/* * gpio_backlight.c - Simple GPIO-controlled backlight * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include struct gpio_backlight { struct device *dev; struct device *fbdev; int gpio; int active; int def_value; }; static int gpio_backlight_update_status(struct backlight_device *bl) { struct gpio_backlight *gbl = bl_get_data(bl); int brightness = bl->props.brightness; if (bl->props.power != FB_BLANK_UNBLANK || bl->props.fb_blank != FB_BLANK_UNBLANK || bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) brightness = 0; gpio_set_value_cansleep(gbl->gpio, brightness ? gbl->active : !gbl->active); return 0; } static int gpio_backlight_check_fb(struct backlight_device *bl, struct fb_info *info) { struct gpio_backlight *gbl = bl_get_data(bl); return gbl->fbdev == NULL || gbl->fbdev == info->dev; } static const struct backlight_ops gpio_backlight_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = gpio_backlight_update_status, .check_fb = gpio_backlight_check_fb, }; static int gpio_backlight_probe_dt(struct platform_device *pdev, struct gpio_backlight *gbl) { struct device_node *np = pdev->dev.of_node; enum of_gpio_flags gpio_flags; gbl->gpio = of_get_gpio_flags(np, 0, &gpio_flags); if (!gpio_is_valid(gbl->gpio)) { if (gbl->gpio != -EPROBE_DEFER) { dev_err(&pdev->dev, "Error: The gpios parameter is missing or invalid.\n"); } return gbl->gpio; } gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; gbl->def_value = of_property_read_bool(np, "default-on"); return 0; } static int gpio_backlight_probe(struct platform_device *pdev) { struct gpio_backlight_platform_data *pdata = dev_get_platdata(&pdev->dev); struct backlight_properties props; struct backlight_device *bl; struct gpio_backlight *gbl; struct device_node *np = pdev->dev.of_node; unsigned long flags = GPIOF_DIR_OUT; int ret; if (!pdata && !np) { dev_err(&pdev->dev, "failed to find platform data or device tree node.\n"); return -ENODEV; } gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL); if (gbl == NULL) return -ENOMEM; gbl->dev = &pdev->dev; if (np) { ret = gpio_backlight_probe_dt(pdev, gbl); if (ret) return ret; } else { gbl->fbdev = pdata->fbdev; gbl->gpio = pdata->gpio; gbl->active = pdata->active_low ? 0 : 1; gbl->def_value = pdata->def_value; } if (gbl->active) flags |= gbl->def_value ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW; else flags |= gbl->def_value ? GPIOF_INIT_LOW : GPIOF_INIT_HIGH; ret = devm_gpio_request_one(gbl->dev, gbl->gpio, flags, pdata ? pdata->name : "backlight"); if (ret < 0) { dev_err(&pdev->dev, "unable to request GPIO\n"); return ret; } memset(&props, 0, sizeof(props)); props.type = BACKLIGHT_RAW; props.max_brightness = 1; bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev), &pdev->dev, gbl, &gpio_backlight_ops, &props); if (IS_ERR(bl)) { dev_err(&pdev->dev, "failed to register backlight\n"); return PTR_ERR(bl); } bl->props.brightness = gbl->def_value; backlight_update_status(bl); platform_set_drvdata(pdev, bl); return 0; } #ifdef CONFIG_OF static struct of_device_id gpio_backlight_of_match[] = { { .compatible = "gpio-backlight" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, gpio_backlight_of_match); #endif static struct platform_driver gpio_backlight_driver = { .driver = { .name = "gpio-backlight", .of_match_table = of_match_ptr(gpio_backlight_of_match), }, .probe = gpio_backlight_probe, }; module_platform_driver(gpio_backlight_driver); MODULE_AUTHOR("Laurent Pinchart "); MODULE_DESCRIPTION("GPIO-based Backlight Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:gpio-backlight"); n>
authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 20:50:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 20:50:02 -0800
commite34bac726d27056081d0250c0e173e4b155aa340 (patch)
tree85607d0b3b185380fb3267866020c6a4372b9298 /net/mac80211/cfg.c
parentfe6bce8d30a86c693bf7cfbf4759cbafd121289f (diff)
parent39a0e975c37dee93fa1b8ea5f7eacd1c4c8a586e (diff)
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - various misc bits - most of MM (quite a lot of MM material is awaiting the merge of linux-next dependencies) - kasan - printk updates - procfs updates - MAINTAINERS - /lib updates - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (123 commits) init: reduce rootwait polling interval time to 5ms binfmt_elf: use vmalloc() for allocation of vma_filesz checkpatch: don't emit unified-diff error for rename-only patches checkpatch: don't check c99 types like uint8_t under tools checkpatch: avoid multiple line dereferences checkpatch: don't check .pl files, improve absolute path commit log test scripts/checkpatch.pl: fix spelling checkpatch: don't try to get maintained status when --no-tree is given lib/ida: document locking requirements a bit better lib/rbtree.c: fix typo in comment of ____rb_erase_color lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM MAINTAINERS: add drm and drm/i915 irc channels MAINTAINERS: add "C:" for URI for chat where developers hang out MAINTAINERS: add drm and drm/i915 bug filing info MAINTAINERS: add "B:" for URI where to file bugs get_maintainer: look for arbitrary letter prefixes in sections printk: add Kconfig option to set default console loglevel printk/sound: handle more message headers printk/btrfs: handle more message headers printk/kdb: handle more message headers ...
Diffstat (limited to 'net/mac80211/cfg.c')