drm/bridge: synopsys: dw-mipi-dsi: Use pixel clock rate to calculate lbcc

To get better accuration, use pixel clock rate to calculate lbcc instead of
lane_mbps since the pixel clock rate is in KHz while lane_mbps is in MHz.
Without this, distorted image can be seen on a HDMI monitor connected with
i.MX93 11x11 EVK through ADV7535 DSI to HDMI bridge in 1920x1080p@60 video
mode.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230821034008.3876938-6-victor.liu@nxp.com
This commit is contained in:
Liu Ying 2023-08-21 11:40:04 +08:00 committed by Robert Foss
parent 5a67ec8c64
commit ac87d23694
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@ -12,6 +12,7 @@
#include <linux/component.h>
#include <linux/debugfs.h>
#include <linux/iopoll.h>
#include <linux/math64.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/platform_device.h>
@ -764,8 +765,15 @@ static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi,
u32 hcomponent)
{
u32 frac, lbcc;
int bpp;
lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 8;
bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
if (bpp < 0) {
dev_err(dsi->dev, "failed to get bpp\n");
return 0;
}
lbcc = div_u64((u64)hcomponent * mode->clock * bpp, dsi->lanes * 8);
frac = lbcc % mode->clock;
lbcc = lbcc / mode->clock;