blob: 37f05d0f07939e696eb8657fbd80ce08bab7ef15 [file] [log] [blame]
Mark Grossd82b3512008-02-04 22:30:08 -08001/*
2 * This module exposes the interface to kernel space for specifying
3 * QoS dependencies. It provides infrastructure for registration of:
4 *
Mark Grossed771342010-05-06 01:59:26 +02005 * Dependents on a QoS value : register requests
Mark Grossd82b3512008-02-04 22:30:08 -08006 * Watchers of QoS value : get notified when target QoS value changes
7 *
8 * This QoS design is best effort based. Dependents register their QoS needs.
9 * Watchers register to keep track of the current QoS needs of the system.
10 *
11 * There are 3 basic classes of QoS parameter: latency, timeout, throughput
12 * each have defined units:
13 * latency: usec
14 * timeout: usec <-- currently not used.
15 * throughput: kbs (kilo byte / sec)
16 *
Mark Grossed771342010-05-06 01:59:26 +020017 * There are lists of pm_qos_objects each one wrapping requests, notifiers
Mark Grossd82b3512008-02-04 22:30:08 -080018 *
Mark Grossed771342010-05-06 01:59:26 +020019 * User mode requests on a QOS parameter register themselves to the
Mark Grossd82b3512008-02-04 22:30:08 -080020 * subsystem by opening the device node /dev/... and writing there request to
21 * the node. As long as the process holds a file handle open to the node the
22 * client continues to be accounted for. Upon file release the usermode
Mark Grossed771342010-05-06 01:59:26 +020023 * request is removed and a new qos target is computed. This way when the
24 * request that the application has is cleaned up when closes the file
Mark Grossd82b3512008-02-04 22:30:08 -080025 * pointer or exits the pm_qos_object will get an opportunity to clean up.
26 *
Richard Hughesbf1db692008-08-05 13:01:35 -070027 * Mark Gross <mgross@linux.intel.com>
Mark Grossd82b3512008-02-04 22:30:08 -080028 */
29
Mark Grossed771342010-05-06 01:59:26 +020030/*#define DEBUG*/
31
Mark Grossd82b3512008-02-04 22:30:08 -080032#include <linux/pm_qos_params.h>
33#include <linux/sched.h>
34#include <linux/spinlock.h>
35#include <linux/slab.h>
36#include <linux/time.h>
37#include <linux/fs.h>
38#include <linux/device.h>
39#include <linux/miscdevice.h>
40#include <linux/string.h>
41#include <linux/platform_device.h>
42#include <linux/init.h>
Rafael J. Wysocki0775a602011-05-27 00:05:23 +020043#include <linux/kernel.h>
Mark Grossd82b3512008-02-04 22:30:08 -080044
45#include <linux/uaccess.h>
46
47/*
Mark Grossed771342010-05-06 01:59:26 +020048 * locking rule: all changes to requests or notifiers lists
Mark Grossd82b3512008-02-04 22:30:08 -080049 * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
50 * held, taken with _irqsave. One lock to rule them all
51 */
James Bottomley5f279842010-07-19 02:00:18 +020052enum pm_qos_type {
53 PM_QOS_MAX, /* return the largest value */
54 PM_QOS_MIN /* return the smallest value */
55};
Mark Grossd82b3512008-02-04 22:30:08 -080056
Tim Chen333c5ae2011-02-11 12:49:04 -080057/*
58 * Note: The lockless read path depends on the CPU accessing
59 * target_value atomically. Atomic access is only guaranteed on all CPU
60 * types linux supports for 32 bit quantites
61 */
Mark Grossd82b3512008-02-04 22:30:08 -080062struct pm_qos_object {
James Bottomley5f279842010-07-19 02:00:18 +020063 struct plist_head requests;
Mark Grossd82b3512008-02-04 22:30:08 -080064 struct blocking_notifier_head *notifiers;
65 struct miscdevice pm_qos_power_miscdev;
66 char *name;
Tim Chen333c5ae2011-02-11 12:49:04 -080067 s32 target_value; /* Do not change to 64 bit */
Mark Grossd82b3512008-02-04 22:30:08 -080068 s32 default_value;
James Bottomley5f279842010-07-19 02:00:18 +020069 enum pm_qos_type type;
Mark Grossd82b3512008-02-04 22:30:08 -080070};
71
James Bottomley5f279842010-07-19 02:00:18 +020072static DEFINE_SPINLOCK(pm_qos_lock);
73
Mark Grossd82b3512008-02-04 22:30:08 -080074static struct pm_qos_object null_pm_qos;
75static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
