xref: /openbmc/linux/drivers/net/phy/national.c (revision 3c6ee770)
1 /*
2  * drivers/net/phy/national.c
3  *
4  * Driver for National Semiconductor PHYs
5  *
6  * Author: Stuart Menefy <stuart.menefy@st.com>
7  * Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
8  *
9  * Copyright (c) 2008 STMicroelectronics Limited
10  *
11  * This program is free software; you can redistribute  it and/or modify it
12  * under  the terms of  the GNU General  Public License as published by the
13  * Free Software Foundation;  either version 2 of the  License, or (at your
14  * option) any later version.
15  *
16  */
17 
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mii.h>
23 #include <linux/ethtool.h>
24 #include <linux/phy.h>
25 #include <linux/netdevice.h>
26 
27 #define DEBUG
28 
29 /* DP83865 phy identifier values */
30 #define DP83865_PHY_ID	0x20005c7a
31 
32 #define DP83865_INT_STATUS	0x14
33 #define DP83865_INT_MASK	0x15
34 #define DP83865_INT_CLEAR	0x17
35 
36 #define DP83865_INT_REMOTE_FAULT 0x0008
37 #define DP83865_INT_ANE_COMPLETED 0x0010
38 #define DP83865_INT_LINK_CHANGE	0xe000
39 #define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
40 				DP83865_INT_ANE_COMPLETED | \
41 				DP83865_INT_LINK_CHANGE)
42 
43 /* Advanced proprietary configuration */
44 #define NS_EXP_MEM_CTL	0x16
45 #define NS_EXP_MEM_DATA	0x1d
46 #define NS_EXP_MEM_ADD	0x1e
47 
48 #define LED_CTRL_REG 0x13
49 #define AN_FALLBACK_AN 0x0001
50 #define AN_FALLBACK_CRC 0x0002
51 #define AN_FALLBACK_IE 0x0004
52 #define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)
53 
54 enum hdx_loopback {
55 	hdx_loopback_on = 0,
56 	hdx_loopback_off = 1,
57 };
58 
59 static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
60 {
61 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
62 	return phy_read(phydev, NS_EXP_MEM_DATA);
63 }
64 
65 static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
66 {
67 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
68 	phy_write(phydev, NS_EXP_MEM_DATA, data);
69 }
70 
71 static int ns_config_intr(struct phy_device *phydev)
72 {
73 	int err;
74 
75 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
76 		err = phy_write(phydev, DP83865_INT_MASK,
77 				DP83865_INT_MASK_DEFAULT);
78 	else
79 		err = phy_write(phydev, DP83865_INT_MASK, 0);
80 
81 	return err;
82 }
83 
84 static int ns_ack_interrupt(struct phy_device *phydev)
85 {
86 	int ret = phy_read(phydev, DP83865_INT_STATUS);
87 	if (ret < 0)
88 		return ret;
89 
90 	/* Clear the interrupt status bit by writing a “1”
91 	 * to the corresponding bit in INT_CLEAR (2:0 are reserved) */
92 	ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
93 
94 	return ret;
95 }
96 
97 static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
98 {
99 	int bmcr = phy_read(phydev, MII_BMCR);
100 
101 	phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
102 
103 	/* Enable 8 bit expended memory read/write (no auto increment) */
104 	phy_write(phydev, NS_EXP_MEM_CTL, 0);
105 	phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
106 	phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
107 	phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
108 	phy_write(phydev, LED_CTRL_REG, mode);
109 }
110 
111 static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
112 {
113 	if (disable)
114 		ns_exp_write(phydev, 0x1c0, ns_exp_read(phydev, 0x1c0) | 1);
115 	else
116 		ns_exp_write(phydev, 0x1c0,
117 			     ns_exp_read(phydev, 0x1c0) & 0xfffe);
118 
119 	pr_debug("10BASE-T HDX loopback %s\n",
120 		 (ns_exp_read(phydev, 0x1c0) & 0x0001) ? "off" : "on");
121 }
122 
123 static int ns_config_init(struct phy_device *phydev)
124 {
125 	ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
126 	/* In the latest MAC or switches design, the 10 Mbps loopback
127 	   is desired to be turned off. */
128 	ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
129 	return ns_ack_interrupt(phydev);
130 }
131 
132 static struct phy_driver dp83865_driver[] = { {
133 	.phy_id = DP83865_PHY_ID,
134 	.phy_id_mask = 0xfffffff0,
135 	.name = "NatSemi DP83865",
136 	.features = PHY_GBIT_FEATURES,
137 	.config_init = ns_config_init,
138 	.ack_interrupt = ns_ack_interrupt,
139 	.config_intr = ns_config_intr,
140 } };
141 
142 module_phy_driver(dp83865_driver);
143 
144 MODULE_DESCRIPTION("NatSemi PHY driver");
145 MODULE_AUTHOR("Stuart Menefy");
146 MODULE_LICENSE("GPL");
147 
148 static struct mdio_device_id __maybe_unused ns_tbl[] = {
149 	{ DP83865_PHY_ID, 0xfffffff0 },
150 	{ }
151 };
152 
153 MODULE_DEVICE_TABLE(mdio, ns_tbl);
154