1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Driver for AMD am79c PHYs
  4 *
  5 * Author: Heiko Schocher <hs@denx.de>
  6 *
  7 * Copyright (c) 2011 DENX Software Engineering GmbH
  8 */
  9#include <linux/kernel.h>
 10#include <linux/errno.h>
 11#include <linux/init.h>
 12#include <linux/module.h>
 13#include <linux/mii.h>
 14#include <linux/phy.h>
 15
 16#define PHY_ID_AM79C874		0x0022561b
 17
 18#define MII_AM79C_IR		17	/* Interrupt Status/Control Register */
 19#define MII_AM79C_IR_EN_LINK	0x0400	/* IR enable Linkstate */
 20#define MII_AM79C_IR_EN_ANEG	0x0100	/* IR enable Aneg Complete */
 21#define MII_AM79C_IR_IMASK_INIT	(MII_AM79C_IR_EN_LINK | MII_AM79C_IR_EN_ANEG)
 22
 23#define MII_AM79C_IR_LINK_DOWN	BIT(2)
 24#define MII_AM79C_IR_ANEG_DONE	BIT(0)
 25#define MII_AM79C_IR_IMASK_STAT	(MII_AM79C_IR_LINK_DOWN | MII_AM79C_IR_ANEG_DONE)
 26
 27MODULE_DESCRIPTION("AMD PHY driver");
 28MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
 29MODULE_LICENSE("GPL");
 30
 31static int am79c_ack_interrupt(struct phy_device *phydev)
 32{
 33	int err;
 34
 35	err = phy_read(phydev, MII_BMSR);
 36	if (err < 0)
 37		return err;
 38
 39	err = phy_read(phydev, MII_AM79C_IR);
 40	if (err < 0)
 41		return err;
 42
 43	return 0;
 44}
 45
 46static int am79c_config_init(struct phy_device *phydev)
 47{
 48	return 0;
 49}
 50
 51static int am79c_config_intr(struct phy_device *phydev)
 52{
 53	int err;
 54
 55	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
 56		err = am79c_ack_interrupt(phydev);
 57		if (err)
 58			return err;
 59
 60		err = phy_write(phydev, MII_AM79C_IR, MII_AM79C_IR_IMASK_INIT);
 61	} else {
 62		err = phy_write(phydev, MII_AM79C_IR, 0);
 63		if (err)
 64			return err;
 65
 66		err = am79c_ack_interrupt(phydev);
 67	}
 68
 69	return err;
 70}
 71
 72static irqreturn_t am79c_handle_interrupt(struct phy_device *phydev)
 73{
 74	int irq_status;
 75
 76	irq_status = phy_read(phydev, MII_AM79C_IR);
 77	if (irq_status < 0) {
 78		phy_error(phydev);
 79		return IRQ_NONE;
 80	}
 81
 82	if (!(irq_status & MII_AM79C_IR_IMASK_STAT))
 83		return IRQ_NONE;
 84
 85	phy_trigger_machine(phydev);
 86
 87	return IRQ_HANDLED;
 88}
 89
 90static struct phy_driver am79c_driver[] = { {
 91	.phy_id		= PHY_ID_AM79C874,
 92	.name		= "AM79C874",
 93	.phy_id_mask	= 0xfffffff0,
 94	/* PHY_BASIC_FEATURES */
 95	.config_init	= am79c_config_init,
 96	.config_intr	= am79c_config_intr,
 97	.handle_interrupt = am79c_handle_interrupt,
 98} };
 99
100module_phy_driver(am79c_driver);
101
102static struct mdio_device_id __maybe_unused amd_tbl[] = {
103	{ PHY_ID_AM79C874, 0xfffffff0 },
104	{ }
105};
106
107MODULE_DEVICE_TABLE(mdio, amd_tbl);