76static struct pm_qos_object cpu_dma_pm_qos = {
Dima Zavin732375c2011-07-07 17:27:59 -070077 .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests),
Mark Grossd82b3512008-02-04 22:30:08 -080078 .notifiers = &cpu_dma_lat_notifier,
79 .name = "cpu_dma_latency",
Tim Chen333c5ae2011-02-11 12:49:04 -080080 .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
81 .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
James Bottomley5f279842010-07-19 02:00:18 +020082 .type = PM_QOS_MIN,
Mark Grossd82b3512008-02-04 22:30:08 -080083};
84
85static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
86static struct pm_qos_object network_lat_pm_qos = {
Dima Zavin732375c2011-07-07 17:27:59 -070087 .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests),
Mark Grossd82b3512008-02-04 22:30:08 -080088 .notifiers = &network_lat_notifier,
89 .name = "network_latency",
Tim Chen333c5ae2011-02-11 12:49:04 -080090 .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
91 .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
James Bottomley5f279842010-07-19 02:00:18 +020092 .type = PM_QOS_MIN
Mark Grossd82b3512008-02-04 22:30:08 -080093};
94
95
96static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
97static struct pm_qos_object network_throughput_pm_qos = {
Dima Zavin732375c2011-07-07 17:27:59 -070098 .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests),
Mark Grossd82b3512008-02-04 22:30:08 -080099 .notifiers = &network_throughput_notifier,
100 .name = "network_throughput",
Tim Chen333c5ae2011-02-11 12:49:04 -0800101 .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
102 .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
James Bottomley5f279842010-07-19 02:00:18 +0200103 .type = PM_QOS_MAX,
Mark Grossd82b3512008-02-04 22:30:08 -0800104};
105
106
107static struct pm_qos_object *pm_qos_array[] = {
108 &null_pm_qos,
109 &cpu_dma_pm_qos,
110 &network_lat_pm_qos,
111 &network_throughput_pm_qos
112};
113
Mark Grossd82b3512008-02-04 22:30:08 -0800114static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
115 size_t count, loff_t *f_pos);
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100116static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
117 size_t count, loff_t *f_pos);
Mark Grossd82b3512008-02-04 22:30:08 -0800118static int pm_qos_power_open(struct inode *inode, struct file *filp);
119static int pm_qos_power_release(struct inode *inode, struct file *filp);
120
121static const struct file_operations pm_qos_power_fops = {
122 .write = pm_qos_power_write,
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100123 .read = pm_qos_power_read,
Mark Grossd82b3512008-02-04 22:30:08 -0800124 .open = pm_qos_power_open,
125 .release = pm_qos_power_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200126 .llseek = noop_llseek,
Mark Grossd82b3512008-02-04 22:30:08 -0800127};
128
James Bottomley5f279842010-07-19 02:00:18 +0200129/* unlocked internal variant */
130static inline int pm_qos_get_value(struct pm_qos_object *o)
Mark Grossd82b3512008-02-04 22:30:08 -0800131{
James Bottomley5f279842010-07-19 02:00:18 +0200132 if (plist_head_empty(&o->requests))
133 return o->default_value;
134
135 switch (o->type) {
136 case PM_QOS_MIN:
Colin Cross00fafcd2010-11-15 22:45:22 +0100137 return plist_first(&o->requests)->prio;
James Bottomley5f279842010-07-19 02:00:18 +0200138
139 case PM_QOS_MAX:
Colin Cross00fafcd2010-11-15 22:45:22 +0100140 return plist_last(&o->requests)->prio;
James Bottomley5f279842010-07-19 02:00:18 +0200141
142 default:
143 /* runtime check for not using enum */
144 BUG();
145 }
Mark Grossd82b3512008-02-04 22:30:08 -0800146}
147
Tim Chen333c5ae2011-02-11 12:49:04 -0800148static inline s32 pm_qos_read_value(struct pm_qos_object *o)
149{
150 return o->target_value;
151}
152
153static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value)
154{
155 o->target_value = value;
156}
157
