SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
This section provides recommended steps for initializing the DSS module.
| Step | Register / Bit Field / Chapter | Value |
|---|---|---|
| Enable DSS clock domain | ||
| Configure DPLL_PER and associated HS12 divider, according to the desired DSS_GFCLK frequency | Refer to Power, Reset, and Clock Management, section DPLL_PER Description | - |
| Enable DES_HDCP clock | Set CTRL_CORE_CONTROL_IO_2[0] DSS_DESHDCP_CLKEN register bit; | 0x1 |
| Refer to Control Module Register Manual | ||
| Set SW wake-up transition for DSS clock domain | Set CM_DSS_CLKSTCTRL[1:0] CLKTRCTRL register bitfield; | 0x2 |
| Refer to PRCM Register Manual | ||
| Enable (ungate) DSS_GFCLK clock | Set CM_DSS_DSS_CLKCTRL[8] OPTFCLKEN_DSSCLK register bit; | 0x1 |
| Refer to PRCM Register Manual | ||
| Enable DSS clocks | Set CM_DSS_DSS_CLKCTRL[1:0] MODULEMODE register bitfield; | 0x2 |
| Refer to PRCM Register Manual | ||
| Wait for DSS idle status (functional or in idle mode) | Read CM_DSS_DSS_CLKCTRL[17:16] IDLEST register bit-field; | 0x0 or 0x2 |
| Refer to PRCM Register Manual | ||
| Make DSS DPLLs accessible via DSS address space | ||
| Make VIDEO1 and HDMI DPLLs accessible via DSS | Clear the following bits in CTRL_CORE_DSS_PLL_CONTROL register: | 0x0 |
| [2] PLL_HDMI_DSS_CONTROL_DISABLE bit; | ||
| [1] PLL_VIDEO2_DSS_CONTROL_DISABLE bit; | ||
| [0] PLL_VIDEO1_DSS_CONTROL_DISABLE bit; | ||
| Refer to Control Module Register Manual | ||
| Enable DSS internal SCP interface | ||
| Enable DSS internal SCP interface for VIDEO1 register configuration | Set DSI_CLK_CTRL[14] CIO_CLK_ICG register bit | 0x1 |
| Configure DSS internal SCP interface for HDMI DPLL register configuration | Set HDMI_WP_CLK[ 10:8] SCP_PWR_DIV register bit-field | 0x- |
| Configure DSS DPLLs | ||
| Enable (ungate) VIDEO1 and HDMI DPLLs source clocks | Set the following bits in CM_DSS_DSS_CLKCTRL register: | 0x1 |
| [13] OPTFCLKEN_VIDEO2_CLK bit; | ||
| [12] OPTFCLKEN_VIDEO1_CLK bit; | ||
| [10] OPTFCLKEN_HDMI_CLK bit; | ||
| Refer to PRCM Register Manual | ||
| Proceed with VIDEO1 and HDMI DPLLs configuration | Refer to Display Subsystem DPLL Controllers Functional Description | - |