phy: cadence: Sierra: Add support for PHY multilink configurations

Add support for multilink configuration of Sierra PHY. Currently,
maximum two links are supported.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Reviewed-by: Aswath Govindraju <a-govindraju@ti.com>
Link: https://lore.kernel.org/r/20211223060137.9252-13-sjakhade@cadence.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/cadence/phy-cadence-sierra.c

@@ -24,7 +24,7 @@
 #include <dt-bindings/phy/phy-cadence.h>
 
 #define NUM_SSC_MODE		3
-#define NUM_PHY_TYPE		3
+#define NUM_PHY_TYPE		4
 
 /* PHY register offsets */
 #define SIERRA_COMMON_CDB_OFFSET			0x0
@@ -184,6 +184,13 @@
 				     (0xE000 << (block_offset))
 #define SIERRA_PHY_PMA_CMN_CTRL				0x000
 
+/* PHY PMA lane registers */
+#define SIERRA_PHY_PMA_LANE_CDB_OFFSET(ln, block_offset, reg_offset)	\
+				       ((0xF000 << (block_offset)) +	\
+				       (((ln) << 8) << (reg_offset)))
+
+#define SIERRA_PHY_PMA_XCVR_CTRL			0x000
+
 #define SIERRA_MACRO_ID					0x00007364
 #define SIERRA_MAX_LANES				16
 #define PLL_LOCK_TIME					100000
@@ -299,6 +306,8 @@ struct cdns_sierra_data {
 	u8 reg_offset_shift;
 	struct cdns_sierra_vals *pcs_cmn_vals[NUM_PHY_TYPE][NUM_PHY_TYPE]
 					     [NUM_SSC_MODE];
+	struct cdns_sierra_vals *phy_pma_ln_vals[NUM_PHY_TYPE][NUM_PHY_TYPE]
+						[NUM_SSC_MODE];
 	struct cdns_sierra_vals *pma_cmn_vals[NUM_PHY_TYPE][NUM_PHY_TYPE]
 					     [NUM_SSC_MODE];
 	struct cdns_sierra_vals *pma_ln_vals[NUM_PHY_TYPE][NUM_PHY_TYPE]
@@ -322,6 +331,7 @@ struct cdns_sierra_phy {
 	struct regmap *regmap_phy_pcs_common_cdb;
 	struct regmap *regmap_phy_pcs_lane_cdb[SIERRA_MAX_LANES];
 	struct regmap *regmap_phy_pma_common_cdb;
+	struct regmap *regmap_phy_pma_lane_cdb[SIERRA_MAX_LANES];
 	struct regmap *regmap_common_cdb;
 	struct regmap_field *macro_id_type;
 	struct regmap_field *phy_pll_cfg_1;
@@ -438,6 +448,34 @@ static const struct regmap_config cdns_sierra_phy_pma_cmn_cdb_config = {
 	.reg_read = cdns_regmap_read,
 };
 
+#define SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF(n) \
+{ \
+	.name = "sierra_phy_pma_lane" n "_cdb", \
+	.reg_stride = 1, \
+	.fast_io = true, \
+	.reg_write = cdns_regmap_write, \
+	.reg_read = cdns_regmap_read, \
+}
+
+static const struct regmap_config cdns_sierra_phy_pma_lane_cdb_config[] = {
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("0"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("1"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("2"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("3"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("4"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("5"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("6"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("7"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("8"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("9"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("10"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("11"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("12"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("13"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("14"),
+	SIERRA_PHY_PMA_LANE_CDB_REGMAP_CONF("15"),
+};
+
 static int cdns_sierra_phy_init(struct phy *gphy)
 {
 	struct cdns_sierra_inst *ins = phy_get_drvdata(gphy);
@@ -446,6 +484,7 @@ static int cdns_sierra_phy_init(struct phy *gphy)
 	struct cdns_sierra_vals *pma_cmn_vals, *pma_ln_vals;
 	enum cdns_sierra_phy_type phy_type = ins->phy_type;
 	enum cdns_sierra_ssc_mode ssc = ins->ssc_mode;
+	struct cdns_sierra_vals *phy_pma_ln_vals;
 	const struct cdns_reg_pairs *reg_pairs;
 	struct cdns_sierra_vals *pcs_cmn_vals;
 	struct regmap *regmap;
@@ -453,7 +492,7 @@ static int cdns_sierra_phy_init(struct phy *gphy)
 	int i, j;
 
