reset: sandbox: Cover reset_reset() fallback with second sandbox provider

Add a sandbox reset controller compatible string
"sandbox,reset-ctl-fallback-only" that reuses the existing sandbox assert,
deassert, request, and free helpers but omits rst_reset. That forces
reset_reset() through the core assert / udelay / deassert fallback.

Extend the reset-ctl-test DT node with a fifth reset line named "fallback"
that points at the new provider, and add dm_test_reset_reset_fallback_path
which verifies sandbox_reset_get_count() stays zero (rst_reset is never
invoked) while the line ends deasserted after reset_reset().

This complements the existing rst_reset coverage on sandbox,reset-ctl and
matches the approach of using a separate controller to exercise the
fallback path in unit tests.

Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Michal Simek <[email protected]>
Link: https://lore.kernel.org/r/c1d40db6e2332a8b23ba842385b3f8c3d0290109.1779709539.git.michal.simek@amd.com

1 files changed, 40 insertions, 0 deletions

diff --git a/test/dm/reset.c b/test/dm/reset.c
index 043d7cb7e0f..91fa7ff723b 100644
--- a/test/dm/reset.c
+++ b/test/dm/reset.c
@@ -19,6 +19,9 @@
 /* This is the other reset phandle specifier handled by bulk */
 #define OTHER_RESET_ID 2
 
+/* Line on reset-ctl-fallback (sandbox,reset-ctl-fallback-only); see test.dts */
+#define FALLBACK_RESET_ID 5
+
 /* Base test of the reset uclass */
 static int dm_test_reset_base(struct unit_test_state *uts)
 {
@@ -151,6 +154,43 @@ static int dm_test_reset_reset(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_reset_reset, UTF_SCAN_FDT);
 
+/*
+ * reset_reset() fallback path: controller has no rst_reset op, so the
+ * core does assert -> udelay -> deassert. rst_reset-only accounting
+ * (reset_count) stays zero. Leave the line asserted before reset_reset()
+ * so we verify the fallback actually pulses it back to deasserted.
+ */
+static int dm_test_reset_reset_fallback_path(struct unit_test_state *uts)
+{
+	struct udevice *dev_reset_fb;
+	struct udevice *dev_test;
+	struct reset_ctl ctl;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_RESET, "reset-ctl-fallback",
+					      &dev_reset_fb));
+	ut_asserteq(0, sandbox_reset_query(dev_reset_fb, FALLBACK_RESET_ID));
+	ut_asserteq(0, sandbox_reset_get_count(dev_reset_fb, FALLBACK_RESET_ID));
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "reset-ctl-test",
+					      &dev_test));
+	ut_assertok(reset_get_by_name(dev_test, "fallback", &ctl));
+	ut_asserteq_ptr(ctl.dev, dev_reset_fb);
+	ut_asserteq(FALLBACK_RESET_ID, ctl.id);
+
+	ut_assertok(reset_assert(&ctl));
+	ut_asserteq(1, sandbox_reset_query(dev_reset_fb, FALLBACK_RESET_ID));
+	ut_asserteq(0, sandbox_reset_get_count(dev_reset_fb, FALLBACK_RESET_ID));
+
+	ut_assertok(reset_reset(&ctl, 1));
+	ut_asserteq(0, sandbox_reset_get_count(dev_reset_fb, FALLBACK_RESET_ID));
+	ut_asserteq(0, sandbox_reset_query(dev_reset_fb, FALLBACK_RESET_ID));
+
+	ut_assertok(reset_free(&ctl));
+
+	return 0;
+}
+DM_TEST(dm_test_reset_reset_fallback_path, UTF_SCAN_FDT);
+
 static int dm_test_reset_reset_bulk(struct unit_test_state *uts)
 {
 	struct udevice *dev_reset;