[PATCH v6] api: timer: support period setting directly with frequency

[TuomasTaipale]

On top of #2320

v5:

• Petri's comments
• Fixed implementation and tests
• Ready for review

v6:

• Rebased
• Shijith's comment

[psavol]

Reviewed API changes.

[shijith]

Hi @TuomasTaipale ,

Instead of adding ODP_TIMER_TYPE_PERIODIC_2, could the period configuration method be a separate mode field inside the periodic sub-struct? as there is really only one periodic timer concept.

typedef enum {
ODP_TIMER_PERIODIC_MODE_MULT = 0, /* base_freq × multiplier /
ODP_TIMER_PERIODIC_MODE_FREQ, / direct frequency */
} odp_timer_periodic_mode_t;

The mode would sit next to the union it discriminates.
struct {
odp_timer_periodic_mode_t mode;
union {
struct { ... } mult; /* used when mode == MODE_MULT /
struct { ... } freq; / used when mode == MODE_FREQ */
};
uint32_t uarea_size;
} periodic;

This would also avoid needing to recall a type_1 -> PERIODIC, type_2 -> PERIODIC_2 mapping.

[TuomasTaipale]

Hi @TuomasTaipale ,

Instead of adding ODP_TIMER_TYPE_PERIODIC_2, could the period configuration method be a separate mode field inside the periodic sub-struct? as there is really only one periodic timer concept.

typedef enum { ODP_TIMER_PERIODIC_MODE_MULT = 0, /* base_freq × multiplier / ODP_TIMER_PERIODIC_MODE_FREQ, / direct frequency */ } odp_timer_periodic_mode_t;

The mode would sit next to the union it discriminates. struct { odp_timer_periodic_mode_t mode; union { struct { ... } mult; /* used when mode == MODE_MULT / struct { ... } freq; / used when mode == MODE_FREQ */ }; uint32_t uarea_size; } periodic;

This would also avoid needing to recall a type_1 -> PERIODIC, type_2 -> PERIODIC_2 mapping.

@shijith Thanks for checking. Initially we had this two-level structure for the new periodic types but decided not to go with that as it would be perhaps a bit cumbersome/error-prone for application. Using the existing odp_timer_type_t should be clear enough.

In v6, swapped the type_x fields to base_mul and freq and modified the type constants accordingly.