1/*
2 * IBM PowerPC IBM eBus Infrastructure Support.
3 *
4 * Copyright (c) 2005 IBM Corporation
5 *  Joachim Fenkes <fenkes@de.ibm.com>
6 *  Heiko J Schick <schickhj@de.ibm.com>
7 *
8 * All rights reserved.
9 *
10 * This source code is distributed under a dual license of GPL v2.0 and OpenIB
11 * BSD.
12 *
13 * OpenIB BSD License
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions are met:
17 *
18 * Redistributions of source code must retain the above copyright notice, this
19 * list of conditions and the following disclaimer.
20 *
21 * Redistributions in binary form must reproduce the above copyright notice,
22 * this list of conditions and the following disclaimer in the documentation
23 * and/or other materials
24 * provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
33 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
34 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include <linux/init.h>
40#include <linux/console.h>
41#include <linux/kobject.h>
42#include <linux/dma-mapping.h>
43#include <linux/interrupt.h>
44#include <asm/ibmebus.h>
45#include <asm/abs_addr.h>
46
47static struct device ibmebus_bus_device = { /* fake "parent" device */
48	.bus_id = "ibmebus",
49};
50
51struct bus_type ibmebus_bus_type;
52
53static void *ibmebus_alloc_coherent(struct device *dev,
54				    size_t size,
55				    dma_addr_t *dma_handle,
56				    gfp_t flag)
57{
58	void *mem;
59
60	mem = kmalloc(size, flag);
61	*dma_handle = (dma_addr_t)mem;
62
63	return mem;
64}
65
66static void ibmebus_free_coherent(struct device *dev,
67				  size_t size, void *vaddr,
68				  dma_addr_t dma_handle)
69{
70	kfree(vaddr);
71}
72
73static dma_addr_t ibmebus_map_single(struct device *dev,
74				     void *ptr,
75				     size_t size,
76				     enum dma_data_direction direction)
77{
78	return (dma_addr_t)(ptr);
79}
80
81static void ibmebus_unmap_single(struct device *dev,
82				 dma_addr_t dma_addr,
83				 size_t size,
84				 enum dma_data_direction direction)
85{
86	return;
87}
88
89static int ibmebus_map_sg(struct device *dev,
90			  struct scatterlist *sg,
91			  int nents, enum dma_data_direction direction)
92{
93	int i;
94
95	for (i = 0; i < nents; i++) {
96		sg[i].dma_address = (dma_addr_t)page_address(sg[i].page)
97			+ sg[i].offset;
98		sg[i].dma_length = sg[i].length;
99	}
100
101	return nents;
102}
103
104static void ibmebus_unmap_sg(struct device *dev,
105			     struct scatterlist *sg,
106			     int nents, enum dma_data_direction direction)
107{
108	return;
109}
110
111static int ibmebus_dma_supported(struct device *dev, u64 mask)
112{
113	return 1;
114}
115
116static struct dma_mapping_ops ibmebus_dma_ops = {
117	.alloc_coherent = ibmebus_alloc_coherent,
118	.free_coherent  = ibmebus_free_coherent,
119	.map_single     = ibmebus_map_single,
120	.unmap_single   = ibmebus_unmap_single,
121	.map_sg         = ibmebus_map_sg,
122	.unmap_sg       = ibmebus_unmap_sg,
123	.dma_supported  = ibmebus_dma_supported,
124};
125
126static int ibmebus_bus_probe(struct device *dev)
127{
128	struct ibmebus_dev *ibmebusdev    = to_ibmebus_dev(dev);
129	struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
130	const struct of_device_id *id;
131	int error = -ENODEV;
132
133	if (!ibmebusdrv->probe)
134		return error;
135
136	id = of_match_device(ibmebusdrv->id_table, &ibmebusdev->ofdev);
137	if (id) {
138		error = ibmebusdrv->probe(ibmebusdev, id);
139	}
140
141	return error;
142}
143
144static int ibmebus_bus_remove(struct device *dev)
145{
146	struct ibmebus_dev *ibmebusdev    = to_ibmebus_dev(dev);
147	struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
148
149	if (ibmebusdrv->remove) {
150		return ibmebusdrv->remove(ibmebusdev);
151	}
152
153	return 0;
154}
155
156static void __devinit ibmebus_dev_release(struct device *dev)
157{
158	of_node_put(to_ibmebus_dev(dev)->ofdev.node);
159	kfree(to_ibmebus_dev(dev));
160}
161
162static int __devinit ibmebus_register_device_common(
163	struct ibmebus_dev *dev, const char *name)
164{
165	int err = 0;
166
167	dev->ofdev.dev.parent  = &ibmebus_bus_device;
168	dev->ofdev.dev.bus     = &ibmebus_bus_type;
169	dev->ofdev.dev.release = ibmebus_dev_release;
170
171	dev->ofdev.dev.archdata.of_node = dev->ofdev.node;
172	dev->ofdev.dev.archdata.dma_ops = &ibmebus_dma_ops;
173	dev->ofdev.dev.archdata.numa_node = of_node_to_nid(dev->ofdev.node);
174
175	/* An ibmebusdev is based on a of_device. We have to change the
176	 * bus type to use our own DMA mapping operations.
