Re: [PATCH v2] phy: qcom-qmp: add support for display port voltage and pre-emphasis swing

From: Dmitry Baryshkov
Date: Fri Sep 03 2021 - 15:09:21 EST

On 28/08/2021 00:10, Kuogee Hsieh wrote:
Both voltage and pre-emphasis swing level are set during link training
negotiation between host and sink. There are totally four tables added.
A voltage swing table for both hbr and hbr1, a voltage table for both
hbr2 and hbr3, a pre-emphasis table for both hbr and hbr1 and a pre-emphasis
table for both hbr2 and hbr3. In addition, write 0x0a to TX_TX_POL_INV is
added to complete the sequence of configure dp phy base on HPG.

Chnages in v2:
-- revise commit test
-- add Fixes tag
-- replaced voltage_swing_cfg with voltage
-- replaced pre_emphasis_cfg with emphasis
-- delete drv_lvl_reg and emp_post_reg parameters from qcom_qmp_v4_phy_configure_dp_swing()
-- delete drv_lvl_reg and emp_post_reg parameters from qcom_qmp_phy_configure_dp_swing()

Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")
Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
---
drivers/phy/qualcomm/phy-qcom-qmp.c | 117 ++++++++++++++++++++++++++----------
1 file changed, 85 insertions(+), 32 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 31036aa..021cbb0 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -3546,12 +3546,11 @@ static const u8 qmp_dp_v3_voltage_swing_hbr_rbr[4][4] = {
{ 0x1f, 0xff, 0xff, 0xff }
};
-static int qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy,
- unsigned int drv_lvl_reg, unsigned int emp_post_reg)
+static int qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy)

As this becomes a v3-only function, could you please rename it to qcom_qmp_v3_phy_configure_dp_swing()

