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Can Guo <can.guo@oss.qualcomm.com> says: Hi, The UFS v5.0 and UFSHCI v5.0 standards have published, introducing support for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0 interconnect layer and M-PHY V6.0 physical layer specifications. To achieve reliable operation at these higher speeds, UniPro V3.0 introduces TX Equalization and Pre-Coding mechanisms that are essential for signal integrity. This patch series implements TX Equalization support in the UFS core driver as specified in UFSHCI v5.0, along with the necessary vendor operations and a reference implementation for Qualcomm UFS host controllers. Background ========== TX Equalization is a signal conditioning technique that compensates for channel impairments at high data rates (HS-G4 through HS-G6). It works by adjusting two key parameters: - PreShoot: Pre-emphasis applied before the main signal transition - DeEmphasis: De-emphasis applied after the main signal transition UniPro V3.0 defines TX Equalization Training (EQTR) procedure to automatically discover optimal TX Equalization settings. The EQTR procedure: 1. Starts from the most reliable link state (HS-G1) 2. Iterates through all possible PreShoot and DeEmphasis combinations 3. Evaluates signal quality using Figure of Merit (FOM) measurements 4. Selects the best settings for both host and device TX lanes For HS-G6, Pre-Coding is also introduced to further improve signal quality. Pre-Coding must be enabled on both transmitter and receiver when the RX_FOM indicates it is required. Implementation Overview ======================= The implementation follows the UFSHCI v5.0 specification and consists of: Core Infrastructure (Patches 1-6): - New vops callback negotiate_pwr_mode() to allow vendors to negotiate power mode parameters before applying TX Equalization settings - Support for HS-G6 gear enumeration - Complete TX EQTR procedure implementation in ufs-txeq.c - Debugfs interface for TX Equalization parameter inspection and manual retraining - Module parameters for adaptive TX Equalization control Qualcomm Implementation (Patches 7-11): - PHY-specific configurations for TX EQTR procedure - Vendor-specific FOM measurement support - TX Equalization settings application - Enable TX Equalization for HW version 0x7 and onwards The implementation is designed to be vendor-agnostic, with platform- specific details handled through the vops callbacks. Other vendors can add support by implementing the three new vops: - tx_eqtr_notify(): Called before/after TX EQTR for vendor setup - apply_tx_eqtr_settings(): Apply vendor-specific PHY configurations - get_rx_fom(): Retrieve vendor-specific FOM measurements if needed Module Parameters ================= The implementation provides several module parameters for flexibility: - use_adaptive_txeq: Enable/disable adaptive TX Equalization (default: false) - adaptive_txeq_gear: Minimum gear for adaptive TX EQ (default: HS-G6) - use_txeq_presets: Use only the 8 standaird presets (default: false) - txeq_presets_selected[]: Select specific presets for EQTR Testing ======= This patch series has been tested on Qualcomm platforms with UFS 5.0 devices, validating: - Successful TX EQTR completion for HS-G6 - Proper FOM evaluation and optimal settings selection - Pre-Coding enablement for HS-G6 - Power mode changes with TX Equalization settings applied - Report of TX Equalization settings via debugfs entries - Report of TX EQTR histories via debug entries (see next section) - Re-training TX Equalization via debugfs entry Example of TX EQTR history ========================== Device TX EQTR record summary - Target Power Mode: HS-G6, Rate-B Most recent record index: 2 Most recent record timestamp: 219573378 us TX Lane 0 FOM - PreShoot\DeEmphasis \ 0 1 2 3 4 5 6 7 0 50 70 65 - - - - x 1 x x x x x x x x 2 100 90 70 - - - - x 3 x x x x x x x x 4 95 90 - - - - - x 5 - - - - - - - x 6 x x x x x x x x 7 x x x x x x x x TX Lane 1 FOM - PreShoot\DeEmphasis \ 0 1 2 3 4 5 6 7 0 50 70 60 - - - - x 1 x x x x x x x x 2 100 80 65 - - - - x 3 x x x x x x x x 4 95 85 - - - - - x 5 - - - - - - - x 6 x x x x x x x x 7 x x x x x x x x Patch Structure =============== Patches 1-3: Preparatory changes for power mode negotiation and HS-G6 Patch 4: Core TX Equalization and EQTR implementation Patches 5-7: Debugfs support for TX Equalization Patches 8-12: Qualcomm vendor implementation Next ==== One more series has been developed to enhance TX Equalization support, which will be submitted for review after this series is accepted: - Provide board specific (static) TX Equalization settings from DTS - Parse static TX Equalization settings from DTS if provided - Apply static TX Equalization settings if use_adaptive_txeq is disabled - Add support for UFS v5.0 attributes qTxEQGnSettings & wTxEQGnSettingsExt - Enable persistent storage and retrieval of optimal TX Equalization settings Link: https://patch.msgid.link/20260325152154.1604082-1-can.guo@oss.qualcomm.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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| .. | ||
| ufs.h | ||
| ufs_quirks.h | ||
| ufshcd.h | ||
| ufshci.h | ||
| unipro.h | ||