xref: /openbmc/linux/drivers/net/phy/national.c (revision a9d85efb)
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 	 */
73 	ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);
74 
75 	return ret;
76 }
77 
78 static irqreturn_t ns_handle_interrupt(struct phy_device *phydev)
79 {
80 	int irq_status;
81 
82 	irq_status = phy_read(phydev, DP83865_INT_STATUS);
83 	if (irq_status < 0) {
84 		phy_error(phydev);
85 		return IRQ_NONE;
86 	}
87 
88 	if (!(irq_status & DP83865_INT_MASK_DEFAULT))
89 		return IRQ_NONE;
90 
91 	/* clear the interrupt */
92 	phy_write(phydev, DP83865_INT_CLEAR, irq_status & ~0x7);
93 
94 	phy_trigger_machine(phydev);
95 
96 	return IRQ_HANDLED;
97 }
98 
99 static int ns_config_intr(struct phy_device *phydev)
100 {
101 	int err;
102 
103 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
104 		err = ns_ack_interrupt(phydev);
105 		if (err)
106 			return err;
107 
108 		err = phy_write(phydev, DP83865_INT_MASK,
109 				DP83865_INT_MASK_DEFAULT);
110 	} else {
111 		err = phy_write(phydev, DP83865_INT_MASK, 0);
112 		if (err)
113 			return err;
114 
115 		err = ns_ack_interrupt(phydev);
116 	}
117 
118 	return err;
119 }
120 
121 static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
122 {
123 	int bmcr = phy_read(phydev, MII_BMCR);
124 
125 	phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));
126 
127 	/* Enable 8 bit expended memory read/write (no auto increment) */
128 	phy_write(phydev, NS_EXP_MEM_CTL, 0);
129 	phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
130 	phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
131 	phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
132 	phy_write(phydev, LED_CTRL_REG, mode);
133 }
134 
135 static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
136 {
137 	u16 lb_dis = BIT(1);
138 
139 	if (disable)
140 		ns_exp_write(phydev, 0x1c0,
141 			     ns_exp_read(phydev, 0x1c0) | lb_dis);
142 	else
143 		ns_exp_write(phydev, 0x1c0,
144 			     ns_exp_read(phydev, 0x1c0) & ~lb_dis);
145 
146 	pr_debug("10BASE-T HDX loopback %s\n",
147 		 (ns_exp_read(phydev, 0x1c0) & lb_dis) ? "off" : "on");
148 }
149 
150 static int ns_config_init(struct phy_device *phydev)
151 {
152 	ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
153 	/* In the latest MAC or switches design, the 10 Mbps loopback
154 	 * is desired to be turned off.
155 	 */
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