[PATCH v11 0/4] Panel rotation patches

[PATCH v11 0/4] Panel rotation patches

[Dmitry Osipenko]

Hello!

This series adds support for display panel's DT rotation property. It's a
continuation of the work that was initially started by Derek Basehore for
the panel driver that is used by some Mediatek device [1]. I picked up the
Derek's patches and added my t-b and r-b tags to them, I also added
rotation support to the panel-lvds and panel-simple drivers.

We need the rotation support for the Nexus 7 tablet device which is pending
to become supported by upstream kernel, the device has display panel mounted
upside-down and it uses panel-lvds [2].

[1] https://lkml.org/lkml/2020/3/5/1119
[2] https://patchwork.ozlabs.org/project/linux-tegra/patch/20200607154327.18589-3-digetx@gmail.com/

Changelog:

v11: - This series is factored out from this patchset [3] because these
       patches do not have hard dependency on the Tegra DRM patches and
       it should be nicer to review and apply the properly grouped patches.

     - Initially [3] only touched the panel-lvds driver and Emil Velikov
       suggested that it will be better to support more panels in the review
       comments to [3]. So I included the Derek's patch for the BOE panel
       and added rotation support to the panel-simple driver. I tested that
       panel-lvds and panel-simple work properly with the rotated panel using
       the Opentegra Xorg driver [4] and Wayland Weston [5].

     - The panel-lvds driver now prints a error message if rotation property
       fails to be parsed.

[3] https://lore.kernel.org/lkml/20200614200121.14147-1-digetx@gmail.com/
[4] https://github.com/grate-driver/xf86-video-opentegra/commit/28eb20a3959bbe5bc3a3b67e55977093fd5114ca
[5] https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/315

Derek Basehore (2):
  drm/panel: Add helper for reading DT rotation
  drm/panel: Read panel orientation for BOE TV101WUM-NL6

Dmitry Osipenko (2):
  drm/panel: lvds: Read panel orientation
  drm/panel-simple: Read panel orientation

 drivers/gpu/drm/drm_panel.c                   | 43 +++++++++++++++++++
 .../gpu/drm/panel/panel-boe-tv101wum-nl6.c    |  6 +++
 drivers/gpu/drm/panel/panel-lvds.c            | 10 +++++
 drivers/gpu/drm/panel/panel-simple.c          | 11 +++++
 include/drm/drm_panel.h                       |  9 ++++
 5 files changed, 79 insertions(+)

-- 
2.26.0

[PATCH v11 1/4] drm/panel: Add helper for reading DT rotation

[Dmitry Osipenko]

From: Derek Basehore <dbasehore@chromium.org>

This adds a helper function for reading the rotation (panel
orientation) from the device tree.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
 drivers/gpu/drm/drm_panel.c | 43 +++++++++++++++++++++++++++++++++++++
 include/drm/drm_panel.h     |  9 ++++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 8c7bac85a793..5557c75301f1 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -300,6 +300,49 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
 	return ERR_PTR(-EPROBE_DEFER);
 }
 EXPORT_SYMBOL(of_drm_find_panel);
+
+/**
+ * of_drm_get_panel_orientation - look up the orientation of the panel through
+ * the "rotation" binding from a device tree node
+ * @np: device tree node of the panel
+ * @orientation: orientation enum to be filled in
+ *
+ * Looks up the rotation of a panel in the device tree. The orientation of the
+ * panel is expressed as a property name "rotation" in the device tree. The
+ * rotation in the device tree is counter clockwise.
+ *
+ * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
+ * rotation property doesn't exist. -EERROR otherwise.
+ */
+int of_drm_get_panel_orientation(const struct device_node *np,
+				 enum drm_panel_orientation *orientation)
+{
+	int rotation, ret;
+
+	ret = of_property_read_u32(np, "rotation", &rotation);
+	if (ret == -EINVAL) {
+		/* Don't return an error if there's no rotation property. */
+		*orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+		return 0;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	if (rotation == 0)
+		*orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL;
+	else if (rotation == 90)
+		*orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP;
+	else if (rotation == 180)
+		*orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP;
+	else if (rotation == 270)
+		*orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(of_drm_get_panel_orientation);
 #endif
 
 #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 6193cb555acc..781c735f0f9b 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -35,6 +35,8 @@ struct drm_device;
 struct drm_panel;
 struct display_timing;
 
