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

BugLink: https://bugs.launchpad.net/bugs/1837813
[ Upstream commit 9a63bd6fe1b5590ffa42ae2ed22ee21363293e31 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index acac2c1769ad77b9932e863f44e537e950941567..24bb6bfa36f3459e316529ff9544e990bf1d6151 100644 (file)
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -834,12 +834,11 @@ 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) {