Il 17/12/24 10:21, CK Hu (胡俊光) ha scritto:
Hi, Angelo:
On Thu, 2024-12-05 at 12:45 +0100, AngeloGioacchino Del Regno wrote:
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Add support for the newer HDMI-TX (Encoder) v2 and DDC v2 IPs
found in MediaTek's MT8195, MT8188 SoC and their variants, and
including support for display modes up to 4k60 and for HDMI
Audio, as per the HDMI 2.0 spec.
HDCP and CEC functionalities are also supported by this hardware,
but are not included in this commit and that also poses a slight
difference between the V2 and V1 controllers in how they handle
Hotplug Detection (HPD).
While the v1 controller was using the CEC controller to check
HDMI cable connection and disconnection, in this driver the v2
one does not.
This is due to the fact that on parts with v2 designs, like the
MT8195 SoC, there is one CEC controller shared between the HDMI
Transmitter (HDMI-TX) and Receiver (HDMI-RX): before eventually
adding support to use the CEC HW to wake up the HDMI controllers
it is necessary to have support for one TX, one RX *and* for both
at the same time.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
[snip]
+static void mtk_hdmi_v2_bridge_pre_enable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_state)
+{
+ struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
+ struct drm_atomic_state *state = old_state->base.state;
+ struct drm_connector_state *conn_state;
+ union phy_configure_opts opts = {
+ .dp = { .link_rate = hdmi->mode.clock * KILO }
+ };
+
+ /* Retrieve the connector through the atomic state */
+ hdmi->curr_conn = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
+
+ conn_state = drm_atomic_get_new_connector_state(state, hdmi->curr_conn);
+ if (WARN_ON(!conn_state))
+ return;
+
+ /*
+ * Preconfigure the HDMI controller and the HDMI PHY at pre_enable
+ * stage to make sure that this IP is ready and clocked before the
+ * mtk_dpi gets powered on and before it enables the output.
In patch [6/15], you does not power on DPI power in DPI driver.
Could you point out the code about 'mtk_dpi gets powered on'?
DPI gets powered on in mtk_dpi_bridge_enable() -> mtk_dpi_power_on(dpi)
Cheers,
Angelo
Regards,
CK
+ */
+ hdmi->dvi_mode = !hdmi->curr_conn->display_info.is_hdmi;
+ mtk_hdmi_v2_output_set_display_mode(hdmi, &hdmi->mode);
+
+ /* Reconfigure phy clock link with appropriate rate */
+ phy_configure(hdmi->phy, &opts);
+
+ /* Power on the PHY here to make sure that DPI_HDMI is clocked */
+ phy_power_on(hdmi->phy);
+
+ hdmi->powered = true;
+}
+
