lcd_cam: fix wrong buffer length used if 16bit and len<=8192 (#2085)

* lcd_cam: fix wrong buffer length used if 16bit and len<=8192 * changelog

Author: liebman

esp-hal/CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - SHA driver can now be safely used in multiple contexts concurrently (#2049)
 
 - Fixed an issue with DMA transfers potentially not waking up the correct async task (#2065)
+- Fixed an issue with LCD_CAM i8080 where it would send double the clocks in 16bit mode (#2085)
 
 ### Removed
 - Removed `digest::Digest` implementation from SHA (#2049)

esp-hal/src/lcd_cam/lcd/i8080.rs

@@ -488,21 +488,14 @@ impl<'d, CH: DmaChannel, P, DM: Mode> I8080<'d, CH, P, DM> {
  .lcd_user()
  .modify(|_, w| w.lcd_dout().clear_bit());
  } else {
- // Set transfer length.
- self.lcd_cam.lcd_user().modify(|_, w| unsafe {
- if len <= 8192 {
- // Data length in fixed mode. (13 bits)
- w.lcd_always_out_en()
- .clear_bit()
- .lcd_dout_cyclelen()
- .bits((len - 1) as _)
- } else {
- // Enable continuous output.
- w.lcd_always_out_en().set_bit()
- }
- .lcd_dout()
- .set_bit()
- });
+ // Use continous mode for DMA. FROM the S3 TRM:
+ // > In a continuous output, LCD module keeps sending data till:
+ // > i. LCD_CAM_LCD_START is cleared;
+ // > ii. or LCD_CAM_LCD_RESET is set;
+ // > iii. or all the data in GDMA is sent out.
+ self.lcd_cam
+ .lcd_user()
+ .modify(|_, w| w.lcd_always_out_en().set_bit().lcd_dout().set_bit());
 
  unsafe {
  self.tx_chain.fill_for_tx(false, ptr, len)?;