Re: [PATCH RESEND] drm/bridge: tc358764: restore connector support

Hi Marek.

On Wed, Sep 30, 2020 at 01:40:42PM +0200, Marek Szyprowski wrote:

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

Thanks for providing the revert so we can have this fixed in upstream. So far I have had no time to dive deeper into what is going wrong but and the revert is the right cause of action for now.

I expect Andrzej to pick it up as he has already reviewed it.

Sam

---

As I've reported and Andrzej Hajda pointed, the reverted patches break operation of the panel on the Arndale board. Noone suggested how to fix the regression, I've decided to send a revert until a new solution is found.

The issues with tc358764 might be automatically resolved once the Exynos DSI itself is converted to DRM bridge: https://patchwork.kernel.org/cover/11770683/ but that approach has also its own issues so far.

Resend reason: added Sam Ravnborg to CC:

Best regards, Marek Szyprowski

---

drivers/gpu/drm/bridge/tc358764.c | 107 +++++++++++++++++++++++++----- 1 file changed, 92 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358764.c b/drivers/gpu/drm/bridge/tc358764.c index d89394bc5aa4..c1e35bdf9232 100644 --- 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);

-- 2.17.1