On Tue, Nov 17, 2020 at 02:15:55PM -0600, Dan Murphy wrote:

The DP83TD510E is an ultra-low power Ethernet physical layer transceiver
that supports 10M single pair cable.

The device supports both 2.4-V p2p and 1-V p2p output voltage as defined
by IEEE 802.3cg 10Base-T1L specfications. These modes can be forced via
the device tree or the device is defaulted to auto negotiation to
determine the proper p2p voltage.

Signed-off-by: Dan Murphy <redacted>
---

v4 - Considerable rework of the code after secondary test setup was created.
This version also uses the handle_interrupt call back and reduces the
configuration arrays as it was determined that 80% of the array was the same.

 drivers/net/phy/Kconfig     |   6 +
 drivers/net/phy/Makefile    |   1 +
 drivers/net/phy/dp83td510.c | 505 ++++++++++++++++++++++++++++++++++++
 3 files changed, 512 insertions(+)
 create mode 100644 drivers/net/phy/dp83td510.c

[snip]

+static int dp83td510_ack_interrupt(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = phy_read(phydev, DP83TD510_INT_REG1);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_read(phydev, DP83TD510_INT_REG2);
+	if (ret < 0)
+		return ret;
+
+	phy_trigger_machine(phydev);
+
+	return 0;
+}
+
+static irqreturn_t dp83td510_handle_interrupt(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = dp83td510_ack_interrupt(phydev);
+	if (ret)
+		return IRQ_NONE;
+
+	return IRQ_HANDLED;
+}

From what I can see in the datasheet, the INT_REG1 and INT_REG2 are used
for both interrupt configuration and interrupt status.

If this is the case, the state machine should only be triggered if the
interrupt was triggered (eg DP83TD510_INT1_LINK is set), not if _any_
bit from the register is set. This is broken since anytime you have
interrupts enabled, the lower half of the register will be non-zero
since that contains you interrupt enabled bits.

The .handle_interrupt() should look something like:

	ret = phy_read(phydev, DP83TD510_INT_REG1);
	if (ret < 0)
		return ret;
	
	if (!(ret & (DP83TD510_INT1_ESD | DP83TD510_INT1_LINK | DP83TD510_INT1_RHF)))
		return IRQ_NONE;

	ret = phy_read(phydev, DP83TD510_INT_REG2);
	if (ret < 0)
		return ret;
	
	if (!(ret & (DP83TD510_INT2_POR | DP83TD510_INT2_POL | DP83TD510_INT2_PAGE)))
		return IRQ_NONE;

	phy_trigger_machine(phydev);

	return IRQ_HANDLED;

+
+static int dp83td510_config_intr(struct phy_device *phydev)
+{
+	int int_status;
+	int gen_cfg_val;
+	int ret;
+
+	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
+		int_status = phy_read(phydev, DP83TD510_INT_REG1);
+		if (int_status < 0)
+			return int_status;
+
+		int_status = (DP83TD510_INT1_ESD_EN | DP83TD510_INT1_LINK_EN |
+			      DP83TD510_INT1_RHF_EN);
+
+		ret = phy_write(phydev, DP83TD510_INT_REG1, int_status);
+		if (ret)
+			return ret;
+
+		int_status = phy_read(phydev, DP83TD510_INT_REG2);
+		if (int_status < 0)
+			return int_status;
+
+		int_status = (DP83TD510_INT2_POR | DP83TD510_INT2_POL |
+				DP83TD510_INT2_PAGE);
+

Shouldn't you use DP83TD510_INT2_POR_EN, DP83TD510_INT2_POL_EN etc here?
It seems that you are setting up the bits corresponding with the
interrupt status and not the interrupt enable.

Ioana