diff mbox series

[v4,2/2] net: phy: dp83826: support TX data voltage tuning

Message ID 20240212074649.806812-2-catalin.popescu@leica-geosystems.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [v4,1/2] dt-bindings: net: dp83826: support TX data voltage tuning | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 989 this patch: 989
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: edumazet@google.com
netdev/build_clang success Errors and warnings before: 1006 this patch: 1006
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1006 this patch: 1006
netdev/checkpatch warning WARNING: line length of 88 exceeds 80 columns WARNING: line length of 90 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 95 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-02-13--00-00 (tests: 1436)

Commit Message

POPESCU Catalin Feb. 12, 2024, 7:46 a.m. UTC
DP83826 offers the possibility to tune the voltage of logical
levels of the MLT-3 encoded TX data. This is useful when there
is a voltage drop in between the PHY and the connector and we
want to increase the voltage levels to compensate for that drop.

Prior to PHY configuration, the driver SW resets the PHY which has
the same effect as the HW reset pin according to the datasheet.
Hence, there's no need to force update the VOD_CFG registers to make
sure they hold their reset values. VOD_CFG registers need to be
updated only if the DT has been configured with values other than
the reset ones.

Signed-off-by: Catalin Popescu <catalin.popescu@leica-geosystems.com>
---
Changes in v2:
 - remove raw values mapping tables dp83826_cfg_dac_minus_raw/
   dp83826_cfg_dac_plus_raw and replace them with functions
   dp83826_to_dac_minus_one_regval/dp83826_to_dac_plus_one_regval
 - increase readability of function dp83826_config_init
 - change return value of function dp83826_of_init from int to void
   since it never returns any error

Changes in v3:
 - rename DT properties to "-bp"
 - rename DP83826_CFG_DAC_MPERCENT_DEFAULT/DP83826_CFG_DAC_MPERCENT_PER_STEP
   to DP83826_CFG_DAC_PERCENT_DEFAULT/DP83826_CFG_DAC_PERCENT_PER_STEP and
   update their values to reflect the new unit "basis point"
 - update commit message with explanation about the registers reset
   values

Changes in v4:
 - update commit message to be more meaningful
---
 drivers/net/phy/dp83822.c | 130 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 126 insertions(+), 4 deletions(-)

Comments

POPESCU Catalin Feb. 12, 2024, 2:15 p.m. UTC | #1
I just figured out that I forgot to disable WOL in the callback config_init.
It looks the PHY driver should explicitly disable WOL feature at init, 
and leave it to ethtool to be enabled.
I will provide a v5 ASAP to fix that.

