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authorSean Paul <seanpaul@chromium.org>2018-02-20 10:33:04 -0500
committerSean Paul <seanpaul@chromium.org>2018-02-20 10:33:05 -0500
commitf5155876af19f885fec94bbb926b0ce62115e139 (patch)
treef5d4a8d57ef2d7469e7bc9e3568fd9c9986202be
parent07d85290f9b6512d236a33e8617ee00f1b405ac2 (diff)
parent2e4ef3347b4a4eb65c4fd950d94bbd75fed4d798 (diff)
Merge tag 'topic/backlight_for_lag-2018-01-29' of git://anongit.freedesktop.org/drm/drm-misc into drm-misc-next
This contains the backlight portion of Meghana Madhyastha's patch set to migrate the backlight helpers from tinydrm to the backlight subsystem. https://patchwork.freedesktop.org/series/36522/ Cc: Meghana Madhyastha <meghana.madhyastha@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> # gpg: Signature made Mon 29 Jan 2018 02:25:40 PM EST # gpg: using RSA key 7F17297CC4A076740CB3E42A96F70DFDA84A070A # gpg: Good signature from "Sean Paul <seanpaul@chromium.org>" [unknown] # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 1C5E AB9E D7C9 DDE9 E7F2 087C 732C 0025 72DC AF79 # Subkey fingerprint: 7F17 297C C4A0 7674 0CB3 E42A 96F7 0DFD A84A 070A Link: https://patchwork.freedesktop.org/patch/msgid/20180129192950.bvmhkz3h42t5a25r@art_vandelay
-rw-r--r--drivers/video/backlight/backlight.c73
-rw-r--r--include/linux/backlight.h58
2 files changed, 131 insertions, 0 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 8049e7656daa..deb824bef6e2 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -580,6 +580,79 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node)
EXPORT_SYMBOL(of_find_backlight_by_node);
#endif
+/**
+ * of_find_backlight - Get backlight device
+ * @dev: Device
+ *
+ * This function looks for a property named 'backlight' on the DT node
+ * connected to @dev and looks up the backlight device.
+ *
+ * Call backlight_put() to drop the reference on the backlight device.
+ *
+ * Returns:
+ * A pointer to the backlight device if found.
+ * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
+ * device is found.
+ * NULL if there's no backlight property.
+ */
+struct backlight_device *of_find_backlight(struct device *dev)
+{
+ struct backlight_device *bd = NULL;
+ struct device_node *np;
+
+ if (!dev)
+ return NULL;
+
+ if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
+ np = of_parse_phandle(dev->of_node, "backlight", 0);
+ if (np) {
+ bd = of_find_backlight_by_node(np);
+ of_node_put(np);
+ if (!bd)
+ return ERR_PTR(-EPROBE_DEFER);
+ /*
+ * Note: gpio_backlight uses brightness as
+ * power state during probe
+ */
+ if (!bd->props.brightness)
+ bd->props.brightness = bd->props.max_brightness;
+ }
+ }
+
+ return bd;
+}
+EXPORT_SYMBOL(of_find_backlight);
+
+static void devm_backlight_release(void *data)
+{
+ backlight_put(data);
+}
+
+/**
+ * devm_of_find_backlight - Resource-managed of_find_backlight()
+ * @dev: Device
+ *
+ * Device managed version of of_find_backlight().
+ * The reference on the backlight device is automatically
+ * dropped on driver detach.
+ */
+struct backlight_device *devm_of_find_backlight(struct device *dev)
+{
+ struct backlight_device *bd;
+ int ret;
+
+ bd = of_find_backlight(dev);
+ if (IS_ERR_OR_NULL(bd))
+ return bd;
+ ret = devm_add_action(dev, devm_backlight_release, bd);
+ if (ret) {
+ backlight_put(bd);
+ return ERR_PTR(ret);
+ }
+ return bd;
+}
+EXPORT_SYMBOL(devm_of_find_backlight);
+
static void __exit backlight_class_exit(void)
{
class_destroy(backlight_class);
diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index af7003548593..2baab6f3861d 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -130,6 +130,48 @@ static inline int backlight_update_status(struct backlight_device *bd)
return ret;
}
+/**
+ * backlight_enable - Enable backlight
+ * @bd: the backlight device to enable
+ */
+static inline int backlight_enable(struct backlight_device *bd)
+{
+ if (!bd)
+ return 0;
+
+ bd->props.power = FB_BLANK_UNBLANK;
+ bd->props.fb_blank = FB_BLANK_UNBLANK;
+ bd->props.state &= ~BL_CORE_FBBLANK;
+
+ return backlight_update_status(bd);
+}
+
+/**
+ * backlight_disable - Disable backlight
+ * @bd: the backlight device to disable
+ */
+static inline int backlight_disable(struct backlight_device *bd)
+{
+ if (!bd)
+ return 0;
+
+ bd->props.power = FB_BLANK_POWERDOWN;
+ bd->props.fb_blank = FB_BLANK_POWERDOWN;
+ bd->props.state |= BL_CORE_FBBLANK;
+
+ return backlight_update_status(bd);
+}
+
+/**
+ * backlight_put - Drop backlight reference
+ * @bd: the backlight device to put
+ */
+static inline void backlight_put(struct backlight_device *bd)
+{
+ if (bd)
+ put_device(&bd->dev);
+}
+
extern struct backlight_device *backlight_device_register(const char *name,
struct device *dev, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props);
@@ -173,4 +215,20 @@ of_find_backlight_by_node(struct device_node *node)
}
#endif
+#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
+struct backlight_device *of_find_backlight(struct device *dev);
+struct backlight_device *devm_of_find_backlight(struct device *dev);
+#else
+static inline struct backlight_device *of_find_backlight(struct device *dev)
+{
+ return NULL;
+}
+
+static inline struct backlight_device *
+devm_of_find_backlight(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
#endif