[PATCH v3 1/3] net: phy: bcm63xx: add support for BCM63268 GPHY

[Kyle Hendry <kylehendrydev@gmail.com>]

Add support for the internal gigabit PHY on the BCM63268 SoC.
Some of the PHY functionality is configured out of band through
memory mapped registers. The GPHY control register contains bits
which need to be written to enable/disable low power mode. The
register is part of the SoC's GPIO controller, so accessing it
is done through a phandle to that syscon.

Signed-off-by: Kyle Hendry <kylehendrydev@gmail.com>
---
 drivers/net/phy/bcm63xx.c | 101 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/drivers/net/phy/bcm63xx.c b/drivers/net/phy/bcm63xx.c
index b46a736a3130..9467bbf573e5 100644
--- a/drivers/net/phy/bcm63xx.c
+++ b/drivers/net/phy/bcm63xx.c
@@ -3,8 +3,11 @@
  *	Driver for Broadcom 63xx SOCs integrated PHYs
  */
 #include "bcm-phy-lib.h"
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/phy.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
 
 #define MII_BCM63XX_IR		0x1a	/* interrupt register */
 #define MII_BCM63XX_IR_EN	0x4000	/* global interrupt enable */
@@ -13,10 +16,20 @@
 #define MII_BCM63XX_IR_LINK	0x0200	/* link changed */
 #define MII_BCM63XX_IR_GMASK	0x0100	/* global interrupt mask */
 
+#define PHY_ID_BCM63268_GPHY	0x03625f50
+
+#define GPHY_CTRL_OFFSET	0x54
+#define GPHY_CTRL_IDDQ_BIAS	BIT(0)
+#define GPHY_CTRL_LOW_PWR	BIT(3)
+
 MODULE_DESCRIPTION("Broadcom 63xx internal PHY driver");
 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
 MODULE_LICENSE("GPL");
 
+struct bcm_gphy_priv {
+	struct regmap *gpio_ctrl;
+};
+
 static int bcm63xx_config_intr(struct phy_device *phydev)
 {
 	int reg, err;
@@ -69,6 +82,84 @@ static int bcm63xx_config_init(struct phy_device *phydev)
 	return phy_write(phydev, MII_BCM63XX_IR, reg);
 }
 
+static int bcm63268_gphy_set(struct phy_device *phydev, bool enable)
+{
+	struct bcm_gphy_priv *priv = phydev->priv;
+	u32 pwr_bits;
+	int ret;
+
+	pwr_bits = GPHY_CTRL_IDDQ_BIAS | GPHY_CTRL_LOW_PWR;
+
+	if (enable)
+		ret = regmap_update_bits(priv->gpio_ctrl, GPHY_CTRL_OFFSET, pwr_bits, 0);
+	else
+		ret = regmap_update_bits(priv->gpio_ctrl, GPHY_CTRL_OFFSET, pwr_bits, pwr_bits);
+
+	return ret;
+}
+
+static int bcm63268_gphy_resume(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = bcm63268_gphy_set(phydev, true);
+	if (ret)
+		return ret;
+
+	ret = genphy_resume(phydev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int bcm63268_gphy_suspend(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = genphy_suspend(phydev);
+	if (ret)
+		return ret;
+
+	ret = bcm63268_gphy_set(phydev, false);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int bcm63268_gphy_probe(struct phy_device *phydev)
+{
+	struct mdio_device *mdio = &phydev->mdio;
+	struct device *dev = &mdio->dev;
+	struct reset_control *reset;
+	struct bcm_gphy_priv *priv;
+	struct regmap *regmap;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	phydev->priv = priv;
+
+	regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "brcm,gpio-ctrl");
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	priv->gpio_ctrl = regmap;
+
+	reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(reset))
+		return PTR_ERR(reset);
+
+	ret = reset_control_reset(reset);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static struct phy_driver bcm63xx_driver[] = {
 {
 	.phy_id		= 0x00406000,
@@ -89,6 +180,15 @@ static struct phy_driver bcm63xx_driver[] = {
 	.config_init	= bcm63xx_config_init,
 	.config_intr	= bcm63xx_config_intr,
 	.handle_interrupt = bcm_phy_handle_interrupt,
+}, {
+	.phy_id         = PHY_ID_BCM63268_GPHY,
+	.phy_id_mask    = 0xfffffff0,
+	.name           = "Broadcom BCM63268 GPHY",
+	/* PHY_BASIC_FEATURES */
+	.flags          = PHY_IS_INTERNAL,
+	.probe          = bcm63268_gphy_probe,
+	.resume			= bcm63268_gphy_resume,
+	.suspend		= bcm63268_gphy_suspend,
 } };
 
 module_phy_driver(bcm63xx_driver);
@@ -96,6 +196,7 @@ module_phy_driver(bcm63xx_driver);
 static const struct mdio_device_id __maybe_unused bcm63xx_tbl[] = {
 	{ 0x00406000, 0xfffffc00 },
 	{ 0x002bdc00, 0xfffffc00 },
+	{ PHY_ID_MATCH_EXACT(PHY_ID_BCM63268_GPHY) },
 	{ }
 };
 
-- 
2.43.0