1/*
2 *  bay.c - ACPI removable drive bay driver
3 *
4 *  Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 *
8 *  This program is free software; you can redistribute it and/or modify
9 *  it under the terms of the GNU General Public License as published by
10 *  the Free Software Foundation; either version 2 of the License, or (at
11 *  your option) any later version.
12 *
13 *  This program is distributed in the hope that it will be useful, but
14 *  WITHOUT ANY WARRANTY; without even the implied warranty of
15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 *  General Public License for more details.
17 *
18 *  You should have received a copy of the GNU General Public License along
19 *  with this program; if not, write to the Free Software Foundation, Inc.,
20 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 *
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23 */
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/types.h>
28#include <linux/notifier.h>
29#include <acpi/acpi_bus.h>
30#include <acpi/acpi_drivers.h>
31#include <linux/seq_file.h>
32#include <asm/uaccess.h>
33#include <linux/platform_device.h>
34
35ACPI_MODULE_NAME("bay");
36MODULE_AUTHOR("Kristen Carlson Accardi");
37MODULE_DESCRIPTION("ACPI Removable Drive Bay Driver");
38MODULE_LICENSE("GPL");
39#define ACPI_BAY_CLASS "bay"
40#define ACPI_BAY_COMPONENT	0x10000000
41#define _COMPONENT ACPI_BAY_COMPONENT
42#define bay_dprintk(h,s) {\
43	char prefix[80] = {'\0'};\
44	struct acpi_buffer buffer = {sizeof(prefix), prefix};\
45	acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
46	printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
47static void bay_notify(acpi_handle handle, u32 event, void *data);
48
49struct bay {
50	acpi_handle handle;
51	char *name;
52	struct list_head list;
53	struct platform_device *pdev;
54};
55
56static LIST_HEAD(drive_bays);
57
58
59/*****************************************************************************
60 *                         Drive Bay functions                               *
61 *****************************************************************************/
62/**
63 * is_ejectable - see if a device is ejectable
64 * @handle: acpi handle of the device
65 *
66 * If an acpi object has a _EJ0 method, then it is ejectable
67 */
68static int is_ejectable(acpi_handle handle)
69{
70	acpi_status status;
71	acpi_handle tmp;
72
73	status = acpi_get_handle(handle, "_EJ0", &tmp);
74	if (ACPI_FAILURE(status))
75		return 0;
76	return 1;
77}
78
79/**
80 * bay_present - see if the bay device is present
81 * @bay: the drive bay
82 *
83 * execute the _STA method.
84 */
85static int bay_present(struct bay *bay)
86{
87	unsigned long sta;
88	acpi_status status;
89
90	if (bay) {
91		status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
92		if (ACPI_SUCCESS(status) && sta)
93			return 1;
94	}
95	return 0;
96}
97
98/**
99 * eject_device - respond to an eject request
100 * @handle - the device to eject
101 *
102 * Call this devices _EJ0 method.
103 */
104static void eject_device(acpi_handle handle)
105{
106	struct acpi_object_list arg_list;
107	union acpi_object arg;
108
109	bay_dprintk(handle, "Ejecting device");
110
111	arg_list.count = 1;
112	arg_list.pointer = &arg;
113	arg.type = ACPI_TYPE_INTEGER;
114	arg.integer.value = 1;
115
116	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
117					      &arg_list, NULL)))
118		pr_debug("Failed to evaluate _EJ0!\n");
119}
120
121/*
122 * show_present - read method for "present" file in sysfs
123 */
124static ssize_t show_present(struct device *dev,
125			   struct device_attribute *attr, char *buf)
126{
127	struct bay *bay = dev_get_drvdata(dev);
128	return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
129
130}
131DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
132
133/*
134 * write_eject - write method for "eject" file in sysfs
135 */
136static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
137			   const char *buf, size_t count)
138{
139	struct bay *bay = dev_get_drvdata(dev);
140
141	if (!count)
142		return -EINVAL;
143
144	eject_device(bay->handle);
145	return count;
146}
147DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
148
149/**
150 * is_ata - see if a device is an ata device
151 * @handle: acpi handle of the device
152 *
153 * If an acpi object has one of 4 ATA ACPI methods defined,
154 * then it is an ATA device
155 */
156static int is_ata(acpi_handle handle)
157{
158	acpi_handle tmp;
159
160	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
161	   (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
162	   (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
163	   (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
164		return 1;
165
166	return 0;
167}
168
169/**
170 * parent_is_ata(acpi_handle handle)
171 *
172 */
173static int parent_is_ata(acpi_handle handle)
174{
175	acpi_handle phandle;
176
177	if (acpi_get_parent(handle, &phandle))
178		return 0;
179
180	return is_ata(phandle);
181}
182
183/**
184 * is_ejectable_bay - see if a device is an ejectable drive bay
185 * @handle: acpi handle of the device
186 *
187 * If an acpi object is ejectable and has one of the ACPI ATA
188 * methods defined, then we can safely call it an ejectable
189 * drive bay
190 */
191static int is_ejectable_bay(acpi_handle handle)
192{
