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From: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org,
	Thierry Reding <thierry.reding@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Sam Ravnborg <sam@ravnborg.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>,
	David Airlie <airlied@linux.ie>,
	linux-samsung-soc@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Jagan Teki <jagan@amarulasolutions.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Jitao Shi <jitao.shi@mediatek.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	linux-mediatek@lists.infradead.org,
	Abhinav Kumar <abhinavk@codeaurora.org>,
	linux-tegra@vger.kernel.org, Sean Paul <sean@poorly.run>,
	linux-arm-kernel@lists.infradead.org,
	Purism Kernel Team <kernel@puri.sm>,
	linux-renesas-soc@vger.kernel.org,
	Boris Brezillon <boris.brezillon@collabora.com>
Subject: [PATCH v2 01/25] drm/drm_panel: no error when no callback
Date: Sat,  7 Dec 2019 15:03:29 +0100	[thread overview]
Message-ID: <20191207140353.23967-2-sam@ravnborg.org> (raw)
In-Reply-To: <20191207140353.23967-1-sam@ravnborg.org>

The callbacks in drm_panel_funcs are optional, so do not
return an error just because no callback is assigned.

v2:
- Document what functions in drm_panel_funcs are optional (Laurent)
- Return -EOPNOTSUPP if get_modes() is not assigned (Laurent)
  (Sam: -EOPNOTSUPP seems to best error code in this situation)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
---
 drivers/gpu/drm/drm_panel.c | 35 +++++++++++++++++++++++++----------
 include/drm/drm_panel.h     | 18 ++++++++++++++++--
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index ed7985c0535a..4ab7229fb22b 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -151,10 +151,13 @@ EXPORT_SYMBOL(drm_panel_detach);
  */
 int drm_panel_prepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->prepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->prepare)
 		return panel->funcs->prepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_prepare);
 
@@ -171,10 +174,13 @@ EXPORT_SYMBOL(drm_panel_prepare);
  */
 int drm_panel_unprepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->unprepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->unprepare)
 		return panel->funcs->unprepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_unprepare);
 
@@ -190,10 +196,13 @@ EXPORT_SYMBOL(drm_panel_unprepare);
  */
 int drm_panel_enable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->enable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->enable)
 		return panel->funcs->enable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_enable);
 
@@ -209,10 +218,13 @@ EXPORT_SYMBOL(drm_panel_enable);
  */
 int drm_panel_disable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->disable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->disable)
 		return panel->funcs->disable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_disable);
 
@@ -228,10 +240,13 @@ EXPORT_SYMBOL(drm_panel_disable);
  */
 int drm_panel_get_modes(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->get_modes)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->get_modes)
 		return panel->funcs->get_modes(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(drm_panel_get_modes);
 
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index ce8da64022b4..d71655b2634c 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -65,6 +65,8 @@ struct drm_panel_funcs {
 	 * @prepare:
 	 *
 	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
 	 */
 	int (*prepare)(struct drm_panel *panel);
 
@@ -72,6 +74,8 @@ struct drm_panel_funcs {
 	 * @enable:
 	 *
 	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*enable)(struct drm_panel *panel);
 
@@ -79,6 +83,8 @@ struct drm_panel_funcs {
 	 * @disable:
 	 *
 	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*disable)(struct drm_panel *panel);
 
@@ -86,14 +92,20 @@ struct drm_panel_funcs {
 	 * @unprepare:
 	 *
 	 * Turn off panel.
+	 *
+	 * This function is optional.
 	 */
 	int (*unprepare)(struct drm_panel *panel);
 
 	/**
 	 * @get_modes:
 	 *
-	 * Add modes to the connector that the panel is attached to and
-	 * return the number of modes added.
+	 * Add modes to the connector that the panel is attached to.
+	 *
+	 * This function is mandatory.
+	 *
+	 * Returns the number of modes added, -EOPNOTSUPP if callback
+	 * is missing, -EINVAL if panel is NULL.
 	 */
 	int (*get_modes)(struct drm_panel *panel);
 
@@ -102,6 +114,8 @@ struct drm_panel_funcs {
 	 *
 	 * Copy display timings into the provided array and return
 	 * the number of display timings available.
+	 *
+	 * This function is optional.
 	 */
 	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 			   struct display_timing *timings);
-- 
2.20.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

