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/export.h>
41#include <linux/console.h>
42#include <linux/kobject.h>
43#include <linux/dma-map-ops.h>
44#include <linux/interrupt.h>
45#include <linux/irqdomain.h>
46#include <linux/of.h>
47#include <linux/slab.h>
48#include <linux/stat.h>
49#include <linux/of_platform.h>
50#include <linux/platform_device.h>
51#include <asm/ibmebus.h>
52#include <asm/machdep.h>
53
54static struct device ibmebus_bus_device = { /* fake "parent" device */
55	.init_name = "ibmebus",
56};
57
58const struct bus_type ibmebus_bus_type;
59
60/* These devices will automatically be added to the bus during init */
61static const struct of_device_id ibmebus_matches[] __initconst = {
62	{ .compatible = "IBM,lhca" },
63	{ .compatible = "IBM,lhea" },
64	{},
65};
66
67static void *ibmebus_alloc_coherent(struct device *dev,
68				    size_t size,
69				    dma_addr_t *dma_handle,
70				    gfp_t flag,
71				    unsigned long attrs)
72{
73	void *mem;
74
75	mem = kmalloc(size, flag);
76	*dma_handle = (dma_addr_t)mem;
77
78	return mem;
79}
80
81static void ibmebus_free_coherent(struct device *dev,
82				  size_t size, void *vaddr,
83				  dma_addr_t dma_handle,
84				  unsigned long attrs)
85{
86	kfree(vaddr);
87}
88
89static dma_addr_t ibmebus_map_page(struct device *dev,
90				   struct page *page,
91				   unsigned long offset,
92				   size_t size,
93				   enum dma_data_direction direction,
94				   unsigned long attrs)
95{
96	return (dma_addr_t)(page_address(page) + offset);
97}
98
99static void ibmebus_unmap_page(struct device *dev,
100			       dma_addr_t dma_addr,
101			       size_t size,
102			       enum dma_data_direction direction,
103			       unsigned long attrs)
104{
105	return;
106}
107
108static int ibmebus_map_sg(struct device *dev,
109			  struct scatterlist *sgl,
110			  int nents, enum dma_data_direction direction,
111			  unsigned long attrs)
112{
113	struct scatterlist *sg;
114	int i;
115
116	for_each_sg(sgl, sg, nents, i) {
117		sg->dma_address = (dma_addr_t) sg_virt(sg);
118		sg->dma_length = sg->length;
119	}
120
121	return nents;
122}
123
124static void ibmebus_unmap_sg(struct device *dev,
125			     struct scatterlist *sg,
126			     int nents, enum dma_data_direction direction,
127			     unsigned long attrs)
128{
129	return;
130}
131
132static int ibmebus_dma_supported(struct device *dev, u64 mask)
133{
134	return mask == DMA_BIT_MASK(64);
135}
136
137static u64 ibmebus_dma_get_required_mask(struct device *dev)
138{
139	return DMA_BIT_MASK(64);
140}
141
142static const struct dma_map_ops ibmebus_dma_ops = {
143	.alloc              = ibmebus_alloc_coherent,
144	.free               = ibmebus_free_coherent,
145	.map_sg             = ibmebus_map_sg,
146	.unmap_sg           = ibmebus_unmap_sg,
147	.dma_supported      = ibmebus_dma_supported,
148	.get_required_mask  = ibmebus_dma_get_required_mask,
149	.map_page           = ibmebus_map_page,
150	.unmap_page         = ibmebus_unmap_page,
151};
152
153static int ibmebus_match_path(struct device *dev, const void *data)
154{
155	struct device_node *dn = to_platform_device(dev)->dev.of_node;
156	struct device_node *tn = of_find_node_by_path(data);
157
158	of_node_put(tn);
159
160	return (tn == dn);
161}
162
163static int ibmebus_match_node(struct device *dev, const void *data)
164{
165	return to_platform_device(dev)->dev.of_node == data;
166}
167
168static int ibmebus_create_device(struct device_node *dn)
169{
170	struct platform_device *dev;
171	int ret;
172
173	dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
174	if (!dev)
175		return -ENOMEM;
176
177	dev->dev.bus = &ibmebus_bus_type;
178	dev->dev.dma_ops = &ibmebus_dma_ops;
179
180	ret = of_device_add(dev);
