[PATCH v4 3/6] phy: qcom-qmp-pcie: support separate tables for EP mode

[Dmitry Baryshkov]

The PCIe QMP PHY requires different programming sequences when being
used for the RC (Root Complex) or for the EP (End Point) modes. Allow
selecting the submode and thus selecting a set of PHY programming
tables.

Since the RC and EP modes share common some common init sequence, the
common sequence is kept in the main table and the sequence differences
are pushed to the extra tables.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 67 ++++++++++++++++++++----
 1 file changed, 58 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 6e8c74585670..1fc23df59454 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1320,10 +1320,14 @@ struct qmp_phy_cfg {
 	/* Main init sequence for PHY blocks - serdes, tx, rx, pcs */
 	struct qmp_phy_cfg_tables common;
 	/*
-	 * Additional init sequence for PHY blocks, providing additional
-	 * register programming. Unless required it can be left omitted.
+	 * Additional init sequences for PHY blocks, providing additional
+	 * register programming. They are used for providing separate sequences
+	 * for the Root Complex and for the End Point usecases.
+	 *
+	 * If EP mode is not supported, both tables can be left empty.
 	 */
-	struct qmp_phy_cfg_tables *extra;
+	struct qmp_phy_cfg_tables *extra_rc; /* for the RC only */
+	struct qmp_phy_cfg_tables *extra_ep; /* for the EP only */
 
 	/* clock ids to be requested */
 	const char * const *clk_list;
@@ -1367,6 +1371,7 @@ struct qmp_phy_cfg {
  * @pcs_misc: iomapped memory space for lane's pcs_misc
  * @pipe_clk: pipe clock
  * @qmp: QMP phy to which this lane belongs
+ * @extra: currently selected PHY extra init table set
  */
 struct qmp_phy {
 	struct phy *phy;
@@ -1379,6 +1384,7 @@ struct qmp_phy {
 	void __iomem *rx2;
 	void __iomem *pcs_misc;
 	struct clk *pipe_clk;
+	const struct qmp_phy_cfg_tables *extra;
 	struct qcom_qmp *qmp;
 };
 
@@ -1624,7 +1630,15 @@ static const struct qmp_phy_cfg sm8250_qmp_gen3x1_pciephy_cfg = {
 	.pcs_misc_tbl		= sm8250_qmp_pcie_pcs_misc_tbl,
 	.pcs_misc_tbl_num	= ARRAY_SIZE(sm8250_qmp_pcie_pcs_misc_tbl),
 	},
-	.extra = &(struct qmp_phy_cfg_tables) {
+	/*
+	 * For sm8250 the split between the primary and extra_rc tables is
+	 * historical, it reflects the programming sequence common to all PCIe
+	 * PHYs on this platform and a sequence required for this particular
+	 * PHY type. If EP support for sm8250 is required, the
+	 * primary/extra_rc split is to be reconsidered and adjusted
+	 * according to EP programming sequence.
+	 */
+	.extra_rc = &(struct qmp_phy_cfg_tables) {
 	.serdes_tbl		= sm8250_qmp_gen3x1_pcie_serdes_tbl,
 	.serdes_tbl_num		= ARRAY_SIZE(sm8250_qmp_gen3x1_pcie_serdes_tbl),
 	.rx_tbl			= sm8250_qmp_gen3x1_pcie_rx_tbl,
@@ -1666,7 +1680,15 @@ static const struct qmp_phy_cfg sm8250_qmp_gen3x2_pciephy_cfg = {
 	.pcs_misc_tbl		= sm8250_qmp_pcie_pcs_misc_tbl,
 	.pcs_misc_tbl_num	= ARRAY_SIZE(sm8250_qmp_pcie_pcs_misc_tbl),
 	},
-	.extra = &(struct qmp_phy_cfg_tables) {
+	/*
+	 * For sm8250 the split between the primary and extra_rc tables is
+	 * historical, it reflects the programming sequence common to all PCIe
+	 * PHYs on this platform and a sequence required for this particular
+	 * PHY type. If EP support for sm8250 is required, the
+	 * primary/extra_rc split is to be reconsidered and adjusted
+	 * according to EP programming sequence.
+	 */
+	.extra_rc = &(struct qmp_phy_cfg_tables) {
 	.tx_tbl			= sm8250_qmp_gen3x2_pcie_tx_tbl,
 	.tx_tbl_num		= ARRAY_SIZE(sm8250_qmp_gen3x2_pcie_tx_tbl),
 	.rx_tbl			= sm8250_qmp_gen3x2_pcie_rx_tbl,
@@ -2000,8 +2022,12 @@ static int qmp_pcie_power_on(struct phy *phy)
 	unsigned int mask, val, ready;
 	int ret;
 
