[PATCH v3 2/4] net: phy: dp83867: add support for MAC impedance configuration

Mugunthan V N
2016-10-06T05:13:53Z

Add support for programmable MAC impedance configuration

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
drivers/net/phy/dp83867.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 91177a4..1b63924 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -33,6 +33,7 @@
/* 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)
@@ -62,10 +63,17 @@
/* 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)
@@ -111,6 +119,14 @@ static int dp83867_of_init(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);
if (ret)
@@ -184,6 +200,18 @@ static int dp83867_config_init(struct phy_device *phydev)

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;
--
2.10.0.372.g6fe1b14