summaryrefslogtreecommitdiffstats
path: root/arch/sh/kernel/cpu/shmobile/pm_runtime.c
blob: bf280c812d2f238cbe8044e28a930377419ba66d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * arch/sh/kernel/cpu/shmobile/pm_runtime.c
 *
 * Runtime PM support code for SuperH Mobile
 *
 *  Copyright (C) 2009 Magnus Damm
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <asm/hwblk.h>

static DEFINE_SPINLOCK(hwblk_lock);
static LIST_HEAD(hwblk_idle_list);
static struct work_struct hwblk_work;

extern struct hwblk_info *hwblk_info;

static void platform_pm_runtime_not_idle(struct platform_device *pdev)
{
	unsigned long flags;

	/* remove device from idle list */
	spin_lock_irqsave(&hwblk_lock, flags);
	if (test_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags)) {
		list_del(&pdev->archdata.entry);
		__clear_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags);
	}
	spin_unlock_irqrestore(&hwblk_lock, flags);
}

static int __platform_pm_runtime_resume(struct platform_device *pdev)
{
	struct device *d = &pdev->dev;
	struct pdev_archdata *ad = &pdev->archdata;
	int hwblk = ad->hwblk_id;
	int ret = -ENOSYS;

	dev_dbg(d, "__platform_pm_runtime_resume() [%d]\n", hwblk);

	if (d->driver) {
		hwblk_enable(hwblk_info, hwblk);
		ret = 0;

		if (test_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags)) {
			if (d->driver->pm && d->driver->pm->runtime_resume)
				ret = d->driver->pm->runtime_resume(d);

			if (!ret)
				clear_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
			else
				hwblk_disable(hwblk_info, hwblk);
		}
	}

	dev_dbg(d, "__platform_pm_runtime_resume() [%d] - returns %d\n",
		hwblk, ret);

	return ret;
}

static int __platform_pm_runtime_suspend(struct platform_device *pdev)
{
	struct device *d = &pdev->dev;
	struct pdev_archdata *ad = &pdev->archdata;
	int hwblk = ad->hwblk_id;
	int ret = -ENOSYS;

	dev_dbg(d, "__platform_pm_runtime_suspend() [%d]\n", hwblk);

	if (d->driver) {
		BUG_ON(!test_bit(PDEV_ARCHDATA_FLAG_IDLE, &ad->flags));
		ret = 0;

		if (d->driver->pm && d->driver->pm->runtime_suspend) {
			hwblk_enable(hwblk_info, hwblk);
			ret = d->driver->pm->runtime_suspend(d);
			hwblk_disable(hwblk_info, hwblk);
		}

		if (!ret) {
			set_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
			platform_pm_runtime_not_idle(pdev);
			hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);
		}
	}

	dev_dbg(d, "__platform_pm_runtime_suspend() [%d] - returns %d\n",
		hwblk, ret);

	return ret;
}

static void platform_pm_runtime_work(struct work_struct *work)
{
	struct platform_device *pdev;
	unsigned long flags;
	int ret;

	/* go through the idle list and suspend one device at a time */
	do {
		spin_lock_irqsave(&hwblk_lock, flags);
		if (list_empty(&hwblk_idle_list))
			pdev = NULL;
		else
			pdev = list_first_entry(&hwblk_idle_list,
						struct platform_device,
						archdata.entry);
		spin_unlock_irqrestore(&hwblk_lock, flags);

		if (pdev) {
			mutex_lock(&pdev->archdata.mutex);
			ret = __platform_pm_runtime_suspend(pdev);

			/* at this point the platform device may be:
			 * suspended: ret = 0, FLAG_SUSP set, clock stopped
			 * failed: ret < 0, FLAG_IDLE set, clock stopped
			 */
			mutex_unlock(&pdev->archdata.mutex);
		} else {
			ret = -ENODEV;
		}
	} while (!ret);
}

/* this function gets called from cpuidle context when all devices in the
 * main power domain are unused but some are counted as idle, ie the hwblk
 * counter values are (HWBLK_CNT_USAGE == 0) && (HWBLK_CNT_IDLE != 0)
 */
void platform_pm_runtime_suspend_idle(void)
{
	queue_work(pm_wq, &hwblk_work);
}

static int default_platform_runtime_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct pdev_archdata *ad = &pdev->archdata;
	unsigned long flags;
	int hwblk = ad->hwblk_id;
	int ret = 0;

	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);

	/* ignore off-chip platform devices */
	if (!hwblk)
		goto out;

	/* interrupt context not allowed */
	might_sleep();