WARNING: multiple messages have this Message-ID
From: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org,
	Thierry Reding <thierry.reding@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Sam Ravnborg <sam@ravnborg.org>
Cc: Abhinav Kumar <abhinavk@codeaurora.org>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Benjamin Gaignard <benjamin.gaignard@linaro.org>,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	Jagan Teki <jagan@amarulasolutions.com>,
	Jitao Shi <jitao.shi@mediatek.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	linux-renesas-soc@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Neil Armstrong <narmstrong@baylibre.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Purism Kernel Team <kernel@puri.sm>, Sean Paul <sean@poorly.run>,
	Stefan Agner <stefan@agner.ch>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>
Subject: [PATCH v2 01/25] drm/drm_panel: no error when no callback
Date: Sat,  7 Dec 2019 15:03:29 +0100	[thread overview]
Message-ID: <20191207140353.23967-2-sam@ravnborg.org> (raw)
In-Reply-To: <20191207140353.23967-1-sam@ravnborg.org>

The callbacks in drm_panel_funcs are optional, so do not
return an error just because no callback is assigned.

v2:
- Document what functions in drm_panel_funcs are optional (Laurent)
- Return -EOPNOTSUPP if get_modes() is not assigned (Laurent)
  (Sam: -EOPNOTSUPP seems to best error code in this situation)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
---
 drivers/gpu/drm/drm_panel.c | 35 +++++++++++++++++++++++++----------
 include/drm/drm_panel.h     | 18 ++++++++++++++++--
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index ed7985c0535a..4ab7229fb22b 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -151,10 +151,13 @@ EXPORT_SYMBOL(drm_panel_detach);
  */
 int drm_panel_prepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->prepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->prepare)
 		return panel->funcs->prepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_prepare);
 
@@ -171,10 +174,13 @@ EXPORT_SYMBOL(drm_panel_prepare);
  */
 int drm_panel_unprepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->unprepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->unprepare)
 		return panel->funcs->unprepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_unprepare);
 
@@ -190,10 +196,13 @@ EXPORT_SYMBOL(drm_panel_unprepare);
  */
 int drm_panel_enable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->enable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->enable)
 		return panel->funcs->enable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_enable);
 
@@ -209,10 +218,13 @@ EXPORT_SYMBOL(drm_panel_enable);
  */
 int drm_panel_disable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->disable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->disable)
 		return panel->funcs->disable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_disable);
 
@@ -228,10 +240,13 @@ EXPORT_SYMBOL(drm_panel_disable);
  */
 int drm_panel_get_modes(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->get_modes)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->get_modes)
 		return panel->funcs->get_modes(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(drm_panel_get_modes);
 
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index ce8da64022b4..d71655b2634c 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -65,6 +65,8 @@ struct drm_panel_funcs {
 	 * @prepare:
 	 *
 	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
 	 */
 	int (*prepare)(struct drm_panel *panel);
 
@@ -72,6 +74,8 @@ struct drm_panel_funcs {
 	 * @enable:
 	 *
 	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*enable)(struct drm_panel *panel);
 
@@ -79,6 +83,8 @@ struct drm_panel_funcs {
 	 * @disable:
 	 *
 	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*disable)(struct drm_panel *panel);
 
@@ -86,14 +92,20 @@ struct drm_panel_funcs {
 	 * @unprepare:
 	 *
 	 * Turn off panel.
+	 *
+	 * This function is optional.
 	 */
 	int (*unprepare)(struct drm_panel *panel);
 
 	/**
 	 * @get_modes:
 	 *
-	 * Add modes to the connector that the panel is attached to and
-	 * return the number of modes added.
+	 * Add modes to the connector that the panel is attached to.
+	 *
+	 * This function is mandatory.
+	 *
+	 * Returns the number of modes added, -EOPNOTSUPP if callback
+	 * is missing, -EINVAL if panel is NULL.
 	 */
 	int (*get_modes)(struct drm_panel *panel);
 
@@ -102,6 +114,8 @@ struct drm_panel_funcs {
 	 *
 	 * Copy display timings into the provided array and return
 	 * the number of display timings available.
+	 *
+	 * This function is optional.
 	 */
 	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 			   struct display_timing *timings);
-- 
2.20.1


