Determine the result of a hypothetical set frequency operation.
This allows the OS to determine what rate would be set given a set of parameters. A nack will be received if a frequency is not available in the given range.
- Parameters
-
| hdr | TISCI header |
| device | The device ID that the clock is connected to. |
| min_freq_hz | The minimum allowable frequency in Hz. This is the minimum allowable programmed frequency and does not account for clock tolerances and jitter. |
| target_freq_hz | The target clock frequency. A frequency will be found as close to the target frequency as possible. |
| max_freq_hz | The maximum allowable frequency in Hz. This is the maximum allowable programmed frequency and does not account for clock tolerances and jitter. The firmware will actually accept any frequency up to but not including max + 1. |
| clk | Each device has its own set of clock inputs. This indexes which clock input to query. |
If the clock index is 255 or greater, this field should be set to 255 and the full value placed in the clk32 field. This is kept for backwards compatibility with older firmwares.
- Parameters
-
| clk32 | Stores the actual clock index if clk field is set to 255. This field is ignored otherwise. This field can hold the full range of possible clock indexes, but for compatibility with older firmwares should only be used when the index is 255 or greater. |
1.8.20