From 16b6bde90baa67b199ac64e4e1c6446188cf4250 Mon Sep 17 00:00:00 2001
From: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Date: Tue, 15 Dec 2020 11:13:09 -0800
Subject: drm/kmb: Work around for higher system clock
Git-commit: 3e4c31e8f70251732529a10934355084c7fab0ac
Patch-mainline: v5.15-rc7
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Use a different value for system clock offset in the
ppl/llp ratio calculations for clocks higher than 500 Mhz.
Fixes: 98521f4d4b4c ("drm/kmb: Mipi DSI part of the display driver")
Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211013233632.471892-1-anitha.chrisanthus@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/kmb/kmb_dsi.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/kmb/kmb_dsi.c b/drivers/gpu/drm/kmb/kmb_dsi.c
index 1793cd31b117..86e8e7943e89 100644
--- a/drivers/gpu/drm/kmb/kmb_dsi.c
+++ b/drivers/gpu/drm/kmb/kmb_dsi.c
@@ -482,6 +482,10 @@ static u32 mipi_tx_fg_section_cfg(struct kmb_dsi *kmb_dsi,
return 0;
}
+#define CLK_DIFF_LOW 50
+#define CLK_DIFF_HI 60
+#define SYSCLK_500 500
+
static void mipi_tx_fg_cfg_regs(struct kmb_dsi *kmb_dsi, u8 frame_gen,
struct mipi_tx_frame_timing_cfg *fg_cfg)
{
@@ -492,7 +496,12 @@ static void mipi_tx_fg_cfg_regs(struct kmb_dsi *kmb_dsi, u8 frame_gen,
/* 500 Mhz system clock minus 50 to account for the difference in
* MIPI clock speed in RTL tests
*/
- sysclk = kmb_dsi->sys_clk_mhz - 50;
+ if (kmb_dsi->sys_clk_mhz == SYSCLK_500) {
+ sysclk = kmb_dsi->sys_clk_mhz - CLK_DIFF_LOW;
+ } else {
+ /* 700 Mhz clk*/
+ sysclk = kmb_dsi->sys_clk_mhz - CLK_DIFF_HI;
+ }
/* PPL-Pixel Packing Layer, LLP-Low Level Protocol
* Frame genartor timing parameters are clocked on the system clock,
--
2.38.1