drm/bridge: tc358767: fix initial DP0/1_SRCCTRL value

Initially DP0_SRCCTRL is set to a static value which includes
DP0_SRCCTRL_LANES_2 and DP0_SRCCTRL_BW27, even when only 1 lane of
1.62Gbps speed is used. DP1_SRCCTRL is configured to a magic number.

This patch changes the configuration as follows:

Configure DP0_SRCCTRL by using tc_srcctrl() which provides the correct
value.

DP1_SRCCTRL needs two bits to be set to the same value as DP0_SRCCTRL:
SSCG and BW27. All other bits can be zero.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190103115954.12785-5-tomi.valkeinen@ti.com

drivers/gpu/drm/bridge/tc358767.c

@@ -836,12 +836,11 @@ static int tc_main_link_setup(struct tc_data *tc)
 	if (!tc->mode)
 		return -EINVAL;
 
-	/* from excel file - DP0_SrcCtrl */
-	tc_write(DP0_SRCCTRL, DP0_SRCCTRL_SCRMBLDIS | DP0_SRCCTRL_EN810B |
-		 DP0_SRCCTRL_LANESKEW | DP0_SRCCTRL_LANES_2 |
-		 DP0_SRCCTRL_BW27 | DP0_SRCCTRL_AUTOCORRECT);
-	/* from excel file - DP1_SrcCtrl */
-	tc_write(DP1_SRCCTRL, 0x00003083);
+	tc_write(DP0_SRCCTRL, tc_srcctrl(tc));
+	/* SSCG and BW27 on DP1 must be set to the same as on DP0 */
+	tc_write(DP1_SRCCTRL,
+		 (tc->link.spread ? DP0_SRCCTRL_SSCG : 0) |
+		 ((tc->link.base.rate != 162000) ? DP0_SRCCTRL_BW27 : 0));
 
 	rate = clk_get_rate(tc->refclk);
 	switch (rate) {