+enum drm_panel_orientation;
+
 /**
  * struct drm_panel_funcs - perform operations on a given panel
  *
@@ -191,11 +193,18 @@ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector
 
 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 struct drm_panel *of_drm_find_panel(const struct device_node *np);
+int of_drm_get_panel_orientation(const struct device_node *np,
+				 enum drm_panel_orientation *orientation);
 #else
 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 {
 	return ERR_PTR(-ENODEV);
 }
+static inline int of_drm_get_panel_orientation(const struct device_node *np,
+		enum drm_panel_orientation *orientation)
+{
+	return -ENODEV;
+}
 #endif
 
 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
-- 
2.26.0

[PATCH v11 2/4] drm/panel: Read panel orientation for BOE TV101WUM-NL6

[Dmitry Osipenko]

From: Derek Basehore <dbasehore@chromium.org>

This reads the DT setting for the panel rotation to set the panel
orientation in the get_modes callback.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
---
 drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
index db5b866357f2..4bd9397972e8 100644
--- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
+++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
@@ -11,6 +11,7 @@
 #include <linux/of_device.h>
 #include <linux/regulator/consumer.h>
 
+#include <drm/drm_connector.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_panel.h>
@@ -43,6 +44,7 @@ struct boe_panel {
 
 	const struct panel_desc *desc;
 
+	enum drm_panel_orientation orientation;
 	struct regulator *pp1800;
 	struct regulator *avee;
 	struct regulator *avdd;
@@ -740,6 +742,7 @@ static int boe_panel_get_modes(struct drm_panel *panel,
 	connector->display_info.width_mm = boe->desc->size.width_mm;
 	connector->display_info.height_mm = boe->desc->size.height_mm;
 	connector->display_info.bpc = boe->desc->bpc;
+	drm_connector_set_panel_orientation(connector, boe->orientation);
 
 	return 1;
 }
@@ -779,6 +782,9 @@ static int boe_panel_add(struct boe_panel *boe)
 
 	drm_panel_init(&boe->base, dev, &boe_panel_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
+	err = of_drm_get_panel_orientation(dev->of_node, &boe->orientation);
+	if (err < 0)
+		return err;
 
 	err = drm_panel_of_backlight(&boe->base);
 	if (err)
-- 
2.26.0

[PATCH v11 3/4] drm/panel: lvds: Read panel orientation

[Dmitry Osipenko]

The panel orientation needs to parsed from a device-tree and assigned to
the panel's connector in order to make orientation property available to
userspace. That's what this patch does for the generic LVDS panel.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/panel/panel-lvds.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-lvds.c b/drivers/gpu/drm/panel/panel-lvds.c
index 5ce3f4a2b7a1..f62227059090 100644
--- a/drivers/gpu/drm/panel/panel-lvds.c
+++ b/drivers/gpu/drm/panel/panel-lvds.c
@@ -37,6 +37,8 @@ struct panel_lvds {
 
 	struct gpio_desc *enable_gpio;
 	struct gpio_desc *reset_gpio;
+
+	enum drm_panel_orientation orientation;
 };
 
 static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
@@ -99,6 +101,7 @@ static int panel_lvds_get_modes(struct drm_panel *panel,
 	connector->display_info.bus_flags = lvds->data_mirror
 					  ? DRM_BUS_FLAG_DATA_LSB_TO_MSB
 					  : DRM_BUS_FLAG_DATA_MSB_TO_LSB;
+	drm_connector_set_panel_orientation(connector, lvds->orientation);
 
 	return 1;
 }
@@ -116,6 +119,13 @@ static int panel_lvds_parse_dt(struct panel_lvds *lvds)
 	const char *mapping;
 	int ret;
 
+	ret = of_drm_get_panel_orientation(np, &lvds->orientation);
+	if (ret < 0) {
+		dev_err(lvds->dev, "%pOF: problems parsing rotation (%d)\n",
+			np, ret);
+		return ret;
+	}
+
 	ret = of_get_display_timing(np, "panel-timing", &timing);
 	if (ret < 0) {
 		dev_err(lvds->dev, "%pOF: problems parsing panel-timing (%d)\n",
-- 
2.26.0

[PATCH v11 4/4] drm/panel-simple: Read panel orientation

[Dmitry Osipenko]

