soc/mediatek: dsi: Increase pcw precision

When configuring MIPI DSI Tx, the value of pcw was calculated from data
rate in MHz, leading to loss of precision. This patch changes to use
data rate in Hz for the calculation so that the resulting value should
be consistent with the one in kernel (CL:1786327).

In addition, change the type of data rate to u32, and calculation of
data rate from pixel clock is changed to use DIV_ROUND_UP for
consistency with kernel (CL:1761843).

Also remove unused variable txdiv.

BRANCH=kukui
BUG=b:149051882
TEST=emerge-jacuzzi coreboot
TEST=No scrolling issue on Juniper AUO and InnoLux panels

Change-Id: I23220d446833b956431006027bbc8cb20fc696a5
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38827
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/src/soc/mediatek/mt8173/dsi.c b/src/soc/mediatek/mt8173/dsi.c
index dae23f5a0c..48bfbef1a5 100644
--- a/src/soc/mediatek/mt8173/dsi.c
+++ b/src/soc/mediatek/mt8173/dsi.c
@@ -20,7 +20,7 @@
 #include <soc/dsi.h>
 #include <timer.h>
 
-void mtk_dsi_configure_mipi_tx(int data_rate, u32 lanes)
+void mtk_dsi_configure_mipi_tx(u32 data_rate, u32 lanes)
 {
 	u32 txdiv0, txdiv1;
 	u64 pcw;
@@ -51,21 +51,21 @@ void mtk_dsi_configure_mipi_tx(int data_rate, u32 lanes)
 
 	clrbits32(&mipi_tx0->dsi_pll_con0, RG_DSI0_MPPLL_PLL_EN);
 
-	if (data_rate > 500) {
+	if (data_rate > 500 * MHz) {
 		txdiv0 = 0;
 		txdiv1 = 0;
-	} else if (data_rate >= 250) {
+	} else if (data_rate >= 250 * MHz) {
 		txdiv0 = 1;
 		txdiv1 = 0;
-	} else if (data_rate >= 125) {
+	} else if (data_rate >= 125 * MHz) {
 		txdiv0 = 2;
 		txdiv1 = 0;
-	} else if (data_rate >= 62) {
+	} else if (data_rate >= 62 * MHz) {
 		txdiv0 = 2;
 		txdiv1 = 1;
 	} else {
 		/* MIN = 50 */
-		assert(data_rate >= MTK_DSI_DATA_RATE_MIN_MHZ);
+		assert(data_rate >= MTK_DSI_DATA_RATE_MIN_MHZ * MHz);
 		txdiv0 = 2;
 		txdiv1 = 2;
 	}
@@ -83,7 +83,7 @@ void mtk_dsi_configure_mipi_tx(int data_rate, u32 lanes)
 	 * Ref_clk is 26MHz
 	 */
 	pcw = (u64)(data_rate * (1 << txdiv0) * (1 << txdiv1)) << 24;
-	pcw /= 13;
+	pcw /= 13 * MHz;
 	write32(&mipi_tx0->dsi_pll_con2, pcw);
 
 	setbits32(&mipi_tx0->dsi_pll_con1, RG_DSI0_MPPLL_SDM_FRA_EN);