Re: [PATCH v3 4/4] phy: qualcomm: qmp-combo: Rework DP PHY runtime configuration

From: Konrad Dybcio

Date: Fri Aug 28 2026 - 08:16:28 EST

On 8/28/26 11:43 AM, Nabige Aala wrote:
> From: Ritesh Kumar <ritesh.kumar@xxxxxxxxxxxxxxxx>

[...]

> +static int qmp_combo_configure_dp_phy_common(struct qmp_combo *qmp)
> +{
> + const struct qmp_phy_cfg *cfg = qmp->cfg;
> + u32 status;
> + int ret;
> +
> + if (!cfg->dp_aux_cfg2) {
> + dev_err(qmp->dev, "DP AUX CFG2 value not configured\n");
> + return -EINVAL;
> + }
> +
> + writel(0x0f, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG_1);
> +
> + qmp_combo_configure_dp_mode(qmp);
> +
> + writel(0x13, qmp->dp_dp_phy + QSERDES_DP_PHY_AUX_CFG1);
> + writel(cfg->dp_aux_cfg2, qmp->dp_dp_phy + QSERDES_DP_PHY_AUX_CFG2);
> +
> + writel(0x05, qmp->dp_dp_phy + QSERDES_V4_DP_PHY_TX0_TX1_LANE_CTL);
> + writel(0x05, qmp->dp_dp_phy + QSERDES_V4_DP_PHY_TX2_TX3_LANE_CTL);
> +
> + ret = qmp->cfg->configure_dp_clocks(qmp);
> + if (ret)
> + return ret;
> +
> + writel(0x01, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG);
> + writel(0x05, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG);
> + writel(0x01, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG);
> + writel(0x09, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG);
> +
> + writel(0x20, qmp->dp_serdes + cfg->regs[QPHY_COM_RESETSM_CNTRL]);
> +
> + if (readl_poll_timeout(qmp->dp_serdes + cfg->regs[QPHY_COM_C_READY_STATUS],
> + status,
> + ((status & BIT(0)) > 0),
> + 500,
> + 10000))
> + return -ETIMEDOUT;
> +
> + if (readl_poll_timeout(qmp->dp_serdes + cfg->regs[QPHY_COM_CMN_STATUS],
> + status,
> + ((status & BIT(0)) > 0),
> + 500,
> + 10000))
> + return -ETIMEDOUT;
> +
> + if (readl_poll_timeout(qmp->dp_serdes + cfg->regs[QPHY_COM_CMN_STATUS],
> + status,
> + ((status & BIT(1)) > 0),
> + 500,
> + 10000))
> + return -ETIMEDOUT;
> +
> + return 0;
> +}
> +
> static void qmp_v8_dp_aux_init(struct qmp_combo *qmp)
> {
> const struct qmp_phy_cfg *cfg = qmp->cfg;
>
> - writel(DP_PHY_PD_CTL_PWRDN | DP_PHY_PD_CTL_PSR_PWRDN | DP_PHY_PD_CTL_AUX_PWRDN |
> - DP_PHY_PD_CTL_PLL_PWRDN | DP_PHY_PD_CTL_DP_CLAMP_EN,
> - qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
> + writel(0x3f, qmp->dp_serdes + QSERDES_V8_USB43_COM_CLK_FWD_CONFIG_1);
> +
> + writel(DP_PHY_PD_CTL_PWRDN | DP_PHY_PD_CTL_AUX_PWRDN |
> + DP_PHY_PD_CTL_LANE_0_1_PWRDN | DP_PHY_PD_CTL_LANE_2_3_PWRDN |
> + DP_PHY_PD_CTL_PLL_PWRDN | DP_PHY_PD_CTL_DP_CLAMP_EN,
> + qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
>
> /* Turn on BIAS current for PHY/PLL */
> - writel(0x1c, qmp->dp_serdes + cfg->regs[QPHY_COM_BIAS_EN_CLKBUFLR_EN]);
> + writel(0x17, qmp->dp_serdes + cfg->regs[QPHY_COM_BIAS_EN_CLKBUFLR_EN]);
>
> writel(0x00, qmp->dp_dp_phy + QSERDES_DP_PHY_AUX_CFG0);
> writel(0x13, qmp->dp_dp_phy + QSERDES_DP_PHY_AUX_CFG1);
> @@ -3729,8 +3807,8 @@ static void qmp_v4_configure_dp_tx(struct qmp_combo *qmp)
> writel(0x27, qmp->dp_tx + cfg->regs[QPHY_TX_TX_DRV_LVL]);
> writel(0x27, qmp->dp_tx2 + cfg->regs[QPHY_TX_TX_DRV_LVL]);
>
> - writel(0x20, qmp->dp_tx + cfg->regs[QPHY_TX_TX_EMP_POST1_LVL]);
> - writel(0x20, qmp->dp_tx2 + cfg->regs[QPHY_TX_TX_EMP_POST1_LVL]);
> + writel(0x2b, qmp->dp_tx + cfg->regs[QPHY_TX_TX_EMP_POST1_LVL]);
> + writel(0x2b, qmp->dp_tx2 + cfg->regs[QPHY_TX_TX_EMP_POST1_LVL]);
>
> qmp_combo_configure_dp_swing(qmp);
> }
> @@ -3738,48 +3816,41 @@ static void qmp_v4_configure_dp_tx(struct qmp_combo *qmp)
> static int qmp_v8_configure_dp_clocks(struct qmp_combo *qmp)
> {
> const struct phy_configure_opts_dp *dp_opts = &qmp->dp_opts;
> - u32 phy_vco_div;
> unsigned long pixel_freq;
> - const struct qmp_phy_cfg *cfg = qmp->cfg;
>
> switch (dp_opts->link_rate) {
> case 1620:
> - phy_vco_div = 0x4;
> pixel_freq = 1620000000UL / 2;
> break;
> case 2700:
> - phy_vco_div = 0x2;
> pixel_freq = 2700000000UL / 2;
> break;
> case 5400:
> - phy_vco_div = 0x4;
> pixel_freq = 5400000000UL / 4;
> break;
> case 8100:
> - phy_vco_div = 0x3;
> pixel_freq = 8100000000UL / 6;
> break;
> default:
> /* Other link rates aren't supported */
> return -EINVAL;
> }
> - writel(phy_vco_div, qmp->dp_dp_phy + cfg->regs[QPHY_DP_PHY_VCO_DIV]);
>
> /* disable core reset tsync */
> writel(0x09, qmp->dp_dp_phy + QSERDES_DP_PHY_CFG);
>
> - writel(0x04, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_AUXLESS_SETUP_CYC);
> - writel(0x08, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_AUXLESS_SILENCE_CYC);
> + writel(0x09, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_AUXLESS_SETUP_CYC);
> + writel(0x11, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_AUXLESS_SILENCE_CYC);
> writel(0x08, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LFPS_CYC);
> - writel(0x11, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LFPS_PERIOD);
> + writel(0x33, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LFPS_PERIOD);

