diff options
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 94 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 5 |
2 files changed, 93 insertions, 6 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b30001f..4fc0cb7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -223,7 +223,7 @@ static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) } if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || - (val == CPUFREQ_RESUMECHANGE)) { + (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new); dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new); } @@ -866,11 +866,90 @@ EXPORT_SYMBOL(cpufreq_get); /** + * cpufreq_suspend - let the low level driver prepare for suspend + */ + +static int cpufreq_suspend(struct sys_device * sysdev, u32 state) +{ + int cpu = sysdev->id; + unsigned int ret = 0; + unsigned int cur_freq = 0; + struct cpufreq_policy *cpu_policy; + + dprintk("resuming cpu %u\n", cpu); + + if (!cpu_online(cpu)) + return 0; + + /* we may be lax here as interrupts are off. Nonetheless + * we need to grab the correct cpu policy, as to check + * whether we really run on this CPU. + */ + + cpu_policy = cpufreq_cpu_get(cpu); + if (!cpu_policy) + return -EINVAL; + + /* only handle each CPU group once */ + if (unlikely(cpu_policy->cpu != cpu)) { + cpufreq_cpu_put(cpu_policy); + return 0; + } + + if (cpufreq_driver->suspend) { + ret = cpufreq_driver->suspend(cpu_policy, state); + if (ret) { + printk(KERN_ERR "cpufreq: suspend failed in ->suspend " + "step on CPU %u\n", cpu_policy->cpu); + cpufreq_cpu_put(cpu_policy); + return ret; + } + } + + + if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) + goto out; + + if (cpufreq_driver->get) + cur_freq = cpufreq_driver->get(cpu_policy->cpu); + + if (!cur_freq || !cpu_policy->cur) { + printk(KERN_ERR "cpufreq: suspend failed to assert current " + "frequency is what timing core thinks it is.\n"); + goto out; + } + + if (unlikely(cur_freq != cpu_policy->cur)) { + struct cpufreq_freqs freqs; + + if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) + printk(KERN_DEBUG "Warning: CPU frequency is %u, " + "cpufreq assumed %u kHz.\n", + cur_freq, cpu_policy->cur); + + freqs.cpu = cpu; + freqs.old = cpu_policy->cur; + freqs.new = cur_freq; + + notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_SUSPENDCHANGE, &freqs); + adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); + + cpu_policy->cur = cur_freq; + } + + out: + cpufreq_cpu_put(cpu_policy); + return 0; +} + +/** * cpufreq_resume - restore proper CPU frequency handling after resume * * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync - * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are restored. + * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are + * restored. */ static int cpufreq_resume(struct sys_device * sysdev) { @@ -915,7 +994,9 @@ static int cpufreq_resume(struct sys_device * sysdev) cur_freq = cpufreq_driver->get(cpu_policy->cpu); if (!cur_freq || !cpu_policy->cur) { - printk(KERN_ERR "cpufreq: resume failed to assert current frequency is what timing core thinks it is.\n"); + printk(KERN_ERR "cpufreq: resume failed to assert " + "current frequency is what timing core " + "thinks it is.\n"); goto out; } @@ -923,13 +1004,15 @@ static int cpufreq_resume(struct sys_device * sysdev) struct cpufreq_freqs freqs; printk(KERN_WARNING "Warning: CPU frequency is %u, " - "cpufreq assumed %u kHz.\n", cur_freq, cpu_policy->cur); + "cpufreq assumed %u kHz.\n", + cur_freq, cpu_policy->cur); freqs.cpu = cpu; freqs.old = cpu_policy->cur; freqs.new = cur_freq; - notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_RESUMECHANGE, &freqs); + notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_RESUMECHANGE, &freqs); adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); cpu_policy->cur = cur_freq; @@ -945,6 +1028,7 @@ out: static struct sysdev_driver cpufreq_sysdev_driver = { .add = cpufreq_add_dev, .remove = cpufreq_remove_dev, + .suspend = cpufreq_suspend, .resume = cpufreq_resume, }; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 910eca3..f21af06 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -103,6 +103,7 @@ struct cpufreq_policy { #define CPUFREQ_PRECHANGE (0) #define CPUFREQ_POSTCHANGE (1) #define CPUFREQ_RESUMECHANGE (8) +#define CPUFREQ_SUSPENDCHANGE (9) struct cpufreq_freqs { unsigned int cpu; /* cpu nr */ @@ -200,6 +201,7 @@ struct cpufreq_driver { /* optional */ int (*exit) (struct cpufreq_policy *policy); + int (*suspend) (struct cpufreq_policy *policy, u32 state); int (*resume) (struct cpufreq_policy *policy); struct freq_attr **attr; }; @@ -211,7 +213,8 @@ struct cpufreq_driver { #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel * "constants" aren't affected by * frequency transitions */ - +#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed + * mismatches */ int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); |
