diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-06 13:34:43 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-06 13:34:43 -0700 |
commit | 44598f98b98e54beca34dc836b38eaea40be1abf (patch) | |
tree | 42a498e0267b23289ffe240907fd9bacb9156a2c /drivers/video/backlight/gpio_backlight.c | |
parent | b4b50fd78b1e31989940dfc647e64453d0f7176a (diff) | |
parent | 4e5f67fa538ded704c904157e3ca23ceef9c7e64 (diff) |
Merge tag 'boards-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC board updates from Olof Johansson:
"Board updates for 3.12. Again, a bit of domain overlap with SoC and
DT branches, but most of this is around legacy code and board support.
We've found that platform maintainers have a hard time separating all
of these out and might move towards fewer branches for next release.
- Removal of a number of Marvell Kirkwood board files, since contents
is now common and mostly configured via DT.
- Device-tree updates for Marvell Dove, including irqchip and
clocksource setup.
- Defconfig updates. Gotta go somewhere. One new one for Renesas
Lager.
- New backlight drivers for backlights used on Renesas shmobile
platforms.
- Removal of Renesas leds driver.
- Shuffling of some of the new Broadcom platforms to give room for
others in the same mach directory. More in 3.13"
* tag 'boards-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (67 commits)
mmc: sdhci-bcm-kona: Staticize sdhci_bcm_kona_card_event
mmc: sdhci-bcm-kona: Remove unneeded version.h inclusion
ARM: bcm: Make secure API call optional
ARM: DT: binding fixup to align with vendor-prefixes.txt (drivers)
ARM: mmc: fix NONREMOVABLE test in sdhci-bcm-kona
ARM: bcm: Rename board_bcm
mmc: sdhci-bcm-kona: make linker-section warning go away
ARM: tegra: defconfig updates
ARM: dove: add initial DT file for Globalscale D2Plug
ARM: dove: add GPIO IR receiver node to SolidRun CuBox
ARM: dove: add common pinmux functions to DT
ARM: dove: add cpu device tree node
ARM: dove: update dove_defconfig with SI5351, PCI, and xHCI
arch/arm/mach-kirkwood: Avoid using ARRAY_AND_SIZE(e) as a function argument
ARM: kirkwood: fix DT building and update defconfig
ARM: kirkwood: Remove all remaining trace of DNS-320/325 platform code
ARM: configs: disable DEBUG_LL in bcm_defconfig
ARM: bcm281xx: Board specific reboot code
ARM bcm281xx: Turn on socket & network support.
ARM: bcm281xx: Turn on L2 cache.
...
Diffstat (limited to 'drivers/video/backlight/gpio_backlight.c')
-rw-r--r-- | drivers/video/backlight/gpio_backlight.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c new file mode 100644 index 000000000000..5fa217f9f445 --- /dev/null +++ b/drivers/video/backlight/gpio_backlight.c @@ -0,0 +1,133 @@ +/* + * 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 <linux/backlight.h> +#include <linux/err.h> +#include <linux/fb.h> +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_data/gpio_backlight.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +struct gpio_backlight { + struct device *dev; + struct device *fbdev; + + int gpio; + int active; +}; + +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(gbl->gpio, brightness ? gbl->active : !gbl->active); + + return 0; +} + +static int gpio_backlight_get_brightness(struct backlight_device *bl) +{ + return bl->props.brightness; +} + +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, + .get_brightness = gpio_backlight_get_brightness, + .check_fb = gpio_backlight_check_fb, +}; + +static int gpio_backlight_probe(struct platform_device *pdev) +{ + struct gpio_backlight_platform_data *pdata = pdev->dev.platform_data; + struct backlight_properties props; + struct backlight_device *bl; + struct gpio_backlight *gbl; + int ret; + + if (!pdata) { + dev_err(&pdev->dev, "failed to find platform data\n"); + return -ENODEV; + } + + gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL); + if (gbl == NULL) + return -ENOMEM; + + gbl->dev = &pdev->dev; + gbl->fbdev = pdata->fbdev; + gbl->gpio = pdata->gpio; + gbl->active = pdata->active_low ? 0 : 1; + + ret = devm_gpio_request_one(gbl->dev, gbl->gpio, GPIOF_DIR_OUT | + (gbl->active ? GPIOF_INIT_LOW + : GPIOF_INIT_HIGH), + pdata->name); + 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 = backlight_device_register(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 = pdata->def_value; + backlight_update_status(bl); + + platform_set_drvdata(pdev, bl); + return 0; +} + +static int gpio_backlight_remove(struct platform_device *pdev) +{ + struct backlight_device *bl = platform_get_drvdata(pdev); + + backlight_device_unregister(bl); + return 0; +} + +static struct platform_driver gpio_backlight_driver = { + .driver = { + .name = "gpio-backlight", + .owner = THIS_MODULE, + }, + .probe = gpio_backlight_probe, + .remove = gpio_backlight_remove, +}; + +module_platform_driver(gpio_backlight_driver); + +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); +MODULE_DESCRIPTION("GPIO-based Backlight Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:gpio-backlight"); |