From 061091098a5ec55ff4b68b61592af8619c2c7d88 Mon Sep 17 00:00:00 2001 From: Alim Akhtar Date: Thu, 13 Nov 2014 22:38:18 +0530 Subject: DMC: Exynos5: Enable update mode for DREX controller As per Exynos5800 UM ver 0.00 section 17.13.2.1 CONCONTROL register bit 3 [update_mode], Exynos5800 does not support the PHY initiated update. And it is recommanded to set this field to 1'b1 during initialization. This patch sets this bit. Applying MC-initiated mode makes DDL tracking ON, that helps in compensate MIF voltage variation. Signed-off-by: Alim Akhtar Signed-off-by: Doug Anderson Signed-off-by: Akshay Saraswat Acked-by: Simon Glass Tested-by: Simon Glass Signed-off-by: Minkyu Kang --- arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'arch/arm/cpu/armv7/exynos') diff --git a/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c b/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c index b86dd2d650..4d73b45435 100644 --- a/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c +++ b/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c @@ -832,6 +832,25 @@ int ddr3_mem_ctrl_init(struct mem_timings *mem, int reset) setbits_le32(&drex0->cgcontrol, DMC_INTERNAL_CG); setbits_le32(&drex1->cgcontrol, DMC_INTERNAL_CG); + /* + * As per Exynos5800 UM ver 0.00 section 17.13.2.1 + * CONCONTROL register bit 3 [update_mode], Exynos5800 does not + * support the PHY initiated update. And it is recommended to set + * this field to 1'b1 during initialization + * + * When we apply PHY-initiated mode, DLL lock value is determined + * once at DMC init time and not updated later when we change the MIF + * voltage based on ASV group in kernel. Applying MC-initiated mode + * makes sure that DLL tracing is ON so that silicon is able to + * compensate the voltage variation. + */ + val = readl(&drex0->concontrol); + val |= CONCONTROL_UPDATE_MODE; + writel(val , &drex0->concontrol); + val = readl(&drex1->concontrol); + val |= CONCONTROL_UPDATE_MODE; + writel(val , &drex1->concontrol); + return 0; } #endif -- cgit v1.2.1