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
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
|
/*
* OMAP3/OMAP4 DVFS Management Routines
*
* Author: Vishwanath BS <vishwanath.bs@ti.com>
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Vishwanath BS <vishwanath.bs@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/plist.h>
#include <linux/slab.h>
#include <linux/opp.h>
#include <plat/common.h>
#include <plat/omap_device.h>
#include <plat/voltage.h>
/**
* struct omap_dev_user_list - Structure maitain userlist per devide
*
* @dev: The device requesting for a particular frequency
* @node: The list head entry
* @freq: frequency being requested
*
* Using this structure, user list (requesting dev * and frequency) for
* each device is maintained. This is how we can have different devices
* at different frequencies (to support frequency locking and throttling).
* Even if one of the devices in a given vdd has locked it's frequency,
* other's can still scale their frequency using this list.
* If no one has placed a frequency request for a device, then device is
* set to the frequency from it's opp table.
*/
struct omap_dev_user_list {
struct device *dev;
struct plist_node node;
u32 freq;
};
/**
* struct omap_vdd_dev_list - Device list per vdd
*
* @dev: The device belonging to a particular vdd
* @node: The list head entry
*/
struct omap_vdd_dev_list {
struct device *dev;
struct list_head node;
struct plist_head user_list;
spinlock_t user_lock; /* spinlock for plist */
};
/**
* struct omap_vdd_user_list - The per vdd user list
*
* @dev: The device asking for the vdd to be set at a particular
* voltage
* @node: The list head entry
* @volt: The voltage requested by the device <dev>
*/
struct omap_vdd_user_list {
struct device *dev;
struct plist_node node;
u32 volt;
};
/**
* struct omap_vdd_dvfs_info - The per vdd dvfs info
*
* @user_lock: spinlock for plist operations
* @user_list: The vdd user list
* @scaling_mutex: Mutex for protecting dvfs data structures for a vdd
* @voltdm: Voltage domains for which dvfs info stored
*
* This is a fundamental structure used to store all the required
* DVFS related information for a vdd.
*/
struct omap_vdd_dvfs_info {
spinlock_t user_lock; /* spin lock */
struct plist_head user_list;
struct mutex scaling_mutex; /* dvfs mutex */
struct voltagedomain *voltdm;
struct list_head dev_list;
};
static struct omap_vdd_dvfs_info *omap_dvfs_info_list;
static int omap_nr_vdd;
static struct voltagedomain omap3_vdd[] = {
{
.name = "mpu",
},
{
.name = "core",
},
};
static int __init omap_dvfs_init(void);
static struct omap_vdd_dvfs_info *get_dvfs_info(struct voltagedomain *voltdm)
{
int i;
if (!voltdm || !omap_dvfs_info_list)
return NULL;
for (i = 0; i < omap_nr_vdd; i++)
if (omap_dvfs_info_list[i].voltdm == voltdm)
return &omap_dvfs_info_list[i];
pr_warning("%s: unable find dvfs info for vdd %s\n",
__func__, voltdm->name);
return NULL;
}
/**
* omap_dvfs_find_voltage() - search for given voltage
* @dev: device pointer associated with the opp type
* @volt: voltage to search for
*
* Searches for exact match in the opp list and returns handle to the matching
* opp if found, else returns ERR_PTR in case of error and should be handled
* using IS_ERR. If there are multiple opps with same voltage, it will return
* the first available entry.
*/
static struct opp *omap_dvfs_find_voltage(struct device *dev,
unsigned long volt)
{
struct opp *opp = ERR_PTR(-ENODEV);
unsigned long f = 0;
do {
opp = opp_find_freq_ceil(dev, &f);
if (IS_ERR(opp))
break;
if (opp_get_voltage(opp) >= volt)
break;
f++;
} while (1);
return opp;
}
/**
* omap_dvfs_add_vdd_user() - Add a voltage request
* @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd
* @dev: device making the request
* @volt: requesting voltage in uV
*
* Adds the given devices' voltage request into corresponding
* vdd's omap_vdd_dvfs_info user list (plist). This list is used
* to find the maximum voltage request for a given vdd.
*
* Returns 0 on success.
