diff mbox series

[v5,7/8] scsi: ufs-qcom: Delay specific time before gate ref clk

Message ID 1580721472-10784-8-git-send-email-cang@codeaurora.org (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Can Guo Feb. 3, 2020, 9:17 a.m. UTC
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.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufs-qcom.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Comments

hongwus@codeaurora.org Feb. 5, 2020, 7:20 a.m. UTC | #1
On 2020-02-03 17:17, Can Guo wrote:
> 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.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-qcom.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 85d7c17..3b5b2d9 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -833,6 +833,8 @@ static int ufs_qcom_bus_register(struct 
> ufs_qcom_host *host)
> 
>  static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool 
> enable)
>  {
> +	unsigned long gating_wait;
> +
>  	if (host->dev_ref_clk_ctrl_mmio &&
>  	    (enable ^ host->is_dev_ref_clk_enabled)) {
>  		u32 temp = readl_relaxed(host->dev_ref_clk_ctrl_mmio);
> @@ -845,11 +847,16 @@ 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) {
> +			gating_wait = host->hba->dev_info.clk_gating_wait_us;
> +			if (!gating_wait)
> +				udelay(1);
> +			else
> +				usleep_range(gating_wait, gating_wait + 10);
> +		}
> 
>  		writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);


Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 85d7c17..3b5b2d9 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -833,6 +833,8 @@  static int ufs_qcom_bus_register(struct ufs_qcom_host *host)
 
 static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 {
+	unsigned long gating_wait;
+
 	if (host->dev_ref_clk_ctrl_mmio &&
 	    (enable ^ host->is_dev_ref_clk_enabled)) {
 		u32 temp = readl_relaxed(host->dev_ref_clk_ctrl_mmio);
@@ -845,11 +847,16 @@  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) {
+			gating_wait = host->hba->dev_info.clk_gating_wait_us;
+			if (!gating_wait)
+				udelay(1);
+			else
+				usleep_range(gating_wait, gating_wait + 10);
+		}
 
 		writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);