Merge branch 'dp83867-impedance-control'

Mugunthan V N says:

====================
add support for impedance control for TI dp83867 phy and fix 2nd ethernet on dra72 rev C evm

Add support for configurable impedance control for TI dp83867
phy via devicetree. More documentation in [1].
CPSW second ethernet is not working, fix it by enabling
impedance configuration on the phy.

Verified the patch on DRA72 Rev C evm, logs at [2]. Also pushed
a branch [3] for others to test.

Changes from v3:
* Fixup change log text and no code changes.

Changes from v2:
* Fixed a typo in dts and driver.

Changes from initial version:
* As per Sekhar's comment, instead of passing impedance values,
change to max and min impedance from DT
* Adopted phy_read_mmd_indirect() to cunnrent implementation.
* Corrected the phy delay timings to the optimal value.

[1] - http://www.ti.com/lit/ds/symlink/dp83867ir.pdf
[2] - http://pastebin.ubuntu.com/23343139/
[3] - git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux.git dp83867-v4
====================

Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/ti,dp83867.txt

···
 	- ti,fifo-depth - Transmitt FIFO depth- see dt-bindings/net/ti-dp83867.h
 		for applicable values
 
+Optional property:
+	- ti,min-output-impedance - MAC Interface Impedance control to set
+				    the programmable output impedance to
+				    minimum value (35 ohms).
+	- ti,max-output-impedance - MAC Interface Impedance control to set
+				    the programmable output impedance to
+				    maximum value (70 ohms).
+
+Note: ti,min-output-impedance and ti,max-output-impedance are mutually
+      exclusive. When both properties are present ti,max-output-impedance
+      takes precedence.
+
 Default child nodes are standard Ethernet PHY device
 nodes as described in Documentation/devicetree/bindings/net/phy.txt
 

arch/arm/boot/dts/dra72-evm-revc.dts

···
 &davinci_mdio {
 	dp83867_0: ethernet-phy@2 {
 		reg = <2>;
-		ti,rx-internal-delay = <DP83867_RGMIIDCTL_2_00_NS>;
-		ti,tx-internal-delay = <DP83867_RGMIIDCTL_1_NS>;
+		ti,rx-internal-delay = <DP83867_RGMIIDCTL_2_25_NS>;
+		ti,tx-internal-delay = <DP83867_RGMIIDCTL_250_PS>;
 		ti,fifo-depth = <DP83867_PHYCR_FIFO_DEPTH_8_B_NIB>;
+		ti,min-output-impedance;
 	};
 
 	dp83867_1: ethernet-phy@3 {
 		reg = <3>;
-		ti,rx-internal-delay = <DP83867_RGMIIDCTL_2_00_NS>;
-		ti,tx-internal-delay = <DP83867_RGMIIDCTL_1_NS>;
+		ti,rx-internal-delay = <DP83867_RGMIIDCTL_2_25_NS>;
+		ti,tx-internal-delay = <DP83867_RGMIIDCTL_250_PS>;
 		ti,fifo-depth = <DP83867_PHYCR_FIFO_DEPTH_8_B_NIB>;
+		ti,min-output-imepdance;
 	};
 };

drivers/net/phy/dp83867.c

···
 /* Extended Registers */
 #define DP83867_RGMIICTL	0x0032
 #define DP83867_RGMIIDCTL	0x0086
+#define DP83867_IO_MUX_CFG	0x0170
 
 #define DP83867_SW_RESET	BIT(15)
 #define DP83867_SW_RESTART	BIT(14)
···
 /* RGMIIDCTL bits */
 #define DP83867_RGMII_TX_CLK_DELAY_SHIFT	4
 
+/* IO_MUX_CFG bits */
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL	0x1f
+
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX	0x0
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN	0x1f
+
 struct dp83867_private {
 	int rx_id_delay;
 	int tx_id_delay;
 	int fifo_depth;
+	int io_impedance;
 };
 
 static int dp83867_ack_interrupt(struct phy_device *phydev)
···
 
 	if (!of_node)
 		return -ENODEV;
+
+	dp83867->io_impedance = -EINVAL;
+
+	/* Optional configuration */
+	if (of_property_read_bool(of_node, "ti,max-output-impedance"))
+		dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX;
+	else if (of_property_read_bool(of_node, "ti,min-output-impedance"))
+		dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN;
 
 	ret = of_property_read_u32(of_node, "ti,rx-internal-delay",
 				   &dp83867->rx_id_delay);
···
 
 		phy_write_mmd_indirect(phydev, DP83867_RGMIIDCTL,
 				       DP83867_DEVADDR, delay);
+
+		if (dp83867->io_impedance >= 0) {
+			val = phy_read_mmd_indirect(phydev, DP83867_IO_MUX_CFG,
+						    DP83867_DEVADDR);
+
+			val &= ~DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL;
+			val |= dp83867->io_impedance &
+			       DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL;
+
+			phy_write_mmd_indirect(phydev, DP83867_IO_MUX_CFG,
+					       DP83867_DEVADDR, val);
+		}
 	}
 
 	return 0;