diff options
Diffstat (limited to 'drivers/video/backlight/backlight.c')
| -rw-r--r-- | drivers/video/backlight/backlight.c | 272 |
1 files changed, 235 insertions, 37 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index bf5b1ece716..428089009cd 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -5,6 +5,8 @@ * */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/module.h> #include <linux/init.h> #include <linux/device.h> @@ -19,6 +21,10 @@ #include <asm/backlight.h> #endif +static struct list_head backlight_dev_list; +static struct mutex backlight_dev_list_mutex; +static struct blocking_notifier_head backlight_notifier; + static const char *const backlight_types[] = { [BACKLIGHT_RAW] = "raw", [BACKLIGHT_PLATFORM] = "platform", @@ -29,13 +35,15 @@ static const char *const backlight_types[] = { defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) /* This callback gets called when something important happens inside a * framebuffer driver. We're looking if that important event is blanking, - * and if it is, we're switching backlight power as well ... + * and if it is and necessary, we're switching backlight power as well ... */ static int fb_notifier_callback(struct notifier_block *self, unsigned long event, void *data) { struct backlight_device *bd; struct fb_event *evdata = data; + int node = evdata->info->node; + int fb_blank = 0; /* If we aren't interested in this event, skip it immediately ... */ if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK) @@ -46,12 +54,24 @@ static int fb_notifier_callback(struct notifier_block *self, if (bd->ops) if (!bd->ops->check_fb || bd->ops->check_fb(bd, evdata->info)) { - bd->props.fb_blank = *(int *)evdata->data; - if (bd->props.fb_blank == FB_BLANK_UNBLANK) - bd->props.state &= ~BL_CORE_FBBLANK; - else - bd->props.state |= BL_CORE_FBBLANK; - backlight_update_status(bd); + fb_blank = *(int *)evdata->data; + if (fb_blank == FB_BLANK_UNBLANK && + !bd->fb_bl_on[node]) { + bd->fb_bl_on[node] = true; + if (!bd->use_count++) { + bd->props.state &= ~BL_CORE_FBBLANK; + bd->props.fb_blank = FB_BLANK_UNBLANK; + backlight_update_status(bd); + } + } else if (fb_blank != FB_BLANK_UNBLANK && + bd->fb_bl_on[node]) { + bd->fb_bl_on[node] = false; + if (!(--bd->use_count)) { + bd->props.state |= BL_CORE_FBBLANK; + bd->props.fb_blank = fb_blank; + backlight_update_status(bd); + } + } } mutex_unlock(&bd->ops_lock); return 0; @@ -101,16 +121,16 @@ static void backlight_generate_event(struct backlight_device *bd, sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness"); } -static ssize_t backlight_show_power(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t bl_power_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct backlight_device *bd = to_backlight_device(dev); return sprintf(buf, "%d\n", bd->props.power); } -static ssize_t backlight_store_power(struct device *dev, - struct device_attribute *attr, const char *buf, size_t count) +static ssize_t bl_power_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { int rc; struct backlight_device *bd = to_backlight_device(dev); @@ -123,7 +143,7 @@ static ssize_t backlight_store_power(struct device *dev, rc = -ENXIO; mutex_lock(&bd->ops_lock); if (bd->ops) { - pr_debug("backlight: set power to %lu\n", power); + pr_debug("set power to %lu\n", power); if (bd->props.power != power) { bd->props.power = power; backlight_update_status(bd); @@ -134,8 +154,9 @@ static ssize_t backlight_store_power(struct device *dev, return rc; } +static DEVICE_ATTR_RW(bl_power); -static ssize_t backlight_show_brightness(struct device *dev, +static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf) { struct backlight_device *bd = to_backlight_device(dev); @@ -143,7 +164,7 @@ static ssize_t backlight_show_brightness(struct device *dev, return sprintf(buf, "%d\n", bd->props.brightness); } -static ssize_t backlight_store_brightness(struct device *dev, +static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int rc; @@ -161,8 +182,7 @@ static ssize_t backlight_store_brightness(struct device *dev, if (brightness > bd->props.max_brightness) rc = -EINVAL; else { - pr_debug("backlight: set brightness to %lu\n", - brightness); + pr_debug("set brightness to %lu\n", brightness); bd->props.brightness = brightness; backlight_update_status(bd); rc = count; @@ -174,24 +194,27 @@ static ssize_t backlight_store_brightness(struct device *dev, return rc; } +static DEVICE_ATTR_RW(brightness); -static ssize_t backlight_show_type(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t type_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct backlight_device *bd = to_backlight_device(dev); return sprintf(buf, "%s\n", backlight_types[bd->props.type]); } +static DEVICE_ATTR_RO(type); -static ssize_t backlight_show_max_brightness(struct device *dev, +static ssize_t max_brightness_show(struct device *dev, struct device_attribute *attr, char *buf) { struct backlight_device *bd = to_backlight_device(dev); return sprintf(buf, "%d\n", bd->props.max_brightness); } +static DEVICE_ATTR_RO(max_brightness); -static ssize_t backlight_show_actual_brightness(struct device *dev, +static ssize_t actual_brightness_show(struct device *dev, struct device_attribute *attr, char *buf) { int rc = -ENXIO; @@ -204,10 +227,12 @@ static ssize_t backlight_show_actual_brightness(struct device *dev, return rc; } +static DEVICE_ATTR_RO(actual_brightness); static struct class *backlight_class; -static int backlight_suspend(struct device *dev, pm_message_t state) +#ifdef CONFIG_PM_SLEEP +static int backlight_suspend(struct device *dev) { struct backlight_device *bd = to_backlight_device(dev); @@ -234,6 +259,10 @@ static int backlight_resume(struct device *dev) return 0; } +#endif + +static SIMPLE_DEV_PM_OPS(backlight_class_dev_pm_ops, backlight_suspend, + backlight_resume); static void bl_device_release(struct device *dev) { @@ -241,16 +270,15 @@ static void bl_device_release(struct device *dev) kfree(bd); } -static struct device_attribute bl_device_attributes[] = { - __ATTR(bl_power, 0644, backlight_show_power, backlight_store_power), - __ATTR(brightness, 0644, backlight_show_brightness, - backlight_store_brightness), - __ATTR(actual_brightness, 0444, backlight_show_actual_brightness, - NULL), - __ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), - __ATTR(type, 0444, backlight_show_type, NULL), - __ATTR_NULL, +static struct attribute *bl_device_attrs[] = { + &dev_attr_bl_power.attr, + &dev_attr_brightness.attr, + &dev_attr_actual_brightness.attr, + &dev_attr_max_brightness.attr, + &dev_attr_type.attr, + NULL, }; +ATTRIBUTE_GROUPS(bl_device); /** * backlight_force_update - tell the backlight subsystem that hardware state @@ -303,7 +331,7 @@ struct backlight_device *backlight_device_register(const char *name, new_bd->dev.class = backlight_class; new_bd->dev.parent = parent; new_bd->dev.release = bl_device_release; - dev_set_name(&new_bd->dev, name); + dev_set_name(&new_bd->dev, "%s", name); dev_set_drvdata(&new_bd->dev, devdata); /* Set default properties */ @@ -320,7 +348,7 @@ struct backlight_device *backlight_device_register(const char *name, rc = device_register(&new_bd->dev); if (rc) { - kfree(new_bd); + put_device(&new_bd->dev); return ERR_PTR(rc); } @@ -339,10 +367,35 @@ struct backlight_device *backlight_device_register(const char *name, mutex_unlock(&pmac_backlight_mutex); #endif + mutex_lock(&backlight_dev_list_mutex); + list_add(&new_bd->entry, &backlight_dev_list); + mutex_unlock(&backlight_dev_list_mutex); + + blocking_notifier_call_chain(&backlight_notifier, + BACKLIGHT_REGISTERED, new_bd); + return new_bd; } EXPORT_SYMBOL(backlight_device_register); +bool backlight_device_registered(enum backlight_type type) +{ + bool found = false; + struct backlight_device *bd; + + mutex_lock(&backlight_dev_list_mutex); + list_for_each_entry(bd, &backlight_dev_list, entry) { + if (bd->props.type == type) { + found = true; + break; + } + } + mutex_unlock(&backlight_dev_list_mutex); + + return found; +} +EXPORT_SYMBOL(backlight_device_registered); + /** * backlight_device_unregister - unregisters a backlight device object. * @bd: the backlight device object to be unregistered and freed. @@ -354,12 +407,20 @@ void backlight_device_unregister(struct backlight_device *bd) if (!bd) return; + mutex_lock(&backlight_dev_list_mutex); + list_del(&bd->entry); + mutex_unlock(&backlight_dev_list_mutex); + #ifdef CONFIG_PMAC_BACKLIGHT mutex_lock(&pmac_backlight_mutex); if (pmac_backlight == bd) pmac_backlight = NULL; mutex_unlock(&pmac_backlight_mutex); #endif + + blocking_notifier_call_chain(&backlight_notifier, + BACKLIGHT_UNREGISTERED, bd); + mutex_lock(&bd->ops_lock); bd->ops = NULL; mutex_unlock(&bd->ops_lock); @@ -369,6 +430,140 @@ void backlight_device_unregister(struct backlight_device *bd) } EXPORT_SYMBOL(backlight_device_unregister); +static void devm_backlight_device_release(struct device *dev, void *res) +{ + struct backlight_device *backlight = *(struct backlight_device **)res; + + backlight_device_unregister(backlight); +} + +static int devm_backlight_device_match(struct device *dev, void *res, + void *data) +{ + struct backlight_device **r = res; + + return *r == data; +} + +/** + * backlight_register_notifier - get notified of backlight (un)registration + * @nb: notifier block with the notifier to call on backlight (un)registration + * + * @return 0 on success, otherwise a negative error code + * + * Register a notifier to get notified when backlight devices get registered + * or unregistered. + */ +int backlight_register_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&backlight_notifier, nb); +} +EXPORT_SYMBOL(backlight_register_notifier); + +/** + * backlight_unregister_notifier - unregister a backlight notifier + * @nb: notifier block to unregister + * + * @return 0 on success, otherwise a negative error code + * + * Register a notifier to get notified when backlight devices get registered + * or unregistered. + */ +int backlight_unregister_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&backlight_notifier, nb); +} +EXPORT_SYMBOL(backlight_unregister_notifier); + +/** + * devm_backlight_device_register - resource managed backlight_device_register() + * @dev: the device to register + * @name: the name of the device + * @parent: a pointer to the parent device + * @devdata: an optional pointer to be stored for private driver use + * @ops: the backlight operations structure + * @props: the backlight properties + * + * @return a struct backlight on success, or an ERR_PTR on error + * + * Managed backlight_device_register(). The backlight_device returned + * from this function are automatically freed on driver detach. + * See backlight_device_register() for more information. + */ +struct backlight_device *devm_backlight_device_register(struct device *dev, + const char *name, struct device *parent, void *devdata, + const struct backlight_ops *ops, + const struct backlight_properties *props) +{ + struct backlight_device **ptr, *backlight; + + ptr = devres_alloc(devm_backlight_device_release, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + backlight = backlight_device_register(name, parent, devdata, ops, + props); + if (!IS_ERR(backlight)) { + *ptr = backlight; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return backlight; +} +EXPORT_SYMBOL(devm_backlight_device_register); + +/** + * devm_backlight_device_unregister - resource managed backlight_device_unregister() + * @dev: the device to unregister + * @bd: the backlight device to unregister + * + * Deallocated a backlight allocated with devm_backlight_device_register(). + * Normally this function will not need to be called and the resource management + * code will ensure that the resource is freed. + */ +void devm_backlight_device_unregister(struct device *dev, + struct backlight_device *bd) +{ + int rc; + + rc = devres_release(dev, devm_backlight_device_release, + devm_backlight_device_match, bd); + WARN_ON(rc); +} +EXPORT_SYMBOL(devm_backlight_device_unregister); + +#ifdef CONFIG_OF +static int of_parent_match(struct device *dev, const void *data) +{ + return dev->parent && dev->parent->of_node == data; +} + +/** + * of_find_backlight_by_node() - find backlight device by device-tree node + * @node: device-tree node of the backlight device + * + * Returns a pointer to the backlight device corresponding to the given DT + * node or NULL if no such backlight device exists or if the device hasn't + * been probed yet. + * + * This function obtains a reference on the backlight device and it is the + * caller's responsibility to drop the reference by calling put_device() on + * the backlight device's .dev field. + */ +struct backlight_device *of_find_backlight_by_node(struct device_node *node) +{ + struct device *dev; + + dev = class_find_device(backlight_class, NULL, node, of_parent_match); + + return dev ? to_backlight_device(dev) : NULL; +} +EXPORT_SYMBOL(of_find_backlight_by_node); +#endif + static void __exit backlight_class_exit(void) { class_destroy(backlight_class); @@ -378,14 +573,17 @@ static int __init backlight_class_init(void) { backlight_class = class_create(THIS_MODULE, "backlight"); if (IS_ERR(backlight_class)) { - printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n", - PTR_ERR(backlight_class)); + pr_warn("Unable to create backlight class; errno = %ld\n", + PTR_ERR(backlight_class)); return PTR_ERR(backlight_class); } - backlight_class->dev_attrs = bl_device_attributes; - backlight_class->suspend = backlight_suspend; - backlight_class->resume = backlight_resume; + backlight_class->dev_groups = bl_device_groups; + backlight_class->pm = &backlight_class_dev_pm_ops; + INIT_LIST_HEAD(&backlight_dev_list); + mutex_init(&backlight_dev_list_mutex); + BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier); + return 0; } |