From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/video/backlight/lcd.c | 263 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 263 insertions(+) create mode 100644 drivers/video/backlight/lcd.c (limited to 'drivers/video/backlight/lcd.c') diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c new file mode 100644 index 0000000..470e6f0 --- /dev/null +++ b/drivers/video/backlight/lcd.c @@ -0,0 +1,263 @@ +/* + * LCD Lowlevel Control Abstraction + * + * Copyright (C) 2003,2004 Hewlett-Packard Company + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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, power; + char *endp; + struct lcd_device *ld = to_lcd_device(cdev); + + power = simple_strtoul(buf, &endp, 0); + if (*endp && !isspace(*endp)) + 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; + } else + rc = -ENXIO; + up(&ld->sem); + + return rc; +} + +static ssize_t lcd_show_contrast(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_contrast)) + rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld)); + else + rc = -ENXIO; + up(&ld->sem); + + return rc; +} + +static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count) +{ + int rc, contrast; + char *endp; + struct lcd_device *ld = to_lcd_device(cdev); + + contrast = simple_strtoul(buf, &endp, 0); + if (*endp && !isspace(*endp)) + 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; + } else + rc = -ENXIO; + up(&ld->sem); + + return rc; +} + +static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf) +{ + int rc; + struct lcd_device *ld = to_lcd_device(cdev); + + down(&ld->sem); + if (likely(ld->props)) + rc = sprintf(buf, "%d\n", ld->props->max_contrast); + else + rc = -ENXIO; + 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 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), +}; + +/* 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 =(struct fb_event *)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; +} + +/** + * 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); + } + + memset(&new_ld->fb_notif, 0, sizeof(new_ld->fb_notif)); + new_ld->fb_notif.notifier_call = fb_notifier_callback; + + rc = fb_register_client(&new_ld->fb_notif); + 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); + + fb_unregister_client(&ld->fb_notif); + + 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 , Andrew Zabolotny "); +MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction"); -- cgit v1.1