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 
54 static struct device ibmebus_bus_device = { /* fake "parent" device */
55 	.init_name = "ibmebus",
56 };
57 
58 struct bus_type ibmebus_bus_type;
59 
60 /* These devices will automatically be added to the bus during init */
61 static const struct of_device_id ibmebus_matches[] __initconst = {
62 	{ .compatible = "IBM,lhca" },
63 	{ .compatible = "IBM,lhea" },
64 	{},
65 };
66 
67 static 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 
81 static 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 
89 static 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 
99 static 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 
108 static 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 
124 static 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 
132 static int ibmebus_dma_supported(struct device *dev, u64 mask)
133 {
134 	return mask == DMA_BIT_MASK(64);
135 }
136 
137 static u64 ibmebus_dma_get_required_mask(struct device *dev)
138 {
139 	return DMA_BIT_MASK(64);
140 }
141 
142 static 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 
153 static 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 
163 static int ibmebus_match_node(struct device *dev, const void *data)
164 {
165 	return to_platform_device(dev)->dev.of_node == data;
166 }
167 
168 static 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 
186 static 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 
218 int 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 }
226 EXPORT_SYMBOL(ibmebus_register_driver);
227 
228 void ibmebus_unregister_driver(struct platform_driver *drv)
229 {
230 	driver_unregister(&drv->driver);
231 }
232 EXPORT_SYMBOL(ibmebus_unregister_driver);
233 
234 int 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 }
245 EXPORT_SYMBOL(ibmebus_request_irq);
246 
247 void 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 }
254 EXPORT_SYMBOL(ibmebus_free_irq);
255 
256 static 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 
271 static 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 
301 out:
302 	kfree(path);
303 	if (rc)
304 		return rc;
305 	return count;
306 }
307 static BUS_ATTR_WO(probe);
308 
309 static 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 }
333 static BUS_ATTR_WO(remove);
334 
335 static struct attribute *ibmbus_bus_attrs[] = {
336 	&bus_attr_probe.attr,
337 	&bus_attr_remove.attr,
338 	NULL,
339 };
340 ATTRIBUTE_GROUPS(ibmbus_bus);
341 
342 static 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 
352 static 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 
374 static 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 
383 static 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  */
395 static 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 }
403 static DEVICE_ATTR_RO(devspec);
404 
405 static 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 }
413 static DEVICE_ATTR_RO(name);
414 
415 static 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 }
420 static DEVICE_ATTR_RO(modalias);
421 
422 static struct attribute *ibmebus_bus_device_attrs[] = {
423 	&dev_attr_devspec.attr,
424 	&dev_attr_name.attr,
425 	&dev_attr_modalias.attr,
426 	NULL,
427 };
428 ATTRIBUTE_GROUPS(ibmebus_bus_device);
429 
430 static int ibmebus_bus_modalias(const struct device *dev, struct kobj_uevent_env *env)
431 {
432 	return of_device_uevent_modalias(dev, env);
433 }
434 
435 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 };
445 EXPORT_SYMBOL(ibmebus_bus_type);
446 
447 static 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 }
479 machine_postcore_initcall(pseries, ibmebus_bus_init);
480