PCI: dwc: Rename 'dw_pcie::link_gen' to 'dw_pcie::max_link_speed'

The 'link_gen' field is now holding the maximum supported link speed set
either by the controller driver or by DT through 'max-link-speed'
property.

However, the name 'link_gen' sounds like the negotiated link speed of
the PCIe link.

So rename it to 'max_link_speed' to make it clear that it holds the
maximum supported link speed of the controller.

Link: https://lore.kernel.org/linux-pci/20240911-pci-qcom-gen4-stability-v7-1-743f5c1fd027@linaro.orgTested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>

drivers/pci/controller/dwc/pci-imx6.c

@@ -847,12 +847,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
 	if (ret)
 		goto err_reset_phy;
 
-	if (pci->link_gen > 1) {
+	if (pci->max_link_speed > 1) {
 		/* Allow faster modes after the link is up */
 		dw_pcie_dbi_ro_wr_en(pci);
 		tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
 		tmp &= ~PCI_EXP_LNKCAP_SLS;
-		tmp |= pci->link_gen;
+		tmp |= pci->max_link_speed;
 		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
 
 		/*
@@ -1386,8 +1386,8 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 		imx6_pcie->tx_swing_low = 127;
 
 	/* Limit link speed */
-	pci->link_gen = 1;
-	of_property_read_u32(node, "fsl,max-link-speed", &pci->link_gen);
+	pci->max_link_speed = 1;
+	of_property_read_u32(node, "fsl,max-link-speed", &pci->max_link_speed);
 
 	imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
 	if (IS_ERR(imx6_pcie->vpcie)) {

drivers/pci/controller/dwc/pcie-designware.c

@@ -168,8 +168,8 @@ int dw_pcie_get_resources(struct dw_pcie *pci)
 			return ret;
 	}
 
-	if (pci->link_gen < 1)
-		pci->link_gen = of_pci_get_max_link_speed(np);
+	if (pci->max_link_speed < 1)
+		pci->max_link_speed = of_pci_get_max_link_speed(np);
 
 	of_property_read_u32(np, "num-lanes", &pci->num_lanes);
 
@@ -689,7 +689,7 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci)
 }
 EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup);
 
-static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
+static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 max_link_speed)
 {
 	u32 cap, ctrl2, link_speed;
 	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
@@ -698,7 +698,7 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
 	ctrl2 = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCTL2);
 	ctrl2 &= ~PCI_EXP_LNKCTL2_TLS;
 
-	switch (pcie_link_speed[link_gen]) {
+	switch (pcie_link_speed[max_link_speed]) {
 	case PCIE_SPEED_2_5GT:
 		link_speed = PCI_EXP_LNKCTL2_TLS_2_5GT;
 		break;
@@ -1060,8 +1060,8 @@ void dw_pcie_setup(struct dw_pcie *pci)
 {
 	u32 val;
 
-	if (pci->link_gen > 0)
-		dw_pcie_link_set_max_speed(pci, pci->link_gen);
+	if (pci->max_link_speed > 0)
+		dw_pcie_link_set_max_speed(pci, pci->max_link_speed);
 
 	/* Configure Gen1 N_FTS */
 	if (pci->n_fts[0]) {

drivers/pci/controller/dwc/pcie-designware.h

@@ -423,7 +423,7 @@ struct dw_pcie {
 	u32			type;
 	unsigned long		caps;
 	int			num_lanes;
-	int			link_gen;
+	int			max_link_speed;
 	u8			n_fts[2];
 	struct dw_edma_chip	edma;
 	struct clk_bulk_data	app_clks[DW_PCIE_NUM_APP_CLKS];

drivers/pci/controller/dwc/pcie-intel-gw.c

@@ -132,7 +132,7 @@ static void intel_pcie_link_setup(struct intel_pcie *pcie)
 
 static void intel_pcie_init_n_fts(struct dw_pcie *pci)
 {
-	switch (pci->link_gen) {
+	switch (pci->max_link_speed) {
 	case 3:
 		pci->n_fts[1] = PORT_AFR_N_FTS_GEN3;
 		break;
@@ -252,7 +252,7 @@ static int intel_pcie_wait_l2(struct intel_pcie *pcie)
 	int ret;
 	struct dw_pcie *pci = &pcie->pci;
 
-	if (pci->link_gen < 3)
+	if (pci->max_link_speed < 3)
 		return 0;
 
 	/* Send PME_TURN_OFF message */

drivers/pci/controller/dwc/pcie-rcar-gen4.c

@@ -141,10 +141,10 @@ static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
 	}
 
 	/*
-	 * Require direct speed change with retrying here if the link_gen is
-	 * PCIe Gen2 or higher.
+	 * Require direct speed change with retrying here if the max_link_speed
+	 * is PCIe Gen2 or higher.
 	 */
-	changes = min_not_zero(dw->link_gen, RCAR_MAX_LINK_SPEED) - 1;
+	changes = min_not_zero(dw->max_link_speed, RCAR_MAX_LINK_SPEED) - 1;
 
 	/*
 	 * Since dw_pcie_setup_rc() sets it once, PCIe Gen2 will be trained.

drivers/pci/controller/dwc/pcie-spear13xx.c

@@ -233,7 +233,7 @@ static int spear13xx_pcie_probe(struct platform_device *pdev)
 	}
 
 	if (of_property_read_bool(np, "st,pcie-is-gen1"))
-		pci->link_gen = 1;
+		pci->max_link_speed = 1;
 
 	platform_set_drvdata(pdev, spear13xx_pcie);