[PATCH net-next v4 0/2] Add support for VSC85xx DT RGMII delays

[PATCH net-next v4 0/2] Add support for VSC85xx DT RGMII delays

[Harini Katakam]

Provide an option to change RGMII delay value via devicetree.

v4:
- Remove VSC8531_02 support. Existing code will identify VSC8531_01/02
and there is no unique functionality to be added for either version.
- Correct type of rx/tx_delay to accept correct return value.
- Added Andrew's tag to patch 1

Lore link for v3: 
https://lore.kernel.org/netdev/20230511120808.28646-1-harini.katakam@amd.com/

v3 changes:
- Remove patch 2/3 from v2 as custom mscc properties dont need to be
defined. rx-internal-delay-ps and tx-internal-delay-ps can be used.
- Change RGMII delay precedence as advised by Vladimir:
 phy-mode                       rgmii                          rgmii-rxid/rgmii-id
 --------------------------------------------------------------------------------------------
 rx-internal-delay-ps absent    0.2 ns                         2 ns
 rx-internal-delay-ps present   follow rx-internal-delay-ps    follow rx-internal-delay-ps
- Split VSC8531-02 and RGMII delay config into separate patches.
- Correct vendor ID
- Update commit description and subject everywhere to say RGMII delays
instead of RGMII tuning.

v2 changes:
- Added patch to use a common vendor phy id match
- Removed dt include header patch because delays should be specied in
ps, not register values
- Updated DT binding description and commit for optional delay tuning to
be clearer on the precedence
- Updated dt property name to include vendor instead of phy device name
- Switch both VSC8531 and VSC8531-02 to use exact phy id match as they
share the same model number
- Ensure RCT
- Improve optional property read

Harini Katakam (2):
  phy: mscc: Use PHY_ID_MATCH_VENDOR to minimize PHY ID table
  phy: mscc: Add support for RGMII delay configuration

 drivers/net/phy/mscc/mscc.h      |  3 ++
 drivers/net/phy/mscc/mscc_main.c | 49 +++++++++++++++++++-------------
 2 files changed, 32 insertions(+), 20 deletions(-)

-- 
2.17.1

[PATCH net-next v4 1/2] phy: mscc: Use PHY_ID_MATCH_VENDOR to minimize PHY ID table

[Harini Katakam]

All the PHY devices variants specified have the same mask and
hence can be simplified to one vendor look up for 0x00070400.
Any individual config can be identified by PHY_ID_MATCH_EXACT
in the respective structure.

Signed-off-by: Harini Katakam <harini.katakam@amd.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
v4:
Added Andrew's tag
v3:
Correct vendor ID
v2:
New patch
 drivers/net/phy/mscc/mscc.h      |  1 +
 drivers/net/phy/mscc/mscc_main.c | 14 +-------------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
index a50235fdf7d9..9acee8759105 100644
--- a/drivers/net/phy/mscc/mscc.h
+++ b/drivers/net/phy/mscc/mscc.h
@@ -290,6 +290,7 @@ enum rgmii_clock_delay {
 #define PHY_ID_VSC8575			  0x000707d0
 #define PHY_ID_VSC8582			  0x000707b0
 #define PHY_ID_VSC8584			  0x000707c0
+#define PHY_VENDOR_MSCC			0x00070400
 
 #define MSCC_VDDMAC_1500		  1500
 #define MSCC_VDDMAC_1800		  1800
diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index 62bf99e45af1..91010524e03d 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -2656,19 +2656,7 @@ static struct phy_driver vsc85xx_driver[] = {
 module_phy_driver(vsc85xx_driver);
 