177	 */
178	if ((err = of_device_register(&dev->ofdev)) != 0) {
179		printk(KERN_ERR "%s: failed to register device (%d).\n",
180		       __FUNCTION__, err);
181		return -ENODEV;
182	}
183
184	return 0;
185}
186
187static struct ibmebus_dev* __devinit ibmebus_register_device_node(
188	struct device_node *dn)
189{
190	struct ibmebus_dev *dev;
191	const char *loc_code;
192	int length;
193
194	loc_code = of_get_property(dn, "ibm,loc-code", NULL);
195	if (!loc_code) {
196                printk(KERN_WARNING "%s: node %s missing 'ibm,loc-code'\n",
197		       __FUNCTION__, dn->name ? dn->name : "<unknown>");
198		return ERR_PTR(-EINVAL);
199        }
200
201	if (strlen(loc_code) == 0) {
202	        printk(KERN_WARNING "%s: 'ibm,loc-code' is invalid\n",
203		       __FUNCTION__);
204		return ERR_PTR(-EINVAL);
205	}
206
207	dev = kzalloc(sizeof(struct ibmebus_dev), GFP_KERNEL);
208	if (!dev) {
209		return ERR_PTR(-ENOMEM);
210	}
211
212	dev->ofdev.node = of_node_get(dn);
213
214	length = strlen(loc_code);
215	memcpy(dev->ofdev.dev.bus_id, loc_code
216		+ (length - min(length, BUS_ID_SIZE - 1)),
217		min(length, BUS_ID_SIZE - 1));
218
219	/* Register with generic device framework. */
220	if (ibmebus_register_device_common(dev, dn->name) != 0) {
221		kfree(dev);
222		return ERR_PTR(-ENODEV);
223	}
224
225	return dev;
226}
227
228static void ibmebus_probe_of_nodes(char* name)
229{
230	struct device_node *dn = NULL;
231
232	while ((dn = of_find_node_by_name(dn, name))) {
233		if (IS_ERR(ibmebus_register_device_node(dn))) {
234			of_node_put(dn);
235			return;
236		}
237	}
238
239	of_node_put(dn);
240
241	return;
242}
243
244static void ibmebus_add_devices_by_id(struct of_device_id *idt)
245{
246	while (strlen(idt->name) > 0) {
247		ibmebus_probe_of_nodes(idt->name);
248		idt++;
249	}
250
251	return;
252}
253
254static int ibmebus_match_name(struct device *dev, void *data)
255{
256	const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
257	const char *name;
258
259	name = of_get_property(ebus_dev->ofdev.node, "name", NULL);
260
261	if (name && (strcmp(data, name) == 0))
262		return 1;
263
264	return 0;
265}
266
267static int ibmebus_unregister_device(struct device *dev)
268{
269	of_device_unregister(to_of_device(dev));
270
271	return 0;
272}
273
274static void ibmebus_remove_devices_by_id(struct of_device_id *idt)
275{
276	struct device *dev;
277
278	while (strlen(idt->name) > 0) {
279		while ((dev = bus_find_device(&ibmebus_bus_type, NULL,
280					      (void*)idt->name,
281					      ibmebus_match_name))) {
282			ibmebus_unregister_device(dev);
283		}
284		idt++;
285	}
286
287	return;
288}
289
290int ibmebus_register_driver(struct ibmebus_driver *drv)
291{
292	int err = 0;
293
294	drv->driver.name   = drv->name;
295	drv->driver.bus    = &ibmebus_bus_type;
296	drv->driver.probe  = ibmebus_bus_probe;
297	drv->driver.remove = ibmebus_bus_remove;
298
299	if ((err = driver_register(&drv->driver) != 0))
300		return err;
301
302	/* remove all supported devices first, in case someone
303	 * probed them manually before registering the driver */
304	ibmebus_remove_devices_by_id(drv->id_table);
305	ibmebus_add_devices_by_id(drv->id_table);
306
307	return 0;
308}
309EXPORT_SYMBOL(ibmebus_register_driver);
310
311void ibmebus_unregister_driver(struct ibmebus_driver *drv)
312{
313	driver_unregister(&drv->driver);
314	ibmebus_remove_devices_by_id(drv->id_table);
315}
316EXPORT_SYMBOL(ibmebus_unregister_driver);
317
318int ibmebus_request_irq(struct ibmebus_dev *dev,
319			u32 ist,
320			irq_handler_t handler,
321			unsigned long irq_flags, const char * devname,
322			void *dev_id)
323{
324	unsigned int irq = irq_create_mapping(NULL, ist);
325
326	if (irq == NO_IRQ)
327		return -EINVAL;
328
329	return request_irq(irq, handler,
330			   irq_flags, devname, dev_id);
331}
332EXPORT_SYMBOL(ibmebus_request_irq);
333
334void ibmebus_free_irq(struct ibmebus_dev *dev, u32 ist, void *dev_id)
335{
