Re: [PATCH v7] phy: qcom-qmp: add display port v4 voltage and pre-emphasis swing tables

Bjorn Andersson
2021-12-13T23:36:09Z

On Thu 09 Dec 11:24 CST 2021, Kuogee Hsieh wrote:

> From: Kuogee Hsieh <khsieh@codeaurora.org>
>
> The previous patch from Fixes (aff188feb5e1) added functions to support V4

The expected way to reference an existing commit is 'sha1 ("subject")'
(including the ''), i.e. something like:

'aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")'
added functions to support V4 of the PHY, but it did not...

> phy. But it did not update voltage and pre-emphasis tables accordingly.
> This patch add v4 voltage and pre-emphasis swing tables to complete v4
> phy implementation. 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.

The world doesn't know what a HPG is, so you need to spell this out or
simply say "the hardware documentation".

Thanks,
Bjorn

>
> Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")
> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> drivers/phy/qualcomm/phy-qcom-qmp.c | 112 +++++++++++++++++++++++++-----------
> 1 file changed, 77 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 456a59d..d41e30c 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -4255,40 +4255,50 @@ static void qcom_qmp_v3_phy_dp_aux_init(struct qmp_phy *qphy)
> qphy->pcs + QSERDES_V3_DP_PHY_AUX_INTERRUPT_MASK);
> }
>
> -static const u8 qmp_dp_v3_pre_emphasis_hbr3_hbr2[4][4] = {
> +#define MAX_SWING_LEVEL 4
> +#define MAX_VOLTAGE_LEVEL 4
> +#define MAX_EMPHASIS_LEVEL 4
> +
> +static const u8 qmp_dp_v3_pre_emphasis_hbr3_hbr2[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL] = {
> { 0x00, 0x0c, 0x15, 0x1a },
> { 0x02, 0x0e, 0x16, 0xff },
> { 0x02, 0x11, 0xff, 0xff },
> { 0x04, 0xff, 0xff, 0xff }
> };
>
> -static const u8 qmp_dp_v3_voltage_swing_hbr3_hbr2[4][4] = {
> +static const u8 qmp_dp_v3_voltage_swing_hbr3_hbr2[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL] = {
> { 0x02, 0x12, 0x16, 0x1a },
> { 0x09, 0x19, 0x1f, 0xff },
> { 0x10, 0x1f, 0xff, 0xff },
> { 0x1f, 0xff, 0xff, 0xff }
> };
>
> -static const u8 qmp_dp_v3_pre_emphasis_hbr_rbr[4][4] = {
> +static const u8 qmp_dp_v3_pre_emphasis_hbr_rbr[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL] = {
> { 0x00, 0x0c, 0x14, 0x19 },
> { 0x00, 0x0b, 0x12, 0xff },
> { 0x00, 0x0b, 0xff, 0xff },
> { 0x04, 0xff, 0xff, 0xff }
> };
>
> -static const u8 qmp_dp_v3_voltage_swing_hbr_rbr[4][4] = {
> +static const u8 qmp_dp_v3_voltage_swing_hbr_rbr[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL] = {
> { 0x08, 0x0f, 0x16, 0x1f },
> { 0x11, 0x1e, 0x1f, 0xff },
> { 0x19, 0x1f, 0xff, 0xff },
> { 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,
> + unsigned int drv_lvl_reg,
> + unsigned int emp_post_reg,
> + const u8 voltage_swing_hbr_rbr[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL],
> + const u8 pre_emphasis_hbr_rbr[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL],
> + const u8 voltage_swing_hbr3_hbr2[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL],
> + const u8 pre_emphasis_hbr3_hbr2[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL])
> {
> 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++) {
> @@ -4297,26 +4307,25 @@ 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 = voltage_swing_hbr_rbr[v_level][p_level];
> + emphasis = 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 = voltage_swing_hbr3_hbr2[v_level][p_level];
> + emphasis = 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 + drv_lvl_reg);
> + writel(emphasis, qphy->tx + emp_post_reg);
> + writel(voltage, qphy->tx2 + drv_lvl_reg);
> + writel(emphasis, qphy->tx2 + emp_post_reg);
> return 0;
> }
>
> @@ -4325,9 +4334,14 @@ 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,
> + QSERDES_V3_TX_TX_DRV_LVL,
> + QSERDES_V3_TX_TX_EMP_POST1_LVL,
> + qmp_dp_v3_voltage_swing_hbr_rbr,
> + qmp_dp_v3_pre_emphasis_hbr_rbr,
> + qmp_dp_v3_voltage_swing_hbr3_hbr2,
> + qmp_dp_v3_pre_emphasis_hbr3_hbr2) < 0)
> return;
>
> if (dp_opts->lanes == 1) {
> @@ -4465,6 +4479,35 @@ 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[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL] = {
> + { 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[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL] = {
> + { 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[MAX_SWING_LEVEL][MAX_EMPHASIS_LEVEL] = {
> + { 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[MAX_SWING_LEVEL][MAX_VOLTAGE_LEVEL] = {
> + { 0x08, 0x0f, 0x16, 0x1f },
> + { 0x11, 0x1e, 0x1f, 0xff },
> + { 0x16, 0x1f, 0xff, 0xff },
> + { 0x1f, 0xff, 0xff, 0xff }
> +};
> +
> 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 |
> @@ -4494,16 +4537,14 @@ 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_phy_configure_dp_swing
> + (qphy,
> QSERDES_V4_TX_TX_DRV_LVL,
> - QSERDES_V4_TX_TX_EMP_POST1_LVL);
> + QSERDES_V4_TX_TX_EMP_POST1_LVL,
> + qmp_dp_v4_voltage_swing_hbr_rbr,
> + qmp_dp_v4_pre_emphasis_hbr_rbr,
> + qmp_dp_v4_voltage_swing_hbr3_hbr2,
> + qmp_dp_v4_pre_emphasis_hbr3_hbr2);
> }
>
> static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
> @@ -4622,6 +4663,9 @@ 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);
> @@ -4633,11 +4677,9 @@ 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);
> --
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>