diff options
| author |   Can Guo <cang@codeaurora.org> | 2020-02-10 19:40:50 -0800 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2020-02-12 19:42:38 -0500 |
| commit | 1cbadd0c331fb151fafc698bf2ecc35122953715 (patch) | |
| tree | 895e140d8b477e58aad97c1582393b3ba28c9f80 /drivers/scsi/ufs/ufs-qcom.c | |
| parent | scsi: ufs: Add dev ref clock gating wait time support (diff) | |
| download | wireguard-linux-1cbadd0c331fb151fafc698bf2ecc35122953715.tar.xz wireguard-linux-1cbadd0c331fb151fafc698bf2ecc35122953715.zip | |
scsi: ufs-qcom: Delay specific time before gate ref clk
After enter hibern8, as UFS JEDEC ver 3.0 requires, a specific gating wait
time is required before disable the device reference clock. If it is not
specified, use the old delay.
Link: https://lore.kernel.org/r/1581392451-28743-8-git-send-email-cang@codeaurora.org
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ufs/ufs-qcom.c')
| -rw-r--r-- | drivers/scsi/ufs/ufs-qcom.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c index 2800a47d9e6d..8339050f0af2 100644 --- a/drivers/scsi/ufs/ufs-qcom.c +++ b/drivers/scsi/ufs/ufs-qcom.c @@ -843,11 +843,27 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable) /* * If we are here to disable this clock it might be immediately * after entering into hibern8 in which case we need to make - * sure that device ref_clk is active at least 1us after the + * sure that device ref_clk is active for specific time after * hibern8 enter. */ - if (!enable) - udelay(1); + if (!enable) { + unsigned long gating_wait; + + gating_wait = host->hba->dev_info.clk_gating_wait_us; + if (!gating_wait) { + udelay(1); + } else { + /* + * bRefClkGatingWaitTime defines the minimum + * time for which the reference clock is + * required by device during transition from + * HS-MODE to LS-MODE or HIBERN8 state. Give it + * more delay to be on the safe side. + */ + gating_wait += 10; + usleep_range(gating_wait, gating_wait + 10); + } + } writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio); |