[PATCH v1 08/16] drm/i915/bios: support VS/PE Override per each ddi port

["Michał Grzelak" <michal.grzelak@intel.com>]

Add helper function to check if port asks for overriding default VS/PE
tables.

Add ddi_vswing_preemph into bios_encoder_data. This is required because
every devdata needs a separate intel_ddi_buf_trans since each port can
request an override. Store buffer's pointer in ddi_vswing_preemph. Treat
setting .buf_trans to NULL as if the request was invalid.

Initialize port's buffer pointer to NULL when no VBT was provided.

Allocate intel_ddi_buf_trans buffer per port if the request is valid.
Defer index computing to occur later during override_buf_trans(). Set
the index to being not yet computed.

Deallocate buffer on driver removal when port asked for an allocation.

Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 29 +++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_bios.h |  1 +
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index f2f1a57dbdbc..016696de2870 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -77,6 +77,7 @@
 struct intel_bios_encoder_data {
 	struct intel_display *display;
 
+	struct ddi_vswing_preemph vswing_preemph;
 	struct child_device_config child;
 	struct dsc_compression_parameters_entry *dsc;
 	struct list_head node;
@@ -2758,6 +2759,20 @@ static void sanitize_hdmi_level_shift(struct intel_bios_encoder_data *devdata,
 	}
 }
 
+static void override_vswing_preemph(struct intel_bios_encoder_data *devdata)
+{
+	struct intel_ddi_buf_trans *buf_trans;
+
+	devdata->vswing_preemph.buf_trans = NULL;
+	devdata->vswing_preemph.index = (union ddi_vswing_preemph_index) -1;
+
+	if (!intel_bios_encoder_overrides_vswing(devdata))
+		return;
+
+	buf_trans = kzalloc(sizeof(*buf_trans), GFP_KERNEL);
+	devdata->vswing_preemph.buf_trans = buf_trans;
+}
+
 static bool
 intel_bios_encoder_supports_crt(const struct intel_bios_encoder_data *devdata)
 {
@@ -2949,6 +2964,7 @@ static void parse_ddi_port(struct intel_bios_encoder_data *devdata)
 	sanitize_dedicated_external(devdata, port);
 	sanitize_device_type(devdata, port);
 	sanitize_hdmi_level_shift(devdata, port);
+	override_vswing_preemph(devdata);
 }
 
 static bool has_ddi_port_info(struct intel_display *display)
@@ -3157,6 +3173,9 @@ init_vbt_missing_defaults(struct intel_display *display)
 			break;
 
 		devdata->display = display;
+		devdata->vswing_preemph.buf_trans = NULL;
+		devdata->vswing_preemph.index =
+			(union ddi_vswing_preemph_index) -1;
 		child = &devdata->child;
 
 		if (port == PORT_F)
@@ -3490,6 +3509,10 @@ void intel_bios_driver_remove(struct intel_display *display)
 				 node) {
 		list_del(&devdata->node);
 		kfree(devdata->dsc);
+
+		if (devdata->vswing_preemph.buf_trans)
+			kfree(devdata->vswing_preemph.buf_trans);
+
 		kfree(devdata);
 	}
 
@@ -3937,6 +3960,12 @@ bool intel_bios_encoder_supports_tbt(const struct intel_bios_encoder_data *devda
 	return devdata->display->vbt.version >= 209 && devdata->child.tbt;
 }
 
+bool intel_bios_encoder_overrides_vswing(const struct intel_bios_encoder_data *devdata)
+{
+	return devdata->display->vbt.version >= 218 &&
+		devdata->child.use_vbt_vswing;
+}
+
 bool intel_bios_encoder_is_dedicated_external(const struct intel_bios_encoder_data *devdata)
 {
 	return devdata->display->vbt.version >= 264 &&
diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h
index 75dff27b4228..50c8fc91fbe8 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.h
+++ b/drivers/gpu/drm/i915/display/intel_bios.h
@@ -73,6 +73,7 @@ bool intel_bios_get_dsc_params(struct intel_encoder *encoder,
 const struct intel_bios_encoder_data *
 intel_bios_encoder_data_lookup(struct intel_display *display, enum port port);
 
+bool intel_bios_encoder_overrides_vswing(const struct intel_bios_encoder_data *devdata);
 bool intel_bios_encoder_supports_dvi(const struct intel_bios_encoder_data *devdata);
 bool intel_bios_encoder_supports_hdmi(const struct intel_bios_encoder_data *devdata);
 bool intel_bios_encoder_supports_dp(const struct intel_bios_encoder_data *devdata);
-- 
2.45.2