drm/dp: Allow registering AUX channels as I2C busses

[karo-tx-linux.git] / include / drm / drm_dp_helper.h

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index a78711feb0d1241ad853c645ff52569b92534c7a..b7488c9849ad7bb05b50c4242b43bc65f50a2839 100644 (file)
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -291,6 +291,7 @@
 #define DP_SET_POWER                        0x600
 # define DP_SET_POWER_D0                    0x1
 # define DP_SET_POWER_D3                    0x2
+# define DP_SET_POWER_MASK                  0x3
 
 #define DP_PSR_ERROR_STATUS                 0x2006  /* XXX 1.2? */
 # define DP_PSR_LINK_CRC_ERROR              (1 << 0)
@@ -420,6 +421,7 @@ struct drm_dp_aux_msg {
 
 /**
  * struct drm_dp_aux - DisplayPort AUX channel
+ * @ddc: I2C adapter that can be used for I2C-over-AUX communication
  * @dev: pointer to struct device that is the parent for this AUX channel
  * @transfer: transfers a message representing a single AUX transaction
  *
@@ -434,8 +436,16 @@ struct drm_dp_aux_msg {
  * propagate errors from the .transfer() function, with the exception of
  * the -EBUSY error, which causes a transaction to be retried. On a short,
  * helpers will return -EPROTO to make it simpler to check for failure.
+ *
+ * An AUX channel can also be used to transport I2C messages to a sink. A
+ * typical application of that is to access an EDID that's present in the
+ * sink device. The .transfer() function can also be used to execute such
+ * transactions. The drm_dp_aux_register_i2c_bus() function registers an
+ * I2C adapter that can be passed to drm_probe_ddc(). Upon removal, drivers
+ * should call drm_dp_aux_unregister_i2c_bus() to remove the I2C adapter.
  */
 struct drm_dp_aux {
+       struct i2c_adapter ddc;
        struct device *dev;
 
        ssize_t (*transfer)(struct drm_dp_aux *aux,
@@ -480,4 +490,23 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
                                 u8 status[DP_LINK_STATUS_SIZE]);
 
+/*
+ * DisplayPort link
+ */
+#define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
+
+struct drm_dp_link {
+       unsigned char revision;
+       unsigned int rate;
+       unsigned int num_lanes;
+       unsigned long capabilities;
+};
+
+int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
+int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
+int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
+
+int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux);
+void drm_dp_aux_unregister_i2c_bus(struct drm_dp_aux *aux);
+
 #endif /* _DRM_DP_HELPER_H_ */