Re: [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
From: Stephen Boyd <hidden>
Date: 2021-08-25 17:49:51
Also in:
linux-arm-msm, lkml
Quoting Kuogee Hsieh (2021-08-24 16:29:35)
Add voltage and pre emphesis swing tables so that voltage and
Is it "pre-emphasis"?
pre emphsis swing level can be configured base on link rate.
This one is also different.
Signed-off-by: Kuogee Hsieh <redacted>
Presumably
Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")
quoted hunk ↗ jump to hunk
--- drivers/phy/qualcomm/phy-qcom-qmp.c | 95 ++++++++++++++++++++++++++++++++----- 1 file changed, 82 insertions(+), 13 deletions(-)diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c index 31036aa..52bab6e 100644 --- a/drivers/phy/qualcomm/phy-qcom-qmp.c +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c@@ -1916,7 +1916,7 @@ static const struct qmp_phy_init_tbl qmp_v4_dp_tx_tbl[] = { QMP_PHY_INIT_CFG(QSERDES_V4_TX_RES_CODE_LANE_OFFSET_RX, 0x11), QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_BAND, 0x4), QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_POL_INV, 0x0a), - QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x2a), + QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_DRV_LVL, 0x22),
Is 0x22 the better "default"? Can that be described in the commit text?
quoted hunk ↗ jump to hunk
QMP_PHY_INIT_CFG(QSERDES_V4_TX_TX_EMP_POST1_LVL, 0x20), };@@ -3727,6 +3727,81 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct qmp_phy *qphy) return 0; }
Nitpick: Newline here please.
+/*
+ * 0x20 deducted from tables
+ *
+ * swing_value |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ * pre_emphasis_value |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+*/
+static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x00, 0x0c, 0x15, 0x1b }, /* s0 */
+ { 0x02, 0x0e, 0x16, 0xff }, /* s1 */
+ { 0x02, 0x11, 0xff, 0xff }, /* s2 */
+ { 0x04, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {This looks the same as qmp_dp_v3_voltage_swing_hbr3_hbr2. Can that be used?
+ /* p0 p1 p2 p3 */
+ { 0x02, 0x12, 0x16, 0x1a }, /* s0 */
+ { 0x09, 0x19, 0x1f, 0xff }, /* s1 */
+ { 0x10, 0x1f, 0xff, 0xff }, /* s2 */
+ { 0x1f, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x00, 0x0e, 0x15, 0x1b }, /* s0 */
+ { 0x00, 0x0e, 0x15, 0xff }, /* s1 */
+ { 0x00, 0x0e, 0xff, 0xff }, /* s2 */
+ { 0x04, 0xff, 0xff, 0xff } /* s3 */
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
+ /* p0 p1 p2 p3 */
+ { 0x08, 0x0f, 0x16, 0x1f }, /* s0 */
+ { 0x11, 0x1e, 0x1f, 0xff }, /* s1 */
+ { 0x16, 0x1f, 0xff, 0xff }, /* s2 */
+ { 0x1f, 0xff, 0xff, 0xff } /* s3 */Do these comments add any value? Can we drop them?
+};
+
+static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy,
+ unsigned int drv_lvl_reg, unsigned int emp_post_reg)
+{
+ const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
+ unsigned int v_level = 0, p_level = 0;
+ u8 voltage_swing_cfg, pre_emphasis_cfg;
+ int i;
+
+ for (i = 0; i < dp_opts->lanes; i++) {
+ v_level = max(v_level, dp_opts->voltage[i]);
+ p_level = max(p_level, dp_opts->pre[i]);
+ }
+
+Nitpick: Drop extra newline.
+ if (dp_opts->link_rate <= 2700) {
+ voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
+ pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
+ } else {
+ voltage_swing_cfg = qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
+ pre_emphasis_cfg = qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
+ }
+
+ /* TODO: Move check to config check */
+ if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
+ return -EINVAL;
+
+ /* Enable MUX to use Cursor values from these registers */
+ voltage_swing_cfg |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ pre_emphasis_cfg |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+
+ writel(voltage_swing_cfg, qphy->tx + drv_lvl_reg);
+ writel(pre_emphasis_cfg, qphy->tx + emp_post_reg);
+ writel(voltage_swing_cfg, qphy->tx2 + drv_lvl_reg);
+ writel(pre_emphasis_cfg, qphy->tx2 + emp_post_reg);This is copy/pasted from qcom_qmp_phy_configure_dp_swing() right? How about making a function static int __qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy, unsigned int drv_lvl_reg, unsigned int emp_post_reg, const u8 **voltage_rbr_hbr, const u8 **pre_emphasis_rbr_hbr, const u8 **voltage_hbr3_hbr2, const u8 **pre_emphasis_hbr3_hbr2) that does the same stuff but allows the tables to be different.
quoted hunk ↗ jump to hunk
+ + return 0; +} static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy) {@@ -3757,14 +3832,7 @@ static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy) static void qcom_qmp_v4_phy_configure_dp_tx(struct qmp_phy *qphy) { - /* Program default values before writing proper values */ - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL); - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL); - - writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL); - writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL); - - qcom_qmp_phy_configure_dp_swing(qphy, + qcom_qmp_v4_phy_configure_dp_swing(qphy, QSERDES_V4_TX_TX_DRV_LVL, QSERDES_V4_TX_TX_EMP_POST1_LVL); }@@ -3885,6 +3953,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy) writel(drvr1_en, qphy->tx2 + QSERDES_V4_TX_HIGHZ_DRVR_EN); writel(bias1_en, qphy->tx2 + QSERDES_V4_TX_TRANSCEIVER_BIAS_EN); + writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV); + writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV);
Is this mentioned in the commit text? Is this fixing the sequence? It doesn't look like we're adding tables.
quoted hunk ↗ jump to hunk
+ writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG); udelay(2000); writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);@@ -3896,11 +3967,9 @@ static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy) 10000)) return -ETIMEDOUT; - writel(0x0a, qphy->tx + QSERDES_V4_TX_TX_POL_INV); - writel(0x0a, qphy->tx2 + QSERDES_V4_TX_TX_POL_INV); - writel(0x27, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL); - writel(0x27, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL); + writel(0x22, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL); + writel(0x22, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL); writel(0x20, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL); writel(0x20, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);