xref: /kernel/linux/linux-6.6/drivers/net/phy/amd.c (revision 62306a36) 
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);
108