James Bottomley5f279842010-07-19 02:00:18 +0200158static void update_target(struct pm_qos_object *o, struct plist_node *node,
159 int del, int value)
Mark Grossd82b3512008-02-04 22:30:08 -0800160{
Mark Grossd82b3512008-02-04 22:30:08 -0800161 unsigned long flags;
James Bottomley5f279842010-07-19 02:00:18 +0200162 int prev_value, curr_value;
Mark Grossd82b3512008-02-04 22:30:08 -0800163
164 spin_lock_irqsave(&pm_qos_lock, flags);
James Bottomley5f279842010-07-19 02:00:18 +0200165 prev_value = pm_qos_get_value(o);
166 /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */
167 if (value != PM_QOS_DEFAULT_VALUE) {
168 /*
169 * to change the list, we atomically remove, reinit
170 * with new value and add, then see if the extremal
171 * changed
172 */
173 plist_del(node, &o->requests);
174 plist_node_init(node, value);
175 plist_add(node, &o->requests);
176 } else if (del) {
177 plist_del(node, &o->requests);
178 } else {
179 plist_add(node, &o->requests);
Mark Grossd82b3512008-02-04 22:30:08 -0800180 }
James Bottomley5f279842010-07-19 02:00:18 +0200181 curr_value = pm_qos_get_value(o);
Tim Chen333c5ae2011-02-11 12:49:04 -0800182 pm_qos_set_value(o, curr_value);
Mark Grossd82b3512008-02-04 22:30:08 -0800183 spin_unlock_irqrestore(&pm_qos_lock, flags);
184
James Bottomley5f279842010-07-19 02:00:18 +0200185 if (prev_value != curr_value)
186 blocking_notifier_call_chain(o->notifiers,
187 (unsigned long)curr_value,
188 NULL);
Mark Grossd82b3512008-02-04 22:30:08 -0800189}
190
191static int register_pm_qos_misc(struct pm_qos_object *qos)
192{
193 qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
194 qos->pm_qos_power_miscdev.name = qos->name;
195 qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
196
197 return misc_register(&qos->pm_qos_power_miscdev);
198}
199
200static int find_pm_qos_object_by_minor(int minor)
201{
202 int pm_qos_class;
203
204 for (pm_qos_class = 0;
205 pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
206 if (minor ==
207 pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
208 return pm_qos_class;
209 }
210 return -1;
211}
212
213/**
Mark Grossed771342010-05-06 01:59:26 +0200214 * pm_qos_request - returns current system wide qos expectation
Mark Grossd82b3512008-02-04 22:30:08 -0800215 * @pm_qos_class: identification of which qos value is requested
216 *
Tim Chen333c5ae2011-02-11 12:49:04 -0800217 * This function returns the current target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800218 */
Mark Grossed771342010-05-06 01:59:26 +0200219int pm_qos_request(int pm_qos_class)
Mark Grossd82b3512008-02-04 22:30:08 -0800220{
Tim Chen333c5ae2011-02-11 12:49:04 -0800221 return pm_qos_read_value(pm_qos_array[pm_qos_class]);
Mark Grossd82b3512008-02-04 22:30:08 -0800222}
Mark Grossed771342010-05-06 01:59:26 +0200223EXPORT_SYMBOL_GPL(pm_qos_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800224
James Bottomley82f68252010-07-05 22:53:06 +0200225int pm_qos_request_active(struct pm_qos_request_list *req)
226{
227 return req->pm_qos_class != 0;
228}
229EXPORT_SYMBOL_GPL(pm_qos_request_active);
230
Mark Grossd82b3512008-02-04 22:30:08 -0800231/**
Mark Grossed771342010-05-06 01:59:26 +0200232 * pm_qos_add_request - inserts new qos request into the list
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200233 * @dep: pointer to a preallocated handle
234 * @pm_qos_class: identifies which list of qos request to use
Mark Grossd82b3512008-02-04 22:30:08 -0800235 * @value: defines the qos request
236 *
237 * This function inserts a new entry in the pm_qos_class list of requested qos
Richard Hughesbf1db692008-08-05 13:01:35 -0700238 * performance characteristics. It recomputes the aggregate QoS expectations
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200239 * for the pm_qos_class of parameters and initializes the pm_qos_request_list
240 * handle. Caller needs to save this handle for later use in updates and
241 * removal.
