[PATCH v5 0/2] Two changes to fix ufs power down/on specs violation

[Ziqi Chen <ziqichen@codeaurora.org>]

This series is made based on 5.11-scsi-staging branch.

As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs device, RST_N signal and REF_CLK signal
should be between VSS(Ground) and VCCQ/VCCQ2. The sequence after fixing as below:

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

The 1st change let ref-clk to be disabled before VCC & VCCQ turning off while to be enabled after VCC & VCCQ turning on.
The 2nd change is used to pull down RST_n during UFS power off.

Change since v4:
- Split the original change "scsi: ufs: Fix ufs power down/on specs violation" into two changes, one fixs clk specs violation and the other one fixs RST_n specs violation.
- The 2nd change is just only for QCOM platform.

Change since v3:
- Rename vops callback func toggle_device_reset(sturct ufs_hba *hba, bool down) to device_reset(sturct ufs_hba *hba, bool assert).
- Move the dealy after pulling donw RST_n back into vops. 

Change since v2:
- Correct commit message.

Change since v1:
- Rename vops callback func device_reset(sturct ufs_hba *hba) to toggle_device_reset(sturct ufs_hba *hba, bool down) to fix this specs violation for all SoC vendors platform. 

Ziqi Chen (2):
  scsi: ufs: Fix ufs clk specs violation
  scsi: ufs-qcom: Fix ufs RST_n specs violation

 drivers/scsi/ufs/ufs-qcom.c |  4 ++++
 drivers/scsi/ufs/ufshcd.c   | 20 ++++++++++----------
 2 files changed, 14 insertions(+), 10 deletions(-)

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