scsi: ufs: core: Add support for static TX Equalization settings

Parse board-specific static TX Equalization settings from Device Tree for
each HS gear and store them in hba->tx_eq_params.

Parse txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6] as per-lane tuples:
<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].

For HS-G6, parse optional tx-precode-enable-g6 using the same per-lane
Host/Device tuple format. If provided, it must contain values for all
active lanes, and each value must be 0 or 1.

Introduce from_dt in struct ufshcd_tx_eq_params to track whether TX EQ
values came from static Device Tree data.

When adaptive TX Equalization is used, these static settings are not final:

 - If valid settings are retrieved from qTxEQGnSettings/wTxEQGnSettingsExt,
   those retrieved settings override static Device Tree settings.

 - If retrieval is not available/valid, TX EQTR runs and trained settings
   override static Device Tree settings.

So static Device Tree settings are a fallback for cases where adaptive TX
Equalization is not enabled or not used. Adaptive TX Equalization remains
the primary path when enabled.

No behavior changes for platforms that do not provide these properties.

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260616113348.1168248-3-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

0 files changed, 0 insertions, 0 deletions