phy: Add Northstar2 PCI Phy support

Add PCI Phy support for Broadcom Northstar2 SoCs.  This driver uses the
interface from the iproc mdio mux driver to enable the devices
respective phys.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jon Mason <jonmason@broadcom.com>
Signed-off-by: Pramod Kumar <pramod.kumar@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/phy/Kconfig

@@ -434,4 +434,12 @@ config PHY_CYGNUS_PCIE
 
 source "drivers/phy/tegra/Kconfig"
 
+config PHY_NS2_PCIE
+	tristate "Broadcom Northstar2 PCIe PHY driver"
+	depends on OF && MDIO_BUS_MUX_BCM_IPROC
+	select GENERIC_PHY
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Northstar2 PCIe PHY.
+	  If unsure, say N.
 endmenu

drivers/phy/Makefile

@@ -53,5 +53,5 @@ obj-$(CONFIG_PHY_TUSB1210)		+= phy-tusb1210.o
 obj-$(CONFIG_PHY_BRCM_SATA)		+= phy-brcm-sata.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
-
 obj-$(CONFIG_ARCH_TEGRA) += tegra/
+obj-$(CONFIG_PHY_NS2_PCIE)		+= phy-bcm-ns2-pcie.o

drivers/phy/phy-bcm-ns2-pcie.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_mdio.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
+#include <linux/phy/phy.h>
+
+struct ns2_pci_phy {
+	struct mdio_device *mdiodev;
+	struct phy *phy;
+};
+
+#define BLK_ADDR_REG_OFFSET	0x1f
+#define PLL_AFE1_100MHZ_BLK	0x2100
+#define PLL_CLK_AMP_OFFSET	0x03
+#define PLL_CLK_AMP_2P05V	0x2b18
+
+static int ns2_pci_phy_init(struct phy *p)
+{
+	struct ns2_pci_phy *phy = phy_get_drvdata(p);
+	int rc;
+
+	/* select the AFE 100MHz block page */
+	rc = mdiobus_write(phy->mdiodev->bus, phy->mdiodev->addr,
+			   BLK_ADDR_REG_OFFSET, PLL_AFE1_100MHZ_BLK);
+	if (rc)
+		goto err;
+
+	/* set the 100 MHz reference clock amplitude to 2.05 v */
+	rc = mdiobus_write(phy->mdiodev->bus, phy->mdiodev->addr,
+			   PLL_CLK_AMP_OFFSET, PLL_CLK_AMP_2P05V);
+	if (rc)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&phy->mdiodev->dev, "Error %d writing to phy\n", rc);
+	return rc;
+}
+
+static struct phy_ops ns2_pci_phy_ops = {
+	.init = ns2_pci_phy_init,
+};
+
+static int ns2_pci_phy_probe(struct mdio_device *mdiodev)
+{
+	struct device *dev = &mdiodev->dev;
+	struct phy_provider *provider;
+	struct ns2_pci_phy *p;
+	struct phy *phy;
+
+	phy = devm_phy_create(dev, dev->of_node, &ns2_pci_phy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create Phy\n");
+		return PTR_ERR(phy);
+	}
+
+	p = devm_kmalloc(dev, sizeof(struct ns2_pci_phy),
+			 GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p->mdiodev = mdiodev;
+	dev_set_drvdata(dev, p);
+
+	p->phy = phy;
+	phy_set_drvdata(phy, p);
+
+	provider = devm_of_phy_provider_register(&phy->dev,
+						 of_phy_simple_xlate);
+	if (IS_ERR(provider)) {
+		dev_err(dev, "failed to register Phy provider\n");
+		return PTR_ERR(provider);
+	}
+
+	dev_info(dev, "%s PHY registered\n", dev_name(dev));
+
+	return 0;
+}
+
+static const struct of_device_id ns2_pci_phy_of_match[] = {
+	{ .compatible = "brcm,ns2-pcie-phy", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ns2_pci_phy_of_match);
+
+static struct mdio_driver ns2_pci_phy_driver = {
+	.mdiodrv = {
+		.driver = {
+			.name = "phy-bcm-ns2-pci",
+			.of_match_table = ns2_pci_phy_of_match,
+		},
+	},
+	.probe = ns2_pci_phy_probe,
+};
+mdio_module_driver(ns2_pci_phy_driver);
+
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Broadcom Northstar2 PCI Phy driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:phy-bcm-ns2-pci");