drm/connector: Add TV standard property

The TV mode property has been around for a while now to select and get the
current TV mode output on an analog TV connector.

Despite that property name being generic, its content isn't and has been
driver-specific which makes it hard to build any generic behaviour on top
of it, both in kernel and user-space.

Let's create a new enum tv norm property, that can contain any of the
analog TV standards currently supported by kernel drivers. Each driver can
then pass in a bitmask of the modes it supports, and the property
creation function will filter out the modes not supported.

We'll then be able to phase out the older tv mode property.

Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Acked-in-principle-or-something-like-that-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v10-5-256dad125326@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

1 files changed, 121 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 06e737ed15f5..07d449736956 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -984,6 +984,17 @@ static const struct drm_prop_enum_list drm_dvi_i_subconnector_enum_list[] = {
 DRM_ENUM_NAME_FN(drm_get_dvi_i_subconnector_name,
 		 drm_dvi_i_subconnector_enum_list)
 
+static const struct drm_prop_enum_list drm_tv_mode_enum_list[] = {
+	{ DRM_MODE_TV_MODE_NTSC, "NTSC" },
+	{ DRM_MODE_TV_MODE_NTSC_443, "NTSC-443" },
+	{ DRM_MODE_TV_MODE_NTSC_J, "NTSC-J" },
+	{ DRM_MODE_TV_MODE_PAL, "PAL" },
+	{ DRM_MODE_TV_MODE_PAL_M, "PAL-M" },
+	{ DRM_MODE_TV_MODE_PAL_N, "PAL-N" },
+	{ DRM_MODE_TV_MODE_SECAM, "SECAM" },
+};
+DRM_ENUM_NAME_FN(drm_get_tv_mode_name, drm_tv_mode_enum_list)
+
 static const struct drm_prop_enum_list drm_tv_select_enum_list[] = {
 	{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
 	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
@@ -1552,6 +1563,71 @@ EXPORT_SYMBOL(drm_connector_attach_dp_subconnector_property);
  *	infoframe values is done through drm_hdmi_avi_infoframe_content_type().
  */
 
+/*
+ * TODO: Document the properties:
+ *   - left margin
+ *   - right margin
+ *   - top margin
+ *   - bottom margin
+ *   - brightness
+ *   - contrast
+ *   - flicker reduction
+ *   - hue
+ *   - mode
+ *   - overscan
+ *   - saturation
+ *   - select subconnector
+ *   - subconnector
+ */
+/**
+ * DOC: Analog TV Connector Properties
+ *
+ * TV Mode:
+ *	Indicates the TV Mode used on an analog TV connector. The value
+ *	of this property can be one of the following:
+ *
+ *	NTSC:
+ *		TV Mode is CCIR System M (aka 525-lines) together with
+ *		the NTSC Color Encoding.
+ *
+ *	NTSC-443:
+ *
+ *		TV Mode is CCIR System M (aka 525-lines) together with
+ *		the NTSC Color Encoding, but with a color subcarrier
+ *		frequency of 4.43MHz
+ *
+ *	NTSC-J:
+ *
+ *		TV Mode is CCIR System M (aka 525-lines) together with
+ *		the NTSC Color Encoding, but with a black level equal to
+ *		the blanking level.
+ *
+ *	PAL:
+ *
+ *		TV Mode is CCIR System B (aka 625-lines) together with
+ *		the PAL Color Encoding.
+ *
+ *	PAL-M:
+ *
+ *		TV Mode is CCIR System M (aka 525-lines) together with
+ *		the PAL Color Encoding.
+ *
+ *	PAL-N:
+ *
+ *		TV Mode is CCIR System N together with the PAL Color
+ *		Encoding, a color subcarrier frequency of 3.58MHz, the
+ *		SECAM color space, and narrower channels than other PAL
+ *		variants.
+ *
+ *	SECAM:
+ *
+ *		TV Mode is CCIR System B (aka 625-lines) together with
+ *		the SECAM Color Encoding.
+ *
+ *	Drivers can set up this property by calling
+ *	drm_mode_create_tv_properties().
+ */
+
 /**
  * drm_connector_attach_content_type_property - attach content-type property
  * @connector: connector to attach content type property on.
@@ -1649,6 +1725,10 @@ EXPORT_SYMBOL(drm_mode_create_tv_margin_properties);
  * responsible for allocating a list of format names and passing them to
  * this routine.
  *
+ * NOTE: This functions registers the deprecated "mode" connector
+ * property to select the analog TV mode (ie, NTSC, PAL, etc.). New
+ * drivers must use drm_mode_create_tv_properties() instead.
+ *
  * Returns:
  * 0 on success or a negative error code on failure.
  */
@@ -1690,7 +1770,6 @@ int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
 	if (drm_mode_create_tv_margin_properties(dev))
 		goto nomem;
 
-
 	if (num_modes) {
 		dev->mode_config.legacy_tv_mode_property =
 			drm_property_create(dev, DRM_MODE_PROP_ENUM,
@@ -1740,6 +1819,47 @@ nomem:
 EXPORT_SYMBOL(drm_mode_create_tv_properties_legacy);
 
 /**
+ * drm_mode_create_tv_properties - create TV specific connector properties
+ * @dev: DRM device
+ * @supported_tv_modes: Bitmask of TV modes supported (See DRM_MODE_TV_MODE_*)
+
+ * Called by a driver's TV initialization routine, this function creates
+ * the TV specific connector properties for a given device.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_mode_create_tv_properties(struct drm_device *dev,
+				  unsigned int supported_tv_modes)
+{
+	struct drm_prop_enum_list tv_mode_list[DRM_MODE_TV_MODE_MAX];
+	struct drm_property *tv_mode;
+	unsigned int i, len = 0;
+
+	if (dev->mode_config.tv_mode_property)
+		return 0;
+
+	for (i = 0; i < DRM_MODE_TV_MODE_MAX; i++) {
+		if (!(supported_tv_modes & BIT(i)))
+			continue;
+
+		tv_mode_list[len].type = i;
+		tv_mode_list[len].name = drm_get_tv_mode_name(i);
+		len++;
+	}
+
+	tv_mode = drm_property_create_enum(dev, 0, "TV mode",
+					   tv_mode_list, len);
+	if (!tv_mode)
+		return -ENOMEM;
+
+	dev->mode_config.tv_mode_property = tv_mode;
+
+	return drm_mode_create_tv_properties_legacy(dev, 0, NULL);
+}
+EXPORT_SYMBOL(drm_mode_create_tv_properties);
+
+/**
  * drm_mode_create_scaling_mode_property - create scaling mode property
  * @dev: DRM device
  *