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 <asm/ibmebus.h>
51 #include <asm/machdep.h>
52 
53 static struct device ibmebus_bus_device = { /* fake "parent" device */
54 	.init_name = "ibmebus",
55 };
56 
57 struct bus_type ibmebus_bus_type;
58 
59 /* These devices will automatically be added to the bus during init */
60 static const struct of_device_id ibmebus_matches[] __initconst = {
61 	{ .compatible = "IBM,lhca" },
62 	{ .compatible = "IBM,lhea" },
63 	{},
64 };
65 
66 static void *ibmebus_alloc_coherent(struct device *dev,
67 				    size_t size,
68 				    dma_addr_t *dma_handle,
69 				    gfp_t flag,
70 				    unsigned long attrs)
71 {
72 	void *mem;
73 
74 	mem = kmalloc(size, flag);
75 	*dma_handle = (dma_addr_t)mem;
76 
77 	return mem;
78 }
79 
80 static void ibmebus_free_coherent(struct device *dev,
81 				  size_t size, void *vaddr,
82 				  dma_addr_t dma_handle,
83 				  unsigned long attrs)
84 {
85 	kfree(vaddr);
86 }
87 
88 static dma_addr_t ibmebus_map_page(struct device *dev,
89 				   struct page *page,
90 				   unsigned long offset,
91 				   size_t size,
92 				   enum dma_data_direction direction,
93 				   unsigned long attrs)
94 {
95 	return (dma_addr_t)(page_address(page) + offset);
96 }
97 
98 static void ibmebus_unmap_page(struct device *dev,
99 			       dma_addr_t dma_addr,
100 			       size_t size,
101 			       enum dma_data_direction direction,
102 			       unsigned long attrs)
103 {
104 	return;
105 }
106 
107 static int ibmebus_map_sg(struct device *dev,
108 			  struct scatterlist *sgl,
109 			  int nents, enum dma_data_direction direction,
110 			  unsigned long attrs)
111 {
112 	struct scatterlist *sg;
113 	int i;
114 
115 	for_each_sg(sgl, sg, nents, i) {
116 		sg->dma_address = (dma_addr_t) sg_virt(sg);
117 		sg->dma_length = sg->length;
118 	}
119 
120 	return nents;
121 }
122 
123 static void ibmebus_unmap_sg(struct device *dev,
124 			     struct scatterlist *sg,
125 			     int nents, enum dma_data_direction direction,
126 			     unsigned long attrs)
127 {
128 	return;
129 }
130 
131 static int ibmebus_dma_supported(struct device *dev, u64 mask)
132 {
133 	return mask == DMA_BIT_MASK(64);
134 }
135 
136 static u64 ibmebus_dma_get_required_mask(struct device *dev)
137 {
138 	return DMA_BIT_MASK(64);
139 }
140 
141 static const struct dma_map_ops ibmebus_dma_ops = {
142 	.alloc              = ibmebus_alloc_coherent,
143 	.free               = ibmebus_free_coherent,
144 	.map_sg             = ibmebus_map_sg,
145 	.unmap_sg           = ibmebus_unmap_sg,
146 	.dma_supported      = ibmebus_dma_supported,
147 	.get_required_mask  = ibmebus_dma_get_required_mask,
148 	.map_page           = ibmebus_map_page,
149 	.unmap_page         = ibmebus_unmap_page,
150 };
151 
152 static int ibmebus_match_path(struct device *dev, const void *data)
153 {
154 	struct device_node *dn = to_platform_device(dev)->dev.of_node;
155 	return (of_find_node_by_path(data) == dn);
156 }
157 
158 static int ibmebus_match_node(struct device *dev, const void *data)
159 {
160 	return to_platform_device(dev)->dev.of_node == data;
161 }
162 
163 static int ibmebus_create_device(struct device_node *dn)
164 {
165 	struct platform_device *dev;
166 	int ret;
167 
168 	dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
169 	if (!dev)
170 		return -ENOMEM;
171 
172 	dev->dev.bus = &ibmebus_bus_type;
173 	dev->dev.dma_ops = &ibmebus_dma_ops;
174 
175 	ret = of_device_add(dev);
176 	if (ret)
177 		platform_device_put(dev);
178 	return ret;
179 }
180 
181 static int ibmebus_create_devices(const struct of_device_id *matches)
182 {
183 	struct device_node *root, *child;
184 	struct device *dev;
185 	int ret = 0;
186 
187 	root = of_find_node_by_path("/");
188 
189 	for_each_child_of_node(root, child) {
190 		if (!of_match_node(matches, child))
191 			continue;
192 
193 		dev = bus_find_device(&ibmebus_bus_type, NULL, child,
194 				      ibmebus_match_node);
195 		if (dev) {
196 			put_device(dev);
197 			continue;
198 		}
199 
200 		ret = ibmebus_create_device(child);
201 		if (ret) {
202 			printk(KERN_ERR "%s: failed to create device (%i)",
203 			       __func__, ret);
204 			of_node_put(child);
205 			break;
206 		}
207 	}
