diff mbox series

[v4,4/5] drm/bridge: tc358767: Set LSCLK divider for SYSCLK to 1

Message ID 20240625120334.145320-4-marex@denx.de (mailing list archive)
State Accepted
Headers show
Series [v4,1/5] drm/bridge: tc358767: Split tc_pxl_pll_en() into parameter calculation and enablement | expand

Commit Message

Marek Vasut June 25, 2024, 12:02 p.m. UTC 
The only information in the datasheet regarding this divider is a note
in SYS_PLLPARAM register documentation which states that when LSCLK is
270 MHz, LSCLK_DIV should be 1. What should LSCLK_DIV be set to when
LSCLK is 162 MHz (for DP 1.62G mode) is unclear, but empirical test
confirms using LSCLK_DIV 1 has no adverse effects either. In the worst
case, the internal TC358767 clock would run faster.

Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: dri-devel@lists.freedesktop.org
Cc: kernel@dh-electronics.com
---
V2: No change
V3: No change
V4: - Add RB from Alexander
---
 drivers/gpu/drm/bridge/tc358767.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 19684b8400bef..0c6912bd5ec9e 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -738,7 +738,7 @@  static int tc_stream_clock_calc(struct tc_data *tc)
 static int tc_set_syspllparam(struct tc_data *tc)
 {
 	unsigned long rate;
-	u32 pllparam = SYSCLK_SEL_LSCLK | LSCLK_DIV_2;
+	u32 pllparam = SYSCLK_SEL_LSCLK | LSCLK_DIV_1;
 
 	rate = clk_get_rate(tc->refclk);
 	switch (rate) {