2 * bay.c - ACPI removable drive bay driver
4 * Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>
35 #define ACPI_BAY_DRIVER_NAME "ACPI Removable Drive Bay Driver"
37 ACPI_MODULE_NAME("bay")
38 MODULE_AUTHOR("Kristen Carlson Accardi");
39 MODULE_DESCRIPTION(ACPI_BAY_DRIVER_NAME);
40 MODULE_LICENSE("GPL");
41 #define ACPI_BAY_CLASS "bay"
42 #define ACPI_BAY_COMPONENT 0x10000000
43 #define _COMPONENT ACPI_BAY_COMPONENT
44 #define bay_dprintk(h,s) {\
45 char prefix[80] = {'\0'};\
46 struct acpi_buffer buffer = {sizeof(prefix), prefix};\
47 acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
48 printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
49 static void bay_notify(acpi_handle handle, u32 event, void *data);
54 struct list_head list;
55 struct platform_device *pdev;
58 static LIST_HEAD(drive_bays);
61 /*****************************************************************************
62 * Drive Bay functions *
63 *****************************************************************************/
65 * is_ejectable - see if a device is ejectable
66 * @handle: acpi handle of the device
68 * If an acpi object has a _EJ0 method, then it is ejectable
70 static int is_ejectable(acpi_handle handle)
75 status = acpi_get_handle(handle, "_EJ0", &tmp);
76 if (ACPI_FAILURE(status))
82 * bay_present - see if the bay device is present
85 * execute the _STA method.
87 static int bay_present(struct bay *bay)
93 status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
94 if (ACPI_SUCCESS(status) && sta)
101 * eject_device - respond to an eject request
102 * @handle - the device to eject
104 * Call this devices _EJ0 method.
106 static void eject_device(acpi_handle handle)
108 struct acpi_object_list arg_list;
109 union acpi_object arg;
111 bay_dprintk(handle, "Ejecting device");
114 arg_list.pointer = &arg;
115 arg.type = ACPI_TYPE_INTEGER;
116 arg.integer.value = 1;
118 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
120 pr_debug("Failed to evaluate _EJ0!\n");
124 * show_present - read method for "present" file in sysfs
126 static ssize_t show_present(struct device *dev,
127 struct device_attribute *attr, char *buf)
129 struct bay *bay = dev_get_drvdata(dev);
130 return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
133 DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
136 * write_eject - write method for "eject" file in sysfs
138 static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
139 const char *buf, size_t count)
141 struct bay *bay = dev_get_drvdata(dev);
146 eject_device(bay->handle);
149 DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
152 * is_ata - see if a device is an ata device
153 * @handle: acpi handle of the device
155 * If an acpi object has one of 4 ATA ACPI methods defined,
156 * then it is an ATA device
158 static int is_ata(acpi_handle handle)
162 if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
163 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
164 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
165 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
172 * parent_is_ata(acpi_handle handle)
175 static int parent_is_ata(acpi_handle handle)
179 if (acpi_get_parent(handle, &phandle))
182 return is_ata(phandle);
186 * is_ejectable_bay - see if a device is an ejectable drive bay
187 * @handle: acpi handle of the device
189 * If an acpi object is ejectable and has one of the ACPI ATA
190 * methods defined, then we can safely call it an ejectable
193 static int is_ejectable_bay(acpi_handle handle)
195 if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
201 * eject_removable_drive - try to eject this drive
202 * @dev : the device structure of the drive
204 * If a device is a removable drive that requires an _EJ0 method
205 * to be executed in order to safely remove from the system, do
206 * it. ATM - always returns success
208 int eject_removable_drive(struct device *dev)
210 acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
213 bay_dprintk(handle, "Got device handle");
214 if (is_ejectable_bay(handle))
215 eject_device(handle);
217 printk("No acpi handle for device\n");
220 /* should I return an error code? */
223 EXPORT_SYMBOL_GPL(eject_removable_drive);
225 static int acpi_bay_add_fs(struct bay *bay)
228 struct device *dev = &bay->pdev->dev;
230 ret = device_create_file(dev, &dev_attr_present);
233 ret = device_create_file(dev, &dev_attr_eject);
235 device_remove_file(dev, &dev_attr_present);
241 bay_dprintk(bay->handle, "Error adding sysfs files\n");
245 static void acpi_bay_remove_fs(struct bay *bay)
247 struct device *dev = &bay->pdev->dev;
250 device_remove_file(dev, &dev_attr_present);
251 device_remove_file(dev, &dev_attr_eject);
254 static int bay_is_dock_device(acpi_handle handle)
258 acpi_get_parent(handle, &parent);
260 /* if the device or it's parent is dependent on the
261 * dock, then we are a dock device
263 return (is_dock_device(handle) || is_dock_device(parent));
266 static int bay_add(acpi_handle handle, int id)
270 struct platform_device *pdev;
271 struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
272 acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
274 bay_dprintk(handle, "Adding notify handler");
277 * Initialize bay device structure
279 new_bay = kzalloc(GFP_ATOMIC, sizeof(*new_bay));
280 INIT_LIST_HEAD(&new_bay->list);
281 new_bay->handle = handle;
282 new_bay->name = (char *)nbuffer.pointer;
284 /* initialize platform device stuff */
285 pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
287 printk(KERN_ERR PREFIX "Error registering bay device\n");
290 new_bay->pdev = pdev;
291 platform_set_drvdata(pdev, new_bay);
293 if (acpi_bay_add_fs(new_bay)) {
294 platform_device_unregister(new_bay->pdev);
298 /* register for events on this device */
299 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
300 bay_notify, new_bay);
301 if (ACPI_FAILURE(status)) {
302 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
305 /* if we are on a dock station, we should register for dock
308 if (bay_is_dock_device(handle)) {
309 bay_dprintk(handle, "Is dependent on dock\n");
310 register_hotplug_dock_device(handle, bay_notify, new_bay);
312 list_add(&new_bay->list, &drive_bays);
313 printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
317 kfree(new_bay->name);
323 * bay_notify - act upon an acpi bay notification
324 * @handle: the bay handle
325 * @event: the acpi event
326 * @data: our driver data struct
329 static void bay_notify(acpi_handle handle, u32 event, void *data)
331 struct bay *bay_dev = (struct bay *)data;
332 struct device *dev = &bay_dev->pdev->dev;
334 bay_dprintk(handle, "Bay event");
337 case ACPI_NOTIFY_BUS_CHECK:
338 case ACPI_NOTIFY_DEVICE_CHECK:
339 case ACPI_NOTIFY_EJECT_REQUEST:
340 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
343 printk(KERN_ERR PREFIX "Bay: unknown event %d\n", event);
348 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
350 int *count = (int *)context;
353 * there could be more than one ejectable bay.
354 * so, just return AE_OK always so that every object
357 if (is_ejectable_bay(handle)) {
358 bay_dprintk(handle, "found ejectable bay");
359 if (!bay_add(handle, *count))
365 static int __init bay_init(void)
369 INIT_LIST_HEAD(&drive_bays);
371 /* look for dockable drive bays */
372 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
373 ACPI_UINT32_MAX, find_bay, &bays, NULL);
381 static void __exit bay_exit(void)
383 struct bay *bay, *tmp;
385 list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
386 if (is_dock_device(bay->handle))
387 unregister_hotplug_dock_device(bay->handle);
388 acpi_bay_remove_fs(bay);
389 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
391 platform_device_unregister(bay->pdev);
397 postcore_initcall(bay_init);
398 module_exit(bay_exit);