1#include <linux/kernel.h>
  2#include <linux/gfp.h>
  3#include <linux/ide.h>
  4#include <linux/jiffies.h>
  5#include <linux/blkdev.h>
  6
  7DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
  8
  9static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 10{
 11	ide_hwif_t *hwif = drive->hwif;
 12	struct request_queue *q = drive->queue;
 13	struct request *rq;
 14	int rc;
 15
 16	timeout += jiffies;
 17	spin_lock_irq(&hwif->lock);
 18	if (drive->dev_flags & IDE_DFLAG_PARKED) {
 19		int reset_timer = time_before(timeout, drive->sleep);
 20		int start_queue = 0;
 21
 22		drive->sleep = timeout;
 23		wake_up_all(&ide_park_wq);
 24		if (reset_timer && del_timer(&hwif->timer))
 25			start_queue = 1;
 26		spin_unlock_irq(&hwif->lock);
 27
 28		if (start_queue)
 29			blk_run_queue(q);
 30		return;
 31	}
 32	spin_unlock_irq(&hwif->lock);
 33
 34	rq = blk_get_request(q, READ, __GFP_RECLAIM);
 35	rq->cmd[0] = REQ_PARK_HEADS;
 36	rq->cmd_len = 1;
 37	rq->cmd_type = REQ_TYPE_DRV_PRIV;
 38	rq->special = &timeout;
 39	rc = blk_execute_rq(q, NULL, rq, 1);
 40	blk_put_request(rq);
 41	if (rc)
 42		goto out;
 43
 44	/*
 45	 * Make sure that *some* command is sent to the drive after the
 46	 * timeout has expired, so power management will be reenabled.
 47	 */
 48	rq = blk_get_request(q, READ, GFP_NOWAIT);
 49	if (IS_ERR(rq))
 50		goto out;
 51
 52	rq->cmd[0] = REQ_UNPARK_HEADS;
 53	rq->cmd_len = 1;
 54	rq->cmd_type = REQ_TYPE_DRV_PRIV;
 55	elv_add_request(q, rq, ELEVATOR_INSERT_FRONT);
 56
 57out:
 58	return;
 59}
 60
 61ide_startstop_t ide_do_park_unpark(ide_drive_t *drive, struct request *rq)
 62{
 63	struct ide_cmd cmd;
 64	struct ide_taskfile *tf = &cmd.tf;
 65
 66	memset(&cmd, 0, sizeof(cmd));
 67	if (rq->cmd[0] == REQ_PARK_HEADS) {
 68		drive->sleep = *(unsigned long *)rq->special;
 69		drive->dev_flags |= IDE_DFLAG_SLEEPING;
 70		tf->command = ATA_CMD_IDLEIMMEDIATE;
 71		tf->feature = 0x44;
 72		tf->lbal = 0x4c;
 73		tf->lbam = 0x4e;
 74		tf->lbah = 0x55;
 75		cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
 76		cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;
 77	} else		/* cmd == REQ_UNPARK_HEADS */
 78		tf->command = ATA_CMD_CHK_POWER;
 79
 80	cmd.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER;
 81	cmd.protocol = ATA_PROT_NODATA;
 82
 83	cmd.rq = rq;
 84
 85	return do_rw_taskfile(drive, &cmd);
 86}
 87
 88ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
 89		      char *buf)
 90{
 91	ide_drive_t *drive = to_ide_device(dev);
 92	ide_hwif_t *hwif = drive->hwif;
 93	unsigned long now;
 94	unsigned int msecs;
 95
 96	if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
 97		return -EOPNOTSUPP;
 98
 99	spin_lock_irq(&hwif->lock);
100	now = jiffies;
101	if (drive->dev_flags & IDE_DFLAG_PARKED &&
102	    time_after(drive->sleep, now))
103		msecs = jiffies_to_msecs(drive->sleep - now);
104	else
105		msecs = 0;
106	spin_unlock_irq(&hwif->lock);
107
108	return snprintf(buf, 20, "%u\n", msecs);
109}
110
111ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
112		       const char *buf, size_t len)
113{
114#define MAX_PARK_TIMEOUT 30000
115	ide_drive_t *drive = to_ide_device(dev);
116	long int input;
117	int rc;
118
119	rc = kstrtol(buf, 10, &input);
120	if (rc)
121		return rc;
122	if (input < -2)
123		return -EINVAL;
124	if (input > MAX_PARK_TIMEOUT) {
125		input = MAX_PARK_TIMEOUT;
126		rc = -EOVERFLOW;
127	}
128
129	mutex_lock(&ide_setting_mtx);
130	if (input >= 0) {
131		if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
132			rc = -EOPNOTSUPP;
133		else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
134			issue_park_cmd(drive, msecs_to_jiffies(input));
135	} else {
136		if (drive->media == ide_disk)
137			switch (input) {
138			case -1:
139				drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
140				break;
141			case -2:
142				drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
143				break;
144			}
145		else
146			rc = -EOPNOTSUPP;
147	}
148	mutex_unlock(&ide_setting_mtx);
149
150	return rc ? rc : len;
151}