From 95099d4622f8cb224d94e314c7a8e0df60b13f87 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 09 Dec 2023 08:38:01 +0000
Subject: [PATCH] enable docker ppp
---
kernel/drivers/video/backlight/backlight.c | 243 +++++++++++++++++++++++++++++++++---------------
1 files changed, 165 insertions(+), 78 deletions(-)
diff --git a/kernel/drivers/video/backlight/backlight.c b/kernel/drivers/video/backlight/backlight.c
index e2caea4..fc990e5 100644
--- a/kernel/drivers/video/backlight/backlight.c
+++ b/kernel/drivers/video/backlight/backlight.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Backlight Lowlevel Control Abstraction
*
@@ -21,6 +22,47 @@
#include <asm/backlight.h>
#endif
+/**
+ * DOC: overview
+ *
+ * The backlight core supports implementing backlight drivers.
+ *
+ * A backlight driver registers a driver using
+ * devm_backlight_device_register(). The properties of the backlight
+ * driver such as type and max_brightness must be specified.
+ * When the core detect changes in for example brightness or power state
+ * the update_status() operation is called. The backlight driver shall
+ * implement this operation and use it to adjust backlight.
+ *
+ * Several sysfs attributes are provided by the backlight core::
+ *
+ * - brightness R/W, set the requested brightness level
+ * - actual_brightness RO, the brightness level used by the HW
+ * - max_brightness RO, the maximum brightness level supported
+ *
+ * See Documentation/ABI/stable/sysfs-class-backlight for the full list.
+ *
+ * The backlight can be adjusted using the sysfs interface, and
+ * the backlight driver may also support adjusting backlight using
+ * a hot-key or some other platform or firmware specific way.
+ *
+ * The driver must implement the get_brightness() operation if
+ * the HW do not support all the levels that can be specified in
+ * brightness, thus providing user-space access to the actual level
+ * via the actual_brightness attribute.
+ *
+ * When the backlight changes this is reported to user-space using
+ * an uevent connected to the actual_brightness attribute.
+ * When brightness is set by platform specific means, for example
+ * a hot-key to adjust backlight, the driver must notify the backlight
+ * core that brightness has changed using backlight_force_update().
+ *
+ * The backlight driver core receives notifications from fbdev and
+ * if the event is FB_EVENT_BLANK and if the value of blank, from the
+ * FBIOBLANK ioctrl, results in a change in the backlight state the
+ * update_status() operation is called.
+ */
+
static struct list_head backlight_dev_list;
static struct mutex backlight_dev_list_mutex;
static struct blocking_notifier_head backlight_notifier;
@@ -31,11 +73,25 @@
[BACKLIGHT_FIRMWARE] = "firmware",
};
+static const char *const backlight_scale_types[] = {
+ [BACKLIGHT_SCALE_UNKNOWN] = "unknown",
+ [BACKLIGHT_SCALE_LINEAR] = "linear",
+ [BACKLIGHT_SCALE_NON_LINEAR] = "non-linear",
+};
+
#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
-/* 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 and necessary, we're switching backlight power as well ...
+/*
+ * fb_notifier_callback
+ *
+ * This callback gets called when something important happens inside a
+ * framebuffer driver. The backlight core only cares about FB_BLANK_UNBLANK
+ * which is reported to the driver using backlight_update_status()
+ * as a state change.
+ *
+ * There may be several fbdev's connected to the backlight device,
+ * in which case they are kept track of. A state change is only reported
+ * if there is a change in backlight for the specified fbdev.
