diff mbox series

[v3] phy: qcom-qmp: add support for display port voltage and pre-emphasis swing

Message ID 1631223065-12607-1-git-send-email-khsieh@codeaurora.org (mailing list archive)
State Superseded
Headers show
Series [v3] phy: qcom-qmp: add support for display port voltage and pre-emphasis swing | expand

Commit Message

Kuogee Hsieh Sept. 9, 2021, 9:31 p.m. UTC 
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()

Changes in V3:
-- add __qcom_qmp_phy_configure_dp_swing() to commit swing/pre-emphasis level

Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp phy")
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp.c | 102 +++++++++++++++++++++++++-----------
 1 file changed, 70 insertions(+), 32 deletions(-)

Comments

Stephen Boyd Sept. 13, 2021, 8:06 p.m. UTC | #1 
Quoting Kuogee Hsieh (2021-09-09 14:31:05)
> @@ -3757,16 +3796,14 @@ 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,
> +       if (__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,
> +                       (const u8 *)qmp_dp_v4_voltage_swing_hbr_rbr,

Surely we can pass a 2d-array to a function in C? We know the size of
the array is always a 4x4 so we could enforce that in the type so the
compiler complains if we try to pass something else.

> +                       (const u8 *)qmp_dp_v4_pre_emphasis_hbr_rbr,
> +                       (const u8 *)qmp_dp_v4_voltage_swing_hbr3_hbr2,
> +                       (const u8 *)qmp_dp_v4_pre_emphasis_hbr3_hbr2) < 0)
> +               return;

It's void and this is the end of the function. Why is there an if
condition and a return?

>  }
>
>  static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 31036aa..a8097ee 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -3546,40 +3546,46 @@  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,
+				unsigned int drv_lvl_reg,
+				unsigned int emp_post_reg,
+				const u8 *voltage_swing_hbr_rbr,
+				const u8 *pre_emphasis_hbr_rbr,
+				const u8 *voltage_swing_hbr3_hbr2,
+				const u8 *pre_emphasis_hbr3_hbr2)
 {
 	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;
+	u8 voltage, emphasis;
+	int i, offset;
 
 	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]);
 	}
 
+	offset = v_level * 4 + p_level;
+
 	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 + offset);
+		emphasis = *(pre_emphasis_hbr_rbr + offset);
 	} 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 + offset);
+		emphasis = *(pre_emphasis_hbr3_hbr2 + offset);
 	}
 
 	/* 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;
 }
 
@@ -3588,9 +3594,13 @@  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,
+			(const u8 *)qmp_dp_v3_voltage_swing_hbr_rbr,
+			(const u8 *)qmp_dp_v3_pre_emphasis_hbr_rbr,
+			(const u8 *)qmp_dp_v3_voltage_swing_hbr3_hbr2,
+			(const u8 *)qmp_dp_v3_pre_emphasis_hbr3_hbr2) < 0)
 		return;
 
 	if (dp_opts->lanes == 1) {
@@ -3728,6 +3738,35 @@  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[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 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 +3796,14 @@  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,
+	if (__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,
+			(const u8 *)qmp_dp_v4_voltage_swing_hbr_rbr,
+			(const u8 *)qmp_dp_v4_pre_emphasis_hbr_rbr,
+			(const u8 *)qmp_dp_v4_voltage_swing_hbr3_hbr2,
+			(const u8 *)qmp_dp_v4_pre_emphasis_hbr3_hbr2) < 0)
+		return;
 }
 
 static int qcom_qmp_v4_phy_configure_dp_phy(struct qmp_phy *qphy)
@@ -3885,6 +3922,9 @@  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 +3936,9 @@  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);