[PATCH v3 11/12] drm/i915: Read DP branch device SW revision

[Mika Kahola]

SW revision is mandatory field for DisplayPort branch
devices. This is defined in DPCD register field 0x50A.

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 5 +++++
 include/drm/drm_dp_helper.h     | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 12ab26b..7e50d32 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3468,6 +3468,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
                                     sizeof(intel_dp->bd.hw_rev)) == 
sizeof(intel_dp->bd.hw_rev))
                        DRM_DEBUG_KMS("HW revision: %.2d.%.2d\n",
                                      intel_dp->bd.hw_rev & 0xf, 
(intel_dp->bd.hw_rev>>4) & 0xf);
+
+               if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, 
intel_dp->bd.sw_rev,
+                                    sizeof(intel_dp->bd.sw_rev)) == 
sizeof(intel_dp->bd.sw_rev))
+                       DRM_DEBUG_KMS("SW revision: %.2d.%.2d\n",
+                                     intel_dp->bd.sw_rev[0], 
intel_dp->bd.sw_rev[1]);
        }
 }

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index d0965ca..c0ca0c9 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -459,6 +459,7 @@
 #define DP_BRANCH_OUI                      0x500
 #define DP_BRANCH_ID                        0x503
 #define DP_BRANCH_HW_REV                    0x509
+#define DP_BRANCH_SW_REV                    0x50A

 #define DP_SET_POWER                        0x600
 # define DP_SET_POWER_D0                    0x1
@@ -873,6 +874,7 @@ struct drm_dp_bd {
        bool hpd;
        uint8_t id[6];
        uint8_t hw_rev;
+       uint8_t sw_rev[2];
        union {
                struct drm_dp_vga vga;
                struct drm_dp_dvi dvi;
-- 
1.9.1