*/
static int fb_notifier_callback(struct notifier_block *self,
unsigned long event, void *data)
@@ -46,33 +102,34 @@
int fb_blank = 0;
/* If we aren't interested in this event, skip it immediately ... */
- if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
+ if (event != FB_EVENT_BLANK)
return 0;
bd = container_of(self, struct backlight_device, fb_notif);
mutex_lock(&bd->ops_lock);
- if (bd->ops)
- if (!bd->ops->check_fb ||
- bd->ops->check_fb(bd, evdata->info)) {
- fb_blank = *(int *)evdata->data;
- if (fb_blank == FB_BLANK_UNBLANK &&
- !bd->fb_bl_on[node]) {
- bd->fb_bl_on[node] = true;
- if (!bd->use_count++) {
- bd->props.state &= ~BL_CORE_FBBLANK;
- bd->props.fb_blank = FB_BLANK_UNBLANK;
- backlight_update_status(bd);
- }
- } else if (fb_blank != FB_BLANK_UNBLANK &&
- bd->fb_bl_on[node]) {
- bd->fb_bl_on[node] = false;
- if (!(--bd->use_count)) {
- bd->props.state |= BL_CORE_FBBLANK;
- bd->props.fb_blank = fb_blank;
- backlight_update_status(bd);
- }
- }
+
+ if (!bd->ops)
+ goto out;
+ if (bd->ops->check_fb && !bd->ops->check_fb(bd, evdata->info))
+ goto out;
+
+ fb_blank = *(int *)evdata->data;
+ if (fb_blank == FB_BLANK_UNBLANK && !bd->fb_bl_on[node]) {
+ bd->fb_bl_on[node] = true;
+ if (!bd->use_count++) {
+ bd->props.state &= ~BL_CORE_FBBLANK;
+ bd->props.fb_blank = FB_BLANK_UNBLANK;
+ backlight_update_status(bd);
}
+ } else if (fb_blank != FB_BLANK_UNBLANK && bd->fb_bl_on[node]) {
+ bd->fb_bl_on[node] = false;
+ if (!(--bd->use_count)) {
+ bd->props.state |= BL_CORE_FBBLANK;
+ bd->props.fb_blank = fb_blank;
+ backlight_update_status(bd);
+ }
+ }
+out:
mutex_unlock(&bd->ops_lock);
return 0;
}
@@ -245,6 +302,18 @@
}
static DEVICE_ATTR_RO(actual_brightness);
+static ssize_t scale_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct backlight_device *bd = to_backlight_device(dev);
+
+ if (WARN_ON(bd->props.scale > BACKLIGHT_SCALE_NON_LINEAR))
+ return sprintf(buf, "unknown\n");
+
+ return sprintf(buf, "%s\n", backlight_scale_types[bd->props.scale]);
+}
+static DEVICE_ATTR_RO(scale);
+
static struct class *backlight_class;
#ifdef CONFIG_PM_SLEEP
@@ -291,6 +360,7 @@
&dev_attr_brightness.attr,
&dev_attr_actual_brightness.attr,
&dev_attr_max_brightness.attr,
+ &dev_attr_scale.attr,
&dev_attr_type.attr,
NULL,
};
@@ -300,9 +370,13 @@
* backlight_force_update - tell the backlight subsystem that hardware state
* has changed
* @bd: the backlight device to update
+ * @reason: reason for update
*
* Updates the internal state of the backlight in response to a hardware event,
- * and generate a uevent to notify userspace
+ * and generates an uevent to notify userspace. A backlight driver shall call
+ * backlight_force_update() when the backlight is changed using, for example,
+ * a hot-key. The updated brightness is read using get_brightness() and the
+ * brightness value is reported using an uevent.
*/
void backlight_force_update(struct backlight_device *bd,
enum backlight_update_reason reason)
@@ -315,19 +389,7 @@
}
EXPORT_SYMBOL(backlight_force_update);
-/**
- * backlight_device_register - create and register a new object of
- * backlight_device class.
- * @name: the name of the new object(must be the same as the name of the
- * respective framebuffer device).
- * @parent: a pointer to the parent device
- * @devdata: an optional pointer to be stored for private driver use. The
- * methods may retrieve it by using bl_get_data(bd).
- * @ops: the backlight operations structure.
- *
- * Creates and registers new backlight device. Returns either an
- * ERR_PTR() or a pointer to the newly allocated device.
- */
+/* deprecated - use devm_backlight_device_register() */
struct backlight_device *backlight_device_register(const char *name,
struct device *parent, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props)
@@ -394,6 +456,15 @@
}
EXPORT_SYMBOL(backlight_device_register);
+/** backlight_device_get_by_type - find first backlight device of a type
+ * @type: the type of backlight device
+ *
+ * Look up the first backlight device of the specified type
+ *
+ * RETURNS:
+ *
+ * Pointer to backlight device if any was found. Otherwise NULL.
+ */
struct backlight_device *backlight_device_get_by_type(enum backlight_type type)
{
bool found = false;
@@ -413,11 +484,27 @@
EXPORT_SYMBOL(backlight_device_get_by_type);
/**
- * backlight_device_unregister - unregisters a backlight device object.
- * @bd: the backlight device object to be unregistered and freed.
+ * backlight_device_get_by_name - Get backlight device by name
+ * @name: Device name
*
- * Unregisters a previously registered via backlight_device_register object.
+ * This function looks up a backlight device by its name. It obtains a reference
+ * on the backlight device and it is the caller's responsibility to drop the
+ * reference by calling backlight_put().