Mark Grossd82b3512008-02-04 22:30:08 -0800242 */
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200243
James Bottomley82f68252010-07-05 22:53:06 +0200244void pm_qos_add_request(struct pm_qos_request_list *dep,
245 int pm_qos_class, s32 value)
Mark Grossd82b3512008-02-04 22:30:08 -0800246{
James Bottomley82f68252010-07-05 22:53:06 +0200247 struct pm_qos_object *o = pm_qos_array[pm_qos_class];
248 int new_value;
Mark Grossd82b3512008-02-04 22:30:08 -0800249
James Bottomley82f68252010-07-05 22:53:06 +0200250 if (pm_qos_request_active(dep)) {
251 WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
252 return;
Mark Grossd82b3512008-02-04 22:30:08 -0800253 }
James Bottomley82f68252010-07-05 22:53:06 +0200254 if (value == PM_QOS_DEFAULT_VALUE)
255 new_value = o->default_value;
256 else
257 new_value = value;
258 plist_node_init(&dep->list, new_value);
259 dep->pm_qos_class = pm_qos_class;
260 update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE);
Mark Grossd82b3512008-02-04 22:30:08 -0800261}
Mark Grossed771342010-05-06 01:59:26 +0200262EXPORT_SYMBOL_GPL(pm_qos_add_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800263
264/**
Mark Grossed771342010-05-06 01:59:26 +0200265 * pm_qos_update_request - modifies an existing qos request
266 * @pm_qos_req : handle to list element holding a pm_qos request to use
Mark Grossd82b3512008-02-04 22:30:08 -0800267 * @value: defines the qos request
268 *
Mark Grossed771342010-05-06 01:59:26 +0200269 * Updates an existing qos request for the pm_qos_class of parameters along
Mark Grossd82b3512008-02-04 22:30:08 -0800270 * with updating the target pm_qos_class value.
271 *
Mark Grossed771342010-05-06 01:59:26 +0200272 * Attempts are made to make this code callable on hot code paths.
Mark Grossd82b3512008-02-04 22:30:08 -0800273 */
Mark Grossed771342010-05-06 01:59:26 +0200274void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
James Bottomley5f279842010-07-19 02:00:18 +0200275 s32 new_value)
Mark Grossd82b3512008-02-04 22:30:08 -0800276{
Mark Grossed771342010-05-06 01:59:26 +0200277 s32 temp;
James Bottomley5f279842010-07-19 02:00:18 +0200278 struct pm_qos_object *o;
Mark Grossd82b3512008-02-04 22:30:08 -0800279
James Bottomley5f279842010-07-19 02:00:18 +0200280 if (!pm_qos_req) /*guard against callers passing in null */
281 return;
Mark Grossed771342010-05-06 01:59:26 +0200282
James Bottomley82f68252010-07-05 22:53:06 +0200283 if (!pm_qos_request_active(pm_qos_req)) {
284 WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
285 return;
286 }
287
James Bottomley5f279842010-07-19 02:00:18 +0200288 o = pm_qos_array[pm_qos_req->pm_qos_class];
289
290 if (new_value == PM_QOS_DEFAULT_VALUE)
291 temp = o->default_value;
292 else
293 temp = new_value;
294
295 if (temp != pm_qos_req->list.prio)
296 update_target(o, &pm_qos_req->list, 0, temp);
Mark Grossd82b3512008-02-04 22:30:08 -0800297}
Mark Grossed771342010-05-06 01:59:26 +0200298EXPORT_SYMBOL_GPL(pm_qos_update_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800299
300/**
Mark Grossed771342010-05-06 01:59:26 +0200301 * pm_qos_remove_request - modifies an existing qos request
302 * @pm_qos_req: handle to request list element
Mark Grossd82b3512008-02-04 22:30:08 -0800303 *
Mark Grossed771342010-05-06 01:59:26 +0200304 * Will remove pm qos request from the list of requests and
305 * recompute the current target value for the pm_qos_class. Call this
306 * on slow code paths.
