PCI: imx6: Call common PHY API to set mode, speed, and submode

Invoke the common PHY API to configure mode, speed, and submode. While
these functions are optional in the PHY interface, they are necessary for
certain PHY drivers. Lack of support for these functions in a PHY driver
does not cause harm.

Link: https://lore.kernel.org/linux-pci/20240729-pci2_upstream-v8-10-b68ee5ef2b4d@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: nxpfrankli

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

@@ -28,6 +28,7 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/reset.h>
+#include <linux/phy/pcie.h>
 #include <linux/phy/phy.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
@@ -226,6 +227,10 @@ static void imx_pcie_configure_type(struct imx_pcie *imx_pcie)
 
 	id = imx_pcie->controller_id;
 
+	/* If mode_mask is 0, then generic PHY driver is used to set the mode */
+	if (!drvdata->mode_mask[0])
+		return;
+
 	/* If mode_mask[id] is zero, means each controller have its individual gpr */
 	if (!drvdata->mode_mask[id])
 		id = 0;
@@ -801,7 +806,11 @@ static void imx_pcie_ltssm_enable(struct device *dev)
 {
 	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
 	const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
+	u8 offset = dw_pcie_find_capability(imx_pcie->pci, PCI_CAP_ID_EXP);
+	u32 tmp;
 
+	tmp = dw_pcie_readl_dbi(imx_pcie->pci, offset + PCI_EXP_LNKCAP);
+	phy_set_speed(imx_pcie->phy, FIELD_GET(PCI_EXP_LNKCAP_SLS, tmp));
 	if (drvdata->ltssm_mask)
 		regmap_update_bits(imx_pcie->iomuxc_gpr, drvdata->ltssm_off, drvdata->ltssm_mask,
 				   drvdata->ltssm_mask);
@@ -814,6 +823,7 @@ static void imx_pcie_ltssm_disable(struct device *dev)
 	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
 	const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
 
+	phy_set_speed(imx_pcie->phy, 0);
 	if (drvdata->ltssm_mask)
 		regmap_update_bits(imx_pcie->iomuxc_gpr, drvdata->ltssm_off,
 				   drvdata->ltssm_mask, 0);
@@ -949,6 +959,12 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
 			goto err_clk_disable;
 		}
 
+		ret = phy_set_mode_ext(imx_pcie->phy, PHY_MODE_PCIE, PHY_MODE_PCIE_RC);
+		if (ret) {
+			dev_err(dev, "unable to set PCIe PHY mode\n");
+			goto err_phy_exit;
+		}
+
 		ret = phy_power_on(imx_pcie->phy);
 		if (ret) {
 			dev_err(dev, "waiting for PHY ready timeout!\n");