net: Distributed Switch Architecture protocol support
[linux-2.6.git] / net / dsa / dsa.c
1 /*
2  * net/dsa/dsa.c - Hardware switch handling
3  * Copyright (c) 2008 Marvell Semiconductor
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  */
10
11 #include <linux/list.h>
12 #include <linux/netdevice.h>
13 #include <linux/platform_device.h>
14 #include <net/dsa.h>
15 #include "dsa_priv.h"
16
17 char dsa_driver_version[] = "0.1";
18
19
20 /* switch driver registration ***********************************************/
21 static DEFINE_MUTEX(dsa_switch_drivers_mutex);
22 static LIST_HEAD(dsa_switch_drivers);
23
24 void register_switch_driver(struct dsa_switch_driver *drv)
25 {
26         mutex_lock(&dsa_switch_drivers_mutex);
27         list_add_tail(&drv->list, &dsa_switch_drivers);
28         mutex_unlock(&dsa_switch_drivers_mutex);
29 }
30
31 void unregister_switch_driver(struct dsa_switch_driver *drv)
32 {
33         mutex_lock(&dsa_switch_drivers_mutex);
34         list_del_init(&drv->list);
35         mutex_unlock(&dsa_switch_drivers_mutex);
36 }
37
38 static struct dsa_switch_driver *
39 dsa_switch_probe(struct mii_bus *bus, int sw_addr, char **_name)
40 {
41         struct dsa_switch_driver *ret;
42         struct list_head *list;
43         char *name;
44
45         ret = NULL;
46         name = NULL;
47
48         mutex_lock(&dsa_switch_drivers_mutex);
49         list_for_each(list, &dsa_switch_drivers) {
50                 struct dsa_switch_driver *drv;
51
52                 drv = list_entry(list, struct dsa_switch_driver, list);
53
54                 name = drv->probe(bus, sw_addr);
55                 if (name != NULL) {
56                         ret = drv;
57                         break;
58                 }
59         }
60         mutex_unlock(&dsa_switch_drivers_mutex);
61
62         *_name = name;
63
64         return ret;
65 }
66
67
68 /* basic switch operations **************************************************/
69 static struct dsa_switch *
70 dsa_switch_setup(struct device *parent, struct dsa_platform_data *pd,
71                  struct mii_bus *bus, struct net_device *dev)
72 {
73         struct dsa_switch *ds;
74         int ret;
75         struct dsa_switch_driver *drv;
76         char *name;
77         int i;
78
79         /*
80          * Probe for switch model.
81          */
82         drv = dsa_switch_probe(bus, pd->sw_addr, &name);
83         if (drv == NULL) {
84                 printk(KERN_ERR "%s: could not detect attached switch\n",
85                        dev->name);
86                 return ERR_PTR(-EINVAL);
87         }
88         printk(KERN_INFO "%s: detected a %s switch\n", dev->name, name);
89
90
91         /*
92          * Allocate and initialise switch state.
93          */
94         ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL);
95         if (ds == NULL)
96                 return ERR_PTR(-ENOMEM);
97
98         ds->pd = pd;
99         ds->master_netdev = dev;
100         ds->master_mii_bus = bus;
101
102         ds->drv = drv;
103         ds->tag_protocol = drv->tag_protocol;
104
105
106         /*
107          * Validate supplied switch configuration.
108          */
109         ds->cpu_port = -1;
110         for (i = 0; i < DSA_MAX_PORTS; i++) {
111                 char *name;
112
113                 name = pd->port_names[i];
114                 if (name == NULL)
115                         continue;
116
117                 if (!strcmp(name, "cpu")) {
118                         if (ds->cpu_port != -1) {
119                                 printk(KERN_ERR "multiple cpu ports?!\n");
120                                 ret = -EINVAL;
121                                 goto out;
122                         }
123                         ds->cpu_port = i;
124                 } else {
125                         ds->valid_port_mask |= 1 << i;
126                 }
127         }
128
129         if (ds->cpu_port == -1) {
130                 printk(KERN_ERR "no cpu port?!\n");
131                 ret = -EINVAL;
132                 goto out;
133         }
134
135
136         /*
137          * If we use a tagging format that doesn't have an ethertype
138          * field, make sure that all packets from this point on get
139          * sent to the tag format's receive function.  (Which will
140          * discard received packets until we set ds->ports[] below.)
141          */
142         wmb();
143         dev->dsa_ptr = (void *)ds;
144
145
146         /*
147          * Do basic register setup.
148          */
149         ret = drv->setup(ds);
150         if (ret < 0)
151                 goto out;
152
153         ret = drv->set_addr(ds, dev->dev_addr);
154         if (ret < 0)
155                 goto out;
156
157         ds->slave_mii_bus = mdiobus_alloc();
158         if (ds->slave_mii_bus == NULL) {
159                 ret = -ENOMEM;
160                 goto out;
161         }
162         dsa_slave_mii_bus_init(ds);
163
164         ret = mdiobus_register(ds->slave_mii_bus);
165         if (ret < 0)
166                 goto out_free;
167
168
169         /*
170          * Create network devices for physical switch ports.
