xref: /openbmc/linux/drivers/net/phy/amd.c (revision 287dcc2b)
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 
27 MODULE_DESCRIPTION("AMD PHY driver");
28 MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
29 MODULE_LICENSE("GPL");
30 
31 static 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 
46 static int am79c_config_init(struct phy_device *phydev)
47 {
48 	return 0;
49 }
50 
51 static 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 
72 static 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 
90 static 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 
100 module_phy_driver(am79c_driver);
101 
102 static struct mdio_device_id __maybe_unused amd_tbl[] = {
103 	{ PHY_ID_AM79C874, 0xfffffff0 },
104 	{ }
105 };
106 
107 MODULE_DEVICE_TABLE(mdio, amd_tbl);
108