On 12.02.24 08:46, Catalin Popescu wrote:
> DP83826 offers the possibility to tune the voltage of logical
> levels of the MLT-3 encoded TX data. This is useful when there
> is a voltage drop in between the PHY and the connector and we
> want to increase the voltage levels to compensate for that drop.
>
> Prior to PHY configuration, the driver SW resets the PHY which has
> the same effect as the HW reset pin according to the datasheet.
> Hence, there's no need to force update the VOD_CFG registers to make
> sure they hold their reset values. VOD_CFG registers need to be
> updated only if the DT has been configured with values other than
> the reset ones.
>
> Signed-off-by: Catalin Popescu <catalin.popescu@leica-geosystems.com>
> ---
> Changes in v2:
>   - remove raw values mapping tables dp83826_cfg_dac_minus_raw/
>     dp83826_cfg_dac_plus_raw and replace them with functions
>     dp83826_to_dac_minus_one_regval/dp83826_to_dac_plus_one_regval
>   - increase readability of function dp83826_config_init
>   - change return value of function dp83826_of_init from int to void
>     since it never returns any error
>
> Changes in v3:
>   - rename DT properties to "-bp"
>   - rename DP83826_CFG_DAC_MPERCENT_DEFAULT/DP83826_CFG_DAC_MPERCENT_PER_STEP
>     to DP83826_CFG_DAC_PERCENT_DEFAULT/DP83826_CFG_DAC_PERCENT_PER_STEP and
>     update their values to reflect the new unit "basis point"
>   - update commit message with explanation about the registers reset
>     values
>
> Changes in v4:
>   - update commit message to be more meaningful
> ---
>   drivers/net/phy/dp83822.c | 130 ++++++++++++++++++++++++++++++++++++--
>   1 file changed, 126 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
> index b7cb71817780..30f2616ab1c2 100644
> --- a/drivers/net/phy/dp83822.c
> +++ b/drivers/net/phy/dp83822.c
> @@ -12,6 +12,7 @@
>   #include <linux/of.h>
>   #include <linux/phy.h>
>   #include <linux/netdevice.h>
> +#include <linux/bitfield.h>
>   
>   #define DP83822_PHY_ID	        0x2000a240
>   #define DP83825S_PHY_ID		0x2000a140
> @@ -34,6 +35,10 @@
>   #define MII_DP83822_GENCFG	0x465
>   #define MII_DP83822_SOR1	0x467
>   
> +/* DP83826 specific registers */
> +#define MII_DP83826_VOD_CFG1	0x30b
> +#define MII_DP83826_VOD_CFG2	0x30c
> +
>   /* GENCFG */
>   #define DP83822_SIG_DET_LOW	BIT(0)
>   
> @@ -110,6 +115,19 @@
>   #define DP83822_RX_ER_STR_MASK	GENMASK(9, 8)
>   #define DP83822_RX_ER_SHIFT	8
>   
> +/* DP83826: VOD_CFG1 & VOD_CFG2 */
> +#define DP83826_VOD_CFG1_MINUS_MDIX_MASK	GENMASK(13, 12)
> +#define DP83826_VOD_CFG1_MINUS_MDI_MASK		GENMASK(11, 6)
> +#define DP83826_VOD_CFG2_MINUS_MDIX_MASK	GENMASK(15, 12)
> +#define DP83826_VOD_CFG2_PLUS_MDIX_MASK		GENMASK(11, 6)
> +#define DP83826_VOD_CFG2_PLUS_MDI_MASK		GENMASK(5, 0)
> +#define DP83826_CFG_DAC_MINUS_MDIX_5_TO_4	GENMASK(5, 4)
> +#define DP83826_CFG_DAC_MINUS_MDIX_3_TO_0	GENMASK(3, 0)
> +#define DP83826_CFG_DAC_PERCENT_PER_STEP	625
> +#define DP83826_CFG_DAC_PERCENT_DEFAULT		10000
> +#define DP83826_CFG_DAC_MINUS_DEFAULT		0x30
> +#define DP83826_CFG_DAC_PLUS_DEFAULT		0x10
> +
>   #define MII_DP83822_FIBER_ADVERTISE    (ADVERTISED_TP | ADVERTISED_MII | \
>   					ADVERTISED_FIBRE | \
>   					ADVERTISED_Pause | ADVERTISED_Asym_Pause)
> @@ -118,6 +136,8 @@ struct dp83822_private {
>   	bool fx_signal_det_low;
>   	int fx_enabled;
>   	u16 fx_sd_enable;
> +	u8 cfg_dac_minus;
> +	u8 cfg_dac_plus;
>   };
>   
>   static int dp83822_set_wol(struct phy_device *phydev,
> @@ -233,7 +253,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
>   				DP83822_ENERGY_DET_INT_EN |
>   				DP83822_LINK_QUAL_INT_EN);
>   
> -		/* Private data pointer is NULL on DP83825/26 */
> +		/* Private data pointer is NULL on DP83825 */
>   		if (!dp83822 || !dp83822->fx_enabled)
>   			misr_status |= DP83822_ANEG_COMPLETE_INT_EN |
>   				       DP83822_DUP_MODE_CHANGE_INT_EN |
> @@ -254,7 +274,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
>   				DP83822_PAGE_RX_INT_EN |
>   				DP83822_EEE_ERROR_CHANGE_INT_EN);
>   
> -		/* Private data pointer is NULL on DP83825/26 */
> +		/* Private data pointer is NULL on DP83825 */
>   		if (!dp83822 || !dp83822->fx_enabled)
>   			misr_status |= DP83822_ANEG_ERR_INT_EN |
>   				       DP83822_WOL_PKT_INT_EN;
> @@ -474,6 +494,43 @@ static int dp83822_config_init(struct phy_device *phydev)
>   	return dp8382x_disable_wol(phydev);
>   }
>   
> +static int dp83826_config_init(struct phy_device *phydev)
> +{
> +	struct dp83822_private *dp83822 = phydev->priv;
> +	u16 val, mask;
> +	int ret;
> +
> +	if (dp83822->cfg_dac_minus != DP83826_CFG_DAC_MINUS_DEFAULT) {
> +		val = FIELD_PREP(DP83826_VOD_CFG1_MINUS_MDI_MASK, dp83822->cfg_dac_minus) |
> +		      FIELD_PREP(DP83826_VOD_CFG1_MINUS_MDIX_MASK,
