Merge pull request tock#4212 from mateir-7/pio-final

Pio last update
YoeDistro · Oct 23, 2024 · 9ae0348 · 9ae0348
2 parents 0ee6231 + 00d99a8
commit 9ae0348
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/boards/pico_explorer_base/src/main.rs b/boards/pico_explorer_base/src/main.rs
@@ -20,7 +20,6 @@ use components::led::LedsComponent;
 use enum_primitive::cast::FromPrimitive;
 use kernel::component::Component;
 use kernel::hil::led::LedHigh;
-use kernel::hil::pwm::Pwm;
 use kernel::hil::usb::Client;
 use kernel::platform::{KernelResources, SyscallDriverLookup};
 use kernel::scheduler::round_robin::RoundRobinSched;
@@ -702,7 +701,14 @@ pub unsafe fn start() -> (
 
     let pio_pwm = PioPwm::new(&mut pio);
     pio_pwm.set_clocks(&peripherals.clocks);
-    pio_pwm.start(&RPGpio::GPIO7, 12_500_000, 50).unwrap();
+    // This will start a PWM with PIO with the set frequency and duty cycle on the specified pin.
+    // pio_pwm
+    //     .start(
+    //         &RPGpio::GPIO7,
+    //         pio_pwm.get_maximum_frequency_hz() / 125000, /*1_000*/
+    //         pio_pwm.get_maximum_duty_cycle() / 2,
+    //     )
+    //     .unwrap();
 
     (board_kernel, pico_explorer_base, chip)
 }

diff --git a/chips/rp2040/src/pio_pwm.rs b/chips/rp2040/src/pio_pwm.rs
@@ -69,7 +69,7 @@ impl<'a> hil::pwm::Pwm for PioPwm<'a> {
             custom_config.side_set_opt_enable = true;
             custom_config.side_set_pindirs = false;
             let max_freq = self.get_maximum_frequency_hz();
-            let pwm_period = (max_freq / frequency_hz) as u32;
+            let pwm_period = ((max_freq / frequency_hz) / 3) as u32;
             let sm_number = SMNumber::SM0;
             let duty_cycle = duty_cycle_percentage as u32;
             pio.pwm_program_init(
@@ -94,10 +94,12 @@ impl<'a> hil::pwm::Pwm for PioPwm<'a> {
     }
 
     fn get_maximum_duty_cycle(&self) -> usize {
-        // being a percentage, max duty cycle is 100
+        // being a percentage out of 10000, max duty cycle is 10000
         10000
     }
 
+    // For the rp2040, this will always return 125_000_000. Watch out as any value above
+    // 1_000_000 is not precise and WILL give modified frequency and duty cycle values.
     fn get_maximum_frequency_hz(&self) -> usize {
         self.clocks
             .unwrap_or_panic()