From: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org,
Jingoo Han <jingoohan1@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
Daniel Thompson <daniel.thompson@linaro.org>
Cc: Andy Gross <agross@kernel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
David Airlie <airlied@linux.ie>,
Emil Velikov <emil.l.velikov@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
linux-arm-msm@vger.kernel.org, linux-pwm@vger.kernel.org,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Michael Hennerich <michael.hennerich@analog.com>,
patches@opensource.cirrus.com,
Support Opensource <support.opensource@diasemi.com>,
Thierry Reding <thierry.reding@gmail.com>,
Thomas Zimmermann <tzimmermann@suse.de>,
Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>,
Peter Ujfalusi <peter.ujfalusi@ti.com>, Tomi Valkeinen <tomi.v>
Subject: [PATCH v4 04/20] backlight: improve backlight_properties documentation
Date: Fri, 3 Jul 2020 20:45:30 +0200 [thread overview]
Message-ID: <20200703184546.144664-5-sam@ravnborg.org> (raw)
In-Reply-To: <20200703184546.144664-1-sam@ravnborg.org>
Improve the documentation for backlight_properties and
adapt it to kernel-doc style.
v3:
- Added missing '@' in kernel-doc
v2:
- Added into for each field (Daniel)
- Re-written some parts to explain what to do, rather
than what not to do.
Partly based on suggestions from the review (Daniel)
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
---
include/linux/backlight.h | 96 ++++++++++++++++++++++++++++++++++-----
1 file changed, 85 insertions(+), 11 deletions(-)
diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index dfb43ee02ea0..10518b00b059 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -117,28 +117,102 @@ struct backlight_ops {
int (*check_fb)(struct backlight_device *bd, struct fb_info *info);
};
-/* This structure defines all the properties of a backlight */
+/**
+ * struct backlight_properties - backlight properties
+ *
+ * This structure defines all the properties of a backlight.
+ */
struct backlight_properties {
- /* Current User requested brightness (0 - max_brightness) */
+ /**
+ * @brightness: The current brightness requested by the user.
+ *
+ * The backlight core makes sure the range is (0 to max_brightness)
+ * when the brightness is set via the sysfs attribute:
+ * /sys/class/backlight/<backlight>/brightness.
+ *
+ * This value can be set in the backlight_properties passed
+ * to devm_backlight_device_register() to set a default brightness
+ * value.
+ */
int brightness;
- /* Maximal value for brightness (read-only) */
+
+ /**
+ * @max_brightness: The maximum brightness value.
+ *
+ * This value must be set in the backlight_properties passed to
+ * devm_backlight_device_register() and shall not be modified by the
+ * driver after registration.
+ */
int max_brightness;
- /* Current FB Power mode (0: full on, 1..3: power saving
- modes; 4: full off), see FB_BLANK_XXX */
+
+ /**
+ * @power: The current power mode.
+ *
+ * User space can configure the power mode using the sysfs
+ * attribute: /sys/class/backlight/<backlight>/bl_power
+ * When the power property is updated update_status() is called.
+ *
+ * The possible values are: (0: full on, 1 to 3: power saving
+ * modes; 4: full off), see FB_BLANK_XXX.
+ *
+ * When the backlight device is enabled @power is set
+ * to FB_BLANK_UNBLANK. When the backlight device is disabled
+ * @power is set to FB_BLANK_POWERDOWN.
+ */
int power;
- /* FB Blanking active? (values as for power) */
- /* Due to be removed, please use (state & BL_CORE_FBBLANK) */
+
+ /**
+ * @fb_blank: The power state from the FBIOBLANK ioclt.
+ *
+ * When the FBIOBLANK ioctl is called @fb_blank is set to the
+ * blank parameter and the update_status() operation is called.
+ *
+ * When the backlight device is enabled @fb_blank is set
+ * to FB_BLANK_UNBLANK. When the backlight device is disabled
+ * @fb_blank is set to FB_BLANK_POWERDOWN.
