drm/bridge: tc358764: restore connector support

This patch restores DRM connector registration in the TC358764 bridge
driver and restores usage of the old drm_panel_* API, thus allows dynamic
panel registration. This fixes panel operation on Exynos5250-based
Arndale board.

This is equivalent to the revert of the following commits:
1644127f83bc "drm/bridge: tc358764: add drm_panel_bridge support"
385ca38da29c "drm/bridge: tc358764: drop drm_connector_(un)register"
and removal of the calls to drm_panel_attach()/drm_panel_detach(), which
were no-ops and has been removed in meanwhile.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200930114042.5806-1-m.szyprowski@samsung.com

diff --git a/drivers/gpu/drm/bridge/tc358764.c b/drivers/gpu/drm/bridge/tc358764.c
index d89394b..c1e35bd 100644 (file)
--- a/drivers/gpu/drm/bridge/tc358764.c
+++ b/drivers/gpu/drm/bridge/tc358764.c
@@ -153,9 +153,10 @@ static const char * const tc358764_supplies[] = {
 struct tc358764 {
        struct device *dev;
        struct drm_bridge bridge;
+       struct drm_connector connector;
        struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
        struct gpio_desc *gpio_reset;
-       struct drm_bridge *panel_bridge;
+       struct drm_panel *panel;
        int error;
 };
 
@@ -209,6 +210,12 @@ static inline struct tc358764 *bridge_to_tc358764(struct drm_bridge *bridge)
        return container_of(bridge, struct tc358764, bridge);
 }
 
+static inline
+struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
+{
+       return container_of(connector, struct tc358764, connector);
+}
+
 static int tc358764_init(struct tc358764 *ctx)
 {
        u32 v = 0;
@@ -271,11 +278,43 @@ static void tc358764_reset(struct tc358764 *ctx)
        usleep_range(1000, 2000);
 }
 
+static int tc358764_get_modes(struct drm_connector *connector)
+{
+       struct tc358764 *ctx = connector_to_tc358764(connector);
+
+       return drm_panel_get_modes(ctx->panel, connector);
+}
+
+static const
+struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
+       .get_modes = tc358764_get_modes,
+};
+
+static const struct drm_connector_funcs tc358764_connector_funcs = {
+       .fill_modes = drm_helper_probe_single_connector_modes,
+       .destroy = drm_connector_cleanup,
+       .reset = drm_atomic_helper_connector_reset,
+       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static void tc358764_disable(struct drm_bridge *bridge)
+{
+       struct tc358764 *ctx = bridge_to_tc358764(bridge);
+       int ret = drm_panel_disable(bridge_to_tc358764(bridge)->panel);
+
+       if (ret < 0)
+               dev_err(ctx->dev, "error disabling panel (%d)\n", ret);
+}
+
 static void tc358764_post_disable(struct drm_bridge *bridge)
 {
        struct tc358764 *ctx = bridge_to_tc358764(bridge);
        int ret;
 
+       ret = drm_panel_unprepare(ctx->panel);
+       if (ret < 0)
+               dev_err(ctx->dev, "error unpreparing panel (%d)\n", ret);
        tc358764_reset(ctx);
        usleep_range(10000, 15000);
        ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
@@ -296,28 +335,71 @@ static void tc358764_pre_enable(struct drm_bridge *bridge)
        ret = tc358764_init(ctx);
        if (ret < 0)
                dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
+       ret = drm_panel_prepare(ctx->panel);
+       if (ret < 0)
+               dev_err(ctx->dev, "error preparing panel (%d)\n", ret);
+}
+
+static void tc358764_enable(struct drm_bridge *bridge)
+{
+       struct tc358764 *ctx = bridge_to_tc358764(bridge);
+       int ret = drm_panel_enable(ctx->panel);
+
+       if (ret < 0)
+               dev_err(ctx->dev, "error enabling panel (%d)\n", ret);
 }
 
 static int tc358764_attach(struct drm_bridge *bridge,
                           enum drm_bridge_attach_flags flags)
 {
        struct tc358764 *ctx = bridge_to_tc358764(bridge);
+       struct drm_device *drm = bridge->dev;
+       int ret;
+
+       if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
+               DRM_ERROR("Fix bridge driver to make connector optional!");
+               return -EINVAL;
+       }
+
+       ctx->connector.polled = DRM_CONNECTOR_POLL_HPD;
+       ret = drm_connector_init(drm, &ctx->connector,
+                                &tc358764_connector_funcs,
+                                DRM_MODE_CONNECTOR_LVDS);
+       if (ret) {
+               DRM_ERROR("Failed to initialize connector\n");
+               return ret;
+       }
+
+       drm_connector_helper_add(&ctx->connector,
+                                &tc358764_connector_helper_funcs);
+       drm_connector_attach_encoder(&ctx->connector, bridge->encoder);
+       ctx->connector.funcs->reset(&ctx->connector);
+       drm_connector_register(&ctx->connector);
+
+       return 0;
+}
+
+static void tc358764_detach(struct drm_bridge *bridge)
+{
+       struct tc358764 *ctx = bridge_to_tc358764(bridge);
 
-       return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
-                                bridge, flags);
+       drm_connector_unregister(&ctx->connector);
+       ctx->panel = NULL;
+       drm_connector_put(&ctx->connector);
 }
 
 static const struct drm_bridge_funcs tc358764_bridge_funcs = {
+       .disable = tc358764_disable,
        .post_disable = tc358764_post_disable,
+       .enable = tc358764_enable,
        .pre_enable = tc358764_pre_enable,
        .attach = tc358764_attach,
+       .detach = tc358764_detach,
 };
 
 static int tc358764_parse_dt(struct tc358764 *ctx)
 {
-       struct drm_bridge *panel_bridge;
        struct device *dev = ctx->dev;
-       struct drm_panel *panel;
        int ret;
 
        ctx->gpio_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
@@ -326,16 +408,12 @@ static int tc358764_parse_dt(struct tc358764 *ctx)
                return PTR_ERR(ctx->gpio_reset);
        }
 
-       ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
-       if (ret)
-               return ret;
-
-       panel_bridge = devm_drm_panel_bridge_add(dev, panel);
-       if (IS_ERR(panel_bridge))
-               return PTR_ERR(panel_bridge);
+       ret = drm_of_find_panel_or_bridge(ctx->dev->of_node, 1, 0, &ctx->panel,
+                                         NULL);
+       if (ret && ret != -EPROBE_DEFER)
+               dev_err(dev, "cannot find panel (%d)\n", ret);
 
-       ctx->panel_bridge = panel_bridge;
-       return 0;
+       return ret;
 }
 
 static int tc358764_configure_regulators(struct tc358764 *ctx)
@@ -381,7 +459,6 @@ static int tc358764_probe(struct mipi_dsi_device *dsi)
                return ret;
 
        ctx->bridge.funcs = &tc358764_bridge_funcs;
-       ctx->bridge.type = DRM_MODE_CONNECTOR_LVDS;
        ctx->bridge.of_node = dev->of_node;
 
        drm_bridge_add(&ctx->bridge);