 	/* Initialise the PHY registers, unless auto configured */
-	if (phy->autoconf)
+	if (phy->autoconf || phy->nsubnodes > 1)
 		return 0;
 
 	clk_set_rate(phy->input_clks[CMN_REFCLK_DIG_DIV], 25000000);
@@ -469,6 +508,18 @@ static int cdns_sierra_phy_init(struct phy *gphy)
 			regmap_write(regmap, reg_pairs[i].off, reg_pairs[i].val);
 	}
 
+	/* PHY PMA lane registers configurations */
+	phy_pma_ln_vals = init_data->phy_pma_ln_vals[phy_type][TYPE_NONE][ssc];
+	if (phy_pma_ln_vals) {
+		reg_pairs = phy_pma_ln_vals->reg_pairs;
+		num_regs = phy_pma_ln_vals->num_regs;
+		for (i = 0; i < ins->num_lanes; i++) {
+			regmap = phy->regmap_phy_pma_lane_cdb[i + ins->mlane];
+			for (j = 0; j < num_regs; j++)
+				regmap_write(regmap, reg_pairs[j].off, reg_pairs[j].val);
+		}
+	}
+
 	/* PMA common registers configurations */
 	pma_cmn_vals = init_data->pma_cmn_vals[phy_type][TYPE_NONE][ssc];
 	if (pma_cmn_vals) {
@@ -502,10 +553,13 @@ static int cdns_sierra_phy_on(struct phy *gphy)
 	u32 val;
 	int ret;
 
-	ret = reset_control_deassert(sp->phy_rst);
+	if (sp->nsubnodes == 1) {
-	if (ret) {
+		/* Take the PHY out of reset */
-		dev_err(dev, "Failed to take the PHY out of reset\n");
+		ret = reset_control_deassert(sp->phy_rst);
-		return ret;
+		if (ret) {
+			dev_err(dev, "Failed to take the PHY out of reset\n");
+			return ret;
+		}
 	}
 
 	/* Take the PHY lane group out of reset */
@@ -923,6 +977,19 @@ static int cdns_regmap_init_blocks(struct cdns_sierra_phy *sp,
 	}
 	sp->regmap_phy_pma_common_cdb = regmap;
 
+	for (i = 0; i < SIERRA_MAX_LANES; i++) {
+		block_offset = SIERRA_PHY_PMA_LANE_CDB_OFFSET(i, block_offset_shift,
+							      reg_offset_shift);
+		regmap = cdns_regmap_init(dev, base, block_offset,
+					  reg_offset_shift,
+					  &cdns_sierra_phy_pma_lane_cdb_config[i]);
+		if (IS_ERR(regmap)) {
+			dev_err(dev, "Failed to init PHY PMA lane CDB regmap\n");
+			return PTR_ERR(regmap);
+		}
+		sp->regmap_phy_pma_lane_cdb[i] = regmap;
+	}
+
 	return 0;
 }
 
@@ -1030,6 +1097,118 @@ static int cdns_sierra_phy_get_resets(struct cdns_sierra_phy *sp,
 	return 0;
 }
 
