[PATCH 3/4] drm/i915/panel: register drm_panel and call prepare/unprepare for ICL+ DSI
Jani Nikula
jani.nikula at intel.com
Fri Jun 6 09:05:11 UTC 2025
Allocate and register a drm_panel so that drm_panel_followers can find
the panel. Pass the drm_connector::kdev device to drm_panel allocation
for matching. That's only available after drm_sysfs_connector_add(), so
we need to postpone the drm_panel allocation until .late_register()
hook.
The drm_panel framework is moving towards devm_drm_panel_alloc(). It
requires a wrapper struct, and struct intel_panel would be the natural
candidate. However, we can't postpone its allocation until
.late_register(), so we have to use __devm_drm_panel_alloc() directly
for now.
Call the drm_panel_prepare() and drm_panel_unprepare() functions for
ICL+ DSI, so that followers get notified of the panel power state
changes. This can later be expanded to VLV+ DSI and eDP.
Cc: Maxime Ripard <mripard at kernel.org>
Cc: Heikki Krogerus <heikki.krogerus at linux.intel.com>
Cc: Lee Shawn C <shawn.c.lee at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
drivers/gpu/drm/i915/display/icl_dsi.c | 4 +
.../drm/i915/display/intel_display_types.h | 4 +
drivers/gpu/drm/i915/display/intel_panel.c | 82 ++++++++++++++++++-
drivers/gpu/drm/i915/display/intel_panel.h | 4 +
4 files changed, 93 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c
index 026361354e6f..81410b3aed51 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi.c
+++ b/drivers/gpu/drm/i915/display/icl_dsi.c
@@ -1276,6 +1276,8 @@ static void gen11_dsi_enable(struct intel_atomic_state *state,
intel_backlight_enable(crtc_state, conn_state);
intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);
+ intel_panel_prepare(crtc_state, conn_state);
+
intel_crtc_vblank_on(crtc_state);
}
@@ -1409,6 +1411,8 @@ static void gen11_dsi_disable(struct intel_atomic_state *state,
{
struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
+ intel_panel_unprepare(old_conn_state);
+
/* step1: turn off backlight */
intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_OFF);
intel_backlight_disable(old_conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index ed4d743fc7c5..30c7315fc25e 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -37,6 +37,7 @@
#include <drm/drm_crtc.h>
#include <drm/drm_encoder.h>
#include <drm/drm_framebuffer.h>
+#include <drm/drm_panel.h>
#include <drm/drm_rect.h>
#include <drm/drm_vblank_work.h>
#include <drm/intel/i915_hdcp_interface.h>
@@ -384,6 +385,9 @@ struct intel_vbt_panel_data {
};
struct intel_panel {
+ /* Simple drm_panel */
+ struct drm_panel *base;
+
/* Fixed EDID for eDP and LVDS. May hold ERR_PTR for invalid EDID. */
const struct drm_edid *fixed_edid;
diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c
index 5ae302bee191..b1d549e6cf53 100644
--- a/drivers/gpu/drm/i915/display/intel_panel.c
+++ b/drivers/gpu/drm/i915/display/intel_panel.c
@@ -463,12 +463,92 @@ void intel_panel_fini(struct intel_connector *connector)
}
}
+const struct drm_panel_funcs dummy_panel_funcs = {
+};
+
int intel_panel_register(struct intel_connector *connector)
{
- return intel_backlight_device_register(connector);
+ struct intel_display *display = to_intel_display(connector);
+ struct intel_panel *panel = &connector->panel;
+ int ret;
+
+ ret = intel_backlight_device_register(connector);
+ if (ret)
+ return ret;
+
+ if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI) {
+ struct device *dev = connector->base.kdev;
+ struct drm_panel *base;
+
+ /* Sanity check. */
+ if (drm_WARN_ON(display->drm, !dev))
+ goto out;
+
+ /*
+ * We need drm_connector::kdev for allocating the panel, to make
+ * drm_panel_add_follower() lookups work. The kdev is
+ * initialized in drm_sysfs_connector_add(), just before the
+ * connector .late_register() hooks. So we can't allocate the
+ * panel at connector init time, and can't allocate struct
+ * intel_panel with a drm_panel sub-struct. For now, use
+ * __devm_drm_panel_alloc() directly.
+ *
+ * The lookups also depend on drm_connector::fwnode being set in
+ * intel_acpi_assign_connector_fwnodes(). However, if that's
+ * missing, it will gracefully lead to -EPROBE_DEFER in
+ * drm_panel_add_follower().
+ */
+ base = __devm_drm_panel_alloc(dev, sizeof(*base), 0,
+ &dummy_panel_funcs,
+ connector->base.connector_type);
+ if (IS_ERR(base)) {
+ ret = PTR_ERR(base);
+ goto err;
+ }
+
+ panel->base = base;
+
+ drm_panel_add(panel->base);
+
+ drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] Registered panel device '%s', has fwnode: %s\n",
+ connector->base.base.id, connector->base.name,
+ dev_name(dev), str_yes_no(dev_fwnode(dev)));
+ }
+
+out:
+ return 0;
+
+err:
+ intel_backlight_device_unregister(connector);
+
+ return ret;
}
void intel_panel_unregister(struct intel_connector *connector)
{
+ struct intel_panel *panel = &connector->panel;
+
+ if (panel->base)
+ drm_panel_remove(panel->base);
+
intel_backlight_device_unregister(connector);
}
+
+/* Notify followers, if any, about power being up. */
+void intel_panel_prepare(const struct intel_crtc_state *crtc_state,
+ const struct drm_connector_state *conn_state)
+{
+ struct intel_connector *connector = to_intel_connector(conn_state->connector);
+ struct intel_panel *panel = &connector->panel;
+
+ drm_panel_prepare(panel->base);
+}
+
+/* Notify followers, if any, about power going down. */
+void intel_panel_unprepare(const struct drm_connector_state *old_conn_state)
+{
+ struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
+ struct intel_panel *panel = &connector->panel;
+
+ drm_panel_unprepare(panel->base);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_panel.h b/drivers/gpu/drm/i915/display/intel_panel.h
index 3d592a4404f3..56a6412cf0fb 100644
--- a/drivers/gpu/drm/i915/display/intel_panel.h
+++ b/drivers/gpu/drm/i915/display/intel_panel.h
@@ -53,4 +53,8 @@ void intel_panel_add_vbt_sdvo_fixed_mode(struct intel_connector *connector);
void intel_panel_add_encoder_fixed_mode(struct intel_connector *connector,
struct intel_encoder *encoder);
+void intel_panel_prepare(const struct intel_crtc_state *crtc_state,
+ const struct drm_connector_state *conn_state);
+void intel_panel_unprepare(const struct drm_connector_state *old_conn_state);
+
#endif /* __INTEL_PANEL_H__ */
--
2.39.5
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