Mark Grossd82b3512008-02-04 22:30:08 -0800307 */
Mark Grossed771342010-05-06 01:59:26 +0200308void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
Mark Grossd82b3512008-02-04 22:30:08 -0800309{
James Bottomley5f279842010-07-19 02:00:18 +0200310 struct pm_qos_object *o;
Mark Grossd82b3512008-02-04 22:30:08 -0800311
Mark Grossed771342010-05-06 01:59:26 +0200312 if (pm_qos_req == NULL)
313 return;
314 /* silent return to keep pcm code cleaner */
315
James Bottomley82f68252010-07-05 22:53:06 +0200316 if (!pm_qos_request_active(pm_qos_req)) {
317 WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
318 return;
319 }
320
James Bottomley5f279842010-07-19 02:00:18 +0200321 o = pm_qos_array[pm_qos_req->pm_qos_class];
322 update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE);
James Bottomley82f68252010-07-05 22:53:06 +0200323 memset(pm_qos_req, 0, sizeof(*pm_qos_req));
Mark Grossd82b3512008-02-04 22:30:08 -0800324}
Mark Grossed771342010-05-06 01:59:26 +0200325EXPORT_SYMBOL_GPL(pm_qos_remove_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800326
327/**
328 * pm_qos_add_notifier - sets notification entry for changes to target value
329 * @pm_qos_class: identifies which qos target changes should be notified.
330 * @notifier: notifier block managed by caller.
331 *
332 * will register the notifier into a notification chain that gets called
Richard Hughesbf1db692008-08-05 13:01:35 -0700333 * upon changes to the pm_qos_class target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800334 */
Mark Grossed771342010-05-06 01:59:26 +0200335int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
Mark Grossd82b3512008-02-04 22:30:08 -0800336{
337 int retval;
338
339 retval = blocking_notifier_chain_register(
340 pm_qos_array[pm_qos_class]->notifiers, notifier);
341
342 return retval;
343}
344EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
345
346/**
347 * pm_qos_remove_notifier - deletes notification entry from chain.
348 * @pm_qos_class: identifies which qos target changes are notified.
349 * @notifier: notifier block to be removed.
350 *
351 * will remove the notifier from the notification chain that gets called
Richard Hughesbf1db692008-08-05 13:01:35 -0700352 * upon changes to the pm_qos_class target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800353 */
354int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
355{
356 int retval;
357
358 retval = blocking_notifier_chain_unregister(
359 pm_qos_array[pm_qos_class]->notifiers, notifier);
360
361 return retval;
362}
363EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
364
Mark Grossd82b3512008-02-04 22:30:08 -0800365static int pm_qos_power_open(struct inode *inode, struct file *filp)
366{
Mark Grossd82b3512008-02-04 22:30:08 -0800367 long pm_qos_class;
368
369 pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
370 if (pm_qos_class >= 0) {
David Alan Gilbertbac1e742010-08-24 20:22:18 +0200371 struct pm_qos_request_list *req = kzalloc(sizeof(*req), GFP_KERNEL);
James Bottomley82f68252010-07-05 22:53:06 +0200372 if (!req)
373 return -ENOMEM;
374
375 pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
376 filp->private_data = req;
Mark Grossed771342010-05-06 01:59:26 +0200377
378 if (filp->private_data)
Mark Grossd82b3512008-02-04 22:30:08 -0800379 return 0;
380 }
Mark Grossd82b3512008-02-04 22:30:08 -0800381 return -EPERM;
382}
383
384static int pm_qos_power_release(struct inode *inode, struct file *filp)
385{
