From 5fdc62ca62d7e896ef8ad64b68127e81eb3bdc3f Mon Sep 17 00:00:00 2001 From: Jingoo Han Date: Wed, 12 Sep 2012 16:52:09 +0900 Subject: [PATCH] video: exynos_dp: increase AUX channel voltage level The value of AUX channel differential amplitude current is changed from 8 mA to 16 mA, in order to increase AUX channel voltage level. In this case, AUX channel voltage level can be changed from 400 mV to 800 mV, when resistance between AUX TX and RX is 100 ohm. According to DP spec, although the normative voltage level is 390 mV, the informative voltage level is 430 mV. So, 800 mV can be helpful to improve voltage margin of AUX channel. Signed-off-by: Jingoo Han Signed-off-by: Florian Tobias Schandinat --- drivers/video/exynos/exynos_dp_reg.c | 2 +- drivers/video/exynos/exynos_dp_reg.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/video/exynos/exynos_dp_reg.c b/drivers/video/exynos/exynos_dp_reg.c index 365be69d9b5c..3f5ca8a0d5ea 100644 --- a/drivers/video/exynos/exynos_dp_reg.c +++ b/drivers/video/exynos/exynos_dp_reg.c @@ -77,7 +77,7 @@ void exynos_dp_init_analog_param(struct exynos_dp_device *dp) writel(reg, dp->reg_base + EXYNOS_DP_ANALOG_CTL_3); reg = PD_RING_OSC | AUX_TERMINAL_CTRL_50_OHM | - TX_CUR1_2X | TX_CUR_8_MA; + TX_CUR1_2X | TX_CUR_16_MA; writel(reg, dp->reg_base + EXYNOS_DP_PLL_FILTER_CTL_1); reg = CH3_AMP_400_MV | CH2_AMP_400_MV | diff --git a/drivers/video/exynos/exynos_dp_reg.h b/drivers/video/exynos/exynos_dp_reg.h index 9e9af50d7da3..1f2f014cfe88 100644 --- a/drivers/video/exynos/exynos_dp_reg.h +++ b/drivers/video/exynos/exynos_dp_reg.h @@ -187,7 +187,7 @@ #define PD_RING_OSC (0x1 << 6) #define AUX_TERMINAL_CTRL_50_OHM (0x2 << 4) #define TX_CUR1_2X (0x1 << 2) -#define TX_CUR_8_MA (0x2 << 0) +#define TX_CUR_16_MA (0x3 << 0) /* EXYNOS_DP_TX_AMP_TUNING_CTL */ #define CH3_AMP_400_MV (0x0 << 24) -- 2.20.1