xref: /openbmc/linux/drivers/net/phy/lxt.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * drivers/net/phy/lxt.c
4  *
5  * Driver for Intel LXT PHYs
6  *
7  * Author: Andy Fleming
8  *
9  * Copyright (c) 2004 Freescale Semiconductor, Inc.
10  */
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/unistd.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/delay.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/skbuff.h>
21 #include <linux/spinlock.h>
22 #include <linux/mm.h>
23 #include <linux/module.h>
24 #include <linux/mii.h>
25 #include <linux/ethtool.h>
26 #include <linux/phy.h>
27 
28 #include <asm/io.h>
29 #include <asm/irq.h>
30 #include <linux/uaccess.h>
31 
32 /* The Level one LXT970 is used by many boards				     */
33 
34 #define MII_LXT970_IER       17  /* Interrupt Enable Register */
35 
36 #define MII_LXT970_IER_IEN	0x0002
37 
38 #define MII_LXT970_ISR       18  /* Interrupt Status Register */
39 
40 #define MII_LXT970_CONFIG    19  /* Configuration Register    */
41 
42 /* ------------------------------------------------------------------------- */
43 /* The Level one LXT971 is used on some of my custom boards                  */
44 
45 /* register definitions for the 971 */
46 #define MII_LXT971_IER		18  /* Interrupt Enable Register */
47 #define MII_LXT971_IER_IEN	0x00f2
48 
49 #define MII_LXT971_ISR		19  /* Interrupt Status Register */
50 
51 /* register definitions for the 973 */
52 #define MII_LXT973_PCR 16 /* Port Configuration Register */
53 #define PCR_FIBER_SELECT 1
54 
55 MODULE_DESCRIPTION("Intel LXT PHY driver");
56 MODULE_AUTHOR("Andy Fleming");
57 MODULE_LICENSE("GPL");
58 
59 static int lxt970_ack_interrupt(struct phy_device *phydev)
60 {
61 	int err;
62 
63 	err = phy_read(phydev, MII_BMSR);
64 
65 	if (err < 0)
66 		return err;
67 
68 	err = phy_read(phydev, MII_LXT970_ISR);
69 
70 	if (err < 0)
71 		return err;
72 
73 	return 0;
74 }
75 
76 static int lxt970_config_intr(struct phy_device *phydev)
77 {
78 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
79 		return phy_write(phydev, MII_LXT970_IER, MII_LXT970_IER_IEN);
80 	else
81 		return phy_write(phydev, MII_LXT970_IER, 0);
82 }
83 
84 static int lxt970_config_init(struct phy_device *phydev)
85 {
86 	return phy_write(phydev, MII_LXT970_CONFIG, 0);
87 }
88 
89 
90 static int lxt971_ack_interrupt(struct phy_device *phydev)
91 {
92 	int err = phy_read(phydev, MII_LXT971_ISR);
93 
94 	if (err < 0)
95 		return err;
96 
97 	return 0;
98 }
99 
100 static int lxt971_config_intr(struct phy_device *phydev)
101 {
102 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
103 		return phy_write(phydev, MII_LXT971_IER, MII_LXT971_IER_IEN);
104 	else
105 		return phy_write(phydev, MII_LXT971_IER, 0);
106 }
107 
108 /*
109  * A2 version of LXT973 chip has an ERRATA: it randomly return the contents
110  * of the previous even register when you read a odd register regularly
111  */
112 
113 static int lxt973a2_update_link(struct phy_device *phydev)
114 {
115 	int status;
116 	int control;
117 	int retry = 8; /* we try 8 times */
118 
119 	/* Do a fake read */
120 	status = phy_read(phydev, MII_BMSR);
121 
122 	if (status < 0)
123 		return status;
124 
125 	control = phy_read(phydev, MII_BMCR);
126 	if (control < 0)
127 		return control;
128 
129 	do {
130 		/* Read link and autonegotiation status */
131 		status = phy_read(phydev, MII_BMSR);
132 	} while (status >= 0 && retry-- && status == control);
133 
134 	if (status < 0)
135 		return status;
136 
137 	if ((status & BMSR_LSTATUS) == 0)
138 		phydev->link = 0;
139 	else
140 		phydev->link = 1;
141 
142 	return 0;
143 }
144 