+ *
+ * Returns:
+ * A pointer to the backlight device if found, otherwise NULL.
*/
+struct backlight_device *backlight_device_get_by_name(const char *name)
+{
+ struct device *dev;
+
+ dev = class_find_device_by_name(backlight_class, name);
+
+ return dev ? to_backlight_device(dev) : NULL;
+}
+EXPORT_SYMBOL(backlight_device_get_by_name);
+
+/* deprecated - use devm_backlight_device_unregister() */
void backlight_device_unregister(struct backlight_device *bd)
{
if (!bd)
@@ -465,10 +552,12 @@
* backlight_register_notifier - get notified of backlight (un)registration
* @nb: notifier block with the notifier to call on backlight (un)registration
*
- * @return 0 on success, otherwise a negative error code
- *
* Register a notifier to get notified when backlight devices get registered
* or unregistered.
+ *
+ * RETURNS:
+ *
+ * 0 on success, otherwise a negative error code
*/
int backlight_register_notifier(struct notifier_block *nb)
{
@@ -480,10 +569,12 @@
* backlight_unregister_notifier - unregister a backlight notifier
* @nb: notifier block to unregister
*
- * @return 0 on success, otherwise a negative error code
- *
* Register a notifier to get notified when backlight devices get registered
* or unregistered.
+ *
+ * RETURNS:
+ *
+ * 0 on success, otherwise a negative error code
*/
int backlight_unregister_notifier(struct notifier_block *nb)
{
@@ -492,19 +583,21 @@
EXPORT_SYMBOL(backlight_unregister_notifier);
/**
- * devm_backlight_device_register - resource managed backlight_device_register()
+ * devm_backlight_device_register - register a new backlight device
* @dev: the device to register
* @name: the name of the device
- * @parent: a pointer to the parent device
+ * @parent: a pointer to the parent device (often the same as @dev)
* @devdata: an optional pointer to be stored for private driver use
* @ops: the backlight operations structure
* @props: the backlight properties
*
- * @return a struct backlight on success, or an ERR_PTR on error
+ * Creates and registers new backlight device. When a backlight device
+ * is registered the configuration must be specified in the @props
+ * parameter. See description of &backlight_properties.
*
- * Managed backlight_device_register(). The backlight_device returned
- * from this function are automatically freed on driver detach.
- * See backlight_device_register() for more information.
+ * RETURNS:
+ *
+ * struct backlight on success, or an ERR_PTR on error
*/
struct backlight_device *devm_backlight_device_register(struct device *dev,
const char *name, struct device *parent, void *devdata,
@@ -532,13 +625,13 @@
EXPORT_SYMBOL(devm_backlight_device_register);
/**
- * devm_backlight_device_unregister - resource managed backlight_device_unregister()
+ * devm_backlight_device_unregister - unregister backlight device
* @dev: the device to unregister
* @bd: the backlight device to unregister
*
- * Deallocated a backlight allocated with devm_backlight_device_register().
+ * Deallocates a backlight allocated with devm_backlight_device_register().
* Normally this function will not need to be called and the resource management
- * code will ensure that the resource is freed.
+ * code will ensure that the resources are freed.
*/
void devm_backlight_device_unregister(struct device *dev,
struct backlight_device *bd)
@@ -580,22 +673,7 @@
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)
+static struct backlight_device *of_find_backlight(struct device *dev)
{
struct backlight_device *bd = NULL;
struct device_node *np;
@@ -615,20 +693,29 @@
return bd;
}
-EXPORT_SYMBOL(of_find_backlight);
static void devm_backlight_release(void *data)
{
- backlight_put(data);
+ struct backlight_device *bd = data;
+
+ if (bd)
+ put_device(&bd->dev);
}
/**
- * devm_of_find_backlight - Resource-managed of_find_backlight()
- * @dev: Device
+ * devm_of_find_backlight - find backlight for a device
+ * @dev: the device
*
- * Device managed version of of_find_backlight().
- * The reference on the backlight device is automatically
+ * This function looks for a property named 'backlight' on the DT node
+ * connected to @dev and looks up the backlight device. The lookup is
+ * device managed so the reference to the backlight device is automatically
* dropped on driver detach.
+ *
+ * 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 *devm_of_find_backlight(struct device *dev)
{
@@ -640,7 +727,7 @@
return bd;
ret = devm_add_action(dev, devm_backlight_release, bd);
if (ret) {
- backlight_put(bd);
+ put_device(&bd->dev);
return ERR_PTR(ret);
}
return bd;
--
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