Mark Grossed771342010-05-06 01:59:26 +0200386 struct pm_qos_request_list *req;
Mark Grossd82b3512008-02-04 22:30:08 -0800387
James Bottomley82f68252010-07-05 22:53:06 +0200388 req = filp->private_data;
Mark Grossed771342010-05-06 01:59:26 +0200389 pm_qos_remove_request(req);
James Bottomley82f68252010-07-05 22:53:06 +0200390 kfree(req);
Mark Grossd82b3512008-02-04 22:30:08 -0800391
392 return 0;
393}
394
Mark Grossed771342010-05-06 01:59:26 +0200395
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100396static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
397 size_t count, loff_t *f_pos)
398{
399 s32 value;
400 unsigned long flags;
401 struct pm_qos_object *o;
Justin P. Mattock6eab04a2011-04-08 19:49:08 -0700402 struct pm_qos_request_list *pm_qos_req = filp->private_data;
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100403
404 if (!pm_qos_req)
405 return -EINVAL;
406 if (!pm_qos_request_active(pm_qos_req))
407 return -EINVAL;
408
409 o = pm_qos_array[pm_qos_req->pm_qos_class];
410 spin_lock_irqsave(&pm_qos_lock, flags);
411 value = pm_qos_get_value(o);
412 spin_unlock_irqrestore(&pm_qos_lock, flags);
413
414 return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
415}
416
Mark Grossd82b3512008-02-04 22:30:08 -0800417static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
418 size_t count, loff_t *f_pos)
419{
420 s32 value;
Mark Grossed771342010-05-06 01:59:26 +0200421 struct pm_qos_request_list *pm_qos_req;
Mark Grossd82b3512008-02-04 22:30:08 -0800422
Mark Grossed771342010-05-06 01:59:26 +0200423 if (count == sizeof(s32)) {
424 if (copy_from_user(&value, buf, sizeof(s32)))
425 return -EFAULT;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200426 } else if (count <= 11) { /* ASCII perhaps? */
427 char ascii_value[11];
428 unsigned long int ulval;
429 int ret;
430
431 if (copy_from_user(ascii_value, buf, count))
Mark Grossed771342010-05-06 01:59:26 +0200432 return -EFAULT;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200433
434 if (count > 10) {
435 if (ascii_value[10] == '\n')
436 ascii_value[10] = '\0';
437 else
438 return -EINVAL;
439 } else {
440 ascii_value[count] = '\0';
441 }
442 ret = strict_strtoul(ascii_value, 16, &ulval);
443 if (ret) {
444 pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
mark gross0109c2c2010-09-09 23:20:09 +0200445 return -EINVAL;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200446 }
447 value = (s32)lower_32_bits(ulval);
448 } else {
Mark Grossd82b3512008-02-04 22:30:08 -0800449 return -EINVAL;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200450 }
Mark Grossd82b3512008-02-04 22:30:08 -0800451
Joe Perches99a51792010-09-04 18:52:50 -0700452 pm_qos_req = filp->private_data;
Mark Grossed771342010-05-06 01:59:26 +0200453 pm_qos_update_request(pm_qos_req, value);
454
455 return count;
Mark Grossd82b3512008-02-04 22:30:08 -0800456}
457
458
459static int __init pm_qos_power_init(void)
460{
461 int ret = 0;
462
463 ret = register_pm_qos_misc(&cpu_dma_pm_qos);
464 if (ret < 0) {
465 printk(KERN_ERR "pm_qos_param: cpu_dma_latency setup failed\n");
466 return ret;
467 }
468 ret = register_pm_qos_misc(&network_lat_pm_qos);
469 if (ret < 0) {
470 printk(KERN_ERR "pm_qos_param: network_latency setup failed\n");
471 return ret;
472 }
473 ret = register_pm_qos_misc(&network_throughput_pm_qos);
474 if (ret < 0)
475 printk(KERN_ERR
476 "pm_qos_param: network_throughput setup failed\n");
477
478 return ret;
479}
480
481late_initcall(pm_qos_power_init);