/*
* bay.c - ACPI removable drive bay driver
*
* Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/notifier.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include <linux/platform_device.h>
ACPI_MODULE_NAME("bay");
MODULE_AUTHOR("Kristen Carlson Accardi");
MODULE_DESCRIPTION("ACPI Removable Drive Bay Driver");
MODULE_LICENSE("GPL");
#define ACPI_BAY_CLASS "bay"
#define ACPI_BAY_COMPONENT 0x10000000
#define _COMPONENT ACPI_BAY_COMPONENT
#define bay_dprintk(h,s) {\
char prefix[80] = {'\0'};\
struct acpi_buffer buffer = {sizeof(prefix), prefix};\
acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
static void bay_notify(acpi_handle handle, u32 event, void *data);
struct bay {
acpi_handle handle;
char *name;
struct list_head list;
struct platform_device *pdev;
};
static LIST_HEAD(drive_bays);
/*****************************************************************************
* Drive Bay functions *
*****************************************************************************/
/**
* is_ejectable - see if a device is ejectable
* @handle: acpi handle of the device
*
* If an acpi object has a _EJ0 method, then it is ejectable
*/
static int is_ejectable(acpi_handle handle)
{
acpi_status status;
acpi_handle tmp;
status = acpi_get_handle(handle, "_EJ0", &tmp);
if (ACPI_FAILURE(status))
return 0;
return 1;
}
/**
* bay_present - see if the bay device is present
* @bay: the drive bay
*
* execute the _STA method.
*/
static int bay_present(struct bay *bay)
{
unsigned long sta;
acpi_status status;
if (bay) {
status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
if (ACPI_SUCCESS(status) && sta)
return 1;
}
return 0;
}
/**
* eject_device - respond to an eject request
* @handle - the device to eject
*
* Call this devices _EJ0 method.
*/
static void eject_device(acpi_handle handle)
{
struct acpi_object_list arg_list;
union acpi_object arg;
bay_dprintk(handle, "Ejecting device");
arg_list.count = 1;
arg_list.pointer = &arg;
arg.type = ACPI_TYPE_INTEGER;
arg.integer.value = 1;
if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
&arg_list, NULL)))
pr_debug("Failed to evaluate _EJ0!\n");
}
/*
* show_present - read method for "present" file in sysfs
*/
static ssize_t show_present(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct bay *bay = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
}
DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
/*
* write_eject - write method for "eject" file in sysfs
*/
static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct bay *bay = dev_get_drvdata(dev);
if (!count)
return -EINVAL;
eject_device(bay->handle);
return count;
}
DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
/**
* is_ata - see if a device is an ata device
* @handle: acpi handle of the device
*
* If an acpi object has one of 4 ATA ACPI methods defined,
* then it is an ATA device
*/
static int is_ata(acpi_handle handle)
{
acpi_handle tmp;
if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
return 1;
return 0;
}
/**
* parent_is_ata(acpi_handle handle)
*
*/
static int parent_is_ata(acpi_handle handle)
{
acpi_handle phandle;
if (acpi_get_parent(handle, &phandle))
return 0;
return is_ata(phandle);
}
/**
* is_ejectable_bay - see if a device is an ejectable drive bay
* @handle: acpi handle of the device
*
* If an acpi object is ejectable and has one of the ACPI ATA
* methods defined, then we can safely call it an ejectable
* drive bay
*/
static int is_ejectable_bay(acpi_handle handle)
{
if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
return 1;
return 0;
}
/**
* eject_removable_drive - try to eject this drive
* @dev : the device structure of the drive
*
* If a device is a removable drive that requires an _EJ0 method
* to be executed in order to safely remove from the system, do
* it. ATM - always returns success
*/
int eject_removable_drive(struct device *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
if (handle) {
bay_dprintk(handle, "Got device handle");