+static int cdns_sierra_phy_configure_multilink(struct cdns_sierra_phy *sp)
+{
+	const struct cdns_sierra_data *init_data = sp->init_data;
+	struct cdns_sierra_vals *pma_cmn_vals, *pma_ln_vals;
+	enum cdns_sierra_phy_type phy_t1, phy_t2;
+	struct cdns_sierra_vals *phy_pma_ln_vals;
+	const struct cdns_reg_pairs *reg_pairs;
+	struct cdns_sierra_vals *pcs_cmn_vals;
+	int i, j, node, mlane, num_lanes, ret;
+	enum cdns_sierra_ssc_mode ssc;
+	struct regmap *regmap;
+	u32 num_regs;
+
+	/* Maximum 2 links (subnodes) are supported */
+	if (sp->nsubnodes != 2)
+		return -EINVAL;
+
+	clk_set_rate(sp->input_clks[CMN_REFCLK_DIG_DIV], 25000000);
+	clk_set_rate(sp->input_clks[CMN_REFCLK1_DIG_DIV], 25000000);
+
+	/* PHY configured to use both PLL LC and LC1 */
+	regmap_field_write(sp->phy_pll_cfg_1, 0x1);
+
+	phy_t1 = sp->phys[0].phy_type;
+	phy_t2 = sp->phys[1].phy_type;
+
+	/*
+	 * PHY configuration for multi-link operation is done in two steps.
+	 * e.g. Consider a case for a 4 lane PHY with PCIe using 2 lanes and QSGMII other 2 lanes.
+	 * Sierra PHY has 2 PLLs, viz. PLLLC and PLLLC1. So in this case, PLLLC is used for PCIe
+	 * and PLLLC1 is used for QSGMII. PHY is configured in two steps as described below.
+	 *
+	 * [1] For first step, phy_t1 = TYPE_PCIE and phy_t2 = TYPE_QSGMII
+	 *     So the register values are selected as [TYPE_PCIE][TYPE_QSGMII][ssc].
+	 *     This will configure PHY registers associated for PCIe (i.e. first protocol)
+	 *     involving PLLLC registers and registers for first 2 lanes of PHY.
+	 * [2] In second step, the variables phy_t1 and phy_t2 are swapped. So now,
+	 *     phy_t1 = TYPE_QSGMII and phy_t2 = TYPE_PCIE. And the register values are selected as
+	 *     [TYPE_QSGMII][TYPE_PCIE][ssc].
+	 *     This will configure PHY registers associated for QSGMII (i.e. second protocol)
+	 *     involving PLLLC1 registers and registers for other 2 lanes of PHY.
+	 *
+	 * This completes the PHY configuration for multilink operation. This approach enables
+	 * dividing the large number of PHY register configurations into protocol specific
+	 * smaller groups.
+	 */
+	for (node = 0; node < sp->nsubnodes; node++) {
+		if (node == 1) {
+			/*
+			 * If first link with phy_t1 is configured, then configure the PHY for
+			 * second link with phy_t2. Get the array values as [phy_t2][phy_t1][ssc].
+			 */
+			swap(phy_t1, phy_t2);
+		}
+
+		mlane = sp->phys[node].mlane;
+		ssc = sp->phys[node].ssc_mode;
+		num_lanes = sp->phys[node].num_lanes;
+
+		/* PHY PCS common registers configurations */
+		pcs_cmn_vals = init_data->pcs_cmn_vals[phy_t1][phy_t2][ssc];
+		if (pcs_cmn_vals) {
+			reg_pairs = pcs_cmn_vals->reg_pairs;
+			num_regs = pcs_cmn_vals->num_regs;
+			regmap = sp->regmap_phy_pcs_common_cdb;
+			for (i = 0; i < num_regs; i++)
+				regmap_write(regmap, reg_pairs[i].off, reg_pairs[i].val);
+		}
+
+		/* PHY PMA lane registers configurations */
+		phy_pma_ln_vals = init_data->phy_pma_ln_vals[phy_t1][phy_t2][ssc];
+		if (phy_pma_ln_vals) {
+			reg_pairs = phy_pma_ln_vals->reg_pairs;
+			num_regs = phy_pma_ln_vals->num_regs;
+			for (i = 0; i < num_lanes; i++) {
+				regmap = sp->regmap_phy_pma_lane_cdb[i + mlane];
+				for (j = 0; j < num_regs; j++)
+					regmap_write(regmap, reg_pairs[j].off, reg_pairs[j].val);
+			}
+		}
+
+		/* PMA common registers configurations */
+		pma_cmn_vals = init_data->pma_cmn_vals[phy_t1][phy_t2][ssc];
+		if (pma_cmn_vals) {
+			reg_pairs = pma_cmn_vals->reg_pairs;
+			num_regs = pma_cmn_vals->num_regs;
+			regmap = sp->regmap_common_cdb;
+			for (i = 0; i < num_regs; i++)
+				regmap_write(regmap, reg_pairs[i].off, reg_pairs[i].val);
+		}
+
+		/* PMA lane registers configurations */
+		pma_ln_vals = init_data->pma_ln_vals[phy_t1][phy_t2][ssc];
+		if (pma_ln_vals) {
+			reg_pairs = pma_ln_vals->reg_pairs;
+			num_regs = pma_ln_vals->num_regs;
+			for (i = 0; i < num_lanes; i++) {
+				regmap = sp->regmap_lane_cdb[i + mlane];
+				for (j = 0; j < num_regs; j++)
+					regmap_write(regmap, reg_pairs[j].off, reg_pairs[j].val);
+			}
+		}
+	}
+
+	/* Take the PHY out of reset */
+	ret = reset_control_deassert(sp->phy_rst);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int cdns_sierra_phy_probe(struct platform_device *pdev)
 {
 	struct cdns_sierra_phy *sp;
@@ -1149,8 +1328,11 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 	}
 
 	/* If more than one subnode, configure the PHY as multilink */
-	if (!sp->autoconf && sp->nsubnodes > 1)
+	if (!sp->autoconf && sp->nsubnodes > 1) {
-		regmap_field_write(sp->phy_pll_cfg_1, 0x1);
+		ret = cdns_sierra_phy_configure_multilink(sp);
+		if (ret)
+			goto put_child2;
+	}
 
 	pm_runtime_enable(dev);
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);