193	if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
194		return 1;
195	return 0;
196}
197
198/**
199 * eject_removable_drive - try to eject this drive
200 * @dev : the device structure of the drive
201 *
202 * If a device is a removable drive that requires an _EJ0 method
203 * to be executed in order to safely remove from the system, do
204 * it.  ATM - always returns success
205 */
206int eject_removable_drive(struct device *dev)
207{
208	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
209
210	if (handle) {
211		bay_dprintk(handle, "Got device handle");
212		if (is_ejectable_bay(handle))
213			eject_device(handle);
214	} else {
215		printk("No acpi handle for device\n");
216	}
217
218	/* should I return an error code? */
219	return 0;
220}
221EXPORT_SYMBOL_GPL(eject_removable_drive);
222
223static int acpi_bay_add_fs(struct bay *bay)
224{
225	int ret;
226	struct device *dev = &bay->pdev->dev;
227
228	ret = device_create_file(dev, &dev_attr_present);
229	if (ret)
230		goto add_fs_err;
231	ret = device_create_file(dev, &dev_attr_eject);
232	if (ret) {
233		device_remove_file(dev, &dev_attr_present);
234		goto add_fs_err;
235	}
236	return 0;
237
238 add_fs_err:
239	bay_dprintk(bay->handle, "Error adding sysfs files\n");
240	return ret;
241}
242
243static void acpi_bay_remove_fs(struct bay *bay)
244{
245	struct device *dev = &bay->pdev->dev;
246
247	/* cleanup sysfs */
248	device_remove_file(dev, &dev_attr_present);
249	device_remove_file(dev, &dev_attr_eject);
250}
251
252static int bay_is_dock_device(acpi_handle handle)
253{
254	acpi_handle parent;
255
256	acpi_get_parent(handle, &parent);
257
258	/* if the device or it's parent is dependent on the
259	 * dock, then we are a dock device
260	 */
261	return (is_dock_device(handle) || is_dock_device(parent));
262}
263
264static int bay_add(acpi_handle handle, int id)
265{
266	acpi_status status;
267	struct bay *new_bay;
268	struct platform_device *pdev;
269	struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
270	acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
271
272	bay_dprintk(handle, "Adding notify handler");
273
274	/*
275	 * Initialize bay device structure
276	 */
277	new_bay = kzalloc(sizeof(*new_bay), GFP_ATOMIC);
278	INIT_LIST_HEAD(&new_bay->list);
279	new_bay->handle = handle;
280	new_bay->name = (char *)nbuffer.pointer;
281
282	/* initialize platform device stuff */
283	pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
284	if (IS_ERR(pdev)) {
285		printk(KERN_ERR PREFIX "Error registering bay device\n");
286		goto bay_add_err;
287	}
288	new_bay->pdev = pdev;
289	platform_set_drvdata(pdev, new_bay);
290
291	if (acpi_bay_add_fs(new_bay)) {
292		platform_device_unregister(new_bay->pdev);
293		goto bay_add_err;
294	}
295
296	/* register for events on this device */
297	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
298			bay_notify, new_bay);
299	if (ACPI_FAILURE(status)) {
300		printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
301	}
302
303	/* if we are on a dock station, we should register for dock
304	 * notifications.
305	 */
306	if (bay_is_dock_device(handle)) {
307		bay_dprintk(handle, "Is dependent on dock\n");
308		register_hotplug_dock_device(handle, bay_notify, new_bay);
309	}
310	list_add(&new_bay->list, &drive_bays);
311	printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
312	return 0;
313
314bay_add_err:
315	kfree(new_bay->name);
316	kfree(new_bay);
317	return -ENODEV;
318}
319
320/**
321 * bay_notify - act upon an acpi bay notification
322 * @handle: the bay handle
323 * @event: the acpi event
324 * @data: our driver data struct
325 *
326 */
327static void bay_notify(acpi_handle handle, u32 event, void *data)
328{
329	struct bay *bay_dev = (struct bay *)data;
330	struct device *dev = &bay_dev->pdev->dev;
331
332	bay_dprintk(handle, "Bay event");
333
334	switch(event) {
335	case ACPI_NOTIFY_BUS_CHECK:
336	case ACPI_NOTIFY_DEVICE_CHECK:
337	case ACPI_NOTIFY_EJECT_REQUEST:
338		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
339		break;
340	default:
341		printk(KERN_ERR PREFIX "Bay: unknown event %d\n", event);
342	}
343}
344
345static acpi_status
346find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
347{
348	int *count = (int *)context;
349
350	/*
351	 * there could be more than one ejectable bay.
352	 * so, just return AE_OK always so that every object
353	 * will be checked.
354	 */
355	if (is_ejectable_bay(handle)) {
356		bay_dprintk(handle, "found ejectable bay");
357		if (!bay_add(handle, *count))
358			(*count)++;
359	}
360	return AE_OK;
361}
362
363static int __init bay_init(void)
364{
365	int bays = 0;
366
367	INIT_LIST_HEAD(&drive_bays);
368
369	/* look for dockable drive bays */
370	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
371		ACPI_UINT32_MAX, find_bay, &bays, NULL);
372
373	if (!bays)
374		return -ENODEV;
375
376	return 0;
377}
378
379static void __exit bay_exit(void)
380{
381	struct bay *bay, *tmp;
382
383	list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
384		if (is_dock_device(bay->handle))
385			unregister_hotplug_dock_device(bay->handle);
386		acpi_bay_remove_fs(bay);
387		acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
388			bay_notify);
389		platform_device_unregister(bay->pdev);
390		kfree(bay->name);
391		kfree(bay);
392	}
393}
394
395postcore_initcall(bay_init);
396module_exit(bay_exit);
397