rockchip64: scope the rk3576 HS400 DLL calibration to rk3576 only

[crackerjacques]

What

The rk3576 HS400 DLL tap calibration added for the Anbernic RG Vita Pro
(rk3576-0013-mmc-sdhci-dwcmshc-rk3576-dll-tap-calibration.patch) was gated on
rockchip_pdata->revision == 1. Revision 1 is shared by every non-rk356x dwcmshc
SoC — rk3576 and rk3588 (the driver's own comment says as much). As written it
also fed the rk3576 tap values, DLL_TAP_VALUE_SEL and BOTH_CLK_EDGE into
rk3588's HS400 path, changing its eMMC timing.

Fix

Gate the calibration on a dedicated needs_hs400_dll_calibration flag in
struct rockchip_pltfm_data, set only for sdhci_dwcmshc_rk3576_pdata. rk3588 and
the other revision-1 SoCs keep their original 90-degree CMDOUT taps and STRBIN
default untouched; only rk3576 gets the calibrated taps and the measured DLL lock
value feedback.

Reported by CodeRabbit on #10321.

Testing

Built rockchip64 edge (7.1) and bleedingedge (7.2-rc6). rk3576 HS400 behaviour
is unchanged (still calibrated, no more Timeout waiting for hardware interrupt on
the RG Vita Pro); the rk3588 path is restored to its pre-patch register values.

Summary by CodeRabbit

• Bug Fixes
  • Improved HS400 eMMC reliability on RK3576 devices through device-specific DLL calibration.
  • Automatically tunes clock and data timing for high-speed memory communication.
  • Preserved existing behavior for other supported Rockchip SoCs.

[coderabbitai]

📝 Walkthrough

Walkthrough

The two Rockchip kernel patch variants add RK3576-specific HS400 DLL calibration. The driver reads and scales the DLL lock value, applies it to clock tap selection, and preserves existing behavior on other revision-1 SoCs.

Changes

RK3576 HS400 DLL calibration

Layer / File(s)	Summary
Calibration contract and platform gating patch/kernel/archive/rockchip64-7.1/..., patch/kernel/archive/rockchip64-7.2/...	The patches add DLL calibration definitions, add needs_hs400_dll_calibration to platform data, and enable the flag for RK3576.
DLL lock and tap programming patch/kernel/archive/rockchip64-7.1/..., patch/kernel/archive/rockchip64-7.2/...	When the flag and HS400 timing are active, the driver reads DLL_STATUS0 and programs RXCLK, TXCLK, CMDOUT, and STRBIN. RK3576 uses taps 7/7/5 and BOTH_CLK_EDGE; other revision-1 SoCs retain their existing settings.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Sequence Diagram(s)

sequenceDiagram
  participant SDHCI_DWCMShc
  participant DLL_STATUS0
  participant DLL_Clock_Registers
  SDHCI_DWCMShc->>DLL_STATUS0: Read and scale DLL lock value
  DLL_STATUS0-->>SDHCI_DWCMShc: Return lock value
  SDHCI_DWCMShc->>DLL_Clock_Registers: Program calibrated RXCLK, TXCLK, CMDOUT, and STRBIN taps

Loading

Possibly related PRs

• armbian/build#10321: Includes the same RK3576 DLL calibration changes while rebasing the 7.2 patch set.
• armbian/build#10329: Updates the same RK3576 HS400 DLL calibration logic across kernel branches.

Suggested reviewers: igorpecovnik, rpardini, ahoneybun

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes scoping rk3576 HS400 DLL calibration to rk3576 only, which is the main change.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In
`@patch/kernel/archive/rockchip64-7.1/rk3576-0013-mmc-sdhci-dwcmshc-rk3576-dll-tap-calibration.patch`:
- Around line 90-95: Limit the calibrated DLL programming in
dwcmshc_rk3568_set_clock() to MMC_TIMING_MMC_HS400 in all four sites: 7.1 lines
90-95 and 137-150, and 7.2 lines 90-95 and 137-150. Require both
needs_hs400_dll_calibration and HS400 timing before updating RXCLK, TXCLK, or
STRBIN, preserving existing settings for HS200.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 3973c1a6-d47c-4d1d-ad7d-00711075097e

📥 Commits

Reviewing files that changed from the base of the PR and between ef2f2c2 and 2364b3f.

📒 Files selected for processing (2)

• patch/kernel/archive/rockchip64-7.1/rk3576-0013-mmc-sdhci-dwcmshc-rk3576-dll-tap-calibration.patch
• patch/kernel/archive/rockchip64-7.2/rk3576-0013-mmc-sdhci-dwcmshc-rk3576-dll-tap-calibration.patch

[github-actions]

✅ This PR has been reviewed and approved — all set for merge!

[igorpecovnik]

There is new rabbit's concern to check.

[EvilOlaf]

Yes, has to be addressed or dismissed

[crackerjacques]

Good catch — addressed in the amended commit. The RXCLK/TXCLK/STRBIN calibration is now gated on needs_hs400_dll_calibration && host->mmc->ios.timing == MMC_TIMING_MMC_HS400, matching the CMDOUT path, so HS200 keeps its existing (non-calibrated) values on rk3576. The RG Vita Pro runs HS400-ES, so its behaviour is unchanged; this only restores the HS200 path for rk3576 boards that use it. Built rockchip64 edge to confirm.

[github-actions]

✅ This PR has been reviewed and approved — all set for merge!