Lookup and attach ACPI nodes for intel connectors. The lookup is done in compliance with ACPI Spec 6.3 https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf (Ref: Pages 1119 - 1123).
This can be useful for any connector specific platform properties. (This will be used for privacy screen in next patch).
Signed-off-by: Rajat Jain rajatja@google.com --- v6: Addressed minor comments from Jani at https://lkml.org/lkml/2020/1/24/1143 - local variable renamed. - used drm_dbg_kms() - used acpi_device_handle() - Used opaque type acpi_handle instead of void* v5: same as v4 v4: Same as v3 v3: fold the code into existing acpi_device_id_update() function v2: formed by splitting the original patch into ACPI lookup, and privacy screen property. Also move it into i915 now that I found existing code in i915 that can be re-used.
drivers/gpu/drm/i915/display/intel_acpi.c | 24 +++++++++++++++++++ .../drm/i915/display/intel_display_types.h | 5 ++++ drivers/gpu/drm/i915/display/intel_dp.c | 3 +++ 3 files changed, 32 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c index 3e6831cca4ac1..870c1ad98df92 100644 --- a/drivers/gpu/drm/i915/display/intel_acpi.c +++ b/drivers/gpu/drm/i915/display/intel_acpi.c @@ -222,11 +222,22 @@ static u32 acpi_display_type(struct intel_connector *connector) return display_type; }
+/* + * Ref: ACPI Spec 6.3 + * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf + * Pages 1119 - 1123 describe, what I believe, a standard way of + * identifying / addressing "display panels" in the ACPI. It provides + * a way for the ACPI to define devices for the display panels attached + * to the system. It thus provides a way for the BIOS to export any panel + * specific properties to the system via ACPI (like device trees). + */ void intel_acpi_device_id_update(struct drm_i915_private *dev_priv) { struct drm_device *dev = &dev_priv->drm; struct intel_connector *connector; struct drm_connector_list_iter conn_iter; + struct acpi_device *conn_dev; + u64 conn_addr; u8 display_index[16] = {};
/* Populate the ACPI IDs for all connectors for a given drm_device */ @@ -242,6 +253,19 @@ void intel_acpi_device_id_update(struct drm_i915_private *dev_priv) device_id |= display_index[type]++ << ACPI_DISPLAY_INDEX_SHIFT;
connector->acpi_device_id = device_id; + + /* Build the _ADR to look for */ + conn_addr = device_id | ACPI_DEVICE_ID_SCHEME | + ACPI_BIOS_CAN_DETECT; + + drm_dbg_kms(dev, "Checking connector ACPI node at _ADR=%llX\n", + conn_addr); + + /* Look up the connector device, under the PCI device */ + conn_dev = acpi_find_child_device( + ACPI_COMPANION(&dev->pdev->dev), + conn_addr, false); + connector->acpi_handle = acpi_device_handle(conn_dev); } drm_connector_list_iter_end(&conn_iter); } diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 5e00e611f077f..d70612cc1ba2a 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -411,9 +411,14 @@ struct intel_connector { */ struct intel_encoder *encoder;
+#ifdef CONFIG_ACPI /* ACPI device id for ACPI and driver cooperation */ u32 acpi_device_id;
+ /* ACPI handle corresponding to this connector display, if found */ + acpi_handle acpi_handle; +#endif + /* Reads out the current hw, returning true if the connector is enabled * and active (i.e. dpms ON state). */ bool (*get_hw_state)(struct intel_connector *); diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 0a417cd2af2bc..171821113d362 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -44,6 +44,7 @@ #include "i915_debugfs.h" #include "i915_drv.h" #include "i915_trace.h" +#include "intel_acpi.h" #include "intel_atomic.h" #include "intel_audio.h" #include "intel_connector.h" @@ -6868,6 +6869,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT;
+ /* Lookup the ACPI node corresponding to the connector */ + intel_acpi_device_id_update(dev_priv); } }