xref: /linux/drivers/net/ethernet/ibm/emac/zmii.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 <asm/io.h>
28 
29 #include "emac.h"
30 #include "core.h"
31 
32 /* ZMIIx_FER */
33 #define ZMII_FER_MDI(idx)	(0x80000000 >> ((idx) * 4))
34 #define ZMII_FER_MDI_ALL	(ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
35 				 ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
36 
37 #define ZMII_FER_SMII(idx)	(0x40000000 >> ((idx) * 4))
38 #define ZMII_FER_RMII(idx)	(0x20000000 >> ((idx) * 4))
39 #define ZMII_FER_MII(idx)	(0x10000000 >> ((idx) * 4))
40 
41 /* ZMIIx_SSR */
42 #define ZMII_SSR_SCI(idx)	(0x40000000 >> ((idx) * 4))
43 #define ZMII_SSR_FSS(idx)	(0x20000000 >> ((idx) * 4))
44 #define ZMII_SSR_SP(idx)	(0x10000000 >> ((idx) * 4))
45 
46 /* ZMII only supports MII, RMII and SMII
47  * we also support autodetection for backward compatibility
48  */
49 static inline int zmii_valid_mode(int mode)
50 {
51 	return  mode == PHY_MODE_MII ||
52 		mode == PHY_MODE_RMII ||
53 		mode == PHY_MODE_SMII ||
54 		mode == PHY_MODE_NA;
55 }
56 
57 static inline const char *zmii_mode_name(int mode)
58 {
59 	switch (mode) {
60 	case PHY_MODE_MII:
61 		return "MII";
62 	case PHY_MODE_RMII:
63 		return "RMII";
64 	case PHY_MODE_SMII:
65 		return "SMII";
66 	default:
67 		BUG();
68 	}
69 }
70 
71 static inline u32 zmii_mode_mask(int mode, int input)
72 {
73 	switch (mode) {
74 	case PHY_MODE_MII:
75 		return ZMII_FER_MII(input);
76 	case PHY_MODE_RMII:
77 		return ZMII_FER_RMII(input);
78 	case PHY_MODE_SMII:
79 		return ZMII_FER_SMII(input);
80 	default:
81 		return 0;
82 	}
83 }
84 
85 int zmii_attach(struct platform_device *ofdev, int input, int *mode)
86 {
87 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
88 	struct zmii_regs __iomem *p = dev->base;
89 
90 	ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
91 
92 	if (!zmii_valid_mode(*mode)) {
93 		/* Probably an EMAC connected to RGMII,
94 		 * but it still may need ZMII for MDIO so
95 		 * we don't fail here.
96 		 */
97 		dev->users++;
98 		return 0;
99 	}
100 
101 	mutex_lock(&dev->lock);
102 
103 	/* Autodetect ZMII mode if not specified.
104 	 * This is only for backward compatibility with the old driver.
105 	 * Please, always specify PHY mode in your board port to avoid
106 	 * any surprises.
107 	 */
108 	if (dev->mode == PHY_MODE_NA) {
109 		if (*mode == PHY_MODE_NA) {
110 			u32 r = dev->fer_save;
111 
112 			ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
113 
114 			if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
115 				dev->mode = PHY_MODE_MII;
116 			else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
117 				dev->mode = PHY_MODE_RMII;
118 			else
119 				dev->mode = PHY_MODE_SMII;
120 		} else
121 			dev->mode = *mode;
122 
123 		printk(KERN_NOTICE "%s: bridge in %s mode\n",
124 		       ofdev->dev.of_node->full_name,
125 		       zmii_mode_name(dev->mode));
126 	} else {
127 		/* All inputs must use the same mode */
128 		if (*mode != PHY_MODE_NA && *mode != dev->mode) {
129 			printk(KERN_ERR
130 			       "%s: invalid mode %d specified for input %d\n",
131 			       ofdev->dev.of_node->full_name, *mode, input);
132 			mutex_unlock(&dev->lock);
133 			return -EINVAL;
134 		}
135 	}
136 
137 	/* Report back correct PHY mode,
138 	 * it may be used during PHY initialization.