if (is_ejectable_bay(handle))
eject_device(handle);
} else {
printk("No acpi handle for device\n");
}
/* should I return an error code? */
return 0;
}
EXPORT_SYMBOL_GPL(eject_removable_drive);
static int acpi_bay_add_fs(struct bay *bay)
{
int ret;
struct device *dev = &bay->pdev->dev;
ret = device_create_file(dev, &dev_attr_present);
if (ret)
goto add_fs_err;
ret = device_create_file(dev, &dev_attr_eject);
if (ret) {
device_remove_file(dev, &dev_attr_present);
goto add_fs_err;
}
return 0;
add_fs_err:
bay_dprintk(bay->handle, "Error adding sysfs files\n");
return ret;
}
static void acpi_bay_remove_fs(struct bay *bay)
{
struct device *dev = &bay->pdev->dev;
/* cleanup sysfs */
device_remove_file(dev, &dev_attr_present);
device_remove_file(dev, &dev_attr_eject);
}
static int bay_is_dock_device(acpi_handle handle)
{
acpi_handle parent;
acpi_get_parent(handle, &parent);
/* if the device or it's parent is dependent on the
* dock, then we are a dock device
*/
return (is_dock_device(handle) || is_dock_device(parent));
}
static int bay_add(acpi_handle handle, int id)
{
acpi_status status;
struct bay *new_bay;
struct platform_device *pdev;
struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
bay_dprintk(handle, "Adding notify handler");
/*
* Initialize bay device structure
*/
new_bay = kzalloc(sizeof(*new_bay), GFP_ATOMIC);
INIT_LIST_HEAD(&new_bay->list);
new_bay->handle = handle;
new_bay->name = (char *)nbuffer.pointer;
/* initialize platform device stuff */
pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
if (IS_ERR(pdev)) {
printk(KERN_ERR PREFIX "Error registering bay device\n");
goto bay_add_err;
}
new_bay->pdev = pdev;
platform_set_drvdata(pdev, new_bay);
/*
* we want the bay driver to be able to send uevents
*/
pdev->dev.uevent_suppress = 0;
if (acpi_bay_add_fs(new_bay)) {
platform_device_unregister(new_bay->pdev);
goto bay_add_err;
}
/* register for events on this device */
status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
bay_notify, new_bay);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
}
/* if we are on a dock station, we should register for dock
* notifications.
*/
if (bay_is_dock_device(handle)) {
bay_dprintk(handle, "Is dependent on dock\n");
register_hotplug_dock_device(handle, bay_notify, new_bay);
}
list_add(&new_bay->list, &drive_bays);
printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
return 0;
bay_add_err:
kfree(new_bay->name);
kfree(new_bay);
return -ENODEV;
}
/**
* bay_notify - act upon an acpi bay notification
* @handle: the bay handle
* @event: the acpi event
* @data: our driver data struct
*
*/
static void bay_notify(acpi_handle handle, u32 event, void *data)
{
struct bay *bay_dev = (struct bay *)data;
struct device *dev = &bay_dev->pdev->dev;
char event_string[12];
char *envp[] = { event_string, NULL };
bay_dprintk(handle, "Bay event");
sprintf(event_string, "BAY_EVENT=%d", event);
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
}
static acpi_status
find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
{
int *count = (int *)context;
/*
* there could be more than one ejectable bay.
* so, just return AE_OK always so that every object
* will be checked.
*/
if (is_ejectable_bay(handle)) {
bay_dprintk(handle, "found ejectable bay");
if (!bay_add(handle, *count))
(*count)++;
}
return AE_OK;
}
static int __init bay_init(void)
{
int bays = 0;
INIT_LIST_HEAD(&drive_bays);
/* look for dockable drive bays */
acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, find_bay, &bays, NULL);
if (!bays)
return -ENODEV;
return 0;
}
static void __exit bay_exit(void)
{
struct bay *bay, *tmp;
list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
if (is_dock_device(bay->handle))
unregister_hotplug_dock_device(bay->handle);
acpi_bay_remove_fs(bay);
acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
bay_notify);
platform_device_unregister(bay->pdev);
kfree(bay->name);
kfree(bay);
}
}
postcore_initcall(bay_init);
module_exit(bay_exit);
