phy: cadence: Sierra: Set cmn_refclk_dig_div/cmn_refclk1_dig_div frequency to 25MHz

Set cmn_refclk_dig_div/cmn_refclk1_dig_div frequency to 25MHz
as specified in "Common Module Clock Configurations" of the Cadence
Sierra 16FFC Multi-Protocol PHY PMA Specification. It is set to 25MHz
since the only user of Cadence Sierra SERDES, TI J721E SoC provides
input clock frequency of 100MHz. For other frequencies,
cmn_refclk_dig_div/cmn_refclk1_dig_div should be configured
based on the "Common Module Clock Configurations".
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

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

@@ -198,6 +198,8 @@ struct cdns_sierra_phy {
 	struct regmap_field *phy_pll_cfg_1;
 	struct regmap_field *pllctrl_lock[SIERRA_MAX_LANES];
 	struct clk *clk;
+	struct clk *cmn_refclk_dig_div;
+	struct clk *cmn_refclk1_dig_div;
 	int nsubnodes;
 	u32 num_lanes;
 	bool autoconf;
@@ -279,6 +281,8 @@ static int cdns_sierra_phy_init(struct phy *gphy)
 	if (phy->autoconf)
 		return 0;
 
+	clk_set_rate(phy->cmn_refclk_dig_div, 25000000);
+	clk_set_rate(phy->cmn_refclk1_dig_div, 25000000);
 	if (ins->phy_type == PHY_TYPE_PCIE) {
 		num_cmn_regs = phy->init_data->pcie_cmn_regs;
 		num_ln_regs = phy->init_data->pcie_ln_regs;
@@ -468,6 +472,7 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 	struct resource *res;
 	int i, ret, node = 0;
 	void __iomem *base;
+	struct clk *clk;
 	struct device_node *dn = dev->of_node, *child;
 
 	if (of_get_child_count(dn) == 0)
@@ -523,6 +528,22 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 		return PTR_ERR(sp->apb_rst);
 	}
 
+	clk = devm_clk_get_optional(dev, "cmn_refclk_dig_div");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "cmn_refclk_dig_div clock not found\n");
+		ret = PTR_ERR(clk);
+		return ret;
+	}
+	sp->cmn_refclk_dig_div = clk;
+
+	clk = devm_clk_get_optional(dev, "cmn_refclk1_dig_div");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "cmn_refclk1_dig_div clock not found\n");
+		ret = PTR_ERR(clk);
+		return ret;
+	}
+	sp->cmn_refclk1_dig_div = clk;
+
 	ret = clk_prepare_enable(sp->clk);
 	if (ret)
 		return ret;