[PATCH 1/1 RFC] net/phy: Add Lantiq PHY driver

[Alexander Stein <alexander.stein@systec-electronic.com>]

This currently only supports PEF7071 and allows to specify max-speed and
is able to read the LED configuration from device-tree.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
---
The main purpose for now is to set a LED configuration from device tree and
to limit the maximum speed. The latter one in my case hardware limited.
As MAC and it's link partner support 1000MBit/s they would try to use that
but will eventually fail due to magnetics only supporting 100MBit/s. So
limit the maximum link speed supported directly from the start.

As this is a RFC I skipped the device tree binding doc.

 drivers/net/phy/Kconfig  |   5 ++
 drivers/net/phy/Makefile |   1 +
 drivers/net/phy/lantiq.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 173 insertions(+)
 create mode 100644 drivers/net/phy/lantiq.c

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 3e28f7a..c004885 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -119,6 +119,11 @@ config STE10XP
 	---help---
 	  This is the driver for the STe100p and STe101p PHYs.
 
+config LANTIQ_PHY
+	tristate "Driver for Lantiq PHYs"
+	---help---
+	  Supports the PEF7071 PHYs.
+
 config LSI_ET1011C_PHY
 	tristate "Driver for LSI ET1011C PHY"
 	---help---
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 8ad4ac6..e886549 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_MDIO_SUN4I)	+= mdio-sun4i.o
 obj-$(CONFIG_MDIO_MOXART)	+= mdio-moxart.o
 obj-$(CONFIG_AMD_XGBE_PHY)	+= amd-xgbe-phy.o
 obj-$(CONFIG_MDIO_BCM_UNIMAC)	+= mdio-bcm-unimac.o
+obj-$(CONFIG_LANTIQ_PHY)	+= lantiq.o
diff --git a/drivers/net/phy/lantiq.c b/drivers/net/phy/lantiq.c
new file mode 100644
index 0000000..876a7d1
--- /dev/null
+++ b/drivers/net/phy/lantiq.c
@@ -0,0 +1,167 @@
+/*
+ * Driver for Lantiq PHYs
+ *
+ * Author: Alexander Stein <alexander.stein@systec-electronic.com>
+ *
+ * Copyright (c) 2015-2016 SYS TEC electronic GmbH
+ *
+ * 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;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/of.h>
+
+#define PHY_ID_PEF7071	0xd565a401
+
+#define MII_LANTIQ_MMD_CTRL_REG		0x0d
+#define MII_LANTIQ_MMD_REGDATA_REG	0x0e
+#define OP_DATA				1
+
+struct lantiqphy_led_ctrl {
+	const char *property;
+	u32 regnum;
+};
+
+static int lantiq_extended_write(struct phy_device *phydev,
+				 u8 mode, u32 dev_addr, u32 regnum, u16 val)
+{
+	phy_write(phydev, MII_LANTIQ_MMD_CTRL_REG, dev_addr);
+	phy_write(phydev, MII_LANTIQ_MMD_REGDATA_REG, regnum);
+	phy_write(phydev, MII_LANTIQ_MMD_CTRL_REG, (mode << 14) | dev_addr);
+	return phy_write(phydev, MII_LANTIQ_MMD_REGDATA_REG, val);
+}
+
+static int lantiq_of_load_led_config(struct phy_device *phydev,
+				     struct device_node *of_node,
+				     const struct lantiqphy_led_ctrl *leds,
+				     u8 entries)
+{
+	u16 val;
+	int i;
+	int ret = 0;
+
+	for (i = 0; i < entries; i++) {
+		if (!of_property_read_u16(of_node, leds[i].property, &val)) {
+			ret = lantiq_extended_write(phydev, OP_DATA, 0x1f,
+						    leds[i].regnum, val);
+			if (ret) {
+				dev_err(&phydev->dev, "Error writing register 0x1f.%04x (%d)\n",
+					leds[i].regnum, ret);
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static const struct lantiqphy_led_ctrl leds[] = {
+	{
+		.property = "led0h",
+		.regnum = 0x01e2,
+	},
+	{
+		.property = "led0l",
+		.regnum = 0x01e3,
+	},
+	{
+		.property = "led1h",
+		.regnum = 0x01e4,
+	},
+	{
+		.property = "led1l",
+		.regnum = 0x01e5,
+	},
+	{
+		.property = "led2h",
+		.regnum = 0x01e6,
+	},
+	{
+		.property = "led2l",
+		.regnum = 0x01e7,
+	},
+};
+
+static int lantiqphy_config_init(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->dev;
+	struct device_node *of_node = dev->of_node;
+	u32 max_speed;
+
+	if (!of_node && dev->parent->of_node)
+		of_node = dev->parent->of_node;
+
+	if (of_node) {
+		lantiq_of_load_led_config(phydev, of_node, leds,
+					  ARRAY_SIZE(leds));
+
+		if (!of_property_read_u32(of_node, "max-speed",
+					  &max_speed)) {
+			/* The default values for phydev->supported are
+			 * provided by the PHY driver "features" member,
+			 * we want to reset to sane defaults fist before
+			 * supporting higher speeds.
+			 */
+			phydev->supported &= PHY_DEFAULT_FEATURES;
+
+			switch (max_speed) {
+			default:
+				break;
+
+			case SPEED_1000:
+				phydev->supported |= PHY_1000BT_FEATURES;
+			case SPEED_100:
+				phydev->supported |= PHY_100BT_FEATURES;
+			case SPEED_10:
+				phydev->supported |= PHY_10BT_FEATURES;
+			}
+		}
+	}
+	return 0;
+}
+
+static struct phy_driver lantiqphy_driver[] = {
+{
+	.phy_id		= PHY_ID_PEF7071,
+	.phy_id_mask	= 0x00fffffe,
+	.name		= "Lantiq PEF7071",
+	.features	= (PHY_GBIT_FEATURES | SUPPORTED_Pause),
+	.flags		= PHY_HAS_MAGICANEG,
+	.config_init	= lantiqphy_config_init,
+	.config_aneg	= genphy_config_aneg,
+	.read_status	= genphy_read_status,
+	.suspend	= genphy_suspend,
+	.resume		= genphy_resume,
+	.driver		= { .owner = THIS_MODULE,},
+} };
+
+static int __init lantiqphy_init(void)
+{
+	return phy_drivers_register(lantiqphy_driver,
+				    ARRAY_SIZE(lantiqphy_driver));
+}
+
+static void __exit lantiqphy_exit(void)
+{
+	phy_drivers_unregister(lantiqphy_driver,
+			       ARRAY_SIZE(lantiqphy_driver));
+}
+
+module_init(lantiqphy_init);
+module_exit(lantiqphy_exit);
+
+MODULE_DESCRIPTION("Lantiq PHY driver");
+MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
+MODULE_LICENSE("GPL");
+
+static struct mdio_device_id __maybe_unused lantiq_tbl[] = {
+	{ PHY_ID_PEF7071, 0x00fffffe },
+	{ }
+};
+MODULE_DEVICE_TABLE(mdio, lantiq_tbl);
-- 
2.7.3