WARNING: Expect JTAG/SWD clock significantly slower than requested."
 
-# If you define trst or srst, use appropriate reset_config
-# Header pin numbers: TRST - 26, SRST - 18
+	return $default
+}
 
-# bcm2835gpio trst_num 7
-# reset_config trst_only
+set compat [read_file /proc/device-tree/compatible]
+set clocks_per_timing_loop 4
 
-# bcm2835gpio srst_num 24
-# reset_config srst_only srst_push_pull
+if {[string match *bcm2711* $compat]} {
+	set speed_offset 52
+} elseif {[string match *bcm2837* $compat] || [string match *bcm2710* $compat]} {
+	set speed_offset 34
+} elseif {[string match *bcm2836* $compat] || [string match *bcm2709* $compat]} {
+	set speed_offset 36
+} elseif {[string match *bcm2835* $compat] || [string match *bcm2708* $compat]} {
+	set clocks_per_timing_loop 6
+	set speed_offset 32
+} else {
+	set speed_offset 32
+	echo "WARNING: Unknown type of the host SoC. Expect JTAG/SWD clock slower than requested."
+}
+
+set clock [get_max_cpu_clock 2000000]
+set speed_coeff [expr { $clock / $clocks_per_timing_loop }]
+
+# Transition delay calculation: SPEED_COEFF/khz - SPEED_OFFSET
+# The coefficients depend on system clock and CPU frequency scaling.
+bcm2835gpio speed_coeffs $speed_coeff $speed_offset
 
-# or if you have both connected,
-# reset_config trst_and_srst srst_push_pull
+source [find interface/raspberrypi-gpio-connector.cfg]