> +				 FIELD_GET(DP83826_CFG_DAC_MINUS_MDIX_5_TO_4,
> +					   dp83822->cfg_dac_minus));
> +		mask = DP83826_VOD_CFG1_MINUS_MDIX_MASK | DP83826_VOD_CFG1_MINUS_MDI_MASK;
> +		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG1, mask, val);
> +		if (ret)
> +			return ret;
> +
> +		val = FIELD_PREP(DP83826_VOD_CFG2_MINUS_MDIX_MASK,
> +				 FIELD_GET(DP83826_CFG_DAC_MINUS_MDIX_3_TO_0,
> +					   dp83822->cfg_dac_minus));
> +		mask = DP83826_VOD_CFG2_MINUS_MDIX_MASK;
> +		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG2, mask, val);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (dp83822->cfg_dac_plus != DP83826_CFG_DAC_PLUS_DEFAULT) {
> +		val = FIELD_PREP(DP83826_VOD_CFG2_PLUS_MDIX_MASK, dp83822->cfg_dac_plus) |
> +		      FIELD_PREP(DP83826_VOD_CFG2_PLUS_MDI_MASK, dp83822->cfg_dac_plus);
> +		mask = DP83826_VOD_CFG2_PLUS_MDIX_MASK | DP83826_VOD_CFG2_PLUS_MDI_MASK;
> +		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG2, mask, val);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   static int dp8382x_config_init(struct phy_device *phydev)
>   {
>   	return dp8382x_disable_wol(phydev);
> @@ -509,11 +566,44 @@ static int dp83822_of_init(struct phy_device *phydev)
>   
>   	return 0;
>   }
> +
> +static int dp83826_to_dac_minus_one_regval(int percent)
> +{
> +	int tmp = DP83826_CFG_DAC_PERCENT_DEFAULT - percent;
> +
> +	return tmp / DP83826_CFG_DAC_PERCENT_PER_STEP;
> +}
> +
> +static int dp83826_to_dac_plus_one_regval(int percent)
> +{
> +	int tmp = percent - DP83826_CFG_DAC_PERCENT_DEFAULT;
> +
> +	return tmp / DP83826_CFG_DAC_PERCENT_PER_STEP;
> +}
> +
> +static void dp83826_of_init(struct phy_device *phydev)
> +{
> +	struct dp83822_private *dp83822 = phydev->priv;
> +	struct device *dev = &phydev->mdio.dev;
> +	u32 val;
> +
> +	dp83822->cfg_dac_minus = DP83826_CFG_DAC_MINUS_DEFAULT;
> +	if (!device_property_read_u32(dev, "ti,cfg-dac-minus-one-bp", &val))
> +		dp83822->cfg_dac_minus += dp83826_to_dac_minus_one_regval(val);
> +
> +	dp83822->cfg_dac_plus = DP83826_CFG_DAC_PLUS_DEFAULT;
> +	if (!device_property_read_u32(dev, "ti,cfg-dac-plus-one-bp", &val))
> +		dp83822->cfg_dac_plus += dp83826_to_dac_plus_one_regval(val);
> +}
>   #else
>   static int dp83822_of_init(struct phy_device *phydev)
>   {
>   	return 0;
>   }
> +
> +static void dp83826_of_init(struct phy_device *phydev)
> +{
> +}
>   #endif /* CONFIG_OF_MDIO */
>   
>   static int dp83822_read_straps(struct phy_device *phydev)
> @@ -567,6 +657,22 @@ static int dp83822_probe(struct phy_device *phydev)
>   	return 0;
>   }
>   
> +static int dp83826_probe(struct phy_device *phydev)
> +{
> +	struct dp83822_private *dp83822;
> +
> +	dp83822 = devm_kzalloc(&phydev->mdio.dev, sizeof(*dp83822),
> +			       GFP_KERNEL);
> +	if (!dp83822)
> +		return -ENOMEM;
> +
> +	phydev->priv = dp83822;
> +
> +	dp83826_of_init(phydev);
> +
> +	return 0;
> +}
> +
>   static int dp83822_suspend(struct phy_device *phydev)
>   {
>   	int value;
> @@ -610,6 +716,22 @@ static int dp83822_resume(struct phy_device *phydev)
>   		.resume = dp83822_resume,			\
>   	}
>   
> +#define DP83826_PHY_DRIVER(_id, _name)				\
> +	{							\
> +		PHY_ID_MATCH_MODEL(_id),			\
> +		.name		= (_name),			\
> +		/* PHY_BASIC_FEATURES */			\
> +		.probe          = dp83826_probe,		\
> +		.soft_reset	= dp83822_phy_reset,		\
> +		.config_init	= dp83826_config_init,		\
> +		.get_wol = dp83822_get_wol,			\
> +		.set_wol = dp83822_set_wol,			\
> +		.config_intr = dp83822_config_intr,		\
> +		.handle_interrupt = dp83822_handle_interrupt,	\
> +		.suspend = dp83822_suspend,			\
> +		.resume = dp83822_resume,			\
> +	}
> +
>   #define DP8382X_PHY_DRIVER(_id, _name)				\
>   	{							\
>   		PHY_ID_MATCH_MODEL(_id),			\
> @@ -628,8 +750,8 @@ static int dp83822_resume(struct phy_device *phydev)
>   static struct phy_driver dp83822_driver[] = {
>   	DP83822_PHY_DRIVER(DP83822_PHY_ID, "TI DP83822"),
>   	DP8382X_PHY_DRIVER(DP83825I_PHY_ID, "TI DP83825I"),
> -	DP8382X_PHY_DRIVER(DP83826C_PHY_ID, "TI DP83826C"),
> -	DP8382X_PHY_DRIVER(DP83826NC_PHY_ID, "TI DP83826NC"),
> +	DP83826_PHY_DRIVER(DP83826C_PHY_ID, "TI DP83826C"),
> +	DP83826_PHY_DRIVER(DP83826NC_PHY_ID, "TI DP83826NC"),
>   	DP8382X_PHY_DRIVER(DP83825S_PHY_ID, "TI DP83825S"),
>   	DP8382X_PHY_DRIVER(DP83825CM_PHY_ID, "TI DP83825M"),
>   	DP8382X_PHY_DRIVER(DP83825CS_PHY_ID, "TI DP83825CS"),
Andrew Lunn Feb. 12, 2024, 2:37 p.m. UTC | #2
On Mon, Feb 12, 2024 at 02:15:47PM +0000, POPESCU Catalin wrote:
> I just figured out that I forgot to disable WOL in the callback config_init.
> It looks the PHY driver should explicitly disable WOL feature at init, 
> and leave it to ethtool to be enabled.
> I will provide a v5 ASAP to fix that.

