drm: rcar-du: Add support for LVDS mode selection

Retrieve the LVDS mode from the panel and configure the LVDS encoder
accordingly. LVDS mode selection is static as LVDS panels can't be
hot-plugged on any of the device supported by the driver. Support for
dynamic mode selection can be implemented in the future when needed.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
index 31f878a..3a3c937 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
@@ -98,6 +98,8 @@ static void rcar_du_encoder_mode_set(struct drm_encoder *encoder,
                                     struct drm_connector_state *conn_state)
 {
        struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
+       struct drm_display_info *info = &conn_state->connector->display_info;
+       enum rcar_lvds_mode mode;
 
        rcar_du_crtc_route_output(crtc_state->crtc, renc->output);
 
@@ -111,6 +113,31 @@ static void rcar_du_encoder_mode_set(struct drm_encoder *encoder,
        }
 
        renc->connector = to_rcar_connector(conn_state->connector);
+
+       if (!info->num_bus_formats || !info->bus_formats) {
+               dev_err(encoder->dev->dev, "no LVDS bus format reported\n");
+               return;
+       }
+
+       switch (info->bus_formats[0]) {
+       case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+       case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+               mode = RCAR_LVDS_MODE_JEIDA;
+               break;
+       case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+               mode = RCAR_LVDS_MODE_VESA;
+               break;
+       default:
+               dev_err(encoder->dev->dev,
+                       "unsupported LVDS bus format 0x%04x\n",
+                       info->bus_formats[0]);
+               return;
+       }
+
+       if (info->bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
+               mode |= RCAR_LVDS_MODE_MIRROR;
+
+       rcar_du_lvdsenc_set_mode(renc->lvds, mode);
 }
 
 static const struct drm_encoder_helper_funcs encoder_helper_funcs = {

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
index e3a4985..1661f62 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
@@ -31,6 +31,7 @@ struct rcar_du_lvdsenc {
        bool enabled;
 
        enum rcar_lvds_input input;
+       enum rcar_lvds_mode mode;
 };
 
 static void rcar_lvds_write(struct rcar_du_lvdsenc *lvds, u32 reg, u32 data)
@@ -61,7 +62,7 @@ static void rcar_du_lvdsenc_start_gen2(struct rcar_du_lvdsenc *lvds,
        /* Select the input, hardcode mode 0, enable LVDS operation and turn
         * bias circuitry on.
         */
-       lvdcr0 = LVDCR0_BEN | LVDCR0_LVEN;
+       lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_BEN | LVDCR0_LVEN;
        if (rcrtc->index == 2)
                lvdcr0 |= LVDCR0_DUSEL;
        rcar_lvds_write(lvds, LVDCR0, lvdcr0);
@@ -114,7 +115,7 @@ static void rcar_du_lvdsenc_start_gen3(struct rcar_du_lvdsenc *lvds,
         * Turn the PLL on, set it to LVDS normal mode, wait for the startup
         * delay and turn the output on.
         */
-       lvdcr0 = LVDCR0_PLLON;
+       lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_PLLON;
        rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 
        lvdcr0 |= LVDCR0_PWD;
@@ -211,6 +212,12 @@ void rcar_du_lvdsenc_atomic_check(struct rcar_du_lvdsenc *lvds,
                mode->clock = clamp(mode->clock, 25175, 148500);
 }
 
+void rcar_du_lvdsenc_set_mode(struct rcar_du_lvdsenc *lvds,
+                             enum rcar_lvds_mode mode)
+{
+       lvds->mode = mode;
+}
+
 static int rcar_du_lvdsenc_get_resources(struct rcar_du_lvdsenc *lvds,
                                         struct platform_device *pdev)
 {

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
index dfdba74..7218ac8 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
@@ -26,8 +26,17 @@ enum rcar_lvds_input {
        RCAR_LVDS_INPUT_DU2,
 };
 
+/* Keep in sync with the LVDCR0.LVMD hardware register values. */
+enum rcar_lvds_mode {
+       RCAR_LVDS_MODE_JEIDA = 0,
+       RCAR_LVDS_MODE_MIRROR = 1,
+       RCAR_LVDS_MODE_VESA = 4,
+};
+
 #if IS_ENABLED(CONFIG_DRM_RCAR_LVDS)
 int rcar_du_lvdsenc_init(struct rcar_du_device *rcdu);
+void rcar_du_lvdsenc_set_mode(struct rcar_du_lvdsenc *lvds,
+                             enum rcar_lvds_mode mode);
 int rcar_du_lvdsenc_enable(struct rcar_du_lvdsenc *lvds,
                           struct drm_crtc *crtc, bool enable);
 void rcar_du_lvdsenc_atomic_check(struct rcar_du_lvdsenc *lvds,
@@ -37,6 +46,10 @@ static inline int rcar_du_lvdsenc_init(struct rcar_du_device *rcdu)
 {
        return 0;
 }
+static inline void rcar_du_lvdsenc_set_mode(struct rcar_du_lvdsenc *lvds,
+                                           enum rcar_lvds_mode mode)
+{
+}
 static inline int rcar_du_lvdsenc_enable(struct rcar_du_lvdsenc *lvds,
                                         struct drm_crtc *crtc, bool enable)
 {