WARNING: multiple messages have this Message-ID
From: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org,
	Thierry Reding <thierry.reding@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Sam Ravnborg <sam@ravnborg.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>,
	David Airlie <airlied@linux.ie>, Stefan Agner <stefan@agner.ch>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Benjamin Gaignard <benjamin.gaignard@linaro.org>,
	linux-samsung-soc@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Jagan Teki <jagan@amarulasolutions.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Jitao Shi <jitao.shi@mediatek.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	linux-mediatek@lists.infradead.org,
	Abhinav Kumar <abhinavk@codeaurora.org>,
	linux-tegra@vger.kernel.org, Sean Paul <sean@poorly.run>,
	linux-arm-kernel@lists.infradead.org,
	Purism Kernel Team <kernel@puri.sm>,
	linux-renesas-soc@vger.kernel.org,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Daniel Vetter <daniel@ffwll.ch>
Subject: [PATCH v2 01/25] drm/drm_panel: no error when no callback
Date: Sat,  7 Dec 2019 15:03:29 +0100	[thread overview]
Message-ID: <20191207140353.23967-2-sam@ravnborg.org> (raw)
In-Reply-To: <20191207140353.23967-1-sam@ravnborg.org>

The callbacks in drm_panel_funcs are optional, so do not
return an error just because no callback is assigned.

v2:
- Document what functions in drm_panel_funcs are optional (Laurent)
- Return -EOPNOTSUPP if get_modes() is not assigned (Laurent)
  (Sam: -EOPNOTSUPP seems to best error code in this situation)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
---
 drivers/gpu/drm/drm_panel.c | 35 +++++++++++++++++++++++++----------
 include/drm/drm_panel.h     | 18 ++++++++++++++++--
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index ed7985c0535a..4ab7229fb22b 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -151,10 +151,13 @@ EXPORT_SYMBOL(drm_panel_detach);
  */
 int drm_panel_prepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->prepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->prepare)
 		return panel->funcs->prepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_prepare);
 
@@ -171,10 +174,13 @@ EXPORT_SYMBOL(drm_panel_prepare);
  */
 int drm_panel_unprepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->unprepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->unprepare)
 		return panel->funcs->unprepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_unprepare);
 
@@ -190,10 +196,13 @@ EXPORT_SYMBOL(drm_panel_unprepare);
  */
 int drm_panel_enable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->enable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->enable)
 		return panel->funcs->enable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_enable);
 
@@ -209,10 +218,13 @@ EXPORT_SYMBOL(drm_panel_enable);
  */
 int drm_panel_disable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->disable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->disable)
 		return panel->funcs->disable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_disable);
 
@@ -228,10 +240,13 @@ EXPORT_SYMBOL(drm_panel_disable);
  */
 int drm_panel_get_modes(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->get_modes)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->get_modes)
 		return panel->funcs->get_modes(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(drm_panel_get_modes);
 
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index ce8da64022b4..d71655b2634c 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -65,6 +65,8 @@ struct drm_panel_funcs {
 	 * @prepare:
 	 *
 	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
 	 */
 	int (*prepare)(struct drm_panel *panel);
 
@@ -72,6 +74,8 @@ struct drm_panel_funcs {
 	 * @enable:
 	 *
 	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*enable)(struct drm_panel *panel);
 
@@ -79,6 +83,8 @@ struct drm_panel_funcs {
 	 * @disable:
 	 *
 	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*disable)(struct drm_panel *panel);
 
@@ -86,14 +92,20 @@ struct drm_panel_funcs {
 	 * @unprepare:
 	 *
 	 * Turn off panel.
+	 *
+	 * This function is optional.
 	 */
 	int (*unprepare)(struct drm_panel *panel);
 
 	/**
 	 * @get_modes:
 	 *
-	 * Add modes to the connector that the panel is attached to and
-	 * return the number of modes added.
+	 * Add modes to the connector that the panel is attached to.
+	 *
+	 * This function is mandatory.
+	 *
+	 * Returns the number of modes added, -EOPNOTSUPP if callback
+	 * is missing, -EINVAL if panel is NULL.
 	 */
 	int (*get_modes)(struct drm_panel *panel);
 