WoL is a bit murky. On x86, it can be the BIOS which configures WoL,
behind the back of Linux. That is not something i would actually
recommend, so disabling it at boot does make sense. But consider
suspend and resume. If the PHY is used for WoL, the WoL settings
should be kept through suspend/resume. So you need to be careful where
you disable it, so its only disables on boot, not resume.

    Andrew
POPESCU Catalin Feb. 12, 2024, 3:04 p.m. UTC | #3
On 12.02.24 15:37, Andrew Lunn wrote:
> [Some people who received this message don't often get email from andrew@lunn.ch. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> This email is not from Hexagon’s Office 365 instance. Please be careful while clicking links, opening attachments, or replying to this email.
>
>
> On Mon, Feb 12, 2024 at 02:15:47PM +0000, POPESCU Catalin wrote:
>> I just figured out that I forgot to disable WOL in the callback config_init.
>> It looks the PHY driver should explicitly disable WOL feature at init,
>> and leave it to ethtool to be enabled.
>> I will provide a v5 ASAP to fix that.
> WoL is a bit murky. On x86, it can be the BIOS which configures WoL,
> behind the back of Linux. That is not something i would actually
> recommend, so disabling it at boot does make sense. But consider
> suspend and resume. If the PHY is used for WoL, the WoL settings
> should be kept through suspend/resume. So you need to be careful where
> you disable it, so its only disables on boot, not resume.
>
>      Andrew

