From 0fe3a66410a3ba96679be903f1e287d7a0a264a9 Mon Sep 17 00:00:00 2001 From: Chanwoo Choi Date: Tue, 26 Jan 2016 13:21:26 +0900 Subject: [PATCH] PM / devfreq: Add new DEVFREQ_TRANSITION_NOTIFIER notifier This patch adds the new DEVFREQ_TRANSITION_NOTIFIER notifier to send the notification when the frequency of device is changed. This notifier has two state as following: - DEVFREQ_PRECHANGE : Notify it before chaning the frequency of device - DEVFREQ_POSTCHANGE : Notify it after changed the frequency of device And this patch adds the resourced-managed function to release the resource automatically when error happen. Signed-off-by: Chanwoo Choi [m.reichl and linux.amoon: Tested it on exynos4412-odroidu3 board] Tested-by: Markus Reichl Tested-by: Anand Moon Signed-off-by: MyungJoo Ham Acked-by: Krzysztof Kozlowski --- drivers/devfreq/devfreq.c | 163 +++++++++++++++++++++++++++++++++++++- include/linux/devfreq.h | 59 +++++++++++++- 2 files changed, 220 insertions(+), 2 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 20a9422c2552..1d6c803804d5 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -189,6 +189,29 @@ static struct devfreq_governor *find_devfreq_governor(const char *name) return ERR_PTR(-ENODEV); } +static int devfreq_notify_transition(struct devfreq *devfreq, + struct devfreq_freqs *freqs, unsigned int state) +{ + if (!devfreq) + return -EINVAL; + + switch (state) { + case DEVFREQ_PRECHANGE: + srcu_notifier_call_chain(&devfreq->transition_notifier_list, + DEVFREQ_PRECHANGE, freqs); + break; + + case DEVFREQ_POSTCHANGE: + srcu_notifier_call_chain(&devfreq->transition_notifier_list, + DEVFREQ_POSTCHANGE, freqs); + break; + default: + return -EINVAL; + } + + return 0; +} + /* Load monitoring helper functions for governors use */ /** @@ -200,7 +223,8 @@ static struct devfreq_governor *find_devfreq_governor(const char *name) */ int update_devfreq(struct devfreq *devfreq) { - unsigned long freq; + struct devfreq_freqs freqs; + unsigned long freq, cur_freq; int err = 0; u32 flags = 0; @@ -234,10 +258,22 @@ int update_devfreq(struct devfreq *devfreq) flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ } + if (devfreq->profile->get_cur_freq) + devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); + else + cur_freq = devfreq->previous_freq; + + freqs.old = cur_freq; + freqs.new = freq; + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); + err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); if (err) return err; + freqs.new = freq; + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); + if (devfreq->profile->freq_table) if (devfreq_update_status(devfreq, freq)) dev_err(&devfreq->dev, @@ -542,6 +578,8 @@ struct devfreq *devfreq_add_device(struct device *dev, goto err_out; } + srcu_init_notifier_head(&devfreq->transition_notifier_list); + mutex_unlock(&devfreq->lock); mutex_lock(&devfreq_list_lock); @@ -1310,6 +1348,129 @@ void devm_devfreq_unregister_opp_notifier(struct device *dev, } EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); +/** + * devfreq_register_notifier() - Register a driver with devfreq + * @devfreq: The devfreq object. + * @nb: The notifier block to register. + * @list: DEVFREQ_TRANSITION_NOTIFIER. + */ +int devfreq_register_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + int ret = 0; + + if (!devfreq) + return -EINVAL; + + switch (list) { + case DEVFREQ_TRANSITION_NOTIFIER: + ret = srcu_notifier_chain_register( + &devfreq->transition_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL(devfreq_register_notifier); + +/* + * devfreq_unregister_notifier() - Unregister a driver with devfreq + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + * @list: DEVFREQ_TRANSITION_NOTIFIER. + */ +int devfreq_unregister_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + int ret = 0; + + if (!devfreq) + return -EINVAL; + + switch (list) { + case DEVFREQ_TRANSITION_NOTIFIER: + ret = srcu_notifier_chain_unregister( + &devfreq->transition_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL(devfreq_unregister_notifier); + +struct devfreq_notifier_devres { + struct devfreq *devfreq; + struct notifier_block *nb; + unsigned int list; +}; + +static void devm_devfreq_notifier_release(struct device *dev, void *res) +{ + struct devfreq_notifier_devres *this = res; + + devfreq_unregister_notifier(this->devfreq, this->nb, this->list); +} + +/** + * devm_devfreq_register_notifier() + - Resource-managed devfreq_register_notifier() + * @dev: The devfreq user device. (parent of devfreq) + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + * @list: DEVFREQ_TRANSITION_NOTIFIER. + */ +int devm_devfreq_register_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + struct devfreq_notifier_devres *ptr; + int ret; + + ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + ret = devfreq_register_notifier(devfreq, nb, list); + if (ret) { + devres_free(ptr); + return ret; + } + + ptr->devfreq = devfreq; + ptr->nb = nb; + ptr->list = list; + devres_add(dev, ptr); + + return 0; +} +EXPORT_SYMBOL(devm_devfreq_register_notifier); + +/** + * devm_devfreq_unregister_notifier() + - Resource-managed devfreq_unregister_notifier() + * @dev: The devfreq user device. (parent of devfreq) + * @devfreq: The devfreq object. + * @nb: The notifier block to be unregistered. + * @list: DEVFREQ_TRANSITION_NOTIFIER. + */ +void devm_devfreq_unregister_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + WARN_ON(devres_release(dev, devm_devfreq_notifier_release, + devm_devfreq_dev_match, devfreq)); +} +EXPORT_SYMBOL(devm_devfreq_unregister_notifier); + MODULE_AUTHOR("MyungJoo Ham "); MODULE_DESCRIPTION("devfreq class support"); MODULE_LICENSE("GPL"); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index aa0b8424ebc3..98c699304e12 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -19,6 +19,13 @@ #define DEVFREQ_NAME_LEN 16 +/* DEVFREQ notifier interface */ +#define DEVFREQ_TRANSITION_NOTIFIER (0) + +/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */ +#define DEVFREQ_PRECHANGE (0) +#define DEVFREQ_POSTCHANGE (1) + struct devfreq; /** @@ -143,6 +150,7 @@ struct devfreq_governor { * @trans_table: Statistics of devfreq transitions * @time_in_state: Statistics of devfreq states * @last_stat_updated: The last time stat updated + * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier * * This structure stores the devfreq information for a give device. * @@ -177,6 +185,13 @@ struct devfreq { unsigned int *trans_table; unsigned long *time_in_state; unsigned long last_stat_updated; + + struct srcu_notifier_head transition_notifier_list; +}; + +struct devfreq_freqs { + unsigned long old; + unsigned long new; }; #if defined(CONFIG_PM_DEVFREQ) @@ -207,7 +222,20 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq); extern void devm_devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq); - +extern int devfreq_register_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list); +extern int devfreq_unregister_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list); +extern int devm_devfreq_register_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list); +extern void devm_devfreq_unregister_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list); extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index); @@ -310,6 +338,35 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev, { } +static inline int devfreq_register_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + return 0; +} + +static inline int devfreq_unregister_notifier(struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + return 0; +} + +static inline int devm_devfreq_register_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ + return 0; +} + +static inline void devm_devfreq_unregister_notifier(struct device *dev, + struct devfreq *devfreq, + struct notifier_block *nb, + unsigned int list) +{ +} + static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index) { -- 2.20.1