@@ -102,6 +114,8 @@ struct drm_panel_funcs {
 	 *
 	 * Copy display timings into the provided array and return
 	 * the number of display timings available.
+	 *
+	 * This function is optional.
 	 */
 	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 			   struct display_timing *timings);
-- 
2.20.1


_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID
From: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org,
	Thierry Reding <thierry.reding@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Sam Ravnborg <sam@ravnborg.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>,
	David Airlie <airlied@linux.ie>, Stefan Agner <stefan@agner.ch>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Benjamin Gaignard <benjamin.gaignard@linaro.org>,
	linux-samsung-soc@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Jagan Teki <jagan@amarulasolutions.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Jitao Shi <jitao.shi@mediatek.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	linux-mediatek@lists.infradead.org,
	Abhinav Kumar <abhinavk@codeaurora.org>,
	linux-tegra@vger.kernel.org, Sean Paul <sean@poorly.run>,
	linux-arm-kernel@lists.infradead.org,
	Purism Kernel Team <kernel@puri.sm>,
	linux-renesas-soc@vger.kernel.org,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Daniel Vetter <daniel@ffwll.ch>
Subject: [PATCH v2 01/25] drm/drm_panel: no error when no callback
Date: Sat,  7 Dec 2019 15:03:29 +0100	[thread overview]
Message-ID: <20191207140353.23967-2-sam@ravnborg.org> (raw)
In-Reply-To: <20191207140353.23967-1-sam@ravnborg.org>

The callbacks in drm_panel_funcs are optional, so do not
return an error just because no callback is assigned.

v2:
- Document what functions in drm_panel_funcs are optional (Laurent)
- Return -EOPNOTSUPP if get_modes() is not assigned (Laurent)
  (Sam: -EOPNOTSUPP seems to best error code in this situation)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
---
 drivers/gpu/drm/drm_panel.c | 35 +++++++++++++++++++++++++----------
 include/drm/drm_panel.h     | 18 ++++++++++++++++--
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index ed7985c0535a..4ab7229fb22b 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -151,10 +151,13 @@ EXPORT_SYMBOL(drm_panel_detach);
  */
 int drm_panel_prepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->prepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->prepare)
 		return panel->funcs->prepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_prepare);
 
@@ -171,10 +174,13 @@ EXPORT_SYMBOL(drm_panel_prepare);
  */
 int drm_panel_unprepare(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->unprepare)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->unprepare)
 		return panel->funcs->unprepare(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_unprepare);
 
@@ -190,10 +196,13 @@ EXPORT_SYMBOL(drm_panel_unprepare);
  */
 int drm_panel_enable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->enable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->enable)
 		return panel->funcs->enable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_enable);
 
@@ -209,10 +218,13 @@ EXPORT_SYMBOL(drm_panel_enable);
  */
 int drm_panel_disable(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->disable)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->disable)
 		return panel->funcs->disable(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return 0;
 }
 EXPORT_SYMBOL(drm_panel_disable);
 
@@ -228,10 +240,13 @@ EXPORT_SYMBOL(drm_panel_disable);
  */
 int drm_panel_get_modes(struct drm_panel *panel)
 {
-	if (panel && panel->funcs && panel->funcs->get_modes)
+	if (!panel)
+		return -EINVAL;
+
+	if (panel->funcs && panel->funcs->get_modes)
 		return panel->funcs->get_modes(panel);
 
-	return panel ? -ENOSYS : -EINVAL;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(drm_panel_get_modes);
 
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index ce8da64022b4..d71655b2634c 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -65,6 +65,8 @@ struct drm_panel_funcs {
 	 * @prepare:
 	 *
 	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
 	 */
 	int (*prepare)(struct drm_panel *panel);
 
@@ -72,6 +74,8 @@ struct drm_panel_funcs {
 	 * @enable:
 	 *
 	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*enable)(struct drm_panel *panel);
 
@@ -79,6 +83,8 @@ struct drm_panel_funcs {
 	 * @disable:
 	 *
 	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*disable)(struct drm_panel *panel);
 
@@ -86,14 +92,20 @@ struct drm_panel_funcs {
 	 * @unprepare:
 	 *
 	 * Turn off panel.
+	 *
+	 * This function is optional.
 	 */
 	int (*unprepare)(struct drm_panel *panel);
 