{
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;
+ u8 voltage, emphasis;
int i;
for (i = 0; i < dp_opts->lanes; i++) {
@@ -3560,26 +3559,25 @@ static int qcom_qmp_phy_configure_dp_swing(struct qmp_phy *qphy,
}
if (dp_opts->link_rate <= 2700) {
- voltage_swing_cfg = qmp_dp_v3_voltage_swing_hbr_rbr[v_level][p_level];
- pre_emphasis_cfg = qmp_dp_v3_pre_emphasis_hbr_rbr[v_level][p_level];
+ voltage = qmp_dp_v3_voltage_swing_hbr_rbr[v_level][p_level];
+ emphasis = qmp_dp_v3_pre_emphasis_hbr_rbr[v_level][p_level];
} else {
- voltage_swing_cfg = qmp_dp_v3_voltage_swing_hbr3_hbr2[v_level][p_level];
- pre_emphasis_cfg = qmp_dp_v3_pre_emphasis_hbr3_hbr2[v_level][p_level];
+ voltage = qmp_dp_v3_voltage_swing_hbr3_hbr2[v_level][p_level];
+ emphasis = qmp_dp_v3_pre_emphasis_hbr3_hbr2[v_level][p_level];
}
/* TODO: Move check to config check */
- if (voltage_swing_cfg == 0xFF && pre_emphasis_cfg == 0xFF)
+ if (voltage == 0xFF && emphasis == 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);
+ voltage |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ emphasis |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+ writel(voltage, qphy->tx + QSERDES_V3_TX_TX_DRV_LVL);
+ writel(emphasis, qphy->tx + QSERDES_V3_TX_TX_EMP_POST1_LVL);
+ writel(voltage, qphy->tx2 + QSERDES_V3_TX_TX_DRV_LVL);
+ writel(emphasis, qphy->tx2 + QSERDES_V3_TX_TX_EMP_POST1_LVL);
return 0;
}
@@ -3588,9 +3586,7 @@ static void qcom_qmp_v3_phy_configure_dp_tx(struct qmp_phy *qphy)
const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
u32 bias_en, drvr_en;
- if (qcom_qmp_phy_configure_dp_swing(qphy,
- QSERDES_V3_TX_TX_DRV_LVL,
- QSERDES_V3_TX_TX_EMP_POST1_LVL) < 0)
+ if (qcom_qmp_phy_configure_dp_swing(qphy) < 0)
return;
if (dp_opts->lanes == 1) {
@@ -3728,6 +3724,71 @@ static int qcom_qmp_v3_dp_phy_calibrate(struct qmp_phy *qphy)
return 0;
}
+/* The values in these tables are given without MUX_EN (0x20) bit set */
+static const u8 qmp_dp_v4_pre_emphasis_hbr3_hbr2[4][4] = {
+ { 0x00, 0x0c, 0x15, 0x1b },
+ { 0x02, 0x0e, 0x16, 0xff },
+ { 0x02, 0x11, 0xff, 0xff },
+ { 0x04, 0xff, 0xff, 0xff }
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr3_hbr2[4][4] = {
+ { 0x02, 0x12, 0x16, 0x1a },
+ { 0x09, 0x19, 0x1f, 0xff },
+ { 0x10, 0x1f, 0xff, 0xff },
+ { 0x1f, 0xff, 0xff, 0xff }
+};
+
+static const u8 qmp_dp_v4_pre_emphasis_hbr_rbr[4][4] = {
+ { 0x00, 0x0e, 0x15, 0x1b },
+ { 0x00, 0x0e, 0x15, 0xff },
+ { 0x00, 0x0e, 0xff, 0xff },
+ { 0x04, 0xff, 0xff, 0xff }
+};
+
+static const u8 qmp_dp_v4_voltage_swing_hbr_rbr[4][4] = {
+ { 0x08, 0x0f, 0x16, 0x1f },
+ { 0x11, 0x1e, 0x1f, 0xff },
+ { 0x16, 0x1f, 0xff, 0xff },
+ { 0x1f, 0xff, 0xff, 0xff }
+};
+
+static int qcom_qmp_v4_phy_configure_dp_swing(struct qmp_phy *qphy)
+{
+ const struct phy_configure_opts_dp *dp_opts = &qphy->dp_opts;
+ unsigned int v_level = 0, p_level = 0;
+ u8 voltage, emphasis;
+ 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]);
+ }
+
+ if (dp_opts->link_rate <= 2700) {
+ voltage = qmp_dp_v4_voltage_swing_hbr_rbr[v_level][p_level];
+ emphasis = qmp_dp_v4_pre_emphasis_hbr_rbr[v_level][p_level];
+ } else {
+ voltage = qmp_dp_v4_voltage_swing_hbr3_hbr2[v_level][p_level];
+ emphasis = qmp_dp_v4_pre_emphasis_hbr3_hbr2[v_level][p_level];
+ }
+
+ /* TODO: Move check to config check */
+ if (voltage == 0xFF && emphasis == 0xFF)
+ return -EINVAL;
+
+ /* Enable MUX to use Cursor values from these registers */
+ voltage |= DP_PHY_TXn_TX_DRV_LVL_MUX_EN;
+ emphasis |= DP_PHY_TXn_TX_EMP_POST1_LVL_MUX_EN;
+
+ writel(voltage, qphy->tx + QSERDES_V4_TX_TX_DRV_LVL);
+ writel(emphasis, qphy->tx + QSERDES_V4_TX_TX_EMP_POST1_LVL);
+ writel(voltage, qphy->tx2 + QSERDES_V4_TX_TX_DRV_LVL);
+ writel(emphasis, qphy->tx2 + QSERDES_V4_TX_TX_EMP_POST1_LVL);
+
+ return 0;
+}
+
static void qcom_qmp_v4_phy_dp_aux_init(struct qmp_phy *qphy)
{
writel(DP_PHY_PD_CTL_PWRDN | DP_PHY_PD_CTL_PSR_PWRDN | DP_PHY_PD_CTL_AUX_PWRDN |
@@ -3757,16 +3818,7 @@ 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,
- QSERDES_V4_TX_TX_DRV_LVL,
- QSERDES_V4_TX_TX_EMP_POST1_LVL);
+ qcom_qmp_v4_phy_configure_dp_swing(qphy);
}
static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
@@ -3885,6 +3937,9 @@ 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);
+
writel(0x18, qphy->pcs + QSERDES_DP_PHY_CFG);
udelay(2000);
writel(0x19, qphy->pcs + QSERDES_DP_PHY_CFG);
@@ -3896,11 +3951,9 @@ 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);



--
With best wishes
Dmitry