*/
static int omap_dvfs_add_vdd_user(struct omap_vdd_dvfs_info *dvfs_info,
struct device *dev, unsigned long volt)
{
struct omap_vdd_user_list *user = NULL, *temp_user;
struct plist_node *node;
if (!dvfs_info || IS_ERR(dvfs_info)) {
dev_warn(dev, "%s: VDD specified does not exist!\n", __func__);
return -EINVAL;
}
mutex_lock(&dvfs_info->scaling_mutex);
plist_for_each_entry(temp_user, &dvfs_info->user_list, node) {
if (temp_user->dev == dev) {
user = temp_user;
break;
}
}
if (!user) {
user = kzalloc(sizeof(struct omap_vdd_user_list), GFP_KERNEL);
if (!user) {
dev_err(dev, "%s: Unable to creat a new user for vdd_%s\n",
__func__, dvfs_info->voltdm->name);
mutex_unlock(&dvfs_info->scaling_mutex);
return -ENOMEM;
}
user->dev = dev;
} else {
plist_del(&user->node, &dvfs_info->user_list);
}
plist_node_init(&user->node, volt);
plist_add(&user->node, &dvfs_info->user_list);
node = plist_last(&dvfs_info->user_list);
user->volt = node->prio;
mutex_unlock(&dvfs_info->scaling_mutex);
return 0;
}
/**
* omap_dvfs_remove_vdd_user() - Remove a voltage request
* @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd
* @dev: device making the request
*
* Removes the given devices' voltage request from corresponding
* vdd's omap_vdd_dvfs_info user list (plist).
*
* Returns 0 on success.
*/
static int omap_dvfs_remove_vdd_user(struct omap_vdd_dvfs_info *dvfs_info,
struct device *dev)
{
struct omap_vdd_user_list *user = NULL, *temp_user;
int ret = 0;
if (!dvfs_info || IS_ERR(dvfs_info)) {
dev_err(dev, "%s: VDD specified does not exist!\n", __func__);
return -EINVAL;
}
mutex_lock(&dvfs_info->scaling_mutex);
plist_for_each_entry(temp_user, &dvfs_info->user_list, node) {
if (temp_user->dev == dev) {
user = temp_user;
break;
}
}
if (user)
plist_del(&user->node, &dvfs_info->user_list);
else {
dev_err(dev, "%s: Unable to find the user for vdd_%s\n",
__func__, dvfs_info->voltdm->name);
ret = -ENOMEM;
}
mutex_unlock(&dvfs_info->scaling_mutex);
return ret;
}
/**
* omap_dvfs_register_device - Add a device into voltage domain
* @voltdm: voltage domain to which the device is to be added
* @dev: Device to be added
*
* This API will add a given device into user_list of corresponding
* vdd's omap_vdd_dvfs_info strucure. This list is traversed to scale
* frequencies of all the devices on a given vdd. This api is called
* while hwmod db is built for an omap_device.
*
* Returns 0 on success.
*/
int omap_dvfs_register_device(struct voltagedomain *voltdm, struct device *dev)
{
struct omap_vdd_dev_list *temp_dev;
struct omap_vdd_dvfs_info *dvfs_info = get_dvfs_info(voltdm);
if (!voltdm || IS_ERR(voltdm) || !dvfs_info) {
dev_warn(dev, "%s: VDD specified does not exist!\n", __func__);
return -EINVAL;
}
list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) {
if (temp_dev->dev == dev) {
dev_warn(dev, "%s: Device already added to vdee_%s\n",
__func__, dvfs_info->voltdm->name);
return -EINVAL;
}
}
temp_dev = kzalloc(sizeof(struct omap_vdd_dev_list), GFP_KERNEL);
if (!temp_dev) {
dev_err(dev, "%s: Unable to creat a new device for vdd_%s\n",
__func__, dvfs_info->voltdm->name);
return -ENOMEM;
}
/* Initialize priority ordered list */
spin_lock_init(&temp_dev->user_lock);
plist_head_init(&temp_dev->user_list, &temp_dev->user_lock);
temp_dev->dev = dev;
list_add(&temp_dev->node, &dvfs_info->dev_list);
return 0;
}
/**
* omap_dvfs_add_freq_request() - add a requested device frequency
*
*
* @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd
* @req_dev: device making the request
* @target_dev: target device for which frequency request is being made
* @freq: target device frequency
*
* This API adds a requested frequency into target's device frequency list.
*
* Returns 0 on success.
