flash_fp_mcu: Add debug spi bytes activity

In an effort to understand why we see "Device or resource busy"
when binding the raw spidev driver, we add a few byte count prints
to indicate if spi activity occurred between certain operations.

This should be removed when a fix for the linked bug is determined.

BRANCH=none
BUG=b:190744837
TEST=# On Hatch and Zork
     scp util/flash_fp_mcu ${DUT_HOSTNAME}:/usr/local/bin/flash_fp_mcu
     ssh ${DUT_HOSTNAME} flash_fp_mcu --hello

Signed-off-by: Craig Hesling <hesling@chromium.org>
Change-Id: I400ca76ee3451f1e155d7912a7c25613d9f68846
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2954304
Reviewed-by: Patryk Duda <patrykd@google.com>
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/util/flash_fp_mcu b/util/flash_fp_mcu
index a2f7b118a8..4f788bbcd4 100644
--- a/util/flash_fp_mcu
+++ b/util/flash_fp_mcu
@@ -133,6 +133,24 @@ warn_gpio() {
   fi
 }
 
+# TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+print_spi_bytes() {
+  local label="$1"
+
+  local timestamp
+  local deviceid
+  local bytes_rx
+  local bytes_tx
+
+  if [[ "${TRANSPORT}" == "SPI" ]]; then
+    timestamp="$(date)"
+    deviceid="$(get_spiid)"
+    bytes_rx="$(cat "/sys/bus/spi/devices/${deviceid}/statistics/bytes_rx")"
+    bytes_tx="$(cat "/sys/bus/spi/devices/${deviceid}/statistics/bytes_tx")"
+    echo "${label}: SPI Bytes (${timestamp}): ${bytes_rx} RX and ${bytes_tx} TX"
+  fi
+}
+
 # Taken verbatim from
 # https://chromium.googlesource.com/chromiumos/docs/+/master/lsb-release.md#shell
 # This should not be used by anything except get_platform_name.
@@ -298,6 +316,9 @@ flash_fp_mcu_stm32() {
     gpio 1      "${gpio_pwren}"
   fi
 
+  # TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+  print_spi_bytes C
+
   # Remove cros_fp if present
   if [[ "${transport}" == "UART" ]]; then
     echo "${deviceid}" > /sys/bus/serial/drivers/cros-ec-uart/unbind
@@ -314,6 +335,9 @@ flash_fp_mcu_stm32() {
   gpio 0 "${gpio_nrst}"
   sleep 0.001
 
+  # TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+  print_spi_bytes D
+
   if [[ "${transport}" == "UART" ]]; then
     # load AMDI0020:01 ttyS1
     echo AMDI0020:01 > /sys/bus/platform/drivers/dw-apb-uart/unbind;
@@ -326,6 +350,9 @@ flash_fp_mcu_stm32() {
   fi
   sleep 0.5
 
+  # TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+  print_spi_bytes E
+
   # We do not expect the drivers to change the pin state when binding.
   # If you receive this warning, the driver needs to be fixed on this board
   # and this flash attempt will probably fail.
@@ -602,12 +629,18 @@ main() {
     exit "${EXIT_CONFIG}"
   fi
 
+  # TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+  print_spi_bytes A
+
   if [[ "${FLAGS_services}" -eq "${FLAGS_TRUE}" ]]; then
     echo "# Stopping biod and timberslide"
     stop biod
     stop timberslide LOG_PATH=/sys/kernel/debug/cros_fp/console_log
   fi
 
+  # TODO(b/190744837): Remove when "Device or resource busy" bug is resolved.
+  print_spi_bytes B
+
   # If cros-ec driver isn't bound on startup, this means the final rebinding
   # may fail.
   if [[ ! -c "/dev/cros_fp" ]]; then