181	if (ret)
182		platform_device_put(dev);
183	return ret;
184}
185
186static int ibmebus_create_devices(const struct of_device_id *matches)
187{
188	struct device_node *root, *child;
189	struct device *dev;
190	int ret = 0;
191
192	root = of_find_node_by_path("/");
193
194	for_each_child_of_node(root, child) {
195		if (!of_match_node(matches, child))
196			continue;
197
198		dev = bus_find_device(&ibmebus_bus_type, NULL, child,
199				      ibmebus_match_node);
200		if (dev) {
201			put_device(dev);
202			continue;
203		}
204
205		ret = ibmebus_create_device(child);
206		if (ret) {
207			printk(KERN_ERR "%s: failed to create device (%i)",
208			       __func__, ret);
209			of_node_put(child);
210			break;
211		}
212	}
213
214	of_node_put(root);
215	return ret;
216}
217
218int ibmebus_register_driver(struct platform_driver *drv)
219{
220	/* If the driver uses devices that ibmebus doesn't know, add them */
221	ibmebus_create_devices(drv->driver.of_match_table);
222
223	drv->driver.bus = &ibmebus_bus_type;
224	return driver_register(&drv->driver);
225}
226EXPORT_SYMBOL(ibmebus_register_driver);
227
228void ibmebus_unregister_driver(struct platform_driver *drv)
229{
230	driver_unregister(&drv->driver);
231}
232EXPORT_SYMBOL(ibmebus_unregister_driver);
233
234int ibmebus_request_irq(u32 ist, irq_handler_t handler,
235			unsigned long irq_flags, const char *devname,
236			void *dev_id)
237{
238	unsigned int irq = irq_create_mapping(NULL, ist);
239
240	if (!irq)
241		return -EINVAL;
242
243	return request_irq(irq, handler, irq_flags, devname, dev_id);
244}
245EXPORT_SYMBOL(ibmebus_request_irq);
246
247void ibmebus_free_irq(u32 ist, void *dev_id)
248{
249	unsigned int irq = irq_find_mapping(NULL, ist);
250
251	free_irq(irq, dev_id);
252	irq_dispose_mapping(irq);
253}
254EXPORT_SYMBOL(ibmebus_free_irq);
255
256static char *ibmebus_chomp(const char *in, size_t count)
257{
258	char *out = kmalloc(count + 1, GFP_KERNEL);
259
260	if (!out)
261		return NULL;
262
263	memcpy(out, in, count);
264	out[count] = '\0';
265	if (out[count - 1] == '\n')
266		out[count - 1] = '\0';
267
268	return out;
269}
270
271static ssize_t probe_store(const struct bus_type *bus, const char *buf, size_t count)
272{
273	struct device_node *dn = NULL;
274	struct device *dev;
275	char *path;
276	ssize_t rc = 0;
277
278	path = ibmebus_chomp(buf, count);
279	if (!path)
280		return -ENOMEM;
281
282	dev = bus_find_device(&ibmebus_bus_type, NULL, path,
283			      ibmebus_match_path);
284	if (dev) {
285		put_device(dev);
286		printk(KERN_WARNING "%s: %s has already been probed\n",
287		       __func__, path);
288		rc = -EEXIST;
289		goto out;
290	}
291
292	if ((dn = of_find_node_by_path(path))) {
293		rc = ibmebus_create_device(dn);
294		of_node_put(dn);
295	} else {
296		printk(KERN_WARNING "%s: no such device node: %s\n",
297		       __func__, path);
298		rc = -ENODEV;
299	}
300
301out:
302	kfree(path);
303	if (rc)
304		return rc;
305	return count;
306}
307static BUS_ATTR_WO(probe);
308
309static ssize_t remove_store(const struct bus_type *bus, const char *buf, size_t count)
310{
311	struct device *dev;
312	char *path;
313
314	path = ibmebus_chomp(buf, count);
315	if (!path)
316		return -ENOMEM;
317
318	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
319				   ibmebus_match_path))) {
320		of_device_unregister(to_platform_device(dev));
321		put_device(dev);
322
323		kfree(path);
324		return count;
325	} else {
326		printk(KERN_WARNING "%s: %s not on the bus\n",
327		       __func__, path);
328
329		kfree(path);
330		return -ENODEV;
331	}
332}
333static BUS_ATTR_WO(remove);
334
335static struct attribute *ibmbus_bus_attrs[] = {
336	&bus_attr_probe.attr,
