Re: [PATCH] phy: qcom-qmp: add support for voltage and pre emphesis swing
From: khsieh
Date: Fri Aug 27 2021 - 16:00:30 EST
On 2021-08-25 10:49, Stephen Boyd wrote:
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 <khsieh@xxxxxxxxxxxxxx>
Presumably
Fixes: aff188feb5e1 ("phy: qcom-qmp: add support for sm8250-usb3-dp
phy")
---
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?
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?
to avoid confuse, i like to keep them separated.
+ /* 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.
+
+ 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.
add these since they are missed from HPG sequence.
+
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);