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