xref: /linux/drivers/net/phy/national.c (revision b7f8f259896f669f131713b0c74ba4d008daa71d)
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 /* DP83865 phy identifier values */
23 #define DP83865_PHY_ID	0x20005c7a
24 
25 #define DP83865_INT_STATUS	0x14
26 #define DP83865_INT_MASK	0x15
27 #define DP83865_INT_CLEAR	0x17
28 
29 #define DP83865_INT_REMOTE_FAULT 0x0008
30 #define DP83865_INT_ANE_COMPLETED 0x0010
31 #define DP83865_INT_LINK_CHANGE	0xe000
32 #define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
33 				DP83865_INT_ANE_COMPLETED | \
34 				DP83865_INT_LINK_CHANGE)
35 
36 /* Advanced proprietary configuration */
37 #define NS_EXP_MEM_CTL	0x16
38 #define NS_EXP_MEM_DATA	0x1d
39 #define NS_EXP_MEM_ADD	0x1e
40 
41 #define LED_CTRL_REG 0x13
42 #define AN_FALLBACK_AN 0x0001
43 #define AN_FALLBACK_CRC 0x0002
44 #define AN_FALLBACK_IE 0x0004
45 #define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)
46 
47 enum hdx_loopback {
48 	hdx_loopback_on = 0,
49 	hdx_loopback_off = 1,
50 };
51 
52 static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
53 {
54 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
55 	return phy_read(phydev, NS_EXP_MEM_DATA);
56 }
57 
58 static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
59 {
60 	phy_write(phydev, NS_EXP_MEM_ADD, reg);
61 	phy_write(phydev, NS_EXP_MEM_DATA, data);
62 }
63 
64 static int ns_ack_interrupt(struct phy_device *phydev)
65 {
66 	int ret = phy_read(phydev, DP83865_INT_STATUS);
67 	if (ret < 0)
68 		return ret;
69 
70 	/* Clear the interrupt status bit by writing a “1”
71 	 * to the corresponding bit in INT_CLEAR (2:0 are reserved) */
72 	ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
73 
74 	return ret;
75 }
76 
77 static irqreturn_t ns_handle_interrupt(struct phy_device *phydev)
78 {
79 	int irq_status;
80 
81 	irq_status = phy_read(phydev, DP83865_INT_STATUS);
82 	if (irq_status < 0) {
83 		phy_error(phydev);
84 		return IRQ_NONE;
85 	}
86 
87 	if (!(irq_status & DP83865_INT_MASK_DEFAULT))
88 		return IRQ_NONE;
89 
90 	/* clear the interrupt */
91 	phy_write(phydev, DP83865_INT_CLEAR, irq_status & ~0x7);
92 
93 	phy_trigger_machine(phydev);
94 
95 	return IRQ_HANDLED;
96 }
97 
98 static int ns_config_intr(struct phy_device *phydev)
99 {
100 	int err;
101 
102 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
103 		err = ns_ack_interrupt(phydev);
104 		if (err)
105 			return err;
106 
107 		err = phy_write(phydev, DP83865_INT_MASK,
108 				DP83865_INT_MASK_DEFAULT);
109 	} else {
110 		err = phy_write(phydev, DP83865_INT_MASK, 0);
111 		if (err)
112 			return err;
113 
114 		err = ns_ack_interrupt(phydev);
115 	}
116 
117 	return err;
118 }
119 
120 static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
121 {
122 	int bmcr = phy_read(phydev, MII_BMCR);
123 
124 	phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
125 
126 	/* Enable 8 bit expended memory read/write (no auto increment) */
127 	phy_write(phydev, NS_EXP_MEM_CTL, 0);
128 	phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
129 	phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
130 	phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
131 	phy_write(phydev, LED_CTRL_REG, mode);
132 }
133 
134 static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
135 {
136 	u16 lb_dis = BIT(1);
137 
138 	if (disable)
139 		ns_exp_write(phydev, 0x1c0,
140 			     ns_exp_read(phydev, 0x1c0) | lb_dis);
141 	else
142 		ns_exp_write(phydev, 0x1c0,
143 			     ns_exp_read(phydev, 0x1c0) & ~lb_dis);
144 
145 	pr_debug("10BASE-T HDX loopback %s\n",
146 		 (ns_exp_read(phydev, 0x1c0) & lb_dis) ? "off" : "on");
147 }
148 
149 static int ns_config_init(struct phy_device *phydev)
150 {
151 	ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
152 	/* In the latest MAC or switches design, the 10 Mbps loopback
153 	   is desired to be turned off. */
154 	ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
155 	return ns_ack_interrupt(phydev);
156 }
157 
158 static struct phy_driver dp83865_driver[] = { {
159 	.phy_id = DP83865_PHY_ID,
160 	.phy_id_mask = 0xfffffff0,
161 	.name = "NatSemi DP83865",
162 	/* PHY_GBIT_FEATURES */
163 	.config_init = ns_config_init,
164 	.config_intr = ns_config_intr,
165 	.handle_interrupt = ns_handle_interrupt,
166 } };
167 
168 module_phy_driver(dp83865_driver);
169 
170 MODULE_DESCRIPTION("NatSemi PHY driver");
171 MODULE_AUTHOR("Stuart Menefy");
172 MODULE_LICENSE("GPL");
173 
174 static struct mdio_device_id __maybe_unused ns_tbl[] = {
175 	{ DP83865_PHY_ID, 0xfffffff0 },
176 	{ }
177 };
178 
179 MODULE_DEVICE_TABLE(mdio, ns_tbl);
180