From e023b1fb5286e23c224f2ae312831a4fce258c02 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Fri, 22 Sep 2017 09:44:06 -0700 Subject: [PATCH] phy: rockchip-typec: Do the calibration more correctly Calculate the calibration code as per the docs. The docs talk about reading and averaging the pullup and pulldown calibration codes. They also talk about adding in some adjustment codes. Let's do what the docs say. In practice this doesn't seem to matter a whole lot. On a device I tested the pullup and pulldown codes were nearly the same (0x23 and 0x24) and the adjustment codes were 0. Reviewed-by: Chris Zhong Signed-off-by: Douglas Anderson Signed-off-by: Kishon Vijay Abraham I --- drivers/phy/rockchip/phy-rockchip-typec.c | 27 +++++++++++++++-------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/phy/rockchip/phy-rockchip-typec.c b/drivers/phy/rockchip/phy-rockchip-typec.c index e5454eccb57d..ee85fa0ca4b0 100644 --- a/drivers/phy/rockchip/phy-rockchip-typec.c +++ b/drivers/phy/rockchip/phy-rockchip-typec.c @@ -560,24 +560,33 @@ static void tcphy_dp_aux_calibration(struct rockchip_typec_phy *tcphy) u16 val; u16 tx_ana_ctrl_reg_1; u16 tx_ana_ctrl_reg_2; - s32 pu_calib_code; + s32 pu_calib_code, pd_calib_code; + s32 pu_adj, pd_adj; + u16 calib; + + /* + * Calculate calibration code as per docs: use an average of the + * pull down and pull up. Then add in adjustments. + */ + val = readl(tcphy->base + CMN_TXPUCAL_CTRL); + pu_calib_code = CMN_CALIB_CODE_POS(val); + val = readl(tcphy->base + CMN_TXPDCAL_CTRL); + pd_calib_code = CMN_CALIB_CODE_POS(val); + val = readl(tcphy->base + CMN_TXPU_ADJ_CTRL); + pu_adj = CMN_CALIB_CODE(val); + val = readl(tcphy->base + CMN_TXPD_ADJ_CTRL); + pd_adj = CMN_CALIB_CODE(val); + calib = (pu_calib_code + pd_calib_code) / 2 + pu_adj + pd_adj; /* disable txda_cal_latch_en for rewrite the calibration values */ tx_ana_ctrl_reg_1 = readl(tcphy->base + TX_ANA_CTRL_REG_1); tx_ana_ctrl_reg_1 &= ~TXDA_CAL_LATCH_EN; writel(tx_ana_ctrl_reg_1, tcphy->base + TX_ANA_CTRL_REG_1); - /* - * read a resistor calibration code from CMN_TXPUCAL_CTRL[5:0] and - * write it to TX_DIG_CTRL_REG_2[5:0]. - */ - val = readl(tcphy->base + CMN_TXPUCAL_CTRL); - pu_calib_code = CMN_CALIB_CODE_POS(val); - /* write the calibration, then delay 10 ms as sample in docs */ val = readl(tcphy->base + TX_DIG_CTRL_REG_2); val &= ~(TX_RESCAL_CODE_MASK << TX_RESCAL_CODE_OFFSET); - val |= pu_calib_code << TX_RESCAL_CODE_OFFSET; + val |= calib << TX_RESCAL_CODE_OFFSET; writel(val, tcphy->base + TX_DIG_CTRL_REG_2); usleep_range(10000, 10050);