 static struct mdio_device_id __maybe_unused vsc85xx_tbl[] = {
-	{ PHY_ID_VSC8504, 0xfffffff0, },
-	{ PHY_ID_VSC8514, 0xfffffff0, },
-	{ PHY_ID_VSC8530, 0xfffffff0, },
-	{ PHY_ID_VSC8531, 0xfffffff0, },
-	{ PHY_ID_VSC8540, 0xfffffff0, },
-	{ PHY_ID_VSC8541, 0xfffffff0, },
-	{ PHY_ID_VSC8552, 0xfffffff0, },
-	{ PHY_ID_VSC856X, 0xfffffff0, },
-	{ PHY_ID_VSC8572, 0xfffffff0, },
-	{ PHY_ID_VSC8574, 0xfffffff0, },
-	{ PHY_ID_VSC8575, 0xfffffff0, },
-	{ PHY_ID_VSC8582, 0xfffffff0, },
-	{ PHY_ID_VSC8584, 0xfffffff0, },
+	{ PHY_ID_MATCH_VENDOR(PHY_VENDOR_MSCC) },
 	{ }
 };
 
-- 
2.17.1

[PATCH net-next v4 2/2] phy: mscc: Add support for RGMII delay configuration

[Harini Katakam]

Add support for optional rx/tx-internal-delay-ps from devicetree.
- When rx/tx-internal-delay-ps is/are specified, these take priority
- When either is absent,
1) use 2ns for respective settings if rgmii-id/rxid/txid is/are present
2) use 0.2ns for respective settings if mode is rgmii

Signed-off-by: Harini Katakam <harini.katakam@amd.com>
---
v4:
Fix type of rx_delay and tx_delay
Reported by Simon Horman and
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305140248.lh4LUw2j-lkp@intel.com/
v3 - Patch split:
- Use rx/tx-internal-delay-ps with phy_get_internal_delay
- Change RGMII delay selection precedence
- Update commit description and subject everywhere to say RGMII delays
instead of RGMII tuning.
 drivers/net/phy/mscc/mscc.h      |  2 ++
 drivers/net/phy/mscc/mscc_main.c | 35 +++++++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
index 9acee8759105..900bf37db9de 100644
--- a/drivers/net/phy/mscc/mscc.h
+++ b/drivers/net/phy/mscc/mscc.h
@@ -374,6 +374,8 @@ struct vsc8531_private {
 	 * package.
 	 */
 	unsigned int base_addr;
+	s32 rx_delay;
+	s32 tx_delay;
 
 #if IS_ENABLED(CONFIG_MACSEC)
 	/* MACsec fields:
diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index 91010524e03d..9e856231e464 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -525,17 +525,14 @@ static int vsc85xx_rgmii_set_skews(struct phy_device *phydev, u32 rgmii_cntl,
 {
 	u16 rgmii_rx_delay_pos = ffs(rgmii_rx_delay_mask) - 1;
 	u16 rgmii_tx_delay_pos = ffs(rgmii_tx_delay_mask) - 1;
+	struct vsc8531_private *vsc8531 = phydev->priv;
 	u16 reg_val = 0;
 	int rc;
 
 	mutex_lock(&phydev->lock);
 
-	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
-	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
-		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_rx_delay_pos;
-	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
-	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
-		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_tx_delay_pos;
+	reg_val |= vsc8531->rx_delay << rgmii_rx_delay_pos;
+	reg_val |= vsc8531->tx_delay << rgmii_tx_delay_pos;
 
 	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2,
 			      rgmii_cntl,
@@ -1808,10 +1805,34 @@ static irqreturn_t vsc8584_handle_interrupt(struct phy_device *phydev)
 	return IRQ_HANDLED;
 }
 
+static const int vsc8531_internal_delay[] = {200, 800, 1100, 1700, 2000, 2300,
+					     2600, 3400};
 static int vsc85xx_config_init(struct phy_device *phydev)
 {
-	int rc, i, phy_id;
+	int delay_size = ARRAY_SIZE(vsc8531_internal_delay);
 	struct vsc8531_private *vsc8531 = phydev->priv;
+	struct device *dev = &phydev->mdio.dev;
+	int rc, i, phy_id;
+
+	vsc8531->rx_delay = phy_get_internal_delay(phydev, dev, &vsc8531_internal_delay[0],
+						   delay_size, true);
+	if (vsc8531->rx_delay < 0) {
+		if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
+		    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
+			vsc8531->rx_delay = RGMII_CLK_DELAY_2_0_NS;
+		else
+			vsc8531->rx_delay = RGMII_CLK_DELAY_0_2_NS;
+	}
+
+	vsc8531->tx_delay = phy_get_internal_delay(phydev, dev, &vsc8531_internal_delay[0],
+						   delay_size, false);
+	if (vsc8531->tx_delay < 0) {
+		if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
+		    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
+			vsc8531->rx_delay = RGMII_CLK_DELAY_2_0_NS;
+		else
+			vsc8531->rx_delay = RGMII_CLK_DELAY_0_2_NS;
+	}
 
