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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 v5 03/19] backlight: improve backlight_ops documentation
Date: Sun, 19 Jul 2020 10:07:27 +0200
Message-ID: <20200719080743.8560-4-sam@ravnborg.org> (raw)
In-Reply-To: <20200719080743.8560-1-sam@ravnborg.org>

Improve the documentation for backlight_ops and
adapt it to kernel-doc style.

v2:
  - Add intro for each field (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 | 59 +++++++++++++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 6 deletions(-)

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 56e51ebab740..dfb43ee02ea0 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -55,19 +55,66 @@ enum backlight_scale {
 struct backlight_device;
 struct fb_info;
 
+/**
+ * struct backlight_ops - backlight operations
+ *
+ * The backlight operations are specifed when the backlight device is registered.
+ */
 struct backlight_ops {
+	/**
+	 * @options: Configure how operations are called from the core.
+	 *
+	 * The options parameter is used to adjust the behaviour of the core.
+	 * Set BL_CORE_SUSPENDRESUME to get the update_status() operation called
+	 * upon suspend and resume.
+	 */
 	unsigned int options;
 
 #define BL_CORE_SUSPENDRESUME	(1 << 0)
 
-	/* Notify the backlight driver some property has changed */
+	/**
+	 * @update_status: Operation called when properties have changed.
+	 *
+	 * Notify the backlight driver some property has changed.
+	 * The update_status operation is protected by the update_lock.
+	 *
+	 * The backlight driver is expected to use backlight_is_blank()
+	 * to check if the display is blanked and set brightness accordingly.
+	 * update_status() is called when any of the properties has changed.
+	 *
+	 * RETURNS:
+	 *
+	 * 0 on sucees, negative error code if any failure occured.
+	 */
 	int (*update_status)(struct backlight_device *);
-	/* Return the current backlight brightness (accounting for power,
-	   fb_blank etc.) */
+
+	/**
+	 * @get_brightness: Return the current backlight brightness.
+	 *
+	 * The driver may implement this as a readback from the HW.
+	 * This operation is optional and if not present then the current
+	 * brightness property value is used.
+	 *
+	 * RETURNS:
+	 *
+	 * A brightness value which is 0 or a positive numer.
+	 * On failure a negative error code is returned.
+	 */
 	int (*get_brightness)(struct backlight_device *);
-	/* Check if given framebuffer device is the one bound to this backlight;
-	   return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
-	int (*check_fb)(struct backlight_device *, struct fb_info *);
+
+	/**
+	 * @check_fb: Check the framebuffer device.
+	 *
+	 * Check if given framebuffer device is the one bound to this backlight.
+	 * This operation is optional and if not implemented it is assumed that the
+	 * fbdev is always the one bound to the backlight.
+	 *
+	 * RETURNS:
+	 *
+	 * If info is NULL or the info matches the fbdev bound to the backlight return true.
+	 * If info does not match the fbdev bound to the backlight return false.
+	 */
+	int (*check_fb)(struct backlight_device *bd, struct fb_info *info);
 };
 
 /* This structure defines all the properties of a backlight */
-- 
2.25.1

  parent reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-19  8:07 [PATCH v5 0/19] backlight: backlight updates Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 01/19] backlight: refactor fb_notifier_callback() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 02/19] backlight: add backlight_is_blank() Sam Ravnborg
2020-07-19  8:07 ` Sam Ravnborg [this message]
2020-07-19  8:07 ` [PATCH v5 04/19] backlight: improve backlight_properties documentation Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 05/19] backlight: improve backlight_device documentation Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 06/19] backlight: document inline functions in backlight.h Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 07/19] backlight: document enums " Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 08/19] backlight: remove the unused backlight_bl driver Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 09/19] backlight: drop extern from prototypes Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 10/19] backlight: add overview and update existing doc Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 11/19] backlight: wire up kernel-doc documentation Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 12/19] backlight: introduce backlight_get_brightness() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 13/19] backlight: as3711_bl: simplify update_status Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 14/19] backlight: cr_bllcd: introduce gpio-backlight semantics Sam Ravnborg
2020-07-20  8:48   ` Daniel Thompson
2020-07-20  9:14     ` Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 15/19] backlight: gpio_backlight: simplify update_status() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 16/19] backlight: jornada720_bl: introduce backlight_is_blank() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 17/19] backlight: use backlight_get_brightness() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 18/19] backlight: drop backlight_put() Sam Ravnborg
2020-07-19  8:07 ` [PATCH v5 19/19] backlight: make of_find_backlight static Sam Ravnborg
2020-07-20  9:36 ` [PATCH v5 0/19] backlight: backlight updates Lee Jones
2020-07-20 11:01   ` Sam Ravnborg

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