/* * LCD Lowlevel Control Abstraction * * Copyright (C) 2003,2004 Hewlett-Packard Company * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/init.h> #include <linux/device.h> #include <linux/lcd.h> #include <linux/notifier.h> #include <linux/ctype.h> #include <linux/err.h> #include <linux/fb.h> #include <linux/slab.h> #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ defined(CONFIG_LCD_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 lcd power as well ... */ static int fb_notifier_callback(struct notifier_block *self, unsigned long event, void *data) { struct lcd_device *ld; struct fb_event *evdata = data; /* If we aren't interested in this event, skip it immediately ... */ switch (event) { case FB_EVENT_BLANK: case FB_EVENT_MODE_CHANGE: case FB_EVENT_MODE_CHANGE_ALL: case FB_EARLY_EVENT_BLANK: case FB_R_EARLY_EVENT_BLANK: break; default: return 0; } ld = container_of(self, struct lcd_device, fb_notif); if (!ld->ops) return 0; mutex_lock(&ld->ops_lock); if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) { if (event == FB_EVENT_BLANK) { if (ld->ops->set_power) ld->ops->set_power(ld, *(int *)evdata->data); } else if (event == FB_EARLY_EVENT_BLANK) { if (ld->ops->early_set_power) ld->ops->early_set_power(ld, *(int *)evdata->data); } else if (event == FB_R_EARLY_EVENT_BLANK) { if (ld->ops->r_early_set_power) ld->ops->r_early_set_power(ld, *(int *)evdata->data); } else { if (ld->ops->set_mode) ld->ops->set_mode(ld, evdata->data); } } mutex_unlock(&ld->ops_lock); return 0; } static int lcd_register_fb(struct lcd_device *ld) { memset(&ld->fb_notif, 0, sizeof(ld->fb_notif)); ld->fb_notif.notifier_call = fb_notifier_callback; return fb_register_client(&ld->fb_notif); } static void lcd_unregister_fb(struct lcd_device *ld) { fb_unregister_client(&ld->fb_notif); } #else static int lcd_register_fb(struct lcd_device *ld) { return 0; } static inline void lcd_unregister_fb(struct lcd_device *ld) { } #endif /* CONFIG_FB */ static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr, char *buf) { int rc; struct lcd_device *ld = to_lcd_device(dev); mutex_lock(&ld->ops_lock); if (ld->ops && ld->ops->get_power) rc = sprintf(buf, "%d\n", ld->ops->get_power(ld)); else rc = -ENXIO; mutex_unlock(&ld->ops_lock); return rc; } static ssize_t lcd_power_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int rc; struct lcd_device *ld = to_lcd_device(dev); unsigned long power; rc = kstrtoul(buf, 0, &power); if (rc) return rc; rc = -ENXIO; mutex_lock(&ld->ops_lock); if (ld->ops && ld->ops->set_power) { pr_debug("set power to %lu\n", power); ld->ops->set_power(ld, power); rc = count; } mutex_unlock(&ld->ops_lock); return rc; } static DEVICE_ATTR_RW(lcd_power); static ssize_t contrast_show(struct device *dev, struct device_attribute *attr, char *buf) { int rc = -ENXIO; struct lcd_device *ld = to_lcd_device(dev); mutex_lock(&ld->ops_lock); if (ld->ops && ld->ops->get_contrast) rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld)); mutex_unlock(&ld->ops_lock); return rc; } static ssize_t contrast_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int rc; struct lcd_device *ld = to_lcd_device(dev); unsigned long contrast; rc = kstrtoul(buf, 0, &contrast); if (rc) return rc; rc = -ENXIO; mutex_lock(&ld->ops_lock); if (ld->ops && ld->ops->set_contrast) { pr_debug("set contrast to %lu\n", contrast); ld->ops->set_contrast(ld, contrast); rc = count; } mutex_unlock(&ld->ops_lock); return rc; } static DEVICE_ATTR_RW(contrast); static ssize_t max_contrast_show(struct device *dev, struct device_attribute *attr, char *buf) { struct lcd_device *ld = to_lcd_device(dev); return sprintf(buf, "%d\n", ld->props.max_contrast); } static DEVICE_ATTR_RO(max_contrast); static struct class *lcd_class; static void lcd_device_release(struct device *dev) { struct lcd_device *ld = to_lcd_device(dev); kfree(ld); } static struct attribute *lcd_device_attrs[] = { &dev_attr_lcd_power.attr, &dev_attr_contrast.attr, &dev_attr_max_contrast.attr, NULL, }; ATTRIBUTE_GROUPS(lcd_device); /** * lcd_device_register - register a new object of lcd_device class. * @name: the name of the new object(must be the same as the name of the * respective framebuffer device). * @devdata: an optional pointer to be stored in the device. The * methods may retrieve it by using lcd_get_data(ld). * @ops: the lcd operations structure. * * Creates and registers a new lcd device. Returns either an ERR_PTR() * or a pointer to the newly allocated device. */ struct lcd_device *lcd_device_register(const char *name, struct device *parent, void *devdata, struct lcd_ops *ops) { struct lcd_device *new_ld; int rc; pr_debug("lcd_device_register: name=%s\n", name); new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL); if (!new_ld) return ERR_PTR(-ENOMEM); mutex_init(&new_ld->ops_lock); mutex_init(&new_ld->update_lock); new_ld->dev.class = lcd_class; new_ld->dev.parent = parent; new_ld->dev.release = lcd_device_release; dev_set_name(&new_ld->dev, "%s", name); dev_set_drvdata(&new_ld->dev, devdata); rc = device_register(&new_ld->dev); if (rc) { put_device(&new_ld->dev); return ERR_PTR(rc); } rc = lcd_register_fb(new_ld); if (rc) { device_unregister(&new_ld->dev); return ERR_PTR(rc); } new_ld->ops = ops; return new_ld; } EXPORT_SYMBOL(lcd_device_register); /** * lcd_device_unregister - unregisters a object of lcd_device class. * @ld: the lcd device object to be unregistered and freed. * * Unregisters a previously registered via lcd_device_register object. */ void lcd_device_unregister(struct lcd_device *ld) { if (!ld) return; mutex_lock(&ld->ops_lock); ld->ops = NULL; mutex_unlock(&ld->ops_lock); lcd_unregister_fb(ld); device_unregister(&ld->dev); } EXPORT_SYMBOL(lcd_device_unregister); static void devm_lcd_device_release(struct device *dev, void *res) { struct lcd_device *lcd = *(struct lcd_device **)res; lcd_device_unregister(lcd); } static int devm_lcd_device_match(struct device *dev, void *res, void *data) { struct lcd_device **r = res; return *r == data; } /** * devm_lcd_device_register - resource managed lcd_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 lcd operations structure * * @return a struct lcd on success, or an ERR_PTR on error * * Managed lcd_device_register(). The lcd_device returned from this function * are automatically freed on driver detach. See lcd_device_register() * for more information. */ struct lcd_device *devm_lcd_device_register(struct device *dev, const char *name, struct device *parent, void *devdata, struct lcd_ops *ops) { struct lcd_device **ptr, *lcd; ptr = devres_alloc(devm_lcd_device_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); lcd = lcd_device_register(name, parent, devdata, ops); if (!IS_ERR(lcd)) { *ptr = lcd; devres_add(dev, ptr); } else { devres_free(ptr); } return lcd; } EXPORT_SYMBOL(devm_lcd_device_register); /** * devm_lcd_device_unregister - resource managed lcd_device_unregister() * @dev: the device to unregister * @ld: the lcd device to unregister * * Deallocated a lcd allocated with devm_lcd_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_lcd_device_unregister(struct device *dev, struct lcd_device *ld) { int rc; rc = devres_release(dev, devm_lcd_device_release, devm_lcd_device_match, ld); WARN_ON(rc); } EXPORT_SYMBOL(devm_lcd_device_unregister); static void __exit lcd_class_exit(void) { class_destroy(lcd_class); } static int __init lcd_class_init(void) { lcd_class = class_create(THIS_MODULE, "lcd"); if (IS_ERR(lcd_class)) { pr_warn("Unable to create backlight class; errno = %ld\n", PTR_ERR(lcd_class)); return PTR_ERR(lcd_class); } lcd_class->dev_groups = lcd_device_groups; return 0; } /* * if this is compiled into the kernel, we need to ensure that the * class is registered before users of the class try to register lcd's */ postcore_initcall(lcd_class_init); module_exit(lcd_class_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>"); MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");