[PATCH v3 12/38] drm/msm/dp: introduce max_streams for DP controller MST support

[Yongxing Mou]

From: Abhinav Kumar <quic_abhin...@quicinc.com>

Introduce the `mst_streams` field in each DP controller descriptor to
specify the number of supported MST streams. Most platforms support 2 or
4 MST streams, while platforms without MST support default to a single
stream (`DEFAULT_STREAM_COUNT = 1`).

This change also accounts for platforms with asymmetric stream support,
e.g., DP0 supporting 4 streams and DP1 supporting 2.

Signed-off-by: Abhinav Kumar <quic_abhin...@quicinc.com>
Signed-off-by: Yongxing Mou <yongxing....@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 21 +++++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_display.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c 
b/drivers/gpu/drm/msm/dp/dp_display.c
index 
78d932bceb581ee54116926506b1025bd159108f..a8477a0a180137f15cbb1401c3964636aa32626c
 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -33,6 +33,7 @@ module_param(psr_enabled, bool, 0);
 MODULE_PARM_DESC(psr_enabled, "enable PSR for eDP and DP displays");
 
 #define HPD_STRING_SIZE 30
+#define DEFAULT_STREAM_COUNT 1
 
 enum {
        ISR_DISCONNECTED,
@@ -52,6 +53,7 @@ struct msm_dp_display_private {
        bool core_initialized;
        bool phy_initialized;
        bool audio_supported;
+       bool mst_supported;
 
        struct drm_device *drm_dev;
 
@@ -84,12 +86,15 @@ struct msm_dp_display_private {
 
        void __iomem *p0_base;
        size_t p0_len;
+
+       int max_stream;
 };
 
 struct msm_dp_desc {
        phys_addr_t io_start;
        unsigned int id;
        bool wide_bus_supported;
+       int mst_streams;
 };
 
 static const struct msm_dp_desc msm_dp_desc_sa8775p[] = {
@@ -1213,6 +1218,15 @@ static int msm_dp_display_get_io(struct 
msm_dp_display_private *display)
        return 0;
 }
 
+int msm_dp_get_mst_max_stream(struct msm_dp *msm_dp_display)
+{
+       struct msm_dp_display_private *dp;
+
+       dp = container_of(msm_dp_display, struct msm_dp_display_private, 
msm_dp_display);
+
+       return dp->max_stream;
+}
+
 static int msm_dp_display_probe(struct platform_device *pdev)
 {
        int rc = 0;
@@ -1239,6 +1253,13 @@ static int msm_dp_display_probe(struct platform_device 
*pdev)
        dp->msm_dp_display.is_edp =
                (dp->msm_dp_display.connector_type == DRM_MODE_CONNECTOR_eDP);
        dp->hpd_isr_status = 0;
+       dp->max_stream = DEFAULT_STREAM_COUNT;
+       dp->mst_supported = FALSE;
+
+       if (desc->mst_streams > DEFAULT_STREAM_COUNT) {
+               dp->max_stream = desc->mst_streams;
+               dp->mst_supported = TRUE;
+       }
 
        rc = msm_dp_display_get_io(dp);
        if (rc)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h 
b/drivers/gpu/drm/msm/dp/dp_display.h
index 
37c6e87db90ce951274cdae61f26d76dc9ef3840..7727cf325a89b4892d2370a5616c4fa76fc88485
 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -29,6 +29,7 @@ struct msm_dp {
        bool psr_supported;
 };
 
+int msm_dp_get_mst_max_stream(struct msm_dp *msm_dp_display);
 int msm_dp_display_get_modes(struct msm_dp *msm_dp_display);
 bool msm_dp_display_check_video_test(struct msm_dp *msm_dp_display);
 int msm_dp_display_get_test_bpp(struct msm_dp *msm_dp_display);

-- 
2.34.1