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