xref: /openbmc/linux/drivers/net/ethernet/ibm/emac/zmii.c (revision 0c6dfa75)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers/net/ethernet/ibm/emac/zmii.c
4  *
5  * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
6  *
7  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
8  *                <benh@kernel.crashing.org>
9  *
10  * Based on the arch/ppc version of the driver:
11  *
12  * Copyright (c) 2004, 2005 Zultys Technologies.
13  * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
14  *
15  * Based on original work by
16  *      Armin Kuster <akuster@mvista.com>
17  * 	Copyright 2001 MontaVista Softare Inc.
18  */
19 #include <linux/slab.h>
20 #include <linux/kernel.h>
21 #include <linux/ethtool.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/of_address.h>
24 #include <linux/platform_device.h>
25 #include <asm/io.h>
26 
27 #include "emac.h"
28 #include "core.h"
29 
30 /* ZMIIx_FER */
31 #define ZMII_FER_MDI(idx)	(0x80000000 >> ((idx) * 4))
32 #define ZMII_FER_MDI_ALL	(ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
33 				 ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
34 
35 #define ZMII_FER_SMII(idx)	(0x40000000 >> ((idx) * 4))
36 #define ZMII_FER_RMII(idx)	(0x20000000 >> ((idx) * 4))
37 #define ZMII_FER_MII(idx)	(0x10000000 >> ((idx) * 4))
38 
39 /* ZMIIx_SSR */
40 #define ZMII_SSR_SCI(idx)	(0x40000000 >> ((idx) * 4))
41 #define ZMII_SSR_FSS(idx)	(0x20000000 >> ((idx) * 4))
42 #define ZMII_SSR_SP(idx)	(0x10000000 >> ((idx) * 4))
43 
44 /* ZMII only supports MII, RMII and SMII
45  * we also support autodetection for backward compatibility
46  */
47 static inline int zmii_valid_mode(int mode)
48 {
49 	return  mode == PHY_INTERFACE_MODE_MII ||
50 		mode == PHY_INTERFACE_MODE_RMII ||
51 		mode == PHY_INTERFACE_MODE_SMII ||
52 		mode == PHY_INTERFACE_MODE_NA;
53 }
54 
55 static inline const char *zmii_mode_name(int mode)
56 {
57 	switch (mode) {
58 	case PHY_INTERFACE_MODE_MII:
59 		return "MII";
60 	case PHY_INTERFACE_MODE_RMII:
61 		return "RMII";
62 	case PHY_INTERFACE_MODE_SMII:
63 		return "SMII";
64 	default:
65 		BUG();
66 	}
67 }
68 
69 static inline u32 zmii_mode_mask(int mode, int input)
70 {
71 	switch (mode) {
72 	case PHY_INTERFACE_MODE_MII:
73 		return ZMII_FER_MII(input);
74 	case PHY_INTERFACE_MODE_RMII:
75 		return ZMII_FER_RMII(input);
76 	case PHY_INTERFACE_MODE_SMII:
77 		return ZMII_FER_SMII(input);
78 	default:
79 		return 0;
80 	}
81 }
82 
83 int zmii_attach(struct platform_device *ofdev, int input,
84 		phy_interface_t *mode)
85 {
86 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
87 	struct zmii_regs __iomem *p = dev->base;
88 
89 	ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
90 
91 	if (!zmii_valid_mode(*mode)) {
92 		/* Probably an EMAC connected to RGMII,
93 		 * but it still may need ZMII for MDIO so
94 		 * we don't fail here.
95 		 */
96 		dev->users++;
97 		return 0;
98 	}
99 
100 	mutex_lock(&dev->lock);
101 
102 	/* Autodetect ZMII mode if not specified.
103 	 * This is only for backward compatibility with the old driver.
104 	 * Please, always specify PHY mode in your board port to avoid
105 	 * any surprises.
106 	 */
107 	if (dev->mode == PHY_INTERFACE_MODE_NA) {
108 		if (*mode == PHY_INTERFACE_MODE_NA) {
109 			u32 r = dev->fer_save;
110 
111 			ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
112 
113 			if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
114 				dev->mode = PHY_INTERFACE_MODE_MII;
115 			else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
116 				dev->mode = PHY_INTERFACE_MODE_RMII;
117 			else
118 				dev->mode = PHY_INTERFACE_MODE_SMII;
119 		} else {
120 			dev->mode = *mode;
121 		}
122 		printk(KERN_NOTICE "%pOF: bridge in %s mode\n",
123 		       ofdev->dev.of_node,
124 		       zmii_mode_name(dev->mode));
125 	} else {
126 		/* All inputs must use the same mode */
127 		if (*mode != PHY_INTERFACE_MODE_NA && *mode != dev->mode) {
128 			printk(KERN_ERR
129 			       "%pOF: invalid mode %d specified for input %d\n",
130 			       ofdev->dev.of_node, *mode, input);
131 			mutex_unlock(&dev->lock);
132 			return -EINVAL;
133 		}
134 	}
135 
136 	/* Report back correct PHY mode,
137 	 * it may be used during PHY initialization.
