net: phy: dp83867: workaround incorrect RX_CTRL pin strap

Hi,

This patch series adds workaround for incorrect RX_CTRL pin strap setting that can be found on some TI boards.

This is required to be complaint to PHY datamanual specification.

Murali Karicheri (2):
dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL
pin strap
net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap

 Documentation/devicetree/bindings/net/ti,dp83867.txt |  7 +++++++
 drivers/net/phy/dp83867.c                            | 11 +++++++++++
 2 files changed, 18 insertions(+)

2.9.0

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From: Murali Karicheri <[email protected]>

The data manual for DP83867IR/CR, SNLS484E[1], revised march 2017, advises that strapping RX_DV/RX_CTRL pin in mode 1 and 2 is not supported (see note below Table 5 (4-Level Strap Pins)).

It further advises that if a board has this pin strapped in mode 1 and mode 2, then to ensure proper operation of the PHY, a software workaround must be implemented.

Since it is not possible to detect in software if RX_DV/RX_CTRL pin is incorrectly strapped, add a device-tree property for the board to advertise this and allow corrective action in software.

[1] http://www.ti.com/lit/ds/snls484e/snls484e.pdf

---
 Documentation/devicetree/bindings/net/ti,dp83867.txt | 7 +++++++
 1 file changed, 7 insertions(+)

index afe9630a5e7d..02c4353b5cf2 100644
@@ -18,6 +18,13 @@ Optional property:
 	- ti,max-output-impedance - MAC Interface Impedance control to set
 				    the programmable output impedance to
 				    maximum value (70 ohms).
+	- ti,dp83867-rxctrl-strap-quirk - This denotes the fact that the
+				    board has RX_DV/RX_CTRL pin strapped in
+				    mode 1 or 2. To ensure PHY operation,
+				    there are specific actions that
+				    software needs to take when this pin is
+				    strapped in these modes. See data manual
+				    for details.
 
 Note: ti,min-output-impedance and ti,max-output-impedance are mutually
       exclusive. When both properties are present ti,max-output-impedance

2.9.0

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From: Murali Karicheri <[email protected]>

The data manual for DP83867IR/CR, SNLS484E[1], revised march 2017, advises that strapping RX_DV/RX_CTRL pin in mode 1 and 2 is not supported (see note below Table 5 (4-Level Strap Pins)).

There are some boards which have the pin strapped this way and need software workaround suggested by the data manual. Bit[7] of Configuration Register 4 (address 0x0031) must be cleared to 0. This ensures proper operation of the PHY.

Implement driver support for device-tree property meant to advertise the wrong strapping.

[1] http://www.ti.com/lit/ds/snls484e/snls484e.pdf

---
 drivers/net/phy/dp83867.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

index b57f20e552ba..c1ab976cc800 100644
@@ -91,6 +91,7 @@ struct dp83867_private {
 	int fifo_depth;
 	int io_impedance;
 	int port_mirroring;
+	bool rxctrl_strap_quirk;
 };
 
 static int dp83867_ack_interrupt(struct phy_device *phydev)

@@ -164,6 +165,9 @@ static int dp83867_of_init(struct phy_device *phydev)
 	else if (of_property_read_bool(of_node, "ti,min-output-impedance"))
 		dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN;
 
+	dp83867->rxctrl_strap_quirk = of_property_read_bool(of_node,
+					"ti,dp83867-rxctrl-strap-quirk");
+
 	ret = of_property_read_u32(of_node, "ti,rx-internal-delay",
 				   &dp83867->rx_id_delay);
 	if (ret &&

@@ -214,6 +218,13 @@ static int dp83867_config_init(struct phy_device *phydev)
 		dp83867 = (struct dp83867_private *)phydev->priv;
 	}
 
+	/* RX_DV/RX_CTRL strapped in mode 1 or mode 2 workaround */
+	if (dp83867->rxctrl_strap_quirk) {
+		val = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_CFG4);
+		val &= ~BIT(7);
+		phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_CFG4, val);
+	}
+
 	if (phy_interface_is_rgmii(phydev)) {
 		val = phy_read(phydev, MII_DP83867_PHYCTRL);
 		if (val < 0)

2.9.0

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Hi Sekhar

Do you plan to post some DT patches to make use of this? It would be good to seem them as well.

Thanks
Andrew

Hi Andrew,

Actually I ended up posting those prior to this series (done in error) and have promised Tony a resend once this is accepted.

http://www.spinics.net/lists/devicetree/msg183487.html

I will Cc the same audience on the resend.

Thanks,
Sekhar
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From: Sekhar Nori <[email protected]>
Date: Tue, 4 Jul 2017 16:23:22 +0530

Series applied.