1/*
2 *  linux/arch/arm/common/amba.c
3 *
4 *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/device.h>
13#include <linux/string.h>
14#include <linux/slab.h>
15#include <linux/amba/bus.h>
16
17#include <asm/io.h>
18#include <asm/sizes.h>
19
20#define to_amba_device(d)	container_of(d, struct amba_device, dev)
21#define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
22
23static struct amba_id *
24amba_lookup(struct amba_id *table, struct amba_device *dev)
25{
26	int ret = 0;
27
28	while (table->mask) {
29		ret = (dev->periphid & table->mask) == table->id;
30		if (ret)
31			break;
32		table++;
33	}
34
35	return ret ? table : NULL;
36}
37
38static int amba_match(struct device *dev, struct device_driver *drv)
39{
40	struct amba_device *pcdev = to_amba_device(dev);
41	struct amba_driver *pcdrv = to_amba_driver(drv);
42
43	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
44}
45
46#ifdef CONFIG_HOTPLUG
47static int amba_uevent(struct device *dev, char **envp, int nr_env, char *buf, int bufsz)
48{
49	struct amba_device *pcdev = to_amba_device(dev);
50	int retval = 0, i = 0, len = 0;
51
52	retval = add_uevent_var(envp, nr_env, &i,
53				buf, bufsz, &len,
54				"AMBA_ID=%08x", pcdev->periphid);
55	envp[i] = NULL;
56	return retval;
57}
58#else
59#define amba_uevent NULL
60#endif
61
62static int amba_suspend(struct device *dev, pm_message_t state)
63{
64	struct amba_driver *drv = to_amba_driver(dev->driver);
65	int ret = 0;
66
67	if (dev->driver && drv->suspend)
68		ret = drv->suspend(to_amba_device(dev), state);
69	return ret;
70}
71
72static int amba_resume(struct device *dev)
73{
74	struct amba_driver *drv = to_amba_driver(dev->driver);
75	int ret = 0;
76
77	if (dev->driver && drv->resume)
78		ret = drv->resume(to_amba_device(dev));
79	return ret;
80}
81
82#define amba_attr_func(name,fmt,arg...)					\
83static ssize_t name##_show(struct device *_dev,				\
84			   struct device_attribute *attr, char *buf)	\
85{									\
86	struct amba_device *dev = to_amba_device(_dev);			\
87	return sprintf(buf, fmt, arg);					\
88}
89
90#define amba_attr(name,fmt,arg...)	\
91amba_attr_func(name,fmt,arg)		\
92static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
93
94amba_attr_func(id, "%08x\n", dev->periphid);
95amba_attr(irq0, "%u\n", dev->irq[0]);
96amba_attr(irq1, "%u\n", dev->irq[1]);
97amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
98	 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
99	 dev->res.flags);
100
101static struct device_attribute amba_dev_attrs[] = {
102	__ATTR_RO(id),
103	__ATTR_RO(resource),
104	__ATTR_NULL,
105};
106
107/*
108 * Primecells are part of the Advanced Microcontroller Bus Architecture,
109 * so we call the bus "amba".
110 */
111static struct bus_type amba_bustype = {
112	.name		= "amba",
113	.dev_attrs	= amba_dev_attrs,
114	.match		= amba_match,
115	.uevent		= amba_uevent,
116	.suspend	= amba_suspend,
117	.resume		= amba_resume,
118};
119
120static int __init amba_init(void)
121{
122	return bus_register(&amba_bustype);
123}
124
125postcore_initcall(amba_init);
126
127/*
128 * These are the device model conversion veneers; they convert the
129 * device model structures to our more specific structures.
130 */
131static int amba_probe(struct device *dev)
132{
133	struct amba_device *pcdev = to_amba_device(dev);
134	struct amba_driver *pcdrv = to_amba_driver(dev->driver);
135	struct amba_id *id;
136
137	id = amba_lookup(pcdrv->id_table, pcdev);
138
139	return pcdrv->probe(pcdev, id);
140}
141
142static int amba_remove(struct device *dev)
143{
144	struct amba_driver *drv = to_amba_driver(dev->driver);
145	return drv->remove(to_amba_device(dev));
146}
147
148static void amba_shutdown(struct device *dev)
149{
150	struct amba_driver *drv = to_amba_driver(dev->driver);
151	drv->shutdown(to_amba_device(dev));
152}
153
154/**
155 *	amba_driver_register - register an AMBA device driver
156 *	@drv: amba device driver structure
157 *
158 *	Register an AMBA device driver with the Linux device model
159 *	core.  If devices pre-exist, the drivers probe function will
160 *	be called.
161 */
162int amba_driver_register(struct amba_driver *drv)
163{
164	drv->drv.bus = &amba_bustype;
165
166#define SETFN(fn)	if (drv->fn) drv->drv.fn = amba_##fn
167	SETFN(probe);
168	SETFN(remove);
169	SETFN(shutdown);
170
171	return driver_register(&drv->drv);
172}
173
174/**
175 *	amba_driver_unregister - remove an AMBA device driver
176 *	@drv: AMBA device driver structure to remove
177 *
178 *	Unregister an AMBA device driver from the Linux device
179 *	model.  The device model will call the drivers remove function
180 *	for each device the device driver is currently handling.
