/* * LCD Lowlevel Control Abstraction * * Copyright (C) 2003,2004 Hewlett-Packard Company * */ #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> #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 ... */ if (event != FB_EVENT_BLANK) return 0; ld = container_of(self, struct lcd_device, fb_notif); down(&ld->sem); if (ld->props) if (!ld->props->check_fb || ld->props->check_fb(evdata->info)) ld->props->set_power(ld, *(int *)evdata->data); up(&ld->sem); 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_show_power(struct class_device *cdev, char *buf) { int rc; struct lcd_device *ld = to_lcd_device(cdev); down(&ld->sem); if (likely(ld->props && ld->props->get_power)) rc = sprintf(buf, "%d\n", ld->props->get_power(ld)); else rc = -ENXIO; up(&ld->sem); return rc; } static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_t count) { int rc = -ENXIO; char *endp; struct lcd_device *ld = to_lcd_device(cdev); int power = simple_strtoul(buf, &endp, 0); size_t size = endp - buf; if (*endp && isspace(*endp)) size++; if (size != count) return -EINVAL; down(&ld->sem); if (likely(ld->props && ld->props->set_power)) { pr_debug("lcd: set power to %d\n", power); ld->props->set_power(ld, power); rc = count; } up(&ld->sem); return rc; } static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf) { int rc = -ENXIO; struct lcd_device *ld = to_lcd_device(cdev); down(&ld->sem); if (likely(ld->props && ld->props->get_contrast)) rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld)); up(&ld->sem); return rc; } static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count) { int rc = -ENXIO; char *endp; struct lcd_device *ld = to_lcd_device(cdev); int contrast = simple_strtoul(buf, &endp, 0); size_t size = endp - buf; if (*endp && isspace(*endp)) size++; if (size != count) return -EINVAL; down(&ld->sem); if (likely(ld->props && ld->props->set_contrast)) { pr_debug("lcd: set contrast to %d\n", contrast); ld->props->set_contrast(ld, contrast); rc = count; } up(&ld->sem); return rc; } static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf) { int rc = -ENXIO; struct lcd_device *ld = to_lcd_device(cdev); down(&ld->sem); if (likely(ld->props)) rc = sprintf(buf, "%d\n", ld->props->max_contrast); up(&ld->sem); return rc; } static void lcd_class_release(struct class_device *dev) { struct lcd_device *ld = to_lcd_device(dev); kfree(ld); } static struct class lcd_class = { .name = "lcd", .release = lcd_class_release, }; #define DECLARE_ATTR(_name,_mode,_show,_store) \ { \ .attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \ .show = _show, \ .store = _store, \ } static const struct class_device_attribute lcd_class_device_attributes[] = { DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power), DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast), DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL), }; /** * 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 class_device. The * methods may retrieve it by using class_get_devdata(ld->class_dev). * @lp: the lcd properties structure. * * Creates and registers a new lcd class_device. Returns either an ERR_PTR() * or a pointer to the newly allocated device. */ struct lcd_device *lcd_device_register(const char *name, void *devdata, struct lcd_properties *lp) { int i, rc; struct lcd_device *new_ld; pr_debug("lcd_device_register: name=%s\n", name); new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL); if (unlikely(!new_ld)) return ERR_PTR(-ENOMEM); init_MUTEX(&new_ld->sem); new_ld->props = lp; memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev)); new_ld->class_dev.class = &lcd_class; strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN); class_set_devdata(&new_ld->class_dev, devdata); rc = class_device_register(&new_ld->class_dev); if (unlikely(rc)) { error: kfree(new_ld); return ERR_PTR(rc); } rc = lcd_register_fb(new_ld); if (unlikely(rc)) goto error; for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) { rc = class_device_create_file(&new_ld->class_dev, &lcd_class_device_attributes[i]); if (unlikely(rc)) { while (--i >= 0) class_device_remove_file(&new_ld->class_dev, &lcd_class_device_attributes[i]); class_device_unregister(&new_ld->class_dev); /* No need to kfree(new_ld) since release() method was called */ return ERR_PTR(rc); } } 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) { int i; if (!ld) return; pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id); for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) class_device_remove_file(&ld->class_dev, &lcd_class_device_attributes[i]); down(&ld->sem); ld->props = NULL; up(&ld->sem); lcd_unregister_fb(ld); class_device_unregister(&ld->class_dev); } EXPORT_SYMBOL(lcd_device_unregister); static void __exit lcd_class_exit(void) { class_unregister(&lcd_class); } static int __init lcd_class_init(void) { return class_register(&lcd_class); } /* * 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");