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 */
zmii_valid_mode(int mode)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
zmii_mode_name(int mode)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
zmii_mode_mask(int mode,int input)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
zmii_attach(struct platform_device * ofdev,int input,phy_interface_t * mode)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
zmii_get_mdio(struct platform_device * ofdev,int input)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
zmii_put_mdio(struct platform_device * ofdev,int input)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
zmii_set_speed(struct platform_device * ofdev,int input,int speed)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
zmii_detach(struct platform_device * ofdev,int input)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
zmii_get_regs_len(struct platform_device * ofdev)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
zmii_dump_regs(struct platform_device * ofdev,void * buf)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
zmii_probe(struct platform_device * ofdev)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, ®s)) {
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
zmii_remove(struct platform_device * ofdev)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
zmii_init(void)314 int __init zmii_init(void)
315 {
316 return platform_driver_register(&zmii_driver);
317 }
318
zmii_exit(void)319 void zmii_exit(void)
320 {
321 platform_driver_unregister(&zmii_driver);
322 }
323