xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/zmii.c (revision f3539c12)
1 /*
2  * drivers/net/ethernet/ibm/emac/zmii.c
3  *
4  * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
5  *
6  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
7  *                <benh@kernel.crashing.org>
8  *
9  * Based on the arch/ppc version of the driver:
10  *
11  * Copyright (c) 2004, 2005 Zultys Technologies.
12  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
13  *
14  * Based on original work by
15  *      Armin Kuster <akuster@mvista.com>
16  * 	Copyright 2001 MontaVista Softare Inc.
17  *
18  * This program is free software; you can redistribute  it and/or modify it
19  * under  the terms of  the GNU General  Public License as published by the
20  * Free Software Foundation;  either version 2 of the  License, or (at your
21  * option) any later version.
22  *
23  */
24 #include <linux/slab.h>
25 #include <linux/kernel.h>
26 #include <linux/ethtool.h>
27 #include <linux/of_address.h>
28 #include <asm/io.h>
29 
30 #include "emac.h"
31 #include "core.h"
32 
33 /* ZMIIx_FER */
34 #define ZMII_FER_MDI(idx)	(0x80000000 >> ((idx) * 4))
35 #define ZMII_FER_MDI_ALL	(ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
36 				 ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
37 
38 #define ZMII_FER_SMII(idx)	(0x40000000 >> ((idx) * 4))
39 #define ZMII_FER_RMII(idx)	(0x20000000 >> ((idx) * 4))
40 #define ZMII_FER_MII(idx)	(0x10000000 >> ((idx) * 4))
41 
42 /* ZMIIx_SSR */
43 #define ZMII_SSR_SCI(idx)	(0x40000000 >> ((idx) * 4))
44 #define ZMII_SSR_FSS(idx)	(0x20000000 >> ((idx) * 4))
45 #define ZMII_SSR_SP(idx)	(0x10000000 >> ((idx) * 4))
46 
47 /* ZMII only supports MII, RMII and SMII
48  * we also support autodetection for backward compatibility
49  */
50 static inline int zmii_valid_mode(int mode)
51 {
52 	return  mode == PHY_MODE_MII ||
53 		mode == PHY_MODE_RMII ||
54 		mode == PHY_MODE_SMII ||
55 		mode == PHY_MODE_NA;
56 }
57 
58 static inline const char *zmii_mode_name(int mode)
59 {
60 	switch (mode) {
61 	case PHY_MODE_MII:
62 		return "MII";
63 	case PHY_MODE_RMII:
64 		return "RMII";
65 	case PHY_MODE_SMII:
66 		return "SMII";
67 	default:
68 		BUG();
69 	}
70 }
71 
72 static inline u32 zmii_mode_mask(int mode, int input)
73 {
74 	switch (mode) {
75 	case PHY_MODE_MII:
76 		return ZMII_FER_MII(input);
77 	case PHY_MODE_RMII:
78 		return ZMII_FER_RMII(input);
79 	case PHY_MODE_SMII:
80 		return ZMII_FER_SMII(input);
81 	default:
82 		return 0;
83 	}
84 }
85 
86 int zmii_attach(struct platform_device *ofdev, int input, int *mode)
87 {
88 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
89 	struct zmii_regs __iomem *p = dev->base;
90 
91 	ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
92 
93 	if (!zmii_valid_mode(*mode)) {
94 		/* Probably an EMAC connected to RGMII,
95 		 * but it still may need ZMII for MDIO so
96 		 * we don't fail here.
97 		 */
98 		dev->users++;
99 		return 0;
100 	}
101 
102 	mutex_lock(&dev->lock);
103 
104 	/* Autodetect ZMII mode if not specified.
105 	 * This is only for backward compatibility with the old driver.
106 	 * Please, always specify PHY mode in your board port to avoid
107 	 * any surprises.
108 	 */
109 	if (dev->mode == PHY_MODE_NA) {
110 		if (*mode == PHY_MODE_NA) {
111 			u32 r = dev->fer_save;
112 
113 			ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
114 
115 			if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
116 				dev->mode = PHY_MODE_MII;
117 			else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
118 				dev->mode = PHY_MODE_RMII;
119 			else
120 				dev->mode = PHY_MODE_SMII;
121 		} else
122 			dev->mode = *mode;
123 
124 		printk(KERN_NOTICE "%s: bridge in %s mode\n",
125 		       ofdev->dev.of_node->full_name,
126 		       zmii_mode_name(dev->mode));
127 	} else {
128 		/* All inputs must use the same mode */
129 		if (*mode != PHY_MODE_NA && *mode != dev->mode) {
130 			printk(KERN_ERR
131 			       "%s: invalid mode %d specified for input %d\n",
132 			       ofdev->dev.of_node->full_name, *mode, input);
133 			mutex_unlock(&dev->lock);
134 			return -EINVAL;
135 		}
136 	}
137 
138 	/* Report back correct PHY mode,
139 	 * it may be used during PHY initialization.
