[PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Anil Varughese]

Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify()
because if UFSHCD resets the controller ip because of
phy or device related errors then CDNS_UFS_REG_HCLKDIV
is reset to default value and .setup_clock() is not
called later in the sequence whereas hce_enable_notify
will be called everytime controller is reenabled.

Signed-off-by: Anil Varughese <aniljoy@cadence.com>
---
 drivers/scsi/ufs/cdns-pltfrm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
index 86dbb723f..15ee54d28 100644
--- a/drivers/scsi/ufs/cdns-pltfrm.c
+++ b/drivers/scsi/ufs/cdns-pltfrm.c
@@ -78,6 +78,22 @@ static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
 	return cdns_ufs_set_hclkdiv(hba);
 }
 
+/**
+ * Called before and after HCE enable bit is set.
+ * @hba: host controller instance
+ * @status: notify stage (pre, post change)
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
+				      enum ufs_notify_change_status status)
+{
+	if (status != PRE_CHANGE)
+		return 0;
+
+	return cdns_ufs_set_hclkdiv(hba);
+}
+
 /**
  * cdns_ufs_init - performs additional ufs initialization
  * @hba: host controller instance
@@ -115,12 +131,14 @@ static int cdns_ufs_m31_16nm_phy_initialization(struct ufs_hba *hba)
 static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
 	.name = "cdns-ufs-pltfm",
 	.setup_clocks = cdns_ufs_setup_clocks,
+	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 };
 
 static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
 	.name = "cdns-ufs-pltfm",
 	.init = cdns_ufs_init,
 	.setup_clocks = cdns_ufs_setup_clocks,
+	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
 };
 
-- 
2.15.0

[PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Anil Varughese]

Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify()
because if UFSHCD resets the controller ip because of
phy or device related errors then CDNS_UFS_REG_HCLKDIV
is reset to default value and .setup_clock() is not
called later in the sequence whereas hce_enable_notify
will be called everytime controller is reenabled.

Signed-off-by: Anil Varughese <aniljoy@cadence.com>
---
 drivers/scsi/ufs/cdns-pltfrm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
index 86dbb723f..15ee54d28 100644
--- a/drivers/scsi/ufs/cdns-pltfrm.c
+++ b/drivers/scsi/ufs/cdns-pltfrm.c
@@ -78,6 +78,22 @@ static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
 	return cdns_ufs_set_hclkdiv(hba);
 }
 
+/**
+ * Called before and after HCE enable bit is set.
+ * @hba: host controller instance
+ * @status: notify stage (pre, post change)
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
+				      enum ufs_notify_change_status status)
+{
+	if (status != PRE_CHANGE)
+		return 0;
+
+	return cdns_ufs_set_hclkdiv(hba);
+}
+
 /**
  * cdns_ufs_init - performs additional ufs initialization
  * @hba: host controller instance
@@ -115,12 +131,14 @@ static int cdns_ufs_m31_16nm_phy_initialization(struct ufs_hba *hba)
 static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
 	.name = "cdns-ufs-pltfm",
 	.setup_clocks = cdns_ufs_setup_clocks,
+	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 };
 
 static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
 	.name = "cdns-ufs-pltfm",
 	.init = cdns_ufs_init,
 	.setup_clocks = cdns_ufs_setup_clocks,
+	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
 };
 
-- 
2.15.0

RE: [PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Avri Altman]

> 
> Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify()
> because if UFSHCD resets the controller ip because of
> phy or device related errors then CDNS_UFS_REG_HCLKDIV
> is reset to default value and .setup_clock() is not
> called later in the sequence whereas hce_enable_notify
> will be called everytime controller is reenabled.
> 
> Signed-off-by: Anil Varughese <aniljoy@cadence.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>

Re: [PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Vignesh Raghavendra]

Hi,

On 31-Jul-19 2:06 PM, Anil Varughese wrote:
> Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify()
> because if UFSHCD resets the controller ip because of
> phy or device related errors then CDNS_UFS_REG_HCLKDIV
> is reset to default value and .setup_clock() is not
> called later in the sequence whereas hce_enable_notify
> will be called everytime controller is reenabled.
>
So, now that CDNS_UFS_REG_HCLKDIV is configured in .hce_enable_notify(),
is it still required to have the same code in .setup_clock() as well?
Isn't setting up CDNS_UFS_REG_HCLKDIV in .hce_enable_notify() alone not
sufficient?

Regards
Vignesh

> Signed-off-by: Anil Varughese <aniljoy@cadence.com>
> ---
>  drivers/scsi/ufs/cdns-pltfrm.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
> index 86dbb723f..15ee54d28 100644
> --- a/drivers/scsi/ufs/cdns-pltfrm.c
> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
> @@ -78,6 +78,22 @@ static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
>  	return cdns_ufs_set_hclkdiv(hba);
>  }
>  
> +/**
> + * Called before and after HCE enable bit is set.
> + * @hba: host controller instance
> + * @status: notify stage (pre, post change)
> + *
> + * Return zero for success and non-zero for failure
> + */
> +static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
> +				      enum ufs_notify_change_status status)
> +{
> +	if (status != PRE_CHANGE)
> +		return 0;
> +
> +	return cdns_ufs_set_hclkdiv(hba);
> +}
> +
>  /**
>   * cdns_ufs_init - performs additional ufs initialization
>   * @hba: host controller instance
> @@ -115,12 +131,14 @@ static int cdns_ufs_m31_16nm_phy_initialization(struct ufs_hba *hba)
>  static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  };
>  
>  static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.init = cdns_ufs_init,
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
>  };
>  
> 