208 
209 	of_node_put(root);
210 	return ret;
211 }
212 
213 int ibmebus_register_driver(struct platform_driver *drv)
214 {
215 	/* If the driver uses devices that ibmebus doesn't know, add them */
216 	ibmebus_create_devices(drv->driver.of_match_table);
217 
218 	drv->driver.bus = &ibmebus_bus_type;
219 	return driver_register(&drv->driver);
220 }
221 EXPORT_SYMBOL(ibmebus_register_driver);
222 
223 void ibmebus_unregister_driver(struct platform_driver *drv)
224 {
225 	driver_unregister(&drv->driver);
226 }
227 EXPORT_SYMBOL(ibmebus_unregister_driver);
228 
229 int ibmebus_request_irq(u32 ist, irq_handler_t handler,
230 			unsigned long irq_flags, const char *devname,
231 			void *dev_id)
232 {
233 	unsigned int irq = irq_create_mapping(NULL, ist);
234 
235 	if (!irq)
236 		return -EINVAL;
237 
238 	return request_irq(irq, handler, irq_flags, devname, dev_id);
239 }
240 EXPORT_SYMBOL(ibmebus_request_irq);
241 
242 void ibmebus_free_irq(u32 ist, void *dev_id)
243 {
244 	unsigned int irq = irq_find_mapping(NULL, ist);
245 
246 	free_irq(irq, dev_id);
247 	irq_dispose_mapping(irq);
248 }
249 EXPORT_SYMBOL(ibmebus_free_irq);
250 
251 static char *ibmebus_chomp(const char *in, size_t count)
252 {
253 	char *out = kmalloc(count + 1, GFP_KERNEL);
254 
255 	if (!out)
256 		return NULL;
257 
258 	memcpy(out, in, count);
259 	out[count] = '\0';
260 	if (out[count - 1] == '\n')
261 		out[count - 1] = '\0';
262 
263 	return out;
264 }
265 
266 static ssize_t probe_store(struct bus_type *bus, const char *buf, size_t count)
267 {
268 	struct device_node *dn = NULL;
269 	struct device *dev;
270 	char *path;
271 	ssize_t rc = 0;
272 
273 	path = ibmebus_chomp(buf, count);
274 	if (!path)
275 		return -ENOMEM;
276 
277 	dev = bus_find_device(&ibmebus_bus_type, NULL, path,
278 			      ibmebus_match_path);
279 	if (dev) {
280 		put_device(dev);
281 		printk(KERN_WARNING "%s: %s has already been probed\n",
282 		       __func__, path);
283 		rc = -EEXIST;
284 		goto out;
285 	}
286 
287 	if ((dn = of_find_node_by_path(path))) {
288 		rc = ibmebus_create_device(dn);
289 		of_node_put(dn);
290 	} else {
291 		printk(KERN_WARNING "%s: no such device node: %s\n",
292 		       __func__, path);
293 		rc = -ENODEV;
294 	}
295 
296 out:
297 	kfree(path);
298 	if (rc)
299 		return rc;
300 	return count;
301 }
302 static BUS_ATTR_WO(probe);
303 
304 static ssize_t remove_store(struct bus_type *bus, const char *buf, size_t count)
305 {
306 	struct device *dev;
307 	char *path;
308 
309 	path = ibmebus_chomp(buf, count);
310 	if (!path)
311 		return -ENOMEM;
312 
313 	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
314 				   ibmebus_match_path))) {
315 		of_device_unregister(to_platform_device(dev));
316 		put_device(dev);
317 
318 		kfree(path);
319 		return count;
320 	} else {
321 		printk(KERN_WARNING "%s: %s not on the bus\n",
322 		       __func__, path);
323 
324 		kfree(path);
325 		return -ENODEV;
326 	}
327 }
328 static BUS_ATTR_WO(remove);
329 
330 static struct attribute *ibmbus_bus_attrs[] = {
331 	&bus_attr_probe.attr,
332 	&bus_attr_remove.attr,
333 	NULL,
334 };
335 ATTRIBUTE_GROUPS(ibmbus_bus);
336 
337 static int ibmebus_bus_bus_match(struct device *dev, struct device_driver *drv)
338 {
339 	const struct of_device_id *matches = drv->of_match_table;
340 
341 	if (!matches)
342 		return 0;
343 
344 	return of_match_device(matches, dev) != NULL;
345 }
346 
347 static int ibmebus_bus_device_probe(struct device *dev)
348 {
349 	int error = -ENODEV;
350 	struct platform_driver *drv;
351 	struct platform_device *of_dev;
352 
353 	drv = to_platform_driver(dev->driver);
354 	of_dev = to_platform_device(dev);
355 
356 	if (!drv->probe)
357 		return error;
358 
359 	get_device(dev);
360 
361 	if (of_driver_match_device(dev, dev->driver))
362 		error = drv->probe(of_dev);
363 	if (error)
364 		put_device(dev);
365 
366 	return error;
367 }
368 
369 static void ibmebus_bus_device_remove(struct device *dev)
370 {
371 	struct platform_device *of_dev = to_platform_device(dev);
372 	struct platform_driver *drv = to_platform_driver(dev->driver);
373 
374 	if (dev->driver && drv->remove)
375 		drv->remove(of_dev);
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