181 */
182void amba_driver_unregister(struct amba_driver *drv)
183{
184	driver_unregister(&drv->drv);
185}
186
187
188static void amba_device_release(struct device *dev)
189{
190	struct amba_device *d = to_amba_device(dev);
191
192	if (d->res.parent)
193		release_resource(&d->res);
194	kfree(d);
195}
196
197/**
198 *	amba_device_register - register an AMBA device
199 *	@dev: AMBA device to register
200 *	@parent: parent memory resource
201 *
202 *	Setup the AMBA device, reading the cell ID if present.
203 *	Claim the resource, and register the AMBA device with
204 *	the Linux device manager.
205 */
206int amba_device_register(struct amba_device *dev, struct resource *parent)
207{
208	u32 pid, cid;
209	void __iomem *tmp;
210	int i, ret;
211
212	dev->dev.release = amba_device_release;
213	dev->dev.bus = &amba_bustype;
214	dev->dev.dma_mask = &dev->dma_mask;
215	dev->res.name = dev->dev.bus_id;
216
217	if (!dev->dev.coherent_dma_mask && dev->dma_mask)
218		dev_warn(&dev->dev, "coherent dma mask is unset\n");
219
220	ret = request_resource(parent, &dev->res);
221	if (ret)
222		goto err_out;
223
224	tmp = ioremap(dev->res.start, SZ_4K);
225	if (!tmp) {
226		ret = -ENOMEM;
227		goto err_release;
228	}
229
230	for (pid = 0, i = 0; i < 4; i++)
231		pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
232	for (cid = 0, i = 0; i < 4; i++)
233		cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
234
235	iounmap(tmp);
236
237	if (cid == 0xb105f00d)
238		dev->periphid = pid;
239
240	if (!dev->periphid) {
241		ret = -ENODEV;
242		goto err_release;
243	}
244
245	ret = device_register(&dev->dev);
246	if (ret)
247		goto err_release;
248
249	if (dev->irq[0] != NO_IRQ)
250		ret = device_create_file(&dev->dev, &dev_attr_irq0);
251	if (ret == 0 && dev->irq[1] != NO_IRQ)
252		ret = device_create_file(&dev->dev, &dev_attr_irq1);
253	if (ret == 0)
254		return ret;
255
256	device_unregister(&dev->dev);
257
258 err_release:
259	release_resource(&dev->res);
260 err_out:
261	return ret;
262}
263
264/**
265 *	amba_device_unregister - unregister an AMBA device
266 *	@dev: AMBA device to remove
267 *
268 *	Remove the specified AMBA device from the Linux device
269 *	manager.  All files associated with this object will be
270 *	destroyed, and device drivers notified that the device has
271 *	been removed.  The AMBA device's resources including
272 *	the amba_device structure will be freed once all
273 *	references to it have been dropped.
274 */
275void amba_device_unregister(struct amba_device *dev)
276{
277	device_unregister(&dev->dev);
278}
279
280
281struct find_data {
282	struct amba_device *dev;
283	struct device *parent;
284	const char *busid;
285	unsigned int id;
286	unsigned int mask;
287};
288
289static int amba_find_match(struct device *dev, void *data)
290{
291	struct find_data *d = data;
292	struct amba_device *pcdev = to_amba_device(dev);
293	int r;
294
295	r = (pcdev->periphid & d->mask) == d->id;
296	if (d->parent)
297		r &= d->parent == dev->parent;
298	if (d->busid)
299		r &= strcmp(dev->bus_id, d->busid) == 0;
300
301	if (r) {
302		get_device(dev);
303		d->dev = pcdev;
304	}
305
306	return r;
307}
308
309/**
310 *	amba_find_device - locate an AMBA device given a bus id
311 *	@busid: bus id for device (or NULL)
312 *	@parent: parent device (or NULL)
313 *	@id: peripheral ID (or 0)
314 *	@mask: peripheral ID mask (or 0)
315 *
316 *	Return the AMBA device corresponding to the supplied parameters.
317 *	If no device matches, returns NULL.
318 *
319 *	NOTE: When a valid device is found, its refcount is
320 *	incremented, and must be decremented before the returned
321 *	reference.
322 */
323struct amba_device *
324amba_find_device(const char *busid, struct device *parent, unsigned int id,
325		 unsigned int mask)
326{
327	struct find_data data;
328
329	data.dev = NULL;
330	data.parent = parent;
331	data.busid = busid;
332	data.id = id;
333	data.mask = mask;
334
335	bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
336
337	return data.dev;
338}
339
340/**
341 *	amba_request_regions - request all mem regions associated with device
342 *	@dev: amba_device structure for device
343 *	@name: name, or NULL to use driver name
344 */
345int amba_request_regions(struct amba_device *dev, const char *name)
346{
347	int ret = 0;
348
349	if (!name)
350		name = dev->dev.driver->name;
351
352	if (!request_mem_region(dev->res.start, SZ_4K, name))
353		ret = -EBUSY;
354
355	return ret;
356}
357
358/**
359 *	amba_release_regions - release mem regions assoicated with device
360 *	@dev: amba_device structure for device
361 *
362 *	Release regions claimed by a successful call to amba_request_regions.
363 */
364void amba_release_regions(struct amba_device *dev)
365{
366	release_mem_region(dev->res.start, SZ_4K);
367}
368
369EXPORT_SYMBOL(amba_driver_register);
370EXPORT_SYMBOL(amba_driver_unregister);
371EXPORT_SYMBOL(amba_device_register);
372EXPORT_SYMBOL(amba_device_unregister);
373EXPORT_SYMBOL(amba_find_device);
374EXPORT_SYMBOL(amba_request_regions);
375EXPORT_SYMBOL(amba_release_regions);
376