171          */
172         wmb();
173         for (i = 0; i < DSA_MAX_PORTS; i++) {
174                 struct net_device *slave_dev;
175
176                 if (!(ds->valid_port_mask & (1 << i)))
177                         continue;
178
179                 slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]);
180                 if (slave_dev == NULL) {
181                         printk(KERN_ERR "%s: can't create dsa slave "
182                                "device for port %d(%s)\n",
183                                dev->name, i, pd->port_names[i]);
184                         continue;
185                 }
186
187                 ds->ports[i] = slave_dev;
188         }
189
190         return ds;
191
192 out_free:
193         mdiobus_free(ds->slave_mii_bus);
194 out:
195         dev->dsa_ptr = NULL;
196         kfree(ds);
197         return ERR_PTR(ret);
198 }
199
200 static void dsa_switch_destroy(struct dsa_switch *ds)
201 {
202 }
203
204
205 /* link polling *************************************************************/
206 static void dsa_link_poll_work(struct work_struct *ugly)
207 {
208         struct dsa_switch *ds;
209
210         ds = container_of(ugly, struct dsa_switch, link_poll_work);
211
212         ds->drv->poll_link(ds);
213         mod_timer(&ds->link_poll_timer, round_jiffies(jiffies + HZ));
214 }
215
216 static void dsa_link_poll_timer(unsigned long _ds)
217 {
218         struct dsa_switch *ds = (void *)_ds;
219
220         schedule_work(&ds->link_poll_work);
221 }
222
223
224 /* platform driver init and cleanup *****************************************/
225 static int dev_is_class(struct device *dev, void *class)
226 {
227         if (dev->class != NULL && !strcmp(dev->class->name, class))
228                 return 1;
229
230         return 0;
231 }
232
233 static struct device *dev_find_class(struct device *parent, char *class)
234 {
235         if (dev_is_class(parent, class)) {
236                 get_device(parent);
237                 return parent;
238         }
239
240         return device_find_child(parent, class, dev_is_class);
241 }
242
243 static struct mii_bus *dev_to_mii_bus(struct device *dev)
244 {
245         struct device *d;
246
247         d = dev_find_class(dev, "mdio_bus");
248         if (d != NULL) {
249                 struct mii_bus *bus;
250
251                 bus = to_mii_bus(d);
252                 put_device(d);
253
254                 return bus;
255         }
256
257         return NULL;
258 }
259
260 static struct net_device *dev_to_net_device(struct device *dev)
261 {
262         struct device *d;
263
264         d = dev_find_class(dev, "net");
265         if (d != NULL) {
266                 struct net_device *nd;
267
268                 nd = to_net_dev(d);
269                 dev_hold(nd);
270                 put_device(d);
271
272                 return nd;
273         }
274
275         return NULL;
276 }
277
278 static int dsa_probe(struct platform_device *pdev)
279 {
280         static int dsa_version_printed;
281         struct dsa_platform_data *pd = pdev->dev.platform_data;
282         struct net_device *dev;
283         struct mii_bus *bus;
284         struct dsa_switch *ds;
285
286         if (!dsa_version_printed++)
287                 printk(KERN_NOTICE "Distributed Switch Architecture "
288                         "driver version %s\n", dsa_driver_version);
289
290         if (pd == NULL || pd->mii_bus == NULL || pd->netdev == NULL)
291                 return -EINVAL;
292
293         bus = dev_to_mii_bus(pd->mii_bus);
294         if (bus == NULL)
295                 return -EINVAL;
296
297         dev = dev_to_net_device(pd->netdev);
298         if (dev == NULL)
299                 return -EINVAL;
300
301         if (dev->dsa_ptr != NULL) {
302                 dev_put(dev);
303                 return -EEXIST;
304         }
305
306         ds = dsa_switch_setup(&pdev->dev, pd, bus, dev);
307         if (IS_ERR(ds)) {
308                 dev_put(dev);
309                 return PTR_ERR(ds);
310         }
311
312         if (ds->drv->poll_link != NULL) {
313                 INIT_WORK(&ds->link_poll_work, dsa_link_poll_work);
314                 init_timer(&ds->link_poll_timer);
315                 ds->link_poll_timer.data = (unsigned long)ds;
316                 ds->link_poll_timer.function = dsa_link_poll_timer;
317                 ds->link_poll_timer.expires = round_jiffies(jiffies + HZ);
318                 add_timer(&ds->link_poll_timer);
319         }
320
321         platform_set_drvdata(pdev, ds);
322
323         return 0;
324 }
325
326 static int dsa_remove(struct platform_device *pdev)
327 {
328         struct dsa_switch *ds = platform_get_drvdata(pdev);
329
330         if (ds->drv->poll_link != NULL)
331                 del_timer_sync(&ds->link_poll_timer);
332
333         flush_scheduled_work();
334
335         dsa_switch_destroy(ds);
336
337         return 0;
338 }
339
340 static void dsa_shutdown(struct platform_device *pdev)
341 {
342 }
343
344 static struct platform_driver dsa_driver = {
345         .probe          = dsa_probe,
346         .remove         = dsa_remove,
347         .shutdown       = dsa_shutdown,
348         .driver = {
349                 .name   = "dsa",
350                 .owner  = THIS_MODULE,
351         },
352 };
353
354 static int __init dsa_init_module(void)
355 {
356         return platform_driver_register(&dsa_driver);
357 }
358 module_init(dsa_init_module);
359
360 static void __exit dsa_cleanup_module(void)
361 {
362         platform_driver_unregister(&dsa_driver);
363 }
364 module_exit(dsa_cleanup_module);
365
366 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>")
367 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
368 MODULE_LICENSE("GPL");
369 MODULE_ALIAS("platform:dsa");