drm/bridge: Prepare Analogix anx6345 support

Add bit definitions required for the anx6345 and add a
sanity check in anx_dp_aux_transfer.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Torsten Duwe <duwe@suse.de>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107135218.01C2168C4E@verein.lst.de

drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c

@@ -116,7 +116,7 @@ ssize_t anx_dp_aux_transfer(struct regmap *map_dptx,
 	else	/* For non-zero-sized set the length field. */
 		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
 
-	if ((msg->request & DP_AUX_I2C_READ) == 0) {
+	if ((msg->size > 0) && ((msg->request & DP_AUX_I2C_READ) == 0)) {
 		/* When WRITE | MOT write values to data buffer */
 		err = regmap_bulk_write(map_dptx,
 					SP_DP_BUF_DATA0_REG, buffer,

drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h

@@ -72,7 +72,11 @@
 #define SP_CHA_STA			BIT(2)
 /* Bits for DP System Control Register 3 */
 #define SP_HPD_STATUS			BIT(6)
+#define SP_HPD_FORCE			BIT(5)
+#define SP_HPD_CTRL			BIT(4)
 #define SP_STRM_VALID			BIT(2)
+#define SP_STRM_FORCE			BIT(1)
+#define SP_STRM_CTRL			BIT(0)
 /* Bits for DP System Control Register 4 */
 #define SP_ENHANCED_MODE		BIT(3)
 
@@ -117,6 +121,9 @@
 #define SP_LINK_BW_SET_MASK		0x1f
 #define SP_INITIAL_SLIM_M_AUD_SEL	BIT(5)
 
+/* DP Lane Count Setting Register */
+#define SP_DP_LANE_COUNT_SET_REG	0xa1
+
 /* DP Training Pattern Set Register */
 #define SP_DP_TRAINING_PATTERN_SET_REG	0xa2
 
@@ -130,6 +137,7 @@
 
 /* DP Link Training Control Register */
 #define SP_DP_LT_CTRL_REG		0xa8
+#define SP_DP_LT_INPROGRESS		0x80
 #define SP_LT_ERROR_TYPE_MASK		0x70
 #  define SP_LT_NO_ERROR		0x00
 #  define SP_LT_AUX_WRITE_ERROR		0x01

drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h

@@ -177,6 +177,9 @@
 #define SP_VBIT				BIT(1)
 #define SP_AUDIO_LAYOUT			BIT(0)
 
+/* Analog Debug Register 1 */
+#define SP_ANALOG_DEBUG1_REG		0xdc
+
 /* Analog Debug Register 2 */
 #define SP_ANALOG_DEBUG2_REG		0xdd
 #define SP_FORCE_SW_OFF_BYPASS		0x20