*/
static int omap_dvfs_add_freq_request(struct omap_vdd_dvfs_info *dvfs_info,
struct device *req_dev, struct device *target_dev, unsigned long freq)
{
struct omap_dev_user_list *dev_user = NULL, *tmp_user;
struct omap_vdd_dev_list *temp_dev;
if (!dvfs_info || IS_ERR(dvfs_info)) {
dev_warn(target_dev, "%s: VDD specified does not exist!\n",
__func__);
return -EINVAL;
}
mutex_lock(&dvfs_info->scaling_mutex);
list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) {
if (temp_dev->dev == target_dev)
break;
}
if (temp_dev->dev != target_dev) {
dev_warn(target_dev, "%s: target_dev does not exist!\n",
__func__);
mutex_unlock(&dvfs_info->scaling_mutex);
return -EINVAL;
}
plist_for_each_entry(tmp_user, &temp_dev->user_list, node) {
if (tmp_user->dev == req_dev) {
dev_user = tmp_user;
break;
}
}
if (!dev_user) {
dev_user = kzalloc(sizeof(struct omap_dev_user_list),
GFP_KERNEL);
if (!dev_user) {
dev_err(target_dev, "%s: Unable to creat a new user for vdd_%s\n",
__func__, dvfs_info->voltdm->name);
mutex_unlock(&dvfs_info->scaling_mutex);
return -ENOMEM;
}
dev_user->dev = req_dev;
} else {
plist_del(&dev_user->node, &temp_dev->user_list);
}
plist_node_init(&dev_user->node, freq);
plist_add(&dev_user->node, &temp_dev->user_list);
mutex_unlock(&dvfs_info->scaling_mutex);
return 0;
}
/**
* omap_dvfs_remove_freq_request() - Remove the requested device frequency
*
* @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd
* @req_dev: device removing the request
* @target_dev: target device from which frequency request is being removed
*
* This API removes a requested frequency from target's device frequency list.
*
* Returns 0 on success.
*/
static int omap_dvfs_remove_freq_request(struct omap_vdd_dvfs_info *dvfs_info,
struct device *req_dev, struct device *target_dev)
{
struct omap_dev_user_list *dev_user = NULL, *tmp_user;
int ret = 0;
struct omap_vdd_dev_list *temp_dev;
if (!dvfs_info || IS_ERR(dvfs_info)) {
dev_warn(target_dev, "%s: VDD specified does not exist!\n",
__func__);
return -EINVAL;
}
mutex_lock(&dvfs_info->scaling_mutex);
list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) {
if (temp_dev->dev == target_dev)
break;
}
if (temp_dev->dev != target_dev) {
dev_warn(target_dev, "%s: target_dev does not exist!\n",
__func__);
mutex_unlock(&dvfs_info->scaling_mutex);
return -EINVAL;
}
plist_for_each_entry(tmp_user, &temp_dev->user_list, node) {
if (tmp_user->dev == req_dev) {
dev_user = tmp_user;
break;
}
}
if (dev_user)
plist_del(&dev_user->node, &temp_dev->user_list);
else {
dev_err(target_dev, "%s: Unable to remove the user for vdd_%s\n",
__func__, dvfs_info->voltdm->name);
ret = -EINVAL;
}
return ret;
}
/**
* omap_dvfs_init() - Initialize omap dvfs layer
*
* Initalizes omap dvfs layer. It basically allocates memory for
* omap_dvfs_info_list and populates voltdm pointer inside
* omap_vdd_dvfs_info structure for all the VDDs.
*
* Returns 0 on success.
*/
static int __init omap_dvfs_init()
{
int i;
struct voltagedomain *vdd_list;
if (cpu_is_omap34xx()) {
omap_nr_vdd = 2;
vdd_list = omap3_vdd;
}
omap_dvfs_info_list = kzalloc(omap_nr_vdd *
sizeof(struct omap_vdd_dvfs_info), GFP_KERNEL);
if (!omap_dvfs_info_list) {
pr_warning("%s: Unable to allocate memory for vdd_list",
__func__);
return -ENOMEM;
}
for (i = 0; i < omap_nr_vdd; i++) {
omap_dvfs_info_list[i].voltdm =
omap_voltage_domain_lookup(vdd_list[i].name);
/* Init the plist */
spin_lock_init(&omap_dvfs_info_list[i].user_lock);
plist_head_init(&omap_dvfs_info_list[i].user_list,
&omap_dvfs_info_list[i].user_lock);
/* Init the DVFS mutex */
mutex_init(&omap_dvfs_info_list[i].scaling_mutex);
/* Init the device list */
INIT_LIST_HEAD(&omap_dvfs_info_list[i].dev_list);
}
return 0;
}
core_initcall(omap_dvfs_init);
|