Add KUnit test coverage for the assigned-clock-sscs DT property that
configures spread spectrum on clocks before they are used.
Extend the existing test infrastructure to support spread spectrum:
- Add struct clk_spread_spectrum field to clk_dummy_context and a
clk_dummy_set_spread_spectrum callback
- Wire set_spread_spectrum into all dummy clock ops
- Extend clk_assigned_rates_register_clk and test parameter struct
to propagate initial SSCS values
Add a new separate test suite clk_assigned_sscs with three categories:
1. clk_assigned_sscs_assigns_one — verifies that a single
assigned-clock-sscs entry correctly configures spread spectrum
on one clock, testing both provider and consumer paths
2. clk_assigned_sscs_assigns_multiple — verifies that multiple
assigned-clock-sscs entries configure spread spectrum on two
clocks, testing both provider and consumer paths
3. clk_assigned_sscs_skips — verifies that malformed DT properties
are correctly skipped without error: missing assigned-clocks,
zero-valued SSCS, and null phandles, tested for both provider
and consumer scenarios
New DT overlays are added for all test scenarios:
- kunit_clk_assigned_sscs_one{,consumer} — single valid entry
- kunit_clk_assigned_sscs_multiple{,consumer} — two valid entries
- kunit_clk_assigned_sscs_without{,consumer} — missing assigned-clocks
- kunit_clk_assigned_sscs_zero{,consumer} — all-zero SSCS values
- kunit_clk_assigned_sscs_null{,consumer} — null phandle
Co-developed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Brian Masney <bmasney@redhat.com>
