Hello Raspberry Pi Team,
I am working on **enabling DSI1** on the **Raspberry Pi CM4 with latest kernal and os (Debian Bookworm) to interface with a TI DS90UH941AS (DSI to FPD-Link III Serializer) + DS90UH948 (Deserializer to RGB LCD). I need guidance on how to correctly configure the **DSI1 interface** with my specified **resolution and timings**.
My Display Configuration:
- **Panel Resolution:** 800x480 @ 60Hz
- **DSI Lanes:** 4
- **Pixel Clock (fPCLK):** 29.58 MHz
- **Calculated DSI Clock (fDSI):** 88.74 MHz (using formula: `fDSI = fPCLK * 12 / Nlanes`)
What I Have Tried So Far:
1. Enabled DSI1 in `/boot/firmware/config.txt`**2. **Verified DSI1 Detection using `xrandr`**
- `DSI-1` appears, but I am unable to apply my custom timings properly.
3. **Set Custom Mode Using xrandr**
```sh
xrandr --newmode "800x480_60.00" 29.58 800 840 968 1056 480 486 494 500 -hsync +vsync
xrandr --addmode DSI-1 800x480_60.00
xrandr --output DSI-1 --mode 800x480_60.00
```
- However, I only see the **internal test pattern**, not my external timing.
Questions:
1. How can I properly enable DSI1 with my custom configuration on the Raspberry Pi CM4?
2. Do I need to modify the device tree overlay (`dtoverlay`)?
3. How do I ensure the Raspberry Pi outputs the correct timing over DSI to my DS90UH941AS?
4. What additional configurations or drivers are needed for proper synchronization?
This is the communication link for TI Form that I am following: https://e2e.ti.com/support/interface-gr ... 71#5723871
Any guidance on this setup would be greatly appreciated!
Thank you,
Abhimanyu
I am working on **enabling DSI1** on the **Raspberry Pi CM4 with latest kernal and os (Debian Bookworm) to interface with a TI DS90UH941AS (DSI to FPD-Link III Serializer) + DS90UH948 (Deserializer to RGB LCD). I need guidance on how to correctly configure the **DSI1 interface** with my specified **resolution and timings**.
My Display Configuration:
- **Panel Resolution:** 800x480 @ 60Hz
- **DSI Lanes:** 4
- **Pixel Clock (fPCLK):** 29.58 MHz
- **Calculated DSI Clock (fDSI):** 88.74 MHz (using formula: `fDSI = fPCLK * 12 / Nlanes`)
What I Have Tried So Far:
1. Enabled DSI1 in `/boot/firmware/config.txt`**
Code:
dtoverlay=vc4-kms-dsi-generic,panel_width=800,panel_height=480,refresh_rate=60- `DSI-1` appears, but I am unable to apply my custom timings properly.
3. **Set Custom Mode Using xrandr**
```sh
xrandr --newmode "800x480_60.00" 29.58 800 840 968 1056 480 486 494 500 -hsync +vsync
xrandr --addmode DSI-1 800x480_60.00
xrandr --output DSI-1 --mode 800x480_60.00
```
- However, I only see the **internal test pattern**, not my external timing.
Questions:
1. How can I properly enable DSI1 with my custom configuration on the Raspberry Pi CM4?
2. Do I need to modify the device tree overlay (`dtoverlay`)?
3. How do I ensure the Raspberry Pi outputs the correct timing over DSI to my DS90UH941AS?
4. What additional configurations or drivers are needed for proper synchronization?
This is the communication link for TI Form that I am following: https://e2e.ti.com/support/interface-gr ... 71#5723871
Any guidance on this setup would be greatly appreciated!
Thank you,
Abhimanyu
Statistics: Posted by abhimanyukumarmahto — Thu Mar 20, 2025 5:14 pm