xref: /openbmc/linux/drivers/net/phy/lxt.c (revision 36acd5e2)
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_IRS_MINT  BIT(15)
41 
42 #define MII_LXT970_CONFIG    19  /* Configuration Register    */
43 
44 /* ------------------------------------------------------------------------- */
45 /* The Level one LXT971 is used on some of my custom boards                  */
46 
47 /* register definitions for the 971 */
48 #define MII_LXT971_IER		18  /* Interrupt Enable Register */
49 #define MII_LXT971_IER_IEN	0x00f2
50 
51 #define MII_LXT971_ISR		19  /* Interrupt Status Register */
52 #define MII_LXT971_ISR_MASK	0x00f0
53 
54 /* register definitions for the 973 */
55 #define MII_LXT973_PCR 16 /* Port Configuration Register */
56 #define PCR_FIBER_SELECT 1
57 
58 MODULE_DESCRIPTION("Intel LXT PHY driver");
59 MODULE_AUTHOR("Andy Fleming");
60 MODULE_LICENSE("GPL");
61 
62 static int lxt970_ack_interrupt(struct phy_device *phydev)
63 {
64 	int err;
65 
66 	err = phy_read(phydev, MII_BMSR);
67 
68 	if (err < 0)
69 		return err;
70 
71 	err = phy_read(phydev, MII_LXT970_ISR);
72 
73 	if (err < 0)
74 		return err;
75 
76 	return 0;
77 }
78 
79 static int lxt970_config_intr(struct phy_device *phydev)
80 {
81 	int err;
82 
83 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
84 		err = lxt970_ack_interrupt(phydev);
85 		if (err)
86 			return err;
87 
88 		err = phy_write(phydev, MII_LXT970_IER, MII_LXT970_IER_IEN);
89 	} else {
90 		err = phy_write(phydev, MII_LXT970_IER, 0);
91 		if (err)
92 			return err;
93 
94 		err = lxt970_ack_interrupt(phydev);
95 	}
96 
97 	return err;
98 }
99 
100 static irqreturn_t lxt970_handle_interrupt(struct phy_device *phydev)
101 {
102 	int irq_status;
103 
104 	/* The interrupt status register is cleared by reading BMSR
105 	 * followed by MII_LXT970_ISR
106 	 */
107 	irq_status = phy_read(phydev, MII_BMSR);
108 	if (irq_status < 0) {
109 		phy_error(phydev);
110 		return IRQ_NONE;
111 	}
112 
113 	irq_status = phy_read(phydev, MII_LXT970_ISR);
114 	if (irq_status < 0) {
115 		phy_error(phydev);
116 		return IRQ_NONE;
117 	}
118 
119 	if (!(irq_status & MII_LXT970_IRS_MINT))
120 		return IRQ_NONE;
121 
122 	phy_trigger_machine(phydev);
123 
124 	return IRQ_HANDLED;
125 }
126 
127 static int lxt970_config_init(struct phy_device *phydev)
128 {
129 	return phy_write(phydev, MII_LXT970_CONFIG, 0);
130 }
131 
132 
133 static int lxt971_ack_interrupt(struct phy_device *phydev)
134 {
135 	int err = phy_read(phydev, MII_LXT971_ISR);
136 
137 	if (err < 0)
138 		return err;
139 
140 	return 0;
141 }
142 
143 static int lxt971_config_intr(struct phy_device *phydev)
144 {
145 	int err;
146 
147 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
148 		err = lxt971_ack_interrupt(phydev);
149 		if (err)
150 			return err;
151 
152 		err = phy_write(phydev, MII_LXT971_IER, MII_LXT971_IER_IEN);
153 	} else {
154 		err = phy_write(phydev, MII_LXT971_IER, 0);
155 		if (err)
156 			return err;
157 
158 		err = lxt971_ack_interrupt(phydev);
159 	}
160 
161 	return err;
162 }
163 
164 static irqreturn_t lxt971_handle_interrupt(struct phy_device *phydev)
165 {
166 	int irq_status;
167 
168 	irq_status = phy_read(phydev, MII_LXT971_ISR);
169 	if (irq_status < 0) {
170 		phy_error(phydev);
171 		return IRQ_NONE;
172 	}
173 
174 	if (!(irq_status & MII_LXT971_ISR_MASK))
175 		return IRQ_NONE;
176 
177 	phy_trigger_machine(phydev);
178 
179 	return IRQ_HANDLED;
180 }
181 
182 /*
183  * A2 version of LXT973 chip has an ERRATA: it randomly return the contents
184  * of the previous even register when you read a odd register regularly
185  */
186 
187 static int lxt973a2_update_link(struct phy_device *phydev)
188 {
189 	int status;
190 	int control;
191 	int retry = 8; /* we try 8 times */
192 
193 	/* Do a fake read */
194 	status = phy_read(phydev, MII_BMSR);
195 
196 	if (status < 0)
197 		return status;
198 
199 	control = phy_read(phydev, MII_BMCR);
200 	if (control < 0)
201 		return control;
202 
