//! Clock System

use core::cmp;
use pac::{cs, CS};

use crate::time::Hertz;


/// Extension trait that constrains the `CS` peripheral
pub trait CsExt {
    /// Constrains the `CS` peripheral so that it plays nicely with other abstractions
    fn constrain(self) -> Cs;
}

impl CsExt for CS {
    fn constrain(self) -> Cs {
        Cs {

        }
    }
}

/*
+--------+-----------------------+---------------+-------------------------------------+
| Clock  | Default Clock Source  | Default Clock | Description                         |
|        |                       | Frequency     |                                     |
+========+=======================+===============+=====================================+
| MCLK   | DCO                   | 3 MHz         | Master Clock - Sources CPU and      |
|        |                       |               | peripherals                         |
+--------+-----------------------+---------------+-------------------------------------+
| HSMCLK | DCO                   | 3 MHz         | Subsystem Master Clock - Sources    |
|        |                       |               | peripherals                         |
+--------+-----------------------+---------------+-------------------------------------+
| SMCLK  | DCO                   | 3 MHz         | Low-speed subsystem master clock -  |
|        |                       |               | Sources peripherals                 |
+--------+-----------------------+---------------+-------------------------------------+
| ACLK   | LFXT (or REFO if no   | 32.768 kHz    | Auxiliary clock - Sources           |
|        | crystal present)      |               | peripherals                         |
+--------+-----------------------+---------------+-------------------------------------+
| BCLK   | LFXT (or REFO if no   | 32.768 kHz    | Low-speed backup domain clock -     |
|        | crystal present)      |               | Sources LPM peripherals             |
+--------+-----------------------+---------------+-------------------------------------+
*/

pub struct Cs {

}

/// Frozen clock frequencies
///
/// This value holds the current clocks frequencies and indicates that they can
/// no longer be changed
#[derive(Clone, Copy)]
pub struct Clocks {
    sysclk: Hertz,
}

impl Clocks {
    /// Returns the system (core) frequency
    pub fn sysclk(&self) -> Hertz {
        self.sysclk
    }
}