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- Overview
- --------
- The P4080DS is a Freescale reference board that hosts the eight-core P4080 SOC.
- SerDes hwconfig configuration
- -----------------------------
- The P4080 RCW includes three sets of bits the specify which SerDes lanes
- should be powered down: SRDS_LPD_B1 (for bank one), SRDS_LPD_B2 (for bank two),
- and SRDS_LPD_B3 (for bank three). Each of these contains four bits, one for
- each lane in the bank. SerDes Erratum SERDES8 requires that SRDS_LPD_B2 and
- SRDS_LPD_B3 be set to 0b1111. This forces banks two and three to be powered
- down at reset.
- To re-enable these banks in U-Boot, two hwconfig are available:
- "fsl_srds_lpd_b2" and "fsl_srds_lpd_b3". The value passed via fsl_srds_lpd_b2
- is written into SRDS_LPD_B2, and the value passed via fsl_srds_lpd_b3 is into
- SRDS_LPD_B3. Each bit represents one of each bank, and a value of '1'
- indicates that the lane should be powered down.
- For example, to indicate that both SerDes banks 2 and 3 are powered down, add
- the following to hwconfig:
- serdes:fsl_srds_lpd_b2=0xf,fsl_srds_lpd_b3=0xf
- The "0xf" is a mask that corresponds to the 4 lanes A-D. The most significant
- bit corresponds to lane A. To indicate that just lane A of bank 3 is to be
- powered down, use:
- serdes:fsl_srds_lpd_b3=8
- These options should be specified only if U-Boot does not automatically power
- on the correct lanes.
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