diff mbox series

[v4,7/8] scsi: ufs-qcom: Delay specific time before gate ref clk

Message ID 1579764349-15578-8-git-send-email-cang@codeaurora.org (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Can Guo Jan. 23, 2020, 7:25 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>
---
 drivers/scsi/ufs/ufs-qcom.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Comments

Asutosh Das (asd) Jan. 24, 2020, 6:04 p.m. UTC | #1
On 1/22/2020 11:25 PM, 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);
>   
>
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);