The panel orientation needs to parsed from a device-tree and assigned to
the panel's connector in order to make orientation property available to
userspace. That's what this patch does for the panel-simple driver.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 6764ac630e22..2dee1320216c 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -112,6 +112,8 @@ struct panel_simple {
 	struct gpio_desc *hpd_gpio;
 
 	struct drm_display_mode override_mode;
+
+	enum drm_panel_orientation orientation;
 };
 
 static inline struct panel_simple *to_panel_simple(struct drm_panel *panel)
@@ -371,6 +373,9 @@ static int panel_simple_get_modes(struct drm_panel *panel,
 	/* add hard-coded panel modes */
 	num += panel_simple_get_non_edid_modes(p, connector);
 
+	/* set up connector's "panel orientation" property */
+	drm_connector_set_panel_orientation(connector, p->orientation);
+
 	return num;
 }
 
@@ -530,6 +535,12 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
 		return err;
 	}
 
+	err = of_drm_get_panel_orientation(dev->of_node, &panel->orientation);
+	if (err) {
+		dev_err(dev, "failed to parse rotation property: %d\n", err);
+		return err;
+	}
+
 	ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
 	if (ddc) {
 		panel->ddc = of_find_i2c_adapter_by_node(ddc);
-- 
2.26.0

Re: [PATCH v11 1/4] drm/panel: Add helper for reading DT rotation

[Dmitry Osipenko]

18.06.2020 02:18, Dmitry Osipenko пишет:
> From: Derek Basehore <dbasehore@chromium.org>
> 
> This adds a helper function for reading the rotation (panel
> orientation) from the device tree.
> 
> Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> ---

My t-b accidentally got lost after rebase, here it is:

Tested-by: Dmitry Osipenko <digetx@gmail.com>

Re: [PATCH v11 0/4] Panel rotation patches

[Dmitry Osipenko]

18.06.2020 02:18, Dmitry Osipenko пишет:
> Hello!
> 
> This series adds support for display panel's DT rotation property. It's a
> continuation of the work that was initially started by Derek Basehore for
> the panel driver that is used by some Mediatek device [1]. I picked up the
> Derek's patches and added my t-b and r-b tags to them, I also added
> rotation support to the panel-lvds and panel-simple drivers.
> 
> We need the rotation support for the Nexus 7 tablet device which is pending
> to become supported by upstream kernel, the device has display panel mounted
> upside-down and it uses panel-lvds [2].
> 
> [1] https://lkml.org/lkml/2020/3/5/1119
> [2] https://patchwork.ozlabs.org/project/linux-tegra/patch/20200607154327.18589-3-digetx@gmail.com/
> 
> Changelog:
> 
> v11: - This series is factored out from this patchset [3] because these
>        patches do not have hard dependency on the Tegra DRM patches and
>        it should be nicer to review and apply the properly grouped patches.
> 
>      - Initially [3] only touched the panel-lvds driver and Emil Velikov
>        suggested that it will be better to support more panels in the review
>        comments to [3]. So I included the Derek's patch for the BOE panel
>        and added rotation support to the panel-simple driver. I tested that
>        panel-lvds and panel-simple work properly with the rotated panel using
>        the Opentegra Xorg driver [4] and Wayland Weston [5].
> 
>      - The panel-lvds driver now prints a error message if rotation property
>        fails to be parsed.
> 
> [3] https://lore.kernel.org/lkml/20200614200121.14147-1-digetx@gmail.com/
> [4] https://github.com/grate-driver/xf86-video-opentegra/commit/28eb20a3959bbe5bc3a3b67e55977093fd5114ca
> [5] https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/315
> 
> Derek Basehore (2):
>   drm/panel: Add helper for reading DT rotation
>   drm/panel: Read panel orientation for BOE TV101WUM-NL6
> 
> Dmitry Osipenko (2):
>   drm/panel: lvds: Read panel orientation
>   drm/panel-simple: Read panel orientation
> 
>  drivers/gpu/drm/drm_panel.c                   | 43 +++++++++++++++++++
>  .../gpu/drm/panel/panel-boe-tv101wum-nl6.c    |  6 +++
>  drivers/gpu/drm/panel/panel-lvds.c            | 10 +++++
>  drivers/gpu/drm/panel/panel-simple.c          | 11 +++++
>  include/drm/drm_panel.h                       |  9 ++++
>  5 files changed, 79 insertions(+)
> 

Hi! Does anyone have any comments to this patchset? Will be nice if it
could get into 5.9 :) Thanks in advance!