	/* catch misconfigured drivers not starting with resume */
	if (test_bit(PDEV_ARCHDATA_FLAG_INIT, &ad->flags)) {
		ret = -EINVAL;
		goto out;
	}

	/* serialize */
	mutex_lock(&ad->mutex);

	/* disable clock */
	hwblk_disable(hwblk_info, hwblk);

	/* put device on idle list */
	spin_lock_irqsave(&hwblk_lock, flags);
	list_add_tail(&ad->entry, &hwblk_idle_list);
	__set_bit(PDEV_ARCHDATA_FLAG_IDLE, &ad->flags);
	spin_unlock_irqrestore(&hwblk_lock, flags);

	/* increase idle count */
	hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_IDLE);

	/* at this point the platform device is:
	 * idle: ret = 0, FLAG_IDLE set, clock stopped
	 */
	mutex_unlock(&ad->mutex);

out:
	dev_dbg(dev, "%s() [%d] returns %d\n",
		 __func__, hwblk, ret);

	return ret;
}

static int default_platform_runtime_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct pdev_archdata *ad = &pdev->archdata;
	int hwblk = ad->hwblk_id;
	int ret = 0;

	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);

	/* ignore off-chip platform devices */
	if (!hwblk)
		goto out;

	/* interrupt context not allowed */
	might_sleep();

	/* serialize */
	mutex_lock(&ad->mutex);

	/* make sure device is removed from idle list */
	platform_pm_runtime_not_idle(pdev);

	/* decrease idle count */
	if (!test_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags) &&
	    !test_bit(PDEV_ARCHDATA_FLAG_SUSP, &pdev->archdata.flags))
		hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);

	/* resume the device if needed */
	ret = __platform_pm_runtime_resume(pdev);

	/* the driver has been initialized now, so clear the init flag */
	clear_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);

	/* at this point the platform device may be:
	 * resumed: ret = 0, flags = 0, clock started
	 * failed: ret < 0, FLAG_SUSP set, clock stopped
	 */
	mutex_unlock(&ad->mutex);
out:
	dev_dbg(dev, "%s() [%d] returns %d\n",
		__func__, hwblk, ret);

	return ret;
}

static int default_platform_runtime_idle(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	int hwblk = pdev->archdata.hwblk_id;
	int ret = 0;

	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);

	/* ignore off-chip platform devices */
	if (!hwblk)
		goto out;

	/* interrupt context not allowed, use pm_runtime_put()! */
	might_sleep();

	/* suspend synchronously to disable clocks immediately */
	ret = pm_runtime_suspend(dev);
out:
	dev_dbg(dev, "%s() [%d] done!\n", __func__, hwblk);
	return ret;
}

static struct dev_pm_domain default_pm_domain = {
	.ops = {
		.runtime_suspend = default_platform_runtime_suspend,
		.runtime_resume = default_platform_runtime_resume,
		.runtime_idle = default_platform_runtime_idle,
		USE_PLATFORM_PM_SLEEP_OPS
	},
};

static int platform_bus_notify(struct notifier_block *nb,
			       unsigned long action, void *data)
{
	struct device *dev = data;
	struct platform_device *pdev = to_platform_device(dev);
	int hwblk = pdev->archdata.hwblk_id;

	/* ignore off-chip platform devices */
	if (!hwblk)
		return 0;

	switch (action) {
	case BUS_NOTIFY_ADD_DEVICE:
		INIT_LIST_HEAD(&pdev->archdata.entry);
		mutex_init(&pdev->archdata.mutex);
		/* platform devices without drivers should be disabled */
		hwblk_enable(hwblk_info, hwblk);
		hwblk_disable(hwblk_info, hwblk);
		/* make sure driver re-inits itself once */
		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
		dev->pm_domain = &default_pm_domain;
		break;
	/* TODO: add BUS_NOTIFY_BIND_DRIVER and increase idle count */
	case BUS_NOTIFY_BOUND_DRIVER:
		/* keep track of number of devices in use per hwblk */
		hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
		break;
	case BUS_NOTIFY_UNBOUND_DRIVER:
		/* keep track of number of devices in use per hwblk */
		hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
		/* make sure driver re-inits itself once */
		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
		break;
	case BUS_NOTIFY_DEL_DEVICE:
		dev->pm_domain = NULL;
		break;
	}
	return 0;
}

static struct notifier_block platform_bus_notifier = {
	.notifier_call = platform_bus_notify
};

static int __init sh_pm_runtime_init(void)
{
	INIT_WORK(&hwblk_work, platform_pm_runtime_work);

	bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
	return 0;
}
core_initcall(sh_pm_runtime_init);