These 3 altered writes depend on the rate

>
> writel(0x3e, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TSYNC_OVRD);
> writel(0x05, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TX2_TX3_LANE_CTL);
> writel(0x05, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TX0_TX1_LANE_CTL);
> writel(0x01, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_AUXLESS_CFG1);
> - writel(0x11, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LFPS_PERIOD);
> + writel(0x33, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LFPS_PERIOD);

This is duplicated, it seems

> writel(0x1f, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LN0_DRV_LVL);
> - writel(0x1f, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LN1_DRV_LVL);
> + writel(0x02, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_LN1_DRV_LVL);

This depends on swing/preem levels

[...]

> @@ -3938,13 +3971,13 @@ static int qmp_v8_configure_dp_phy(struct qmp_combo *qmp)
> } else if (dp_opts->lanes == 2) {
> bias0_en = reverse ? 0x3f : 0x15;
> bias1_en = reverse ? 0x15 : 0x3f;
> - drvr0_en = 0x10;
> - drvr1_en = 0x10;
> + drvr0_en = 0x30;
> + drvr1_en = 0x30;
> } else {
> bias0_en = 0x3f;
> bias1_en = 0x3f;
> - drvr0_en = 0x34;
> - drvr1_en = 0x34;
> + drvr0_en = 0x30;
> + drvr1_en = 0x30;

2ln settings should also depend on the reverse state

> }
>
> writel(drvr0_en, qmp->dp_tx + cfg->regs[QPHY_TX_HIGHZ_DRVR_EN]);
> @@ -3952,6 +3985,15 @@ static int qmp_v8_configure_dp_phy(struct qmp_combo *qmp)
> writel(drvr1_en, qmp->dp_tx2 + cfg->regs[QPHY_TX_HIGHZ_DRVR_EN]);
> writel(bias1_en, qmp->dp_tx2 + cfg->regs[QPHY_TX_TRANSCEIVER_BIAS_EN]);
>

This should also be preceded by LANE_CLKBUF_EN, I think

> + writel(0x03, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TSYNC_OVRD);
> + writel(0x23, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TSYNC_OVRD);
> + writel(0x22, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TSYNC_OVRD);
> +
> + writel(0x0a, qmp->dp_tx + QSERDES_V8_LALB_RESET_TSYNC_EN_CTRL);
> + writel(0x0a, qmp->dp_tx2 + QSERDES_V8_LALB_RESET_TSYNC_EN_CTRL);
> +
> + writel(0x3e, qmp->dp_dp_phy + QSERDES_V8_DP_PHY_TSYNC_OVRD);

Konrad