I see. Then, I should not disable WOL in config_init, since this 
callback is also called on the resume path : 
mdio_bus_phy_resume->phy_init_hw->config_init.
However, this contrasts with the rest of the driver and my patch is not 
anymore about just adding support for tuning of TX voltage levels ...
Andrew Lunn Feb. 12, 2024, 3:07 p.m. UTC | #4
> I see. Then, I should not disable WOL in config_init, since this 
> callback is also called on the resume path : 
> mdio_bus_phy_resume->phy_init_hw->config_init.
> However, this contrasts with the rest of the driver and my patch is not 
> anymore about just adding support for tuning of TX voltage levels ...

So wait until your patch is merged and then follow up with another
patch disabling WoL. Patches get merged pretty quickly, so there is
plenty of time before the next merge window.

      Andrew
Andrew Lunn Feb. 13, 2024, 1:29 a.m. UTC | #5
On Mon, Feb 12, 2024 at 08:46:49AM +0100, Catalin Popescu wrote:
> DP83826 offers the possibility to tune the voltage of logical
> levels of the MLT-3 encoded TX data. This is useful when there
> is a voltage drop in between the PHY and the connector and we
> want to increase the voltage levels to compensate for that drop.
> 
> Prior to PHY configuration, the driver SW resets the PHY which has
> the same effect as the HW reset pin according to the datasheet.
> Hence, there's no need to force update the VOD_CFG registers to make
> sure they hold their reset values. VOD_CFG registers need to be
> updated only if the DT has been configured with values other than
> the reset ones.
> 
> Signed-off-by: Catalin Popescu <catalin.popescu@leica-geosystems.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

FYI: The WoL discussion should not prevent this from being merged.

    Andrew
diff mbox series

Patch

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index b7cb71817780..30f2616ab1c2 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -12,6 +12,7 @@ 
 #include <linux/of.h>
 #include <linux/phy.h>
 #include <linux/netdevice.h>
+#include <linux/bitfield.h>
 
 #define DP83822_PHY_ID	        0x2000a240
 #define DP83825S_PHY_ID		0x2000a140
@@ -34,6 +35,10 @@ 
 #define MII_DP83822_GENCFG	0x465
 #define MII_DP83822_SOR1	0x467
 
+/* DP83826 specific registers */
+#define MII_DP83826_VOD_CFG1	0x30b
+#define MII_DP83826_VOD_CFG2	0x30c
+
 /* GENCFG */
 #define DP83822_SIG_DET_LOW	BIT(0)
 
@@ -110,6 +115,19 @@ 
 #define DP83822_RX_ER_STR_MASK	GENMASK(9, 8)
 #define DP83822_RX_ER_SHIFT	8
 
+/* DP83826: VOD_CFG1 & VOD_CFG2 */
+#define DP83826_VOD_CFG1_MINUS_MDIX_MASK	GENMASK(13, 12)
+#define DP83826_VOD_CFG1_MINUS_MDI_MASK		GENMASK(11, 6)
+#define DP83826_VOD_CFG2_MINUS_MDIX_MASK	GENMASK(15, 12)
+#define DP83826_VOD_CFG2_PLUS_MDIX_MASK		GENMASK(11, 6)
+#define DP83826_VOD_CFG2_PLUS_MDI_MASK		GENMASK(5, 0)
+#define DP83826_CFG_DAC_MINUS_MDIX_5_TO_4	GENMASK(5, 4)
+#define DP83826_CFG_DAC_MINUS_MDIX_3_TO_0	GENMASK(3, 0)
+#define DP83826_CFG_DAC_PERCENT_PER_STEP	625
+#define DP83826_CFG_DAC_PERCENT_DEFAULT		10000
+#define DP83826_CFG_DAC_MINUS_DEFAULT		0x30
+#define DP83826_CFG_DAC_PLUS_DEFAULT		0x10
+
 #define MII_DP83822_FIBER_ADVERTISE    (ADVERTISED_TP | ADVERTISED_MII | \
 					ADVERTISED_FIBRE | \
 					ADVERTISED_Pause | ADVERTISED_Asym_Pause)
@@ -118,6 +136,8 @@  struct dp83822_private {
 	bool fx_signal_det_low;
 	int fx_enabled;
 	u16 fx_sd_enable;
+	u8 cfg_dac_minus;
+	u8 cfg_dac_plus;
 };
 