203 	do {
204 		/* Read link and autonegotiation status */
205 		status = phy_read(phydev, MII_BMSR);
206 	} while (status >= 0 && retry-- && status == control);
207 
208 	if (status < 0)
209 		return status;
210 
211 	if ((status & BMSR_LSTATUS) == 0)
212 		phydev->link = 0;
213 	else
214 		phydev->link = 1;
215 
216 	return 0;
217 }
218 
219 static int lxt973a2_read_status(struct phy_device *phydev)
220 {
221 	int adv;
222 	int err;
223 	int lpa;
224 
225 	/* Update the link, but return if there was an error */
226 	err = lxt973a2_update_link(phydev);
227 	if (err)
228 		return err;
229 
230 	if (AUTONEG_ENABLE == phydev->autoneg) {
231 		int retry = 1;
232 
233 		adv = phy_read(phydev, MII_ADVERTISE);
234 
235 		if (adv < 0)
236 			return adv;
237 
238 		do {
239 			lpa = phy_read(phydev, MII_LPA);
240 
241 			if (lpa < 0)
242 				return lpa;
243 
244 			/* If both registers are equal, it is suspect but not
245 			* impossible, hence a new try
246 			*/
247 		} while (lpa == adv && retry--);
248 
249 		mii_lpa_to_linkmode_lpa_t(phydev->lp_advertising, lpa);
250 
251 		lpa &= adv;
252 
253 		phydev->speed = SPEED_10;
254 		phydev->duplex = DUPLEX_HALF;
255 		phydev->pause = phydev->asym_pause = 0;
256 
257 		if (lpa & (LPA_100FULL | LPA_100HALF)) {
258 			phydev->speed = SPEED_100;
259 
260 			if (lpa & LPA_100FULL)
261 				phydev->duplex = DUPLEX_FULL;
262 		} else {
263 			if (lpa & LPA_10FULL)
264 				phydev->duplex = DUPLEX_FULL;
265 		}
266 
267 		phy_resolve_aneg_pause(phydev);
268 	} else {
269 		err = genphy_read_status_fixed(phydev);
270 		if (err < 0)
271 			return err;
272 
273 		phydev->pause = phydev->asym_pause = 0;
274 		linkmode_zero(phydev->lp_advertising);
275 	}
276 
277 	return 0;
278 }
279 
280 static int lxt973_probe(struct phy_device *phydev)
281 {
282 	int val = phy_read(phydev, MII_LXT973_PCR);
283 
284 	if (val & PCR_FIBER_SELECT) {
285 		/*
286 		 * If fiber is selected, then the only correct setting
287 		 * is 100Mbps, full duplex, and auto negotiation off.
288 		 */
289 		val = phy_read(phydev, MII_BMCR);
290 		val |= (BMCR_SPEED100 | BMCR_FULLDPLX);
291 		val &= ~BMCR_ANENABLE;
292 		phy_write(phydev, MII_BMCR, val);
293 		/* Remember that the port is in fiber mode. */
294 		phydev->priv = lxt973_probe;
295 	} else {
296 		phydev->priv = NULL;
297 	}
298 	return 0;
299 }
300 
301 static int lxt973_config_aneg(struct phy_device *phydev)
302 {
303 	/* Do nothing if port is in fiber mode. */
304 	return phydev->priv ? 0 : genphy_config_aneg(phydev);
305 }
306 
307 static struct phy_driver lxt97x_driver[] = {
308 {
309 	.phy_id		= 0x78100000,
310 	.name		= "LXT970",
311 	.phy_id_mask	= 0xfffffff0,
312 	/* PHY_BASIC_FEATURES */
313 	.config_init	= lxt970_config_init,
314 	.config_intr	= lxt970_config_intr,
315 	.handle_interrupt = lxt970_handle_interrupt,
316 }, {
317 	.phy_id		= 0x001378e0,
318 	.name		= "LXT971",
319 	.phy_id_mask	= 0xfffffff0,
320 	/* PHY_BASIC_FEATURES */
321 	.config_intr	= lxt971_config_intr,
322 	.handle_interrupt = lxt971_handle_interrupt,
323 	.suspend	= genphy_suspend,
324 	.resume		= genphy_resume,
325 }, {
326 	.phy_id		= 0x00137a10,
327 	.name		= "LXT973-A2",
328 	.phy_id_mask	= 0xffffffff,
329 	/* PHY_BASIC_FEATURES */
330 	.flags		= 0,
331 	.probe		= lxt973_probe,
332 	.config_aneg	= lxt973_config_aneg,
333 	.read_status	= lxt973a2_read_status,
334 	.suspend	= genphy_suspend,
335 	.resume		= genphy_resume,
336 }, {
337 	.phy_id		= 0x00137a10,
338 	.name		= "LXT973",
339 	.phy_id_mask	= 0xfffffff0,
340 	/* PHY_BASIC_FEATURES */
341 	.flags		= 0,
342 	.probe		= lxt973_probe,
343 	.config_aneg	= lxt973_config_aneg,
344 	.suspend	= genphy_suspend,
345 	.resume		= genphy_resume,
346 } };
347 
348 module_phy_driver(lxt97x_driver);
349 
350 static struct mdio_device_id __maybe_unused lxt_tbl[] = {
351 	{ 0x78100000, 0xfffffff0 },
352 	{ 0x001378e0, 0xfffffff0 },
353 	{ 0x00137a10, 0xfffffff0 },
354 	{ }
355 };
356 
357 MODULE_DEVICE_TABLE(mdio, lxt_tbl);
358