exofs: refactor exofs_i_info initialization into common helper
[linux-2.6.git] / net / dsa / dsa.c
1 /*
2  * net/dsa/dsa.c - Hardware switch handling
3  * Copyright (c) 2008-2009 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 dsa_switch_tree *dst, int index,
71                  struct device *parent, struct mii_bus *bus)
72 {
73         struct dsa_chip_data *pd = dst->pd->chip + index;
74         struct dsa_switch_driver *drv;
75         struct dsa_switch *ds;
76         int ret;
77         char *name;
78         int i;
79
80         /*
81          * Probe for switch model.
82          */
83         drv = dsa_switch_probe(bus, pd->sw_addr, &name);
84         if (drv == NULL) {
85                 printk(KERN_ERR "%s[%d]: could not detect attached switch\n",
86                        dst->master_netdev->name, index);
87                 return ERR_PTR(-EINVAL);
88         }
89         printk(KERN_INFO "%s[%d]: detected a %s switch\n",
90                 dst->master_netdev->name, index, name);
91
92
93         /*
94          * Allocate and initialise switch state.
95          */
96         ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL);
97         if (ds == NULL)
98                 return ERR_PTR(-ENOMEM);
99
100         ds->dst = dst;
101         ds->index = index;
102         ds->pd = dst->pd->chip + index;
103         ds->drv = drv;
104         ds->master_mii_bus = bus;
105
106
107         /*
108          * Validate supplied switch configuration.
109          */
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 (dst->cpu_switch != -1) {
119                                 printk(KERN_ERR "multiple cpu ports?!\n");
120                                 ret = -EINVAL;
121                                 goto out;
122                         }
123                         dst->cpu_switch = index;
124                         dst->cpu_port = i;
125                 } else if (!strcmp(name, "dsa")) {
126                         ds->dsa_port_mask |= 1 << i;
127                 } else {
128                         ds->phys_port_mask |= 1 << i;
129                 }
130         }
131
132
133         /*
134          * If the CPU connects to this switch, set the switch tree
135          * tagging protocol to the preferred tagging format of this
136          * switch.
137          */
138         if (ds->dst->cpu_switch == index)
139                 ds->dst->tag_protocol = drv->tag_protocol;
140
141
142         /*
143          * Do basic register setup.
144          */
145         ret = drv->setup(ds);
146         if (ret < 0)
147                 goto out;
148
149         ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
150         if (ret < 0)
151                 goto out;
152
153         ds->slave_mii_bus = mdiobus_alloc();
154         if (ds->slave_mii_bus == NULL) {
155                 ret = -ENOMEM;
156                 goto out;
157         }
158         dsa_slave_mii_bus_init(ds);
159
160         ret = mdiobus_register(ds->slave_mii_bus);
161         if (ret < 0)
162                 goto out_free;
163
164
165         /*
166          * Create network devices for physical switch ports.
167          */
168         for (i = 0; i < DSA_MAX_PORTS; i++) {
169                 struct net_device *slave_dev;
170
171                 if (!(ds->phys_port_mask & (1 << i)))
172                         continue;
173
174                 slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]);
175                 if (slave_dev == NULL) {
176                         printk(KERN_ERR "%s[%d]: can't create dsa "
177                                "slave device for port %d(%s)\n",
178                                dst->master_netdev->name,
179                                index, i, pd->port_names[i]);
180                         continue;
181                 }
182
183                 ds->ports[i] = slave_dev;
184         }
185
186         return ds;
187
188 out_free:
189         mdiobus_free(ds->slave_mii_bus);
190 out:
191         kfree(ds);
192         return ERR_PTR(ret);
193 }
194
195 static void dsa_switch_destroy(struct dsa_switch *ds)
196 {
197 }
198
199
200 /* hooks for ethertype-less tagging formats *********************************/
201 /*
202  * The original DSA tag format and some other tag formats have no
203  * ethertype, which means that we need to add a little hack to the
204  * networking receive path to make sure that received frames get
205  * the right ->protocol assigned to them when one of those tag
206  * formats is in use.