 static int dp83822_set_wol(struct phy_device *phydev,
@@ -233,7 +253,7 @@  static int dp83822_config_intr(struct phy_device *phydev)
 				DP83822_ENERGY_DET_INT_EN |
 				DP83822_LINK_QUAL_INT_EN);
 
-		/* Private data pointer is NULL on DP83825/26 */
+		/* Private data pointer is NULL on DP83825 */
 		if (!dp83822 || !dp83822->fx_enabled)
 			misr_status |= DP83822_ANEG_COMPLETE_INT_EN |
 				       DP83822_DUP_MODE_CHANGE_INT_EN |
@@ -254,7 +274,7 @@  static int dp83822_config_intr(struct phy_device *phydev)
 				DP83822_PAGE_RX_INT_EN |
 				DP83822_EEE_ERROR_CHANGE_INT_EN);
 
-		/* Private data pointer is NULL on DP83825/26 */
+		/* Private data pointer is NULL on DP83825 */
 		if (!dp83822 || !dp83822->fx_enabled)
 			misr_status |= DP83822_ANEG_ERR_INT_EN |
 				       DP83822_WOL_PKT_INT_EN;
@@ -474,6 +494,43 @@  static int dp83822_config_init(struct phy_device *phydev)
 	return dp8382x_disable_wol(phydev);
 }
 
+static int dp83826_config_init(struct phy_device *phydev)
+{
+	struct dp83822_private *dp83822 = phydev->priv;
+	u16 val, mask;
+	int ret;
+
+	if (dp83822->cfg_dac_minus != DP83826_CFG_DAC_MINUS_DEFAULT) {
+		val = FIELD_PREP(DP83826_VOD_CFG1_MINUS_MDI_MASK, dp83822->cfg_dac_minus) |
+		      FIELD_PREP(DP83826_VOD_CFG1_MINUS_MDIX_MASK,
+				 FIELD_GET(DP83826_CFG_DAC_MINUS_MDIX_5_TO_4,
+					   dp83822->cfg_dac_minus));
+		mask = DP83826_VOD_CFG1_MINUS_MDIX_MASK | DP83826_VOD_CFG1_MINUS_MDI_MASK;
+		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG1, mask, val);
+		if (ret)
+			return ret;
+
+		val = FIELD_PREP(DP83826_VOD_CFG2_MINUS_MDIX_MASK,
+				 FIELD_GET(DP83826_CFG_DAC_MINUS_MDIX_3_TO_0,
+					   dp83822->cfg_dac_minus));
+		mask = DP83826_VOD_CFG2_MINUS_MDIX_MASK;
+		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG2, mask, val);
+		if (ret)
+			return ret;
+	}
+
+	if (dp83822->cfg_dac_plus != DP83826_CFG_DAC_PLUS_DEFAULT) {
+		val = FIELD_PREP(DP83826_VOD_CFG2_PLUS_MDIX_MASK, dp83822->cfg_dac_plus) |
+		      FIELD_PREP(DP83826_VOD_CFG2_PLUS_MDI_MASK, dp83822->cfg_dac_plus);
+		mask = DP83826_VOD_CFG2_PLUS_MDIX_MASK | DP83826_VOD_CFG2_PLUS_MDI_MASK;
+		ret = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83826_VOD_CFG2, mask, val);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int dp8382x_config_init(struct phy_device *phydev)
 {
 	return dp8382x_disable_wol(phydev);
@@ -509,11 +566,44 @@  static int dp83822_of_init(struct phy_device *phydev)
 