145 static int lxt973a2_read_status(struct phy_device *phydev)
146 {
147 	int adv;
148 	int err;
149 	int lpa;
150 
151 	/* Update the link, but return if there was an error */
152 	err = lxt973a2_update_link(phydev);
153 	if (err)
154 		return err;
155 
156 	if (AUTONEG_ENABLE == phydev->autoneg) {
157 		int retry = 1;
158 
159 		adv = phy_read(phydev, MII_ADVERTISE);
160 
161 		if (adv < 0)
162 			return adv;
163 
164 		do {
165 			lpa = phy_read(phydev, MII_LPA);
166 
167 			if (lpa < 0)
168 				return lpa;
169 
170 			/* If both registers are equal, it is suspect but not
171 			* impossible, hence a new try
172 			*/
173 		} while (lpa == adv && retry--);
174 
175 		mii_lpa_to_linkmode_lpa_t(phydev->lp_advertising, lpa);
176 
177 		lpa &= adv;
178 
179 		phydev->speed = SPEED_10;
180 		phydev->duplex = DUPLEX_HALF;
181 		phydev->pause = phydev->asym_pause = 0;
182 
183 		if (lpa & (LPA_100FULL | LPA_100HALF)) {
184 			phydev->speed = SPEED_100;
185 
186 			if (lpa & LPA_100FULL)
187 				phydev->duplex = DUPLEX_FULL;
188 		} else {
189 			if (lpa & LPA_10FULL)
190 				phydev->duplex = DUPLEX_FULL;
191 		}
192 
193 		phy_resolve_aneg_pause(phydev);
194 	} else {
195 		err = genphy_read_status_fixed(phydev);
196 		if (err < 0)
197 			return err;
198 
199 		phydev->pause = phydev->asym_pause = 0;
200 		linkmode_zero(phydev->lp_advertising);
201 	}
202 
203 	return 0;
204 }
205 
206 static int lxt973_probe(struct phy_device *phydev)
207 {
208 	int val = phy_read(phydev, MII_LXT973_PCR);
209 
210 	if (val & PCR_FIBER_SELECT) {
211 		/*
212 		 * If fiber is selected, then the only correct setting
213 		 * is 100Mbps, full duplex, and auto negotiation off.
214 		 */
215 		val = phy_read(phydev, MII_BMCR);
216 		val |= (BMCR_SPEED100 | BMCR_FULLDPLX);
217 		val &= ~BMCR_ANENABLE;
218 		phy_write(phydev, MII_BMCR, val);
219 		/* Remember that the port is in fiber mode. */
220 		phydev->priv = lxt973_probe;
221 	} else {
222 		phydev->priv = NULL;
223 	}
224 	return 0;
225 }
226 
227 static int lxt973_config_aneg(struct phy_device *phydev)
228 {
229 	/* Do nothing if port is in fiber mode. */
230 	return phydev->priv ? 0 : genphy_config_aneg(phydev);
231 }
232 
233 static struct phy_driver lxt97x_driver[] = {
234 {
235 	.phy_id		= 0x78100000,
236 	.name		= "LXT970",
237 	.phy_id_mask	= 0xfffffff0,
238 	/* PHY_BASIC_FEATURES */
239 	.config_init	= lxt970_config_init,
240 	.ack_interrupt	= lxt970_ack_interrupt,
241 	.config_intr	= lxt970_config_intr,
242 }, {
243 	.phy_id		= 0x001378e0,
244 	.name		= "LXT971",
245 	.phy_id_mask	= 0xfffffff0,
246 	/* PHY_BASIC_FEATURES */
247 	.ack_interrupt	= lxt971_ack_interrupt,
248 	.config_intr	= lxt971_config_intr,
249 	.suspend	= genphy_suspend,
250 	.resume		= genphy_resume,
251 }, {
252 	.phy_id		= 0x00137a10,
253 	.name		= "LXT973-A2",
254 	.phy_id_mask	= 0xffffffff,
255 	/* PHY_BASIC_FEATURES */
256 	.flags		= 0,
257 	.probe		= lxt973_probe,
258 	.config_aneg	= lxt973_config_aneg,
259 	.read_status	= lxt973a2_read_status,
260 	.suspend	= genphy_suspend,
261 	.resume		= genphy_resume,
262 }, {
263 	.phy_id		= 0x00137a10,
264 	.name		= "LXT973",
265 	.phy_id_mask	= 0xfffffff0,
266 	/* PHY_BASIC_FEATURES */
267 	.flags		= 0,
268 	.probe		= lxt973_probe,
269 	.config_aneg	= lxt973_config_aneg,
270 	.suspend	= genphy_suspend,
271 	.resume		= genphy_resume,
272 } };
273 
274 module_phy_driver(lxt97x_driver);
275 
276 static struct mdio_device_id __maybe_unused lxt_tbl[] = {
277 	{ 0x78100000, 0xfffffff0 },
278 	{ 0x001378e0, 0xfffffff0 },
279 	{ 0x00137a10, 0xfffffff0 },
280 	{ }
281 };
282 
283 MODULE_DEVICE_TABLE(mdio, lxt_tbl);
284