 	rc = vsc85xx_default_config(phydev);
 	if (rc)
-- 
2.17.1

Re: [PATCH net-next v4 2/2] phy: mscc: Add support for RGMII delay configuration

[Jakub Kicinski]

On Mon, 22 May 2023 17:58:29 +0530 Harini Katakam wrote:
> Add support for optional rx/tx-internal-delay-ps from devicetree.
> - When rx/tx-internal-delay-ps is/are specified, these take priority
> - When either is absent,
> 1) use 2ns for respective settings if rgmii-id/rxid/txid is/are present
> 2) use 0.2ns for respective settings if mode is rgmii
> 
> Signed-off-by: Harini Katakam <harini.katakam@amd.com>

PHY folks, looks good?

Re: [PATCH net-next v4 2/2] phy: mscc: Add support for RGMII delay configuration

[Vladimir Oltean]

On Mon, May 22, 2023 at 05:58:29PM +0530, Harini Katakam wrote:
> diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
> index 91010524e03d..9e856231e464 100644
> --- a/drivers/net/phy/mscc/mscc_main.c
> +++ b/drivers/net/phy/mscc/mscc_main.c
> @@ -525,17 +525,14 @@ static int vsc85xx_rgmii_set_skews(struct phy_device *phydev, u32 rgmii_cntl,
>  {
>  	u16 rgmii_rx_delay_pos = ffs(rgmii_rx_delay_mask) - 1;
>  	u16 rgmii_tx_delay_pos = ffs(rgmii_tx_delay_mask) - 1;
> +	struct vsc8531_private *vsc8531 = phydev->priv;
>  	u16 reg_val = 0;
>  	int rc;
>  
>  	mutex_lock(&phydev->lock);
>  
> -	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
> -	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> -		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_rx_delay_pos;
> -	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
> -	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> -		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_tx_delay_pos;
> +	reg_val |= vsc8531->rx_delay << rgmii_rx_delay_pos;
> +	reg_val |= vsc8531->tx_delay << rgmii_tx_delay_pos;

What about vsc8584_config_init() -> vsc85xx_rgmii_set_skews()? Who will
have configured rx_delay and tx_delay for that call path?

Isn't it better to absorb the device tree parsing logic into
vsc85xx_rgmii_set_skews(), I wonder?

And if we do that, is it still necessary to use struct vsc8531_private
as temporary storage space from vsc85xx_config_init() to vsc85xx_rgmii_set_skews(),
or will two local variables (rx_delay, tx_delay) serve that purpose just fine?

>  
>  	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2,
>  			      rgmii_cntl,
> @@ -1808,10 +1805,34 @@ static irqreturn_t vsc8584_handle_interrupt(struct phy_device *phydev)
>  	return IRQ_HANDLED;
>  }
>  
> +static const int vsc8531_internal_delay[] = {200, 800, 1100, 1700, 2000, 2300,
> +					     2600, 3400};

Could you please avoid intermingling this with the function code, and
move it at the top of mscc_main.c?

Also, vsc8531_internal_delay[] or vsc85xx_internal_delay[]? The values
are also good for VSC8572, the other caller of vsc85xx_rgmii_set_skews().

>  static int vsc85xx_config_init(struct phy_device *phydev)
>  {
> -	int rc, i, phy_id;
> +	int delay_size = ARRAY_SIZE(vsc8531_internal_delay);
>  	struct vsc8531_private *vsc8531 = phydev->priv;
> +	struct device *dev = &phydev->mdio.dev;
> +	int rc, i, phy_id;
> +
> +	vsc8531->rx_delay = phy_get_internal_delay(phydev, dev, &vsc8531_internal_delay[0],

You can just write "x" rather than "&x[0]".