138 	 */
139 	*mode = dev->mode;
140 
141 	/* Enable this input */
142 	out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
143 	++dev->users;
144 
145 	mutex_unlock(&dev->lock);
146 
147 	return 0;
148 }
149 
150 void zmii_get_mdio(struct platform_device *ofdev, int input)
151 {
152 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
153 	u32 fer;
154 
155 	ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
156 
157 	mutex_lock(&dev->lock);
158 
159 	fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
160 	out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
161 }
162 
163 void zmii_put_mdio(struct platform_device *ofdev, int input)
164 {
165 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
166 
167 	ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
168 	mutex_unlock(&dev->lock);
169 }
170 
171 
172 void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
173 {
174 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
175 	u32 ssr;
176 
177 	mutex_lock(&dev->lock);
178 
179 	ssr = in_be32(&dev->base->ssr);
180 
181 	ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
182 
183 	if (speed == SPEED_100)
184 		ssr |= ZMII_SSR_SP(input);
185 	else
186 		ssr &= ~ZMII_SSR_SP(input);
187 
188 	out_be32(&dev->base->ssr, ssr);
189 
190 	mutex_unlock(&dev->lock);
191 }
192 
193 void zmii_detach(struct platform_device *ofdev, int input)
194 {
195 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
196 
197 	BUG_ON(!dev || dev->users == 0);
198 
199 	mutex_lock(&dev->lock);
200 
201 	ZMII_DBG(dev, "detach(%d)" NL, input);
202 
203 	/* Disable this input */
204 	out_be32(&dev->base->fer,
205 		 in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
206 
207 	--dev->users;
208 
209 	mutex_unlock(&dev->lock);
210 }
211 
212 int zmii_get_regs_len(struct platform_device *ofdev)
213 {
214 	return sizeof(struct emac_ethtool_regs_subhdr) +
215 		sizeof(struct zmii_regs);
216 }
217 
218 void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
219 {
220 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
221 	struct emac_ethtool_regs_subhdr *hdr = buf;
222 	struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
223 
224 	hdr->version = 0;
225 	hdr->index = 0; /* for now, are there chips with more than one
226 			 * zmii ? if yes, then we'll add a cell_index
227 			 * like we do for emac
228 			 */
229 	memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
230 	return regs + 1;
231 }
232 
233 static int zmii_probe(struct platform_device *ofdev)
234 {
235 	struct device_node *np = ofdev->dev.of_node;
236 	struct zmii_instance *dev;
237 	struct resource regs;
238 	int rc;
239 
240 	rc = -ENOMEM;
241 	dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
242 	if (dev == NULL)
243 		goto err_gone;
244 
245 	mutex_init(&dev->lock);
246 	dev->ofdev = ofdev;
247 	dev->mode = PHY_INTERFACE_MODE_NA;
248 
249 	rc = -ENXIO;
250 	if (of_address_to_resource(np, 0, &regs)) {
251 		printk(KERN_ERR "%pOF: Can't get registers address\n", np);
252 		goto err_free;
253 	}
254 
255 	rc = -ENOMEM;
256 	dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
257 						sizeof(struct zmii_regs));
258 	if (dev->base == NULL) {
259 		printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
260 		goto err_free;
261 	}
262 
263 	/* We may need FER value for autodetection later */
264 	dev->fer_save = in_be32(&dev->base->fer);
265 
266 	/* Disable all inputs by default */
267 	out_be32(&dev->base->fer, 0);
268 
269 	printk(KERN_INFO "ZMII %pOF initialized\n", ofdev->dev.of_node);
270 	wmb();
271 	platform_set_drvdata(ofdev, dev);
272 
273 	return 0;
274 
275  err_free:
276 	kfree(dev);
277  err_gone:
278 	return rc;
279 }
280 
281 static int zmii_remove(struct platform_device *ofdev)
282 {
283 	struct zmii_instance *dev = platform_get_drvdata(ofdev);
284 
285 	WARN_ON(dev->users != 0);
286 
287 	iounmap(dev->base);
288 	kfree(dev);
289 
290 	return 0;
291 }
292 
293 static const struct of_device_id zmii_match[] =
294 {
295 	{
296 		.compatible	= "ibm,zmii",
297 	},
298 	/* For backward compat with old DT */
299 	{
300 		.type		= "emac-zmii",
301 	},
302 	{},
303 };
304 
305 static struct platform_driver zmii_driver = {
306 	.driver = {
307 		.name = "emac-zmii",
308 		.of_match_table = zmii_match,
309 	},
310 	.probe = zmii_probe,
311 	.remove = zmii_remove,
312 };
313 
314 int __init zmii_init(void)
315 {
316 	return platform_driver_register(&zmii_driver);
317 }
318 
319 void zmii_exit(void)
320 {
321 	platform_driver_unregister(&zmii_driver);
322 }
323