139 	 */
140 	*mode = dev->mode;
141 
142 	/* Enable this input */
143 	out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
144 	++dev->users;
145 
146 	mutex_unlock(&dev->lock);
147 
148 	return 0;
149 }
150 
151 void zmii_get_mdio(struct platform_device *ofdev, int input)
152 {
153 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
154 	u32 fer;
155 
156 	ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
157 
158 	mutex_lock(&dev->lock);
159 
160 	fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
161 	out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
162 }
163 
164 void zmii_put_mdio(struct platform_device *ofdev, int input)
165 {
166 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
167 
168 	ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
169 	mutex_unlock(&dev->lock);
170 }
171 
172 
173 void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
174 {
175 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
176 	u32 ssr;
177 
178 	mutex_lock(&dev->lock);
179 
180 	ssr = in_be32(&dev->base->ssr);
181 
182 	ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
183 
184 	if (speed == SPEED_100)
185 		ssr |= ZMII_SSR_SP(input);
186 	else
187 		ssr &= ~ZMII_SSR_SP(input);
188 
189 	out_be32(&dev->base->ssr, ssr);
190 
191 	mutex_unlock(&dev->lock);
192 }
193 
194 void zmii_detach(struct platform_device *ofdev, int input)
195 {
196 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
197 
198 	BUG_ON(!dev || dev->users == 0);
199 
200 	mutex_lock(&dev->lock);
201 
202 	ZMII_DBG(dev, "detach(%d)" NL, input);
203 
204 	/* Disable this input */
205 	out_be32(&dev->base->fer,
206 		 in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
207 
208 	--dev->users;
209 
210 	mutex_unlock(&dev->lock);
211 }
212 
213 int zmii_get_regs_len(struct platform_device *ofdev)
214 {
215 	return sizeof(struct emac_ethtool_regs_subhdr) +
216 		sizeof(struct zmii_regs);
217 }
218 
219 void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
220 {
221 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
222 	struct emac_ethtool_regs_subhdr *hdr = buf;
223 	struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
224 
225 	hdr->version = 0;
226 	hdr->index = 0; /* for now, are there chips with more than one
227 			 * zmii ? if yes, then we'll add a cell_index
228 			 * like we do for emac
229 			 */
230 	memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
231 	return regs + 1;
232 }
233 
234 static int zmii_probe(struct platform_device *ofdev)
235 {
236 	struct device_node *np = ofdev->dev.of_node;
237 	struct zmii_instance *dev;
238 	struct resource regs;
239 	int rc;
240 
241 	rc = -ENOMEM;
242 	dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
243 	if (dev == NULL)
244 		goto err_gone;
245 
246 	mutex_init(&dev->lock);
247 	dev->ofdev = ofdev;
248 	dev->mode = PHY_MODE_NA;
249 
250 	rc = -ENXIO;
251 	if (of_address_to_resource(np, 0, &regs)) {
252 		printk(KERN_ERR "%s: Can't get registers address\n",
253 		       np->full_name);
254 		goto err_free;
255 	}
256 
257 	rc = -ENOMEM;
258 	dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
259 						sizeof(struct zmii_regs));
260 	if (dev->base == NULL) {
261 		printk(KERN_ERR "%s: Can't map device registers!\n",
262 		       np->full_name);
263 		goto err_free;
264 	}
265 
266 	/* We may need FER value for autodetection later */
267 	dev->fer_save = in_be32(&dev->base->fer);
268 
269 	/* Disable all inputs by default */
270 	out_be32(&dev->base->fer, 0);
271 
272 	printk(KERN_INFO
273 	       "ZMII %s initialized\n", ofdev->dev.of_node->full_name);
274 	wmb();
275 	dev_set_drvdata(&ofdev->dev, dev);
276 
277 	return 0;
278 
279  err_free:
280 	kfree(dev);
281  err_gone:
282 	return rc;
283 }
284 
285 static int zmii_remove(struct platform_device *ofdev)
286 {
287 	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
288 
289 	dev_set_drvdata(&ofdev->dev, NULL);
290 
291 	WARN_ON(dev->users != 0);
292 
293 	iounmap(dev->base);
294 	kfree(dev);
295 
296 	return 0;
297 }
298 
299 static struct of_device_id zmii_match[] =
300 {
301 	{
302 		.compatible	= "ibm,zmii",
303 	},
304 	/* For backward compat with old DT */
305 	{
306 		.type		= "emac-zmii",
307 	},
308 	{},
309 };
310 
311 static struct platform_driver zmii_driver = {
312 	.driver = {
313 		.name = "emac-zmii",
314 		.owner = THIS_MODULE,
315 		.of_match_table = zmii_match,
316 	},
317 	.probe = zmii_probe,
318 	.remove = zmii_remove,
319 };
320 
321 int __init zmii_init(void)
322 {
323 	return platform_driver_register(&zmii_driver);
324 }
325 
326 void zmii_exit(void)
327 {
328 	platform_driver_unregister(&zmii_driver);
329 }
330