From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
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@xxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_helper.c | 32 ++++++++++++++++++++++++++++++++
include/drm/drm_dp_helper.h | 2 ++
2 files changed, 34 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index eeaf5a7c3aa7..1f914629031e 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -822,3 +822,35 @@ 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
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 5a848e734422..6aa74f7d45b4 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -657,6 +657,8 @@ struct edp_vsc_psr {
#define EDP_VSC_PSR_UPDATE_RFB (1<<1)
#define EDP_VSC_PSR_CRC_VALUES_VALID (1<<2)
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
+
static inline int
drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
--
2.7.4
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