Re: [PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Vignesh Raghavendra]

Hi,

On 31-Jul-19 2:06 PM, Anil Varughese wrote:
> Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify()
> because if UFSHCD resets the controller ip because of
> phy or device related errors then CDNS_UFS_REG_HCLKDIV
> is reset to default value and .setup_clock() is not
> called later in the sequence whereas hce_enable_notify
> will be called everytime controller is reenabled.
>
So, now that CDNS_UFS_REG_HCLKDIV is configured in .hce_enable_notify(),
is it still required to have the same code in .setup_clock() as well?
Isn't setting up CDNS_UFS_REG_HCLKDIV in .hce_enable_notify() alone not
sufficient?

Regards
Vignesh

> Signed-off-by: Anil Varughese <aniljoy@cadence.com>
> ---
>  drivers/scsi/ufs/cdns-pltfrm.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
> index 86dbb723f..15ee54d28 100644
> --- a/drivers/scsi/ufs/cdns-pltfrm.c
> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
> @@ -78,6 +78,22 @@ static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
>  	return cdns_ufs_set_hclkdiv(hba);
>  }
>  
> +/**
> + * Called before and after HCE enable bit is set.
> + * @hba: host controller instance
> + * @status: notify stage (pre, post change)
> + *
> + * Return zero for success and non-zero for failure
> + */
> +static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
> +				      enum ufs_notify_change_status status)
> +{
> +	if (status != PRE_CHANGE)
> +		return 0;
> +
> +	return cdns_ufs_set_hclkdiv(hba);
> +}
> +
>  /**
>   * cdns_ufs_init - performs additional ufs initialization
>   * @hba: host controller instance
> @@ -115,12 +131,14 @@ static int cdns_ufs_m31_16nm_phy_initialization(struct ufs_hba *hba)
>  static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  };
>  
>  static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.init = cdns_ufs_init,
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
>  };
>  
> 

RE: [PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

[Anil Joy Varughese]

Hi Vignesh,

You are correct I have tested the code here and .setup_clock is not needed anymore; CDNS_UFS_REG_HCLKDIV configured in .hce_enable_notify() is enough. I will fix this in patch v2. 

Thanks,
Anil

-----Original Message-----
From: Vignesh Raghavendra <vigneshr@ti.com> 
Sent: Wednesday, July 31, 2019 10:05 PM
To: Anil Joy Varughese <aniljoy@cadence.com>; alim.akhtar@samsung.com; avri.altman@wdc.com; pedrom.sousa@synopsys.com
Cc: jejb@linux.ibm.com; martin.petersen@oracle.com; hare@suse.de; Rafal Ciepiela <rafalc@cadence.com>; Milind Parab <mparab@cadence.com>; Jan Kotas <jank@cadence.com>; linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: ufs: Additional clock initialization in Cadence UFS

EXTERNAL MAIL


Hi,

On 31-Jul-19 2:06 PM, Anil Varughese wrote:
> Configure CDNS_UFS_REG_HCLKDIV in .hce_enable_notify() because if 
> UFSHCD resets the controller ip because of phy or device related 
> errors then CDNS_UFS_REG_HCLKDIV is reset to default value and 
> .setup_clock() is not called later in the sequence whereas 
> hce_enable_notify will be called everytime controller is reenabled.
>
So, now that CDNS_UFS_REG_HCLKDIV is configured in .hce_enable_notify(), is it still required to have the same code in .setup_clock() as well?
Isn't setting up CDNS_UFS_REG_HCLKDIV in .hce_enable_notify() alone not sufficient?

Regards
Vignesh

> Signed-off-by: Anil Varughese <aniljoy@cadence.com>
> ---
>  drivers/scsi/ufs/cdns-pltfrm.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c 
> b/drivers/scsi/ufs/cdns-pltfrm.c index 86dbb723f..15ee54d28 100644
> --- a/drivers/scsi/ufs/cdns-pltfrm.c
> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
> @@ -78,6 +78,22 @@ static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
>  	return cdns_ufs_set_hclkdiv(hba);
>  }
>  
> +/**
> + * Called before and after HCE enable bit is set.
> + * @hba: host controller instance
> + * @status: notify stage (pre, post change)
> + *
> + * Return zero for success and non-zero for failure  */ static int 
> +cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
> +				      enum ufs_notify_change_status status) {
> +	if (status != PRE_CHANGE)
> +		return 0;
> +
> +	return cdns_ufs_set_hclkdiv(hba);
> +}
> +
>  /**
>   * cdns_ufs_init - performs additional ufs initialization
>   * @hba: host controller instance
> @@ -115,12 +131,14 @@ static int 
> cdns_ufs_m31_16nm_phy_initialization(struct ufs_hba *hba)  static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  };
>  
>  static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
>  	.name = "cdns-ufs-pltfm",
>  	.init = cdns_ufs_init,
>  	.setup_clocks = cdns_ufs_setup_clocks,
> +	.hce_enable_notify = cdns_ufs_hce_enable_notify,
>  	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
>  };
>  
>