xref: /openbmc/linux/drivers/net/phy/national.c (revision 3a35093a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * drivers/net/phy/national.c
4  *
5  * Driver for National Semiconductor PHYs
6  *
7  * Author: Stuart Menefy <stuart.menefy@st.com>
8  * Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
9  *
10  * Copyright (c) 2008 STMicroelectronics Limited
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mii.h>
18 #include <linux/ethtool.h>
19 #include <linux/phy.h>
20 #include <linux/netdevice.h>
21 
22 #define DEBUG
23 
24 /* DP83865 phy identifier values */
25 #define DP83865_PHY_ID	0x20005c7a
26 
27 #define DP83865_INT_STATUS	0x14
28 #define DP83865_INT_MASK	0x15
29 #define DP83865_INT_CLEAR	0x17
30 
31 #define DP83865_INT_REMOTE_FAULT 0x0008
32 #define DP83865_INT_ANE_COMPLETED 0x0010
33 #define DP83865_INT_LINK_CHANGE	0xe000
34 #define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
35 				DP83865_INT_ANE_COMPLETED | \
36 				DP83865_INT_LINK_CHANGE)
37 
38 /* Advanced proprietary configuration */
39 #define NS_EXP_MEM_CTL	0x16
40 #define NS_EXP_MEM_DATA	0x1d
41 #define NS_EXP_MEM_ADD	0x1e
42 
43 #define LED_CTRL_REG 0x13
44 #define AN_FALLBACK_AN 0x0001
45 #define AN_FALLBACK_CRC 0x0002
46 #define AN_FALLBACK_IE 0x0004
47 #define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)
48 
49 enum hdx_loopback {
50 	hdx_loopback_on = 0,
51 	hdx_loopback_off = 1,
52 };
53 
54 static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
55 {
56 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
57 	return phy_read(phydev, NS_EXP_MEM_DATA);
58 }
59 
60 static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
61 {
62 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
63 	phy_write(phydev, NS_EXP_MEM_DATA, data);
64 }
65 
66 static int ns_ack_interrupt(struct phy_device *phydev)
67 {
68 	int ret = phy_read(phydev, DP83865_INT_STATUS);
69 	if (ret < 0)
70 		return ret;
71 
72 	/* Clear the interrupt status bit by writing a “1”
73 	 * to the corresponding bit in INT_CLEAR (2:0 are reserved) */
74 	ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
75 
76 	return ret;
77 }
78 
79 static irqreturn_t ns_handle_interrupt(struct phy_device *phydev)
80 {
81 	int irq_status;
82 
83 	irq_status = phy_read(phydev, DP83865_INT_STATUS);
84 	if (irq_status < 0) {
85 		phy_error(phydev);
86 		return IRQ_NONE;
87 	}
88 
89 	if (!(irq_status & DP83865_INT_MASK_DEFAULT))
90 		return IRQ_NONE;
91 
92 	/* clear the interrupt */
93 	phy_write(phydev, DP83865_INT_CLEAR, irq_status & ~0x7);
94 
95 	phy_trigger_machine(phydev);
96 
97 	return IRQ_HANDLED;
98 }
99 
100 static int ns_config_intr(struct phy_device *phydev)
101 {
102 	int err;
103 
104 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
105 		err = ns_ack_interrupt(phydev);
106 		if (err)
107 			return err;
108 
109 		err = phy_write(phydev, DP83865_INT_MASK,
110 				DP83865_INT_MASK_DEFAULT);
111 	} else {
112 		err = phy_write(phydev, DP83865_INT_MASK, 0);
113 		if (err)
114 			return err;
115 
116 		err = ns_ack_interrupt(phydev);
117 	}
118 
119 	return err;
120 }
121 
122 static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
123 {
124 	int bmcr = phy_read(phydev, MII_BMCR);
125 
126 	phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
127 
128 	/* Enable 8 bit expended memory read/write (no auto increment) */
129 	phy_write(phydev, NS_EXP_MEM_CTL, 0);
130 	phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
131 	phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
132 	phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
133 	phy_write(phydev, LED_CTRL_REG, mode);
134 }
135 
136 static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
137 {
138 	u16 lb_dis = BIT(1);
139 
140 	if (disable)
141 		ns_exp_write(phydev, 0x1c0,
142 			     ns_exp_read(phydev, 0x1c0) | lb_dis);
143 	else
144 		ns_exp_write(phydev, 0x1c0,
145 			     ns_exp_read(phydev, 0x1c0) & ~lb_dis);
146 
147 	pr_debug("10BASE-T HDX loopback %s\n",
148 		 (ns_exp_read(phydev, 0x1c0) & lb_dis) ? "off" : "on");
149 }
150 
151 static int ns_config_init(struct phy_device *phydev)
152 {
153 	ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
154 	/* In the latest MAC or switches design, the 10 Mbps loopback
155 	   is desired to be turned off. */
156 	ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
157 	return ns_ack_interrupt(phydev);
158 }
159 
160 static struct phy_driver dp83865_driver[] = { {
161 	.phy_id = DP83865_PHY_ID,
162 	.phy_id_mask = 0xfffffff0,
163 	.name = "NatSemi DP83865",
164 	/* PHY_GBIT_FEATURES */
165 	.config_init = ns_config_init,
166 	.config_intr = ns_config_intr,
167 	.handle_interrupt = ns_handle_interrupt,
168 } };
169 
170 module_phy_driver(dp83865_driver);
171 
172 MODULE_DESCRIPTION("NatSemi PHY driver");
173 MODULE_AUTHOR("Stuart Menefy");
174 MODULE_LICENSE("GPL");
175 
176 static struct mdio_device_id __maybe_unused ns_tbl[] = {
177 	{ DP83865_PHY_ID, 0xfffffff0 },
178 	{ }
179 };
180 
181 MODULE_DEVICE_TABLE(mdio, ns_tbl);
182