drm: Helper for lspcon in drm_dp_dual_mode

This patch adds lspcon support in dp_dual_mode helper.
lspcon is essentially a dp->hdmi dongle with dual personality.

LS mode: It works as a passive dongle, by level shifting DP++
signals to HDMI signals, in LS mode.
PCON mode: It works as a protocol converter active dongle
in pcon mode, by converting DP++ outputs to HDMI 2.0 outputs.

This patch adds support for lspcon detection and mode set
switch operations, as a dp dual mode dongle.

v2: Addressed review comments from Ville
- add adaptor id for lspcon devices (0x08), use it to identify lspcon
- change function names
  old: drm_lspcon_get_current_mode/drm_lspcon_change_mode
  new: drm_lspcon_get_mode/drm_lspcon_set_mode
- change drm_lspcon_get_mode type to int, to match
  drm_dp_dual_mode_get_tmds_output
- change 'err' to 'ret' to match the rest of the functions
- remove pointless typecasting during call to dual_mode_read
- fix the but while setting value of data, while writing lspcon mode
- fix indentation
- change mdelay(10) -> msleep(10)
- return ETIMEDOUT instead of EFAULT, when lspcon mode change times out
- Add an empty line to separate std regs macros and lspcon regs macros
  Indent bit definition

v3: Addressed review comments from Rodrigo
- change macro name from DP_DUAL_MODE_TYPE_LSPCON to
  DP_DUAL_MODE_TYPE_HAS_DPCD for better readability
- change macro name from DP_DUAL_MODE_LSPCON_MODE_PCON to
  DP_DUAL_MODE_LSPCON_MODE_PCON for better readability
- add comment for MCA specific offsets like 0x40 and 0x41
- remove DP_DUAL_MODE_REV_TYPE2 check while checking lspcon adapter id

v4: Addressed review comments from Ville
- Fixed indentation at few places
- s/current_mode/mode
- s/reqd_mode/mode
- remove unnecessary void* cast
- remove drm_edid.h from includes
- Add a comment for _HAS_DPCD
- Fix enum description, for lspcon_mode.

v5: Rebase
v6: Rebase

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476720277-16298-1-git-send-email-shashank.sharma@intel.com

1 files changed, 26 insertions, 0 deletions

diff --git a/include/drm/drm_dp_dual_mode_helper.h b/include/drm/drm_dp_dual_mode_helper.h
index e8a9dfd0e055..55677704add8 100644
--- a/include/drm/drm_dp_dual_mode_helper.h
+++ b/include/drm/drm_dp_dual_mode_helper.h
@@ -40,6 +40,8 @@
 #define  DP_DUAL_MODE_REV_TYPE2 0x00
 #define  DP_DUAL_MODE_TYPE_MASK 0xf0
 #define  DP_DUAL_MODE_TYPE_TYPE2 0xa0
+/* This field is marked reserved in dual mode spec, used in LSPCON */
+#define  DP_DUAL_MODE_TYPE_HAS_DPCD 0x08
 #define DP_DUAL_MODE_IEEE_OUI 0x11 /* 11-13*/
 #define  DP_DUAL_IEEE_OUI_LEN 3
 #define DP_DUAL_DEVICE_ID 0x14 /* 14-19 */
@@ -55,6 +57,11 @@
 #define  DP_DUAL_MODE_CEC_ENABLE 0x01
 #define DP_DUAL_MODE_I2C_SPEED_CTRL 0x22
 
+/* LSPCON specific registers, defined by MCA */
+#define DP_DUAL_MODE_LSPCON_MODE_CHANGE		0x40
+#define DP_DUAL_MODE_LSPCON_CURRENT_MODE		0x41
+#define  DP_DUAL_MODE_LSPCON_MODE_PCON			0x1
+
 struct i2c_adapter;
 
 ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
@@ -63,6 +70,19 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
 			       u8 offset, const void *buffer, size_t size);
 
 /**
+* enum drm_lspcon_mode
+* @lspcon_mode_ls: Level shifter mode of LSPCON
+*	which drives DP++ to HDMI 1.4 conversion.
+* @lspcon_mode_pcon: Protocol converter mode of LSPCON
+*	which drives DP++ to HDMI 2.0 active conversion.
+*/
+enum drm_lspcon_mode {
+	DRM_LSPCON_MODE_INVALID,
+	DRM_LSPCON_MODE_LS,
+	DRM_LSPCON_MODE_PCON,
+};
+
+/**
  * enum drm_dp_dual_mode_type - Type of the DP dual mode adaptor
  * @DRM_DP_DUAL_MODE_NONE: No DP dual mode adaptor
  * @DRM_DP_DUAL_MODE_UNKNOWN: Could be either none or type 1 DVI adaptor
@@ -70,6 +90,7 @@ ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
  * @DRM_DP_DUAL_MODE_TYPE1_HDMI: Type 1 HDMI adaptor
  * @DRM_DP_DUAL_MODE_TYPE2_DVI: Type 2 DVI adaptor
  * @DRM_DP_DUAL_MODE_TYPE2_HDMI: Type 2 HDMI adaptor
+ * @DRM_DP_DUAL_MODE_TYPE2_LSPCON: Level shifter /protocol converter
  */
 enum drm_dp_dual_mode_type {
 	DRM_DP_DUAL_MODE_NONE,
@@ -78,6 +99,7 @@ enum drm_dp_dual_mode_type {
 	DRM_DP_DUAL_MODE_TYPE1_HDMI,
 	DRM_DP_DUAL_MODE_TYPE2_DVI,
 	DRM_DP_DUAL_MODE_TYPE2_HDMI,
+	DRM_DP_DUAL_MODE_LSPCON,
 };
 
 enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter);
@@ -89,4 +111,8 @@ int drm_dp_dual_mode_set_tmds_output(enum drm_dp_dual_mode_type type,
 				     struct i2c_adapter *adapter, bool enable);
 const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
 
+int drm_lspcon_get_mode(struct i2c_adapter *adapter,
+			enum drm_lspcon_mode *current_mode);
+int drm_lspcon_set_mode(struct i2c_adapter *adapter,
+			enum drm_lspcon_mode reqd_mode);
 #endif