Exynos5420: Remove code for enabling read leveling

This patch intends to remove all code which enables hardware read
leveling. All characterization environments may not cope up with
h/w read leveling enabled, so we must disable this.
Also, disabling h/w read leveling improves the MIF LVcc value
(LVcc value is the value at which DDR will fail to work properly).
Improving LVcc means we have enough voltage margin for MIF.
When h/w leveling is enabled, we have almost zero volatge margin.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

diff --git a/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c b/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c
index 4481ab46bffd88b7783ef854c4dce4d22cf8fee0..1d6048cbfcc957bdbec713e0ff3de6354e9c009a 100644 (file)
--- a/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c
+++ b/arch/arm/cpu/armv7/exynos/dmc_init_ddr3.c
@@ -519,77 +519,6 @@ int ddr3_mem_ctrl_init(struct mem_timings *mem, int reset)
                               &drex1->directcmd);
                }
 
-               if (mem->read_leveling_enable) {
-                       /* Set Read DQ Calibration */
-                       val = (0x3 << DIRECT_CMD_BANK_SHIFT) | 0x4;
-                       for (chip = 0; chip < mem->chips_to_configure; chip++) {
-                               writel(val | (chip << DIRECT_CMD_CHIP_SHIFT),
-                                      &drex0->directcmd);
-                               writel(val | (chip << DIRECT_CMD_CHIP_SHIFT),
-                                      &drex1->directcmd);
-                       }
-
-                       val = readl(&phy0_ctrl->phy_con1);
-                       val |= READ_LEVELLING_DDR3;
-                       writel(val, &phy0_ctrl->phy_con1);
-                       val = readl(&phy1_ctrl->phy_con1);
-                       val |= READ_LEVELLING_DDR3;
-                       writel(val, &phy1_ctrl->phy_con1);
-
-                       val = readl(&phy0_ctrl->phy_con2);
-                       val |= (RDLVL_EN | RDLVL_INCR_ADJ);
-                       writel(val, &phy0_ctrl->phy_con2);
-                       val = readl(&phy1_ctrl->phy_con2);
-                       val |= (RDLVL_EN | RDLVL_INCR_ADJ);
-                       writel(val, &phy1_ctrl->phy_con2);
-
-                       setbits_le32(&drex0->rdlvl_config,
-                                    CTRL_RDLVL_DATA_ENABLE);
-                       i = TIMEOUT;
-                       while (((readl(&drex0->phystatus) & RDLVL_COMPLETE_CHO)
-                                != RDLVL_COMPLETE_CHO) && (i > 0)) {
-                               /*
-                                * TODO(waihong): Comment on how long this take
-                                * to timeout
-                                */
-                               sdelay(100);
-                               i--;
-                       }
-                       if (!i)
-                               return SETUP_ERR_RDLV_COMPLETE_TIMEOUT;
-
-                       clrbits_le32(&drex0->rdlvl_config,
-                                    CTRL_RDLVL_DATA_ENABLE);
-                       setbits_le32(&drex1->rdlvl_config,
-                                    CTRL_RDLVL_DATA_ENABLE);
-                       i = TIMEOUT;
-                       while (((readl(&drex1->phystatus) & RDLVL_COMPLETE_CHO)
-                                != RDLVL_COMPLETE_CHO) && (i > 0)) {
-                               /*
-                                * TODO(waihong): Comment on how long this take
-                                * to timeout
-                                */
-                               sdelay(100);
-                               i--;
-                       }
-                       if (!i)
-                               return SETUP_ERR_RDLV_COMPLETE_TIMEOUT;
-
-                       clrbits_le32(&drex1->rdlvl_config,
-                                    CTRL_RDLVL_DATA_ENABLE);
-
-                       val = (0x3 << DIRECT_CMD_BANK_SHIFT);
-                       for (chip = 0; chip < mem->chips_to_configure; chip++) {
-                               writel(val | (chip << DIRECT_CMD_CHIP_SHIFT),
-                                      &drex0->directcmd);
-                               writel(val | (chip << DIRECT_CMD_CHIP_SHIFT),
-                                      &drex1->directcmd);
-                       }
-
-                       update_reset_dll(&drex0->phycontrol0, DDR_MODE_DDR3);
-                       update_reset_dll(&drex1->phycontrol0, DDR_MODE_DDR3);
-               }
-
                /* Common Settings for Leveling */
                val = PHY_CON12_RESET_VAL;
                writel((val + n_lock_w_phy0), &phy0_ctrl->phy_con12);