phy: freescale: imx8m-pcie: Add i.MX8MP PCIe PHY support

Add i.MX8MP PCIe PHY support.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/1665625622-20551-5-git-send-email-hongxing.zhu@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/freescale/phy-fsl-imx8m-pcie.c

@@ -48,6 +48,7 @@
 
 enum imx8_pcie_phy_type {
 	IMX8MM,
+	IMX8MP,
 };
 
 struct imx8_pcie_phy_drvdata {
@@ -60,6 +61,7 @@ struct imx8_pcie_phy {
 	struct clk		*clk;
 	struct phy		*phy;
 	struct regmap		*iomuxc_gpr;
+	struct reset_control	*perst;
 	struct reset_control	*reset;
 	u32			refclk_pad_mode;
 	u32			tx_deemph_gen1;
@@ -74,11 +76,11 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
 	u32 val, pad_mode;
 	struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
 
-	reset_control_assert(imx8_phy->reset);
-
 	pad_mode = imx8_phy->refclk_pad_mode;
 	switch (imx8_phy->drvdata->variant) {
 	case IMX8MM:
+		reset_control_assert(imx8_phy->reset);
+
 		/* Tune PHY de-emphasis setting to pass PCIe compliance. */
 		if (imx8_phy->tx_deemph_gen1)
 			writel(imx8_phy->tx_deemph_gen1,
@@ -87,6 +89,8 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
 			writel(imx8_phy->tx_deemph_gen2,
 			       imx8_phy->base + PCIE_PHY_TRSV_REG6);
 		break;
+	case IMX8MP: /* Do nothing. */
+		break;
 	}
 
 	if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ||
@@ -141,6 +145,9 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
 			   IMX8MM_GPR_PCIE_CMN_RST);
 
 	switch (imx8_phy->drvdata->variant) {
+	case IMX8MP:
+		reset_control_deassert(imx8_phy->perst);
+		fallthrough;
 	case IMX8MM:
 		reset_control_deassert(imx8_phy->reset);
 		usleep_range(200, 500);
@@ -181,8 +188,14 @@ static const struct imx8_pcie_phy_drvdata imx8mm_drvdata = {
 	.variant = IMX8MM,
 };
 
+static const struct imx8_pcie_phy_drvdata imx8mp_drvdata = {
+	.gpr = "fsl,imx8mp-iomuxc-gpr",
+	.variant = IMX8MP,
+};
+
 static const struct of_device_id imx8_pcie_phy_of_match[] = {
 	{.compatible = "fsl,imx8mm-pcie-phy", .data = &imx8mm_drvdata, },
+	{.compatible = "fsl,imx8mp-pcie-phy", .data = &imx8mp_drvdata, },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);
@@ -238,6 +251,14 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
 		return PTR_ERR(imx8_phy->reset);
 	}
 
+	if (imx8_phy->drvdata->variant == IMX8MP) {
+		imx8_phy->perst =
+			devm_reset_control_get_exclusive(dev, "perst");
+		if (IS_ERR(imx8_phy->perst))
+			dev_err_probe(dev, PTR_ERR(imx8_phy->perst),
+				      "Failed to get PCIE PHY PERST control\n");
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	imx8_phy->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(imx8_phy->base))