207  */
208 bool dsa_uses_dsa_tags(void *dsa_ptr)
209 {
210         struct dsa_switch_tree *dst = dsa_ptr;
211
212         return !!(dst->tag_protocol == htons(ETH_P_DSA));
213 }
214
215 bool dsa_uses_trailer_tags(void *dsa_ptr)
216 {
217         struct dsa_switch_tree *dst = dsa_ptr;
218
219         return !!(dst->tag_protocol == htons(ETH_P_TRAILER));
220 }
221
222
223 /* link polling *************************************************************/
224 static void dsa_link_poll_work(struct work_struct *ugly)
225 {
226         struct dsa_switch_tree *dst;
227         int i;
228
229         dst = container_of(ugly, struct dsa_switch_tree, link_poll_work);
230
231         for (i = 0; i < dst->pd->nr_chips; i++) {
232                 struct dsa_switch *ds = dst->ds[i];
233
234                 if (ds != NULL && ds->drv->poll_link != NULL)
235                         ds->drv->poll_link(ds);
236         }
237
238         mod_timer(&dst->link_poll_timer, round_jiffies(jiffies + HZ));
239 }
240
241 static void dsa_link_poll_timer(unsigned long _dst)
242 {
243         struct dsa_switch_tree *dst = (void *)_dst;
244
245         schedule_work(&dst->link_poll_work);
246 }
247
248
249 /* platform driver init and cleanup *****************************************/
250 static int dev_is_class(struct device *dev, void *class)
251 {
252         if (dev->class != NULL && !strcmp(dev->class->name, class))
253                 return 1;
254
255         return 0;
256 }
257
258 static struct device *dev_find_class(struct device *parent, char *class)
259 {
260         if (dev_is_class(parent, class)) {
261                 get_device(parent);
262                 return parent;
263         }
264
265         return device_find_child(parent, class, dev_is_class);
266 }
267
268 static struct mii_bus *dev_to_mii_bus(struct device *dev)
269 {
270         struct device *d;
271
272         d = dev_find_class(dev, "mdio_bus");
273         if (d != NULL) {
274                 struct mii_bus *bus;
275
276                 bus = to_mii_bus(d);
277                 put_device(d);
278
279                 return bus;
280         }
281
282         return NULL;
283 }
284
285 static struct net_device *dev_to_net_device(struct device *dev)
286 {
287         struct device *d;
288
289         d = dev_find_class(dev, "net");
290         if (d != NULL) {
291                 struct net_device *nd;
292
293                 nd = to_net_dev(d);
294                 dev_hold(nd);
295                 put_device(d);
296
297                 return nd;
298         }
299
300         return NULL;
301 }
302
303 static int dsa_probe(struct platform_device *pdev)
304 {
305         static int dsa_version_printed;
306         struct dsa_platform_data *pd = pdev->dev.platform_data;
307         struct net_device *dev;
308         struct dsa_switch_tree *dst;
309         int i;
310
311         if (!dsa_version_printed++)
312                 printk(KERN_NOTICE "Distributed Switch Architecture "
313                         "driver version %s\n", dsa_driver_version);
314
315         if (pd == NULL || pd->netdev == NULL)
316                 return -EINVAL;
317
318         dev = dev_to_net_device(pd->netdev);
319         if (dev == NULL)
320                 return -EINVAL;
321
322         if (dev->dsa_ptr != NULL) {
323                 dev_put(dev);
324                 return -EEXIST;
325         }
326
327         dst = kzalloc(sizeof(*dst), GFP_KERNEL);
328         if (dst == NULL) {
329                 dev_put(dev);
330                 return -ENOMEM;
331         }
332
333         platform_set_drvdata(pdev, dst);
334
335         dst->pd = pd;
336         dst->master_netdev = dev;
337         dst->cpu_switch = -1;
338         dst->cpu_port = -1;
339
340         for (i = 0; i < pd->nr_chips; i++) {
341                 struct mii_bus *bus;
342                 struct dsa_switch *ds;
343
344                 bus = dev_to_mii_bus(pd->chip[i].mii_bus);
345                 if (bus == NULL) {
346                         printk(KERN_ERR "%s[%d]: no mii bus found for "
347                                 "dsa switch\n", dev->name, i);
348                         continue;
349                 }
350
351                 ds = dsa_switch_setup(dst, i, &pdev->dev, bus);
352                 if (IS_ERR(ds)) {
353                         printk(KERN_ERR "%s[%d]: couldn't create dsa switch "
354                                 "instance (error %ld)\n", dev->name, i,
355                                 PTR_ERR(ds));
356                         continue;
357                 }
358
359                 dst->ds[i] = ds;
360                 if (ds->drv->poll_link != NULL)
361                         dst->link_poll_needed = 1;
362         }
363
364         /*
365          * If we use a tagging format that doesn't have an ethertype
366          * field, make sure that all packets from this point on get
367          * sent to the tag format's receive function.
368          */
369         wmb();
370         dev->dsa_ptr = (void *)dst;
371
372         if (dst->link_poll_needed) {
373                 INIT_WORK(&dst->link_poll_work, dsa_link_poll_work);
374                 init_timer(&dst->link_poll_timer);
375                 dst->link_poll_timer.data = (unsigned long)dst;
376                 dst->link_poll_timer.function = dsa_link_poll_timer;
377                 dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
378                 add_timer(&dst->link_poll_timer);
379         }
380
381         return 0;
382 }
383
384 static int dsa_remove(struct platform_device *pdev)
385 {
386         struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
387         int i;
388
389         if (dst->link_poll_needed)
390                 del_timer_sync(&dst->link_poll_timer);
391
392         flush_scheduled_work();
393
394         for (i = 0; i < dst->pd->nr_chips; i++) {
395                 struct dsa_switch *ds = dst->ds[i];
396
397                 if (ds != NULL)
398                         dsa_switch_destroy(ds);
399         }
400
401         return 0;
402 }
403
404 static void dsa_shutdown(struct platform_device *pdev)
405 {
406 }
407
408 static struct platform_driver dsa_driver = {
409         .probe          = dsa_probe,
410         .remove         = dsa_remove,
411         .shutdown       = dsa_shutdown,
412         .driver = {
413                 .name   = "dsa",
414                 .owner  = THIS_MODULE,
415         },
416 };
417
418 static int __init dsa_init_module(void)
419 {
420         return platform_driver_register(&dsa_driver);
421 }
422 module_init(dsa_init_module);
423
424 static void __exit dsa_cleanup_module(void)
425 {
426         platform_driver_unregister(&dsa_driver);
427 }
428 module_exit(dsa_cleanup_module);
429
430 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>")
431 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
432 MODULE_LICENSE("GPL");
433 MODULE_ALIAS("platform:dsa");