Re: [PATCH net-next v2 2/2] net: phy: qcom: qca808x: Add regulator management

From: Daniel Thompson <redacted>

QCA8081 appears in embedded board designs paired with GPIO controlled
regulators for its power rails. Add logic to allow these regulators to
be turned on during a probe.

In order to avoid the complexity of tracking state for suspend with and
without WoL we take a tremendously simple "always-on" approach to
regulator management, essentially relying on BMCR_PDOWN to conserve
power when the phy device exists.

Signed-off-by: Daniel Thompson <redacted>
Co-developed-by: Alex Elder <redacted>
Signed-off-by: Alex Elder <redacted>
---
 drivers/net/phy/qcom/qca808x.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/net/phy/qcom/qca808x.c b/drivers/net/phy/qcom/qca808x.c
index bab26e4c61408..4aba513b9a512 100644
--- a/drivers/net/phy/qcom/qca808x.c
+++ b/drivers/net/phy/qcom/qca808x.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 
 #include <linux/phy.h>
+#include <linux/regulator/consumer.h>
 #include <linux/module.h>
 
 #include "qcom.h"

@@ -181,15 +182,43 @@ static void qca808x_fill_possible_interfaces(struct phy_device *phydev)
 		__set_bit(PHY_INTERFACE_MODE_2500BASEX, possible);
 }
 
+static int qca808x_power_on(struct phy_device *phydev)
+{
+	static const char * const regulator_names[] = {
+		"avdd18", "vdd", "vdd18", "vdd125"
+	};
+	struct device *dev = &phydev->mdio.dev;
+	u32 count = 0;
+	int ret;
+
+	for (u32 i = 0; i < ARRAY_SIZE(regulator_names); i++) {
+		ret = devm_regulator_get_enable_optional(dev, regulator_names[i]);
+		if (!ret)
+			count++;
+		else if (ret != -ENODEV)
+			return ret;
+	}
+
+	if (count)
+		fsleep(phydev->mdio.reset_assert_delay);

+
+	return 0;
+}
+
 static int qca808x_probe(struct phy_device *phydev)
 {
 	struct device *dev = &phydev->mdio.dev;
 	struct qca808x_priv *priv;
+	int ret;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
+	ret = qca808x_power_on(phydev);
+	if (ret)
+		return ret;
+
 	priv->led_polarity_mode = QCA808X_PHY_LED_UNSET;
 
 	phydev->priv = priv;