140 	 */
141 	*mode = dev->mode;
142 
143 	/* Enable this input */
144 	out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
145 	++dev->users;
146 
147 	mutex_unlock(&dev->lock);
148 
149 	return 0;
150 }
151 
152 void zmii_get_mdio(struct platform_device *ofdev, int input)
153 {
154 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
155 	u32 fer;
156 
157 	ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
158 
159 	mutex_lock(&dev->lock);
160 
161 	fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
162 	out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
163 }
164 
165 void zmii_put_mdio(struct platform_device *ofdev, int input)
166 {
167 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
168 
169 	ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
170 	mutex_unlock(&dev->lock);
171 }
172 
173 
174 void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
175 {
176 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
177 	u32 ssr;
178 
179 	mutex_lock(&dev->lock);
180 
181 	ssr = in_be32(&dev->base->ssr);
182 
183 	ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
184 
185 	if (speed == SPEED_100)
186 		ssr |= ZMII_SSR_SP(input);
187 	else
188 		ssr &= ~ZMII_SSR_SP(input);
189 
190 	out_be32(&dev->base->ssr, ssr);
191 
192 	mutex_unlock(&dev->lock);
193 }
194 
195 void zmii_detach(struct platform_device *ofdev, int input)
196 {
197 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
198 
199 	BUG_ON(!dev || dev->users == 0);
200 
201 	mutex_lock(&dev->lock);
202 
203 	ZMII_DBG(dev, "detach(%d)" NL, input);
204 
205 	/* Disable this input */
206 	out_be32(&dev->base->fer,
207 		 in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
208 
209 	--dev->users;
210 
211 	mutex_unlock(&dev->lock);
212 }
213 
214 int zmii_get_regs_len(struct platform_device *ofdev)
215 {
216 	return sizeof(struct emac_ethtool_regs_subhdr) +
217 		sizeof(struct zmii_regs);
218 }
219 
220 void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
221 {
222 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
223 	struct emac_ethtool_regs_subhdr *hdr = buf;
224 	struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
225 
226 	hdr->version = 0;
227 	hdr->index = 0; /* for now, are there chips with more than one
228 			 * zmii ? if yes, then we'll add a cell_index
229 			 * like we do for emac
230 			 */
231 	memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
232 	return regs + 1;
233 }
234 
235 static int zmii_probe(struct platform_device *ofdev)
236 {
237 	struct device_node *np = ofdev->dev.of_node;
238 	struct zmii_instance *dev;
239 	struct resource regs;
240 	int rc;
241 
242 	rc = -ENOMEM;
243 	dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
244 	if (dev == NULL)
245 		goto err_gone;
246 
247 	mutex_init(&dev->lock);
248 	dev->ofdev = ofdev;
249 	dev->mode = PHY_MODE_NA;
250 
251 	rc = -ENXIO;
252 	if (of_address_to_resource(np, 0, &regs)) {
253 		printk(KERN_ERR "%s: Can't get registers address\n",
254 		       np->full_name);
255 		goto err_free;
256 	}
257 
258 	rc = -ENOMEM;
259 	dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
260 						sizeof(struct zmii_regs));
261 	if (dev->base == NULL) {
262 		printk(KERN_ERR "%s: Can't map device registers!\n",
263 		       np->full_name);
264 		goto err_free;
265 	}
266 
267 	/* We may need FER value for autodetection later */
268 	dev->fer_save = in_be32(&dev->base->fer);
269 
270 	/* Disable all inputs by default */
271 	out_be32(&dev->base->fer, 0);
272 
273 	printk(KERN_INFO
274 	       "ZMII %s initialized\n", ofdev->dev.of_node->full_name);
275 	wmb();
276 	platform_set_drvdata(ofdev, dev);
277 
278 	return 0;
279 
280  err_free:
281 	kfree(dev);
282  err_gone:
283 	return rc;
284 }
285 
286 static int zmii_remove(struct platform_device *ofdev)
287 {
288 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
289 
290 	WARN_ON(dev->users != 0);
291 
292 	iounmap(dev->base);
293 	kfree(dev);
294 
295 	return 0;
296 }
297 
298 static const struct of_device_id zmii_match[] =
299 {
300 	{
301 		.compatible	= "ibm,zmii",
302 	},
303 	/* For backward compat with old DT */
304 	{
305 		.type		= "emac-zmii",
306 	},
307 	{},
308 };
309 
310 static struct platform_driver zmii_driver = {
311 	.driver = {
312 		.name = "emac-zmii",
313 		.of_match_table = zmii_match,
314 	},
315 	.probe = zmii_probe,
316 	.remove = zmii_remove,
317 };
318 
319 int __init zmii_init(void)
320 {
321 	return platform_driver_register(&zmii_driver);
322 }
323 
324 void zmii_exit(void)
325 {
326 	platform_driver_unregister(&zmii_driver);
327 }
328