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>
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 8f11b87..eae5ef9 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -860,3 +860,35 @@
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