ide: merge ide_hwgroup_t with ide_hwif_t (v2)
[linux-2.6.git] / drivers / ide / ide-park.c
1 #include <linux/kernel.h>
2 #include <linux/ide.h>
3 #include <linux/jiffies.h>
4 #include <linux/blkdev.h>
5
6 DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
7
8 static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
9 {
10         ide_hwif_t *hwif = drive->hwif;
11         struct request_queue *q = drive->queue;
12         struct request *rq;
13         int rc;
14
15         timeout += jiffies;
16         spin_lock_irq(&hwif->lock);
17         if (drive->dev_flags & IDE_DFLAG_PARKED) {
18                 int reset_timer = time_before(timeout, drive->sleep);
19                 int start_queue = 0;
20
21                 drive->sleep = timeout;
22                 wake_up_all(&ide_park_wq);
23                 if (reset_timer && del_timer(&hwif->timer))
24                         start_queue = 1;
25                 spin_unlock_irq(&hwif->lock);
26
27                 if (start_queue) {
28                         spin_lock_irq(q->queue_lock);
29                         blk_start_queueing(q);
30                         spin_unlock_irq(q->queue_lock);
31                 }
32                 return;
33         }
34         spin_unlock_irq(&hwif->lock);
35
36         rq = blk_get_request(q, READ, __GFP_WAIT);
37         rq->cmd[0] = REQ_PARK_HEADS;
38         rq->cmd_len = 1;
39         rq->cmd_type = REQ_TYPE_SPECIAL;
40         rq->special = &timeout;
41         rc = blk_execute_rq(q, NULL, rq, 1);
42         blk_put_request(rq);
43         if (rc)
44                 goto out;
45
46         /*
47          * Make sure that *some* command is sent to the drive after the
48          * timeout has expired, so power management will be reenabled.
49          */
50         rq = blk_get_request(q, READ, GFP_NOWAIT);
51         if (unlikely(!rq))
52                 goto out;
53
54         rq->cmd[0] = REQ_UNPARK_HEADS;
55         rq->cmd_len = 1;
56         rq->cmd_type = REQ_TYPE_SPECIAL;
57         elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
58
59 out:
60         return;
61 }
62
63 ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
64                       char *buf)
65 {
66         ide_drive_t *drive = to_ide_device(dev);
67         ide_hwif_t *hwif = drive->hwif;
68         unsigned long now;
69         unsigned int msecs;
70
71         if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
72                 return -EOPNOTSUPP;
73
74         spin_lock_irq(&hwif->lock);
75         now = jiffies;
76         if (drive->dev_flags & IDE_DFLAG_PARKED &&
77             time_after(drive->sleep, now))
78                 msecs = jiffies_to_msecs(drive->sleep - now);
79         else
80                 msecs = 0;
81         spin_unlock_irq(&hwif->lock);
82
83         return snprintf(buf, 20, "%u\n", msecs);
84 }
85
86 ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
87                        const char *buf, size_t len)
88 {
89 #define MAX_PARK_TIMEOUT 30000
90         ide_drive_t *drive = to_ide_device(dev);
91         long int input;
92         int rc;
93
94         rc = strict_strtol(buf, 10, &input);
95         if (rc || input < -2)
96                 return -EINVAL;
97         if (input > MAX_PARK_TIMEOUT) {
98                 input = MAX_PARK_TIMEOUT;
99                 rc = -EOVERFLOW;
100         }
101
102         mutex_lock(&ide_setting_mtx);
103         if (input >= 0) {
104                 if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
105                         rc = -EOPNOTSUPP;
106                 else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
107                         issue_park_cmd(drive, msecs_to_jiffies(input));
108         } else {
109                 if (drive->media == ide_disk)
110                         switch (input) {
111                         case -1:
112                                 drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
113                                 break;
114                         case -2:
115                                 drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
116                                 break;
117                         }
118                 else
119                         rc = -EOPNOTSUPP;
120         }
121         mutex_unlock(&ide_setting_mtx);
122
123         return rc ? rc : len;
124 }