tests: Generalise rp2 timer test into a cross-port test.

Now all ports with machine.Timer except nrf support both hard and
soft callbacks, generalise tests/ports/rp2_machine_timer.py into
tests/extmod/machine_timer.py.

There is an existing machine_soft_timer.py which varies period= and
covers the nrf port but skips esp32/esp8266 because they don't support
software timers. In our new test, we try varying freq= instead of period=,
and cover esp32/esp8266 (with a fixed choice of hardware timer) but skip
nrf because it doesn't support hard= or freq=.

Add a check that the heap is locked (so allocation fails) in hard
callbacks and it is unlocked (so allocation succeeds) in soft callbacks,
to ensure we're getting the right kind of callback, not falling back to
the default.

Signed-off-by: Chris Webb <chris@arachsys.com>

tests/extmod/machine_timer.py

@@ -0,0 +1,48 @@
+import sys
+
+try:
+    from machine import Timer
+    from time import sleep_ms
+except:
+    print("SKIP")
+    raise SystemExit
+
+if sys.platform in ("esp32", "esp8266", "nrf"):
+    # Software timers aren't implemented on the esp32 and esp8266 ports.
+    # The nrf port doesn't support selection of hard and soft callbacks,
+    # and only allows Timer(period=N), not Timer(freq=N).
+    print("SKIP")
+    raise SystemExit
+else:
+    timer_id = -1
+
+# Test both hard and soft IRQ handlers and both one-shot and periodic
+# timers. We adjust period in tests/extmod/machine_soft_timer.py, so try
+# adjusting freq here instead. The heap should be locked in hard callbacks
+# and unlocked in soft callbacks.
+
+
+def callback(t):
+    print("callback", mode[1], kind[1], freq, end=" ")
+    try:
+        allocate = bytearray(1)
+        print("unlocked")
+    except MemoryError:
+        print("locked")
+
+
+modes = [(Timer.ONE_SHOT, "one-shot"), (Timer.PERIODIC, "periodic")]
+kinds = [(False, "soft"), (True, "hard")]
+
+for mode in modes:
+    for kind in kinds:
+        for freq in 50, 25:
+            timer = Timer(
+                timer_id,
+                mode=mode[0],
+                freq=freq,
+                hard=kind[0],
+                callback=callback,
+            )
+            sleep_ms(90)
+            timer.deinit()

tests/extmod/machine_timer.py.exp

@@ -0,0 +1,16 @@
+callback one-shot soft 50 unlocked
+callback one-shot soft 25 unlocked
+callback one-shot hard 50 locked
+callback one-shot hard 25 locked
+callback periodic soft 50 unlocked
+callback periodic soft 50 unlocked
+callback periodic soft 50 unlocked
+callback periodic soft 50 unlocked
+callback periodic soft 25 unlocked
+callback periodic soft 25 unlocked
+callback periodic hard 50 locked
+callback periodic hard 50 locked
+callback periodic hard 50 locked
+callback periodic hard 50 locked
+callback periodic hard 25 locked
+callback periodic hard 25 locked

tests/ports/rp2/rp2_machine_timer.py

@@ -1,20 +0,0 @@
-from machine import Timer
-from time import sleep_ms
-
-# Test the rp2-specific adjustable tick_hz and hard/soft IRQ handlers
-# for both one-shot and periodic timers.
-
-modes = {Timer.ONE_SHOT: "one-shot", Timer.PERIODIC: "periodic"}
-kinds = {False: "soft", True: "hard"}
-
-for mode in modes:
-    for hard in kinds:
-        for period in 2, 4:
-            timer = Timer(
-                mode=mode,
-                period=period,
-                hard=hard,
-                callback=lambda t: print("callback", modes[mode], kinds[hard], period),
-            )
-            sleep_ms(9)
-            timer.deinit()

tests/ports/rp2/rp2_machine_timer.py.exp

@@ -1,16 +0,0 @@
-callback one-shot soft 2
-callback one-shot soft 4
-callback one-shot hard 2
-callback one-shot hard 4
-callback periodic soft 2
-callback periodic soft 2
-callback periodic soft 2
-callback periodic soft 2
-callback periodic soft 4
-callback periodic soft 4
-callback periodic hard 2
-callback periodic hard 2
-callback periodic hard 2
-callback periodic hard 2
-callback periodic hard 4
-callback periodic hard 4