 	/**
 	 * @get_modes:
 	 *
-	 * Add modes to the connector that the panel is attached to and
-	 * return the number of modes added.
+	 * Add modes to the connector that the panel is attached to.
+	 *
+	 * This function is mandatory.
+	 *
+	 * Returns the number of modes added, -EOPNOTSUPP if callback
+	 * is missing, -EINVAL if panel is NULL.
 	 */
 	int (*get_modes)(struct drm_panel *panel);
 
@@ -102,6 +114,8 @@ struct drm_panel_funcs {
 	 *
 	 * Copy display timings into the provided array and return
 	 * the number of display timings available.
+	 *
+	 * This function is optional.
 	 */
 	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 			   struct display_timing *timings);
-- 
2.20.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-12-07 14:03 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-07 14:03 [PATCH v2 0/25] drm/panel infrastructure + backlight update Sam Ravnborg
2019-12-07 14:03 ` Sam Ravnborg
2019-12-07 14:03 ` Sam Ravnborg
2019-12-07 14:03 ` Sam Ravnborg
2019-12-07 14:03 ` Sam Ravnborg [this message]
2019-12-07 14:03   ` [PATCH v2 01/25] drm/drm_panel: no error when no callback Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 19:08   ` Michał Mirosław
2019-12-08  8:41     ` Sam Ravnborg
2019-12-09  0:50   ` Laurent Pinchart
2019-12-09  0:50     ` Laurent Pinchart
2019-12-09  0:50     ` Laurent Pinchart
2019-12-09  0:50     ` Laurent Pinchart
2019-12-07 14:03 ` [PATCH v2 02/25] drm/panel: add backlight support Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-09  0:55   ` Laurent Pinchart
2019-12-09  0:55     ` Laurent Pinchart
2019-12-09  0:55     ` Laurent Pinchart
2019-12-09  0:55     ` Laurent Pinchart
2019-12-13 13:30   ` Linus Walleij
2019-12-13 13:30     ` Linus Walleij
2019-12-13 13:30     ` Linus Walleij
2019-12-13 13:30     ` Linus Walleij
2019-12-13 13:30     ` Linus Walleij
2019-12-07 14:03 ` [PATCH v2 03/25] drm/panel: simple: use drm_panel " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 04/25] drm: get drm_bridge_panel connector via helper Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-10 14:48   ` [PATCH] drm/bridge: panel: export drm_panel_bridge_connector Mihail Atanassov
2019-12-10 14:48     ` Mihail Atanassov
2019-12-10 16:26     ` Laurent Pinchart
2019-12-10 16:26       ` Laurent Pinchart
2019-12-10 17:28       ` Mihail Atanassov
2019-12-10 17:28         ` Mihail Atanassov
2019-12-07 14:03 ` [PATCH v2 05/25] drm/panel: add drm_connector argument to get_modes() Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 06/25] drm/panel: decouple connector from drm_panel Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 07/25] drm/panel: drop drm_device " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 08/25] drm/panel: feiyang-fy07024di26a30d: use drm_panel backlight support Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 09/25] drm/panel: ilitek-ili9881c: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 10/25] drm/panel: innolux-p079zca: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 11/25] drm/panel: kingdisplay-kd097d04: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 12/25] drm/panel: lvds: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 13/25] drm/panel: olimex-lcd-olinuxino: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 14/25] drm/panel: osd-osd101t2587-53ts: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 15/25] drm/panel: panasonic-vvx10f034n00: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 16/25] drm/panel: raydium-rm68200: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 17/25] drm/panel: rocktech-jh057n00900: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 18/25] drm/panel: ronbo-rb070d30: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 19/25] drm/panel: seiko-43wvf1g: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 20/25] drm/panel: sharp-lq101r1sx01: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 21/25] drm/panel: sharp-ls043t1le01: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 22/25] drm/panel: sitronix-st7701: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 23/25] drm/panel: sitronix-st7789v: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 24/25] drm/panel: tpo-td028ttec1: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03 ` [PATCH v2 25/25] drm/panel: tpo-tpg110: " Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-07 14:03   ` Sam Ravnborg
2019-12-09 22:04 ` [PATCH v2 0/25] drm/panel infrastructure + backlight update Sam Ravnborg
2019-12-09 22:04   ` Sam Ravnborg
2019-12-09 22:04   ` Sam Ravnborg
2019-12-09 22:04   ` Sam Ravnborg

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