+	/* Default to RC mode if the mode was not selected using phy_set_mode_ext() */
+	if (!qphy->extra)
+		qphy->extra = cfg->extra_rc;
+
 	qmp_pcie_serdes_init(qphy, &cfg->common);
-	qmp_pcie_serdes_init(qphy, cfg->extra);
+	qmp_pcie_serdes_init(qphy, qphy->extra);
 
 	ret = clk_prepare_enable(qphy->pipe_clk);
 	if (ret) {
@@ -2011,10 +2037,10 @@ static int qmp_pcie_power_on(struct phy *phy)
 
 	/* Tx, Rx, and PCS configurations */
 	qmp_pcie_lanes_init(qphy, &cfg->common);
-	qmp_pcie_lanes_init(qphy, cfg->extra);
+	qmp_pcie_lanes_init(qphy, qphy->extra);
 
 	qmp_pcie_pcs_init(qphy, &cfg->common);
-	qmp_pcie_pcs_init(qphy, cfg->extra);
+	qmp_pcie_pcs_init(qphy, qphy->extra);
 
 	/*
 	 * Pull out PHY from POWER DOWN state.
@@ -2101,6 +2127,26 @@ static int qmp_pcie_disable(struct phy *phy)
 	return qmp_pcie_exit(phy);
 }
 
+static int qmp_pcie_set_mode(struct phy *phy,
+				 enum phy_mode mode, int submode)
+{
+	struct qmp_phy *qphy = phy_get_drvdata(phy);
+
+	switch (submode) {
+	case PHY_MODE_PCIE_RC:
+		qphy->extra = qphy->cfg->extra_rc;
+		break;
+	case PHY_MODE_PCIE_EP:
+		qphy->extra = qphy->cfg->extra_ep;
+		break;
+	default:
+		dev_err(&phy->dev, "Unuspported submode %d\n", submode);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int qmp_pcie_vreg_init(struct device *dev, const struct qmp_phy_cfg *cfg)
 {
 	struct qcom_qmp *qmp = dev_get_drvdata(dev);
@@ -2224,6 +2270,7 @@ static int phy_pipe_clk_register(struct qcom_qmp *qmp, struct device_node *np)
 static const struct phy_ops qmp_pcie_ops = {
 	.power_on	= qmp_pcie_enable,
 	.power_off	= qmp_pcie_disable,
+	.set_mode	= qmp_pcie_set_mode,
 	.owner		= THIS_MODULE,
 };
 
@@ -2278,7 +2325,9 @@ static int qmp_pcie_create(struct device *dev, struct device_node *np, int id,
 		qphy->pcs_misc = qphy->pcs + 0x400;
 
 	if (IS_ERR(qphy->pcs_misc)) {
-		if (cfg->common.pcs_misc_tbl || cfg->extra->pcs_misc_tbl)
+		if (cfg->common.pcs_misc_tbl ||
+		    cfg->extra_rc->pcs_misc_tbl ||
+		    cfg->extra_ep->pcs_misc_tbl)
 			return PTR_ERR(qphy->pcs_misc);
 	}
 
-- 
2.35.1