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