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authorLinus Torvalds <torvalds@linux-foundation.org>2013-09-06 13:34:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-06 13:34:43 -0700
commit44598f98b98e54beca34dc836b38eaea40be1abf (patch)
tree42a498e0267b23289ffe240907fd9bacb9156a2c /drivers/video/backlight/gpio_backlight.c
parentb4b50fd78b1e31989940dfc647e64453d0f7176a (diff)
parent4e5f67fa538ded704c904157e3ca23ceef9c7e64 (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.c133
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");