PCI: imx6: Simplify switch-case logic by introducing init_phy() callback

Instead of using the switch case statement to initialize the PHY handled by
this driver itself, let's introduce a new callback init_phy() and define it
for platforms that require it.

Link: https://lore.kernel.org/r/20240220161924.3871774-7-Frank.Li@nxp.comSigned-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

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

@@ -69,6 +69,9 @@ enum imx6_pcie_variants {
 #define IMX6_PCIE_MAX_CLKS       6
 
 #define IMX6_PCIE_MAX_INSTANCES			2
+
+struct imx6_pcie;
+
 struct imx6_pcie_drvdata {
 	enum imx6_pcie_variants variant;
 	enum dw_pcie_device_mode mode;
@@ -81,6 +84,7 @@ struct imx6_pcie_drvdata {
 	const u32 ltssm_mask;
 	const u32 mode_off[IMX6_PCIE_MAX_INSTANCES];
 	const u32 mode_mask[IMX6_PCIE_MAX_INSTANCES];
+	int (*init_phy)(struct imx6_pcie *pcie);
 };
 
 struct imx6_pcie {
@@ -322,50 +326,35 @@ static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, u16 data)
 	return 0;
 }
 
-static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
+static int imx8mq_pcie_init_phy(struct imx6_pcie *imx6_pcie)
 {
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX8MM:
-	case IMX8MM_EP:
-	case IMX8MP:
-	case IMX8MP_EP:
-		/*
-		 * The PHY initialization had been done in the PHY
-		 * driver, break here directly.
-		 */
-		break;
-	case IMX8MQ:
-	case IMX8MQ_EP:
-		/*
-		 * TODO: Currently this code assumes external
-		 * oscillator is being used
-		 */
+	/* TODO: Currently this code assumes external oscillator is being used */
 	regmap_update_bits(imx6_pcie->iomuxc_gpr,
 			   imx6_pcie_grp_offset(imx6_pcie),
 			   IMX8MQ_GPR_PCIE_REF_USE_PAD,
 			   IMX8MQ_GPR_PCIE_REF_USE_PAD);
 	/*
-		 * Regarding the datasheet, the PCIE_VPH is suggested
-		 * to be 1.8V. If the PCIE_VPH is supplied by 3.3V, the
-		 * VREG_BYPASS should be cleared to zero.
+	 * Regarding the datasheet, the PCIE_VPH is suggested to be 1.8V. If the PCIE_VPH is
+	 * supplied by 3.3V, the VREG_BYPASS should be cleared to zero.
 	 */
-		if (imx6_pcie->vph &&
-		    regulator_get_voltage(imx6_pcie->vph) > 3000000)
+	if (imx6_pcie->vph && regulator_get_voltage(imx6_pcie->vph) > 3000000)
 		regmap_update_bits(imx6_pcie->iomuxc_gpr,
 				   imx6_pcie_grp_offset(imx6_pcie),
 				   IMX8MQ_GPR_PCIE_VREG_BYPASS,
 				   0);
-		break;
-	case IMX7D:
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
-		break;
-	case IMX6SX:
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				   IMX6SX_GPR12_PCIE_RX_EQ_MASