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authorVille Syrjälä <ville.syrjala@linux.intel.com>2016-05-18 11:57:29 +0300
committerDave Airlie <airlied@redhat.com>2016-08-03 00:06:28 +0300
commit6608804b3d7f0552a38641b03a4e3aa1852df15b (patch)
tree4baee53c0298921f701a4969d49cea587b9a0da1 /drivers/gpu
parent44cee85a8824464e7e951e590243c2a85d79c494 (diff)
downloadlinux-6608804b3d7f0552a38641b03a4e3aa1852df15b.tar.xz
drm/dp: Add drm_dp_psr_setup_time()
Add a small helper to parse the PSR setup time from the DPCD PSR capabilities and return the value in microseconds. v2: Don't waste so many bytes on the psr_setup_time_us[] table Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/drm_dp_helper.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 8f11b8741e42..eae5ef963cb7 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -860,3 +860,35 @@ void drm_dp_aux_unregister(struct drm_dp_aux *aux)
i2c_del_adapter(&aux->ddc);
}
EXPORT_SYMBOL(drm_dp_aux_unregister);
+
+#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)
+
+/**
+ * drm_dp_psr_setup_time() - PSR setup in time usec
+ * @psr_cap: PSR capabilities from DPCD
+ *
+ * Returns:
+ * PSR setup time for the panel in microseconds, negative
+ * error code on failure.
+ */
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
+{
+ static const u16 psr_setup_time_us[] = {
+ PSR_SETUP_TIME(330),
+ PSR_SETUP_TIME(275),
+ PSR_SETUP_TIME(165),
+ PSR_SETUP_TIME(110),
+ PSR_SETUP_TIME(55),
+ PSR_SETUP_TIME(0),
+ };
+ int i;
+
+ i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT;
+ if (i >= ARRAY_SIZE(psr_setup_time_us))
+ return -EINVAL;
+
+ return psr_setup_time_us[i];
+}
+EXPORT_SYMBOL(drm_dp_psr_setup_time);
+
+#undef PSR_SETUP_TIME