platform/surface: aggregator_tabletsw: Add support for Type-Cover posture source

Implement support for the Type-Cover posture source (ID 0x00), found on
the Surface Pro 9.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20230304194611.87770-3-luzmaximilian@gmail.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/surface/surface_aggregator_tabletsw.c

@@ -325,9 +325,18 @@ MODULE_PARM_DESC(tablet_mode_in_slate_state, "Enable tablet mode in slate device
 #define SSAM_POS_MAX_SOURCES			4
 
 enum ssam_pos_source_id {
+	SSAM_POS_SOURCE_COVER = 0x00,
 	SSAM_POS_SOURCE_SLS   = 0x03,
 };
 
+enum ssam_pos_state_cover {
+	SSAM_POS_COVER_DISCONNECTED  = 0x01,
+	SSAM_POS_COVER_CLOSED        = 0x02,
+	SSAM_POS_COVER_LAPTOP        = 0x03,
+	SSAM_POS_COVER_FOLDED_CANVAS = 0x04,
+	SSAM_POS_COVER_FOLDED_BACK   = 0x05,
+};
+
 enum ssam_pos_state_sls {
 	SSAM_POS_SLS_LID_CLOSED = 0x00,
 	SSAM_POS_SLS_LAPTOP     = 0x01,
@@ -340,6 +349,30 @@ struct ssam_sources_list {
 	__le32 id[SSAM_POS_MAX_SOURCES];
 } __packed;
 
+static const char *ssam_pos_state_name_cover(struct ssam_tablet_sw *sw, u32 state)
+{
+	switch (state) {
+	case SSAM_POS_COVER_DISCONNECTED:
+		return "disconnected";
+
+	case SSAM_POS_COVER_CLOSED:
+		return "closed";
+
+	case SSAM_POS_COVER_LAPTOP:
+		return "laptop";
+
+	case SSAM_POS_COVER_FOLDED_CANVAS:
+		return "folded-canvas";
+
+	case SSAM_POS_COVER_FOLDED_BACK:
+		return "folded-back";
+
+	default:
+		dev_warn(&sw->sdev->dev, "unknown device posture for type-cover: %u\n", state);
+		return "<unknown>";
+	}
+}
+
 static const char *ssam_pos_state_name_sls(struct ssam_tablet_sw *sw, u32 state)
 {
 	switch (state) {
@@ -365,6 +398,9 @@ static const char *ssam_pos_state_name(struct ssam_tablet_sw *sw,
 				       const struct ssam_tablet_sw_state *state)
 {
 	switch (state->source) {
+	case SSAM_POS_SOURCE_COVER:
+		return ssam_pos_state_name_cover(sw, state->state);
+
 	case SSAM_POS_SOURCE_SLS:
 		return ssam_pos_state_name_sls(sw, state->state);
 
@@ -374,6 +410,24 @@ static const char *ssam_pos_state_name(struct ssam_tablet_sw *sw,
 	}
 }
 
+static bool ssam_pos_state_is_tablet_mode_cover(struct ssam_tablet_sw *sw, u32 state)
+{
+	switch (state) {
+	case SSAM_POS_COVER_DISCONNECTED:
+	case SSAM_POS_COVER_FOLDED_CANVAS:
+	case SSAM_POS_COVER_FOLDED_BACK:
+		return true;
+
+	case SSAM_POS_COVER_CLOSED:
+	case SSAM_POS_COVER_LAPTOP:
+		return false;
+
+	default:
+		dev_warn(&sw->sdev->dev, "unknown device posture for type-cover: %u\n", state);
+		return true;
+	}
+}
+
 static bool ssam_pos_state_is_tablet_mode_sls(struct ssam_tablet_sw *sw, u32 state)
 {
 	switch (state) {
@@ -397,6 +451,9 @@ static bool ssam_pos_state_is_tablet_mode(struct ssam_tablet_sw *sw,
 					  const struct ssam_tablet_sw_state *state)
 {
 	switch (state->source) {
+	case SSAM_POS_SOURCE_COVER:
+		return ssam_pos_state_is_tablet_mode_cover(sw, state->state);
+
 	case SSAM_POS_SOURCE_SLS:
 		return ssam_pos_state_is_tablet_mode_sls(sw, state->state);