tcl/interface: support for Raspberry Pi 5

Make sure raspberrypi-native.cfg cannot be used on RPi5.

Add raspberrypi5-gpiod.cfg which uses linuxgpiod adapter driver.
Issue a warning if PCIe is in power save mode.

While on it, re-format warnings issued from Tcl to look similar
to LOG_WARNING() output.

Change-Id: If19b0350bd5fff83d9a0c65999e33b161fb6957a
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/8333
Tested-by: jenkins
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>

tcl/interface/raspberrypi5-gpiod.cfg

@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Config for Raspberry Pi 5 used as a bitbang adapter.
+# https://www.raspberrypi.com/documentation/computers/raspberry-pi.html
+
+# Raspberry Pi 5 is not compatible with bcm2835gpio native GPIO driver.
+# The linuxgpiod driver without configurable adapter speed runs at approximately
+# 800 kHz (SWD writes) and 360 kHz (SWD reads)
+
+adapter driver linuxgpiod
+
+proc read_file { name } {
+	if {[catch {open $name r} fd]} {
+		return ""
+	}
+	set result [read $fd]
+	close $fd
+	return $result
+}
+
+set pcie_aspm [read_file /sys/module/pcie_aspm/parameters/policy]
+# escaping [ ] characters in string match pattern does not work in Jim-Tcl
+if {![string match "*<performance>*" [string map { "\[" < "\]" > } $pcie_aspm]]} {
+	echo "Warn : Switch PCIe power saving off or the first couple of pulses gets clocked as fast as 20 MHz"
+	echo "Warn : Issue 'echo performance | sudo tee /sys/module/pcie_aspm/parameters/policy'"
+}
+
+set GPIO_CHIP 4
+source [find interface/raspberrypi-gpio-connector.cfg]