microchip_t1: Add driver for Microchip LAN87XX T1 PHYs

Add driver for Microchip LAN87XX T1 PHYs

This patch support driver for Microchp T1 PHYs.
There will be followup patches to this driver to support T1 PHY
features such as cable diagnostics, signal quality indicator(SQI),
sleep and wakeup (TC10) support.

Signed-off-by: Nisar Sayed <Nisar.Sayed@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/Kconfig

@@ -360,6 +360,11 @@ config MICROCHIP_PHY
 	help
 	  Supports the LAN88XX PHYs.
 
+config MICROCHIP_T1_PHY
+	tristate "Microchip T1 PHYs"
+	---help---
+	  Supports the LAN87XX PHYs.
+
 config MICROSEMI_PHY
 	tristate "Microsemi PHYs"
 	---help---

drivers/net/phy/Makefile

@@ -71,6 +71,7 @@ obj-$(CONFIG_MESON_GXL_PHY)	+= meson-gxl.o
 obj-$(CONFIG_MICREL_KS8995MA)	+= spi_ks8995.o
 obj-$(CONFIG_MICREL_PHY)	+= micrel.o
 obj-$(CONFIG_MICROCHIP_PHY)	+= microchip.o
+obj-$(CONFIG_MICROCHIP_T1_PHY)	+= microchip_t1.o
 obj-$(CONFIG_MICROSEMI_PHY)	+= mscc.o
 obj-$(CONFIG_NATIONAL_PHY)	+= national.o
 obj-$(CONFIG_QSEMI_PHY)		+= qsemi.o

drivers/net/phy/microchip_t1.c

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Microchip Technology
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+
+/* Interrupt Source Register */
+#define LAN87XX_INTERRUPT_SOURCE                (0x18)
+
+/* Interrupt Mask Register */
+#define LAN87XX_INTERRUPT_MASK                  (0x19)
+#define LAN87XX_MASK_LINK_UP                    (0x0004)
+#define LAN87XX_MASK_LINK_DOWN                  (0x0002)
+
+#define DRIVER_AUTHOR	"Nisar Sayed <nisar.sayed@microchip.com>"
+#define DRIVER_DESC	"Microchip LAN87XX T1 PHY driver"
+
+static int lan87xx_phy_config_intr(struct phy_device *phydev)
+{
+	int rc, val = 0;
+
+	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
+		/* unmask all source and clear them before enable */
+		rc = phy_write(phydev, LAN87XX_INTERRUPT_MASK, 0x7FFF);
+		rc = phy_read(phydev, LAN87XX_INTERRUPT_SOURCE);
+		val = LAN87XX_MASK_LINK_UP | LAN87XX_MASK_LINK_DOWN;
+	}
+
+	rc = phy_write(phydev, LAN87XX_INTERRUPT_MASK, val);
+
+	return rc < 0 ? rc : 0;
+}
+
+static int lan87xx_phy_ack_interrupt(struct phy_device *phydev)
+{
+	int rc = phy_read(phydev, LAN87XX_INTERRUPT_SOURCE);
+
+	return rc < 0 ? rc : 0;
+}
+
+static struct phy_driver microchip_t1_phy_driver[] = {
+	{
+		.phy_id         = 0x0007c150,
+		.phy_id_mask    = 0xfffffff0,
+		.name           = "Microchip LAN87xx T1",
+
+		.features       = SUPPORTED_100baseT_Full,
+		.flags          = PHY_HAS_INTERRUPT,
+
+		.config_init    = genphy_config_init,
+		.config_aneg    = genphy_config_aneg,
+
+		.ack_interrupt  = lan87xx_phy_ack_interrupt,
+		.config_intr    = lan87xx_phy_config_intr,
+
+		.suspend        = genphy_suspend,
+		.resume         = genphy_resume,
+	}
+};
+
+module_phy_driver(microchip_t1_phy_driver);
+
+static struct mdio_device_id __maybe_unused microchip_t1_tbl[] = {
+	{ 0x0007c150, 0xfffffff0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, microchip_t1_tbl);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");