+ *
+ * Backlight drivers should avoid using this property. It has been
+ * replaced by state & BL_CORE_FBLANK (although most drivers should
+ * use backlight_is_blank() as the preferred means to get the blank
+ * state).
+ *
+ * fb_blank is deprecated and will be removed.
+ */
int fb_blank;
- /* Backlight type */
+
+ /**
+ * @type: The type of backlight supported.
+ *
+ * The backlight type allows userspace to make appropriate
+ * policy desicions based on the backlight type.
+ *
+ * This value must be set in the backlight_properties
+ * passed to devm_backlight_device_register().
+ */
enum backlight_type type;
- /* Flags used to signal drivers of state changes */
+
+ /**
+ * @state: The state of the backlight core.
+ *
+ * The state is a bitmask. BL_CORE_FBBLANK is set when the display
+ * is expected to be blank. BL_CORE_SUSPENDED is set when the
+ * driver is suspended.
+ *
+ * backlight drivers are excpected to use backlight_is_blank()
+ * in their update_status() operation rather than reading the
+ * state property.
+ *
+ * The state is maintained by the core and drivers may not modify it.
+ */
unsigned int state;
- /* Type of the brightness scale (linear, non-linear, ...) */
- enum backlight_scale scale;
#define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
#define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
+ /**
+ * @scale: The type of the brightness scale.
+ */
+ enum backlight_scale scale;
};
struct backlight_device {
--
2.25.1
next prev parent reply other threads:[~2020-07-03 18:45 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-03 18:45 [PATCH v4 0/20] backlight: backlight updates Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 01/20] backlight: refactor fb_notifier_callback() Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 02/20] backlight: add backlight_is_blank() Sam Ravnborg
2020-07-07 5:42 ` Daniel Vetter
2020-07-03 18:45 ` [PATCH v4 03/20] backlight: improve backlight_ops documentation Sam Ravnborg
2020-07-03 18:45 ` Sam Ravnborg [this message]
2020-07-03 18:45 ` [PATCH v4 05/20] backlight: improve backlight_device documentation Sam Ravnborg
2020-07-08 10:23 ` Daniel Thompson
2020-07-16 14:39 ` Lee Jones
2020-07-16 15:00 ` Sam Ravnborg
2020-07-16 15:09 ` Lee Jones
2020-07-18 5:18 ` Jingoo Han
2020-07-18 6:00 ` Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 06/20] backlight: document inline functions in backlight.h Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 07/20] backlight: document enums " Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 08/20] backlight: remove the unused backlight_bl driver Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 09/20] backlight: drop extern from prototypes Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 10/20] backlight: add overview and update existing doc Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 11/20] backlight: wire up kernel-doc documentation Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 12/20] backlight: introduce backlight_get_brightness() Sam Ravnborg
2020-07-08 10:27 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 13/20] backlight: as3711_bl: simplify update_status Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 14/20] backlight: cr_bllcd: introduce backlight_is_blank() Sam Ravnborg
2020-07-08 11:06 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 15/20] backlight: gpio_backlight: simplify update_status() Sam Ravnborg
2020-07-08 11:07 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 16/20] backlight: jornada720_bl: introduce backlight_is_blank() Sam Ravnborg
2020-07-08 11:12 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 17/20] backlight: use backligt_get_brightness() Sam Ravnborg
2020-07-07 5:48 ` Daniel Vetter
2020-07-07 19:59 ` Sam Ravnborg
2020-07-07 20:15 ` Daniel Vetter
2020-07-07 20:23 ` Sam Ravnborg
2020-07-08 11:14 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 18/20] backlight: drop backlight_put() Sam Ravnborg
2020-07-03 18:45 ` [PATCH v4 19/20] backlight: make of_find_backlight static Sam Ravnborg
2020-07-08 11:17 ` Daniel Thompson
2020-07-03 18:45 ` [PATCH v4 20/20] backlight: make of_find_backlight_by_node() static Sam Ravnborg
2020-07-07 21:46 ` kernel test robot
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