336	unsigned int irq = irq_find_mapping(NULL, ist);
337
338	free_irq(irq, dev_id);
339}
340EXPORT_SYMBOL(ibmebus_free_irq);
341
342static int ibmebus_bus_match(struct device *dev, struct device_driver *drv)
343{
344	const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
345	struct ibmebus_driver *ebus_drv    = to_ibmebus_driver(drv);
346	const struct of_device_id *ids     = ebus_drv->id_table;
347	const struct of_device_id *found_id;
348
349	if (!ids)
350		return 0;
351
352	found_id = of_match_device(ids, &ebus_dev->ofdev);
353	if (found_id)
354		return 1;
355
356	return 0;
357}
358
359static ssize_t name_show(struct device *dev,
360			 struct device_attribute *attr, char *buf)
361{
362	struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
363	const char *name = of_get_property(ebus_dev->ofdev.node, "name", NULL);
364	return sprintf(buf, "%s\n", name);
365}
366
367static struct device_attribute ibmebus_dev_attrs[] = {
368	__ATTR_RO(name),
369	__ATTR_NULL
370};
371
372static int ibmebus_match_path(struct device *dev, void *data)
373{
374	int rc;
375	struct device_node *dn =
376		of_node_get(to_ibmebus_dev(dev)->ofdev.node);
377
378	rc = (dn->full_name && (strcasecmp((char*)data, dn->full_name) == 0));
379
380	of_node_put(dn);
381	return rc;
382}
383
384static char *ibmebus_chomp(const char *in, size_t count)
385{
386	char *out = (char*)kmalloc(count + 1, GFP_KERNEL);
387	if (!out)
388		return NULL;
389
390	memcpy(out, in, count);
391	out[count] = '\0';
392	if (out[count - 1] == '\n')
393		out[count - 1] = '\0';
394
395	return out;
396}
397
398static ssize_t ibmebus_store_probe(struct bus_type *bus,
399				   const char *buf, size_t count)
400{
401	struct device_node *dn = NULL;
402	struct ibmebus_dev *dev;
403	char *path;
404	ssize_t rc;
405
406	path = ibmebus_chomp(buf, count);
407	if (!path)
408		return -ENOMEM;
409
410	if (bus_find_device(&ibmebus_bus_type, NULL, path,
411			     ibmebus_match_path)) {
412		printk(KERN_WARNING "%s: %s has already been probed\n",
413		       __FUNCTION__, path);
414		rc = -EINVAL;
415		goto out;
416	}
417
418	if ((dn = of_find_node_by_path(path))) {
419		dev = ibmebus_register_device_node(dn);
420		of_node_put(dn);
421		rc = IS_ERR(dev) ? PTR_ERR(dev) : count;
422	} else {
423		printk(KERN_WARNING "%s: no such device node: %s\n",
424		       __FUNCTION__, path);
425		rc = -ENODEV;
426	}
427
428out:
429	kfree(path);
430	return rc;
431}
432
433static ssize_t ibmebus_store_remove(struct bus_type *bus,
434				    const char *buf, size_t count)
435{
436	struct device *dev;
437	char *path;
438
439	path = ibmebus_chomp(buf, count);
440	if (!path)
441		return -ENOMEM;
442
443	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
444				   ibmebus_match_path))) {
445		ibmebus_unregister_device(dev);
446
447		kfree(path);
448		return count;
449	} else {
450		printk(KERN_WARNING "%s: %s not on the bus\n",
451		       __FUNCTION__, path);
452
453		kfree(path);
454		return -ENODEV;
455	}
456}
457
458static struct bus_attribute ibmebus_bus_attrs[] = {
459	__ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe),
460	__ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove),
461	__ATTR_NULL
462};
463
464struct bus_type ibmebus_bus_type = {
465	.name      = "ibmebus",
466	.match     = ibmebus_bus_match,
467	.dev_attrs = ibmebus_dev_attrs,
468	.bus_attrs = ibmebus_bus_attrs
469};
470EXPORT_SYMBOL(ibmebus_bus_type);
471
472static int __init ibmebus_bus_init(void)
473{
474	int err;
475
476	printk(KERN_INFO "IBM eBus Device Driver\n");
477
478	err = bus_register(&ibmebus_bus_type);
479	if (err) {
480		printk(KERN_ERR ":%s: failed to register IBM eBus.\n",
481		       __FUNCTION__);
482		return err;
483	}
484
485	err = device_register(&ibmebus_bus_device);
486	if (err) {
487		printk(KERN_WARNING "%s: device_register returned %i\n",
488		       __FUNCTION__, err);
489		bus_unregister(&ibmebus_bus_type);
490
491		return err;
492	}
493
494	return 0;
495}
496__initcall(ibmebus_bus_init);
497