337	&bus_attr_remove.attr,
338	NULL,
339};
340ATTRIBUTE_GROUPS(ibmbus_bus);
341
342static int ibmebus_bus_bus_match(struct device *dev, struct device_driver *drv)
343{
344	const struct of_device_id *matches = drv->of_match_table;
345
346	if (!matches)
347		return 0;
348
349	return of_match_device(matches, dev) != NULL;
350}
351
352static int ibmebus_bus_device_probe(struct device *dev)
353{
354	int error = -ENODEV;
355	struct platform_driver *drv;
356	struct platform_device *of_dev;
357
358	drv = to_platform_driver(dev->driver);
359	of_dev = to_platform_device(dev);
360
361	if (!drv->probe)
362		return error;
363
364	get_device(dev);
365
366	if (of_driver_match_device(dev, dev->driver))
367		error = drv->probe(of_dev);
368	if (error)
369		put_device(dev);
370
371	return error;
372}
373
374static void ibmebus_bus_device_remove(struct device *dev)
375{
376	struct platform_device *of_dev = to_platform_device(dev);
377	struct platform_driver *drv = to_platform_driver(dev->driver);
378
379	if (dev->driver && drv->remove)
380		drv->remove(of_dev);
381}
382
383static void ibmebus_bus_device_shutdown(struct device *dev)
384{
385	struct platform_device *of_dev = to_platform_device(dev);
386	struct platform_driver *drv = to_platform_driver(dev->driver);
387
388	if (dev->driver && drv->shutdown)
389		drv->shutdown(of_dev);
390}
391
392/*
393 * ibmebus_bus_device_attrs
394 */
395static ssize_t devspec_show(struct device *dev,
396				struct device_attribute *attr, char *buf)
397{
398	struct platform_device *ofdev;
399
400	ofdev = to_platform_device(dev);
401	return sprintf(buf, "%pOF\n", ofdev->dev.of_node);
402}
403static DEVICE_ATTR_RO(devspec);
404
405static ssize_t name_show(struct device *dev,
406				struct device_attribute *attr, char *buf)
407{
408	struct platform_device *ofdev;
409
410	ofdev = to_platform_device(dev);
411	return sprintf(buf, "%pOFn\n", ofdev->dev.of_node);
412}
413static DEVICE_ATTR_RO(name);
414
415static ssize_t modalias_show(struct device *dev,
416				struct device_attribute *attr, char *buf)
417{
418	return of_device_modalias(dev, buf, PAGE_SIZE);
419}
420static DEVICE_ATTR_RO(modalias);
421
422static struct attribute *ibmebus_bus_device_attrs[] = {
423	&dev_attr_devspec.attr,
424	&dev_attr_name.attr,
425	&dev_attr_modalias.attr,
426	NULL,
427};
428ATTRIBUTE_GROUPS(ibmebus_bus_device);
429
430static int ibmebus_bus_modalias(const struct device *dev, struct kobj_uevent_env *env)
431{
432	return of_device_uevent_modalias(dev, env);
433}
434
435const struct bus_type ibmebus_bus_type = {
436	.name      = "ibmebus",
437	.uevent    = ibmebus_bus_modalias,
438	.bus_groups = ibmbus_bus_groups,
439	.match     = ibmebus_bus_bus_match,
440	.probe     = ibmebus_bus_device_probe,
441	.remove    = ibmebus_bus_device_remove,
442	.shutdown  = ibmebus_bus_device_shutdown,
443	.dev_groups = ibmebus_bus_device_groups,
444};
445EXPORT_SYMBOL(ibmebus_bus_type);
446
447static int __init ibmebus_bus_init(void)
448{
449	int err;
450
451	printk(KERN_INFO "IBM eBus Device Driver\n");
452
453	err = bus_register(&ibmebus_bus_type);
454	if (err) {
455		printk(KERN_ERR "%s: failed to register IBM eBus.\n",
456		       __func__);
457		return err;
458	}
459
460	err = device_register(&ibmebus_bus_device);
461	if (err) {
462		printk(KERN_WARNING "%s: device_register returned %i\n",
463		       __func__, err);
464		put_device(&ibmebus_bus_device);
465		bus_unregister(&ibmebus_bus_type);
466
467		return err;
468	}
469
470	err = ibmebus_create_devices(ibmebus_matches);
471	if (err) {
472		device_unregister(&ibmebus_bus_device);
473		bus_unregister(&ibmebus_bus_type);
474		return err;
475	}
476
477	return 0;
478}
479machine_postcore_initcall(pseries, ibmebus_bus_init);
480