 	return 0;
 }
+
+static int dp83826_to_dac_minus_one_regval(int percent)
+{
+	int tmp = DP83826_CFG_DAC_PERCENT_DEFAULT - percent;
+
+	return tmp / DP83826_CFG_DAC_PERCENT_PER_STEP;
+}
+
+static int dp83826_to_dac_plus_one_regval(int percent)
+{
+	int tmp = percent - DP83826_CFG_DAC_PERCENT_DEFAULT;
+
+	return tmp / DP83826_CFG_DAC_PERCENT_PER_STEP;
+}
+
+static void dp83826_of_init(struct phy_device *phydev)
+{
+	struct dp83822_private *dp83822 = phydev->priv;
+	struct device *dev = &phydev->mdio.dev;
+	u32 val;
+
+	dp83822->cfg_dac_minus = DP83826_CFG_DAC_MINUS_DEFAULT;
+	if (!device_property_read_u32(dev, "ti,cfg-dac-minus-one-bp", &val))
+		dp83822->cfg_dac_minus += dp83826_to_dac_minus_one_regval(val);
+
+	dp83822->cfg_dac_plus = DP83826_CFG_DAC_PLUS_DEFAULT;
+	if (!device_property_read_u32(dev, "ti,cfg-dac-plus-one-bp", &val))
+		dp83822->cfg_dac_plus += dp83826_to_dac_plus_one_regval(val);
+}
 #else
 static int dp83822_of_init(struct phy_device *phydev)
 {
 	return 0;
 }
+
+static void dp83826_of_init(struct phy_device *phydev)
+{
+}
 #endif /* CONFIG_OF_MDIO */
 
 static int dp83822_read_straps(struct phy_device *phydev)
@@ -567,6 +657,22 @@  static int dp83822_probe(struct phy_device *phydev)
 	return 0;
 }
 
+static int dp83826_probe(struct phy_device *phydev)
+{
+	struct dp83822_private *dp83822;
+
+	dp83822 = devm_kzalloc(&phydev->mdio.dev, sizeof(*dp83822),
+			       GFP_KERNEL);
+	if (!dp83822)
+		return -ENOMEM;
+
+	phydev->priv = dp83822;
+
+	dp83826_of_init(phydev);
+
+	return 0;
+}
+
 static int dp83822_suspend(struct phy_device *phydev)
 {
 	int value;
@@ -610,6 +716,22 @@  static int dp83822_resume(struct phy_device *phydev)
 		.resume = dp83822_resume,			\
 	}
 
+#define DP83826_PHY_DRIVER(_id, _name)				\
+	{							\
+		PHY_ID_MATCH_MODEL(_id),			\
+		.name		= (_name),			\
+		/* PHY_BASIC_FEATURES */			\
+		.probe          = dp83826_probe,		\
+		.soft_reset	= dp83822_phy_reset,		\
+		.config_init	= dp83826_config_init,		\
+		.get_wol = dp83822_get_wol,			\
+		.set_wol = dp83822_set_wol,			\
+		.config_intr = dp83822_config_intr,		\
+		.handle_interrupt = dp83822_handle_interrupt,	\
+		.suspend = dp83822_suspend,			\
+		.resume = dp83822_resume,			\
+	}
+
 #define DP8382X_PHY_DRIVER(_id, _name)				\
 	{							\
 		PHY_ID_MATCH_MODEL(_id),			\
@@ -628,8 +750,8 @@  static int dp83822_resume(struct phy_device *phydev)
 static struct phy_driver dp83822_driver[] = {
 	DP83822_PHY_DRIVER(DP83822_PHY_ID, "TI DP83822"),
 	DP8382X_PHY_DRIVER(DP83825I_PHY_ID, "TI DP83825I"),
-	DP8382X_PHY_DRIVER(DP83826C_PHY_ID, "TI DP83826C"),
-	DP8382X_PHY_DRIVER(DP83826NC_PHY_ID, "TI DP83826NC"),
+	DP83826_PHY_DRIVER(DP83826C_PHY_ID, "TI DP83826C"),
+	DP83826_PHY_DRIVER(DP83826NC_PHY_ID, "TI DP83826NC"),
 	DP8382X_PHY_DRIVER(DP83825S_PHY_ID, "TI DP83825S"),
 	DP8382X_PHY_DRIVER(DP83825CM_PHY_ID, "TI DP83825M"),
 	DP8382X_PHY_DRIVER(DP83825CS_PHY_ID, "TI DP83825CS"),