> +						   delay_size, true);
> +	if (vsc8531->rx_delay < 0) {
> +		if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
> +		    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> +			vsc8531->rx_delay = RGMII_CLK_DELAY_2_0_NS;
> +		else
> +			vsc8531->rx_delay = RGMII_CLK_DELAY_0_2_NS;
> +	}
> +
> +	vsc8531->tx_delay = phy_get_internal_delay(phydev, dev, &vsc8531_internal_delay[0],
> +						   delay_size, false);
> +	if (vsc8531->tx_delay < 0) {
> +		if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
> +		    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> +			vsc8531->rx_delay = RGMII_CLK_DELAY_2_0_NS;
> +		else
> +			vsc8531->rx_delay = RGMII_CLK_DELAY_0_2_NS;
> +	}
>  
>  	rc = vsc85xx_default_config(phydev);
>  	if (rc)
> -- 
> 2.17.1
>

RE: [PATCH net-next v4 2/2] phy: mscc: Add support for RGMII delay configuration

[Katakam, Harini]

Hi Vladimir,

> -----Original Message-----
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> Sent: Wednesday, May 24, 2023 3:39 PM
> To: Katakam, Harini <harini.katakam@amd.com>
> Cc: andrew@lunn.ch; hkallweit1@gmail.com; linux@armlinux.org.uk;
> davem@davemloft.net; kuba@kernel.org; edumazet@google.com;
> pabeni@redhat.com; wsa+renesas@sang-engineering.com;
> simon.horman@corigine.com; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; harinikatakamlinux@gmail.com; Simek, Michal
> <michal.simek@amd.com>; Pandey, Radhey Shyam
> <radhey.shyam.pandey@amd.com>
> Subject: Re: [PATCH net-next v4 2/2] phy: mscc: Add support for RGMII delay
> configuration
> 
> On Mon, May 22, 2023 at 05:58:29PM +0530, Harini Katakam wrote:
> > diff --git a/drivers/net/phy/mscc/mscc_main.c
> b/drivers/net/phy/mscc/mscc_main.c
> > index 91010524e03d..9e856231e464 100644
> > --- a/drivers/net/phy/mscc/mscc_main.c
> > +++ b/drivers/net/phy/mscc/mscc_main.c
> > @@ -525,17 +525,14 @@ static int vsc85xx_rgmii_set_skews(struct
> phy_device *phydev, u32 rgmii_cntl,
> >  {
> >  	u16 rgmii_rx_delay_pos = ffs(rgmii_rx_delay_mask) - 1;
> >  	u16 rgmii_tx_delay_pos = ffs(rgmii_tx_delay_mask) - 1;
> > +	struct vsc8531_private *vsc8531 = phydev->priv;
> >  	u16 reg_val = 0;
> >  	int rc;
> >
> >  	mutex_lock(&phydev->lock);
> >
> > -	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
> > -	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> > -		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_rx_delay_pos;
> > -	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
> > -	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> > -		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_tx_delay_pos;
> > +	reg_val |= vsc8531->rx_delay << rgmii_rx_delay_pos;
> > +	reg_val |= vsc8531->tx_delay << rgmii_tx_delay_pos;
> 
> What about vsc8584_config_init() -> vsc85xx_rgmii_set_skews()? Who will
> have configured rx_delay and tx_delay for that call path?

In my current series "rx_delay" and "tx_delay" would end up 0 and a
delay of 0.2 ns will be programmed (default for that field).
I guess if the phy-mode is RGMII/-ID on VSC8584, 2ns will not be programmed.
This will be a problem for any device not using vsc85xx_config_init

> 
> Isn't it better to absorb the device tree parsing logic into
> vsc85xx_rgmii_set_skews(), I wonder?

Yes, that is possible, let me respin. That will ensure existing values are not broken
for any VSC85xx user, if they do not have delay properties in the DT.

> 
> And if we do that, is it still necessary to use struct vsc8531_private
> as temporary storage space from vsc85xx_config_init() to
> vsc85xx_rgmii_set_skews(),
> or will two local variables (rx_delay, tx_delay) serve that purpose just fine?

No need of the structure member, local variables will do.

> 
> >
> >  	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2,
> >  			      rgmii_cntl,
> > @@ -1808,10 +1805,34 @@ static irqreturn_t
> vsc8584_handle_interrupt(struct phy_device *phydev)
> >  	return IRQ_HANDLED;
> >  }
> >
> > +static const int vsc8531_internal_delay[] = {200, 800, 1100, 1700, 2000,
> 2300,
> > +					     2600, 3400};
> 
> Could you please avoid intermingling this with the function code, and
> move it at the top of mscc_main.c?
> 
> Also, vsc8531_internal_delay[] or vsc85xx_internal_delay[]? The values
> are also good for VSC8572, the other caller of vsc85xx_rgmii_set_skews().

vsc85xx_internal_delay is more appropriate, will change.

Thanks for the review.

Regards,
Harini

Re: [PATCH net-next v4 0/2] Add support for VSC85xx DT RGMII delays

[Vladimir Oltean]

Hi Harini,

On Mon, May 22, 2023 at 05:58:27PM +0530, Harini Katakam wrote:
> Provide an option to change RGMII delay value via devicetree.
> 
> v4:
> - Remove VSC8531_02 support. Existing code will identify VSC8531_01/02
> and there is no unique functionality to be added for either version.
> - Correct type of rx/tx_delay to accept correct return value.
> - Added Andrew's tag to patch 1

Would you mind waiting until this patch set for "net" is merged first,
then rebasing your "net-next" work on top of it?
https://patchwork.kernel.org/project/netdevbpf/cover/20230523153108.18548-1-david.epping@missinglinkelectronics.com/

You should be able to resend your patch set tomorrow, after the net pull
request and the subsequent net -> net-next merge.

There are going to be merge conflicts if your series gets applied
simultaneously, and they're ugly enough that I would prefer you to deal
with them locally, before submitting, rather than leaving the netdev
maintainers do it.

RE: [PATCH net-next v4 0/2] Add support for VSC85xx DT RGMII delays

[Katakam, Harini]

Hi Vladimir,

> -----Original Message-----
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> Sent: Wednesday, May 24, 2023 3:27 PM
> To: Katakam, Harini <harini.katakam@amd.com>
> Cc: andrew@lunn.ch; hkallweit1@gmail.com; linux@armlinux.org.uk;
> davem@davemloft.net; kuba@kernel.org; edumazet@google.com;
> pabeni@redhat.com; wsa+renesas@sang-engineering.com;
> simon.horman@corigine.com; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; harinikatakamlinux@gmail.com; Simek, Michal
> <michal.simek@amd.com>; Pandey, Radhey Shyam
> <radhey.shyam.pandey@amd.com>
> Subject: Re: [PATCH net-next v4 0/2] Add support for VSC85xx DT RGMII
> delays
> 
> Hi Harini,
> 
> On Mon, May 22, 2023 at 05:58:27PM +0530, Harini Katakam wrote:
> > Provide an option to change RGMII delay value via devicetree.
> >
> > v4:
> > - Remove VSC8531_02 support. Existing code will identify VSC8531_01/02
> > and there is no unique functionality to be added for either version.
> > - Correct type of rx/tx_delay to accept correct return value.
> > - Added Andrew's tag to patch 1
> 
> Would you mind waiting until this patch set for "net" is merged first, then
> rebasing your "net-next" work on top of it?
> https://patchwork.kernel.org/project/netdevbpf/cover/20230523153108.1854
> 8-1-david.epping@missinglinkelectronics.com/
> 
> You should be able to resend your patch set tomorrow, after the net pull
> request and the subsequent net -> net-next merge.
> 
> There are going to be merge conflicts if your series gets applied
> simultaneously, and they're ugly enough that I would prefer you to deal with
> them locally, before submitting, rather than leaving the netdev maintainers do
> it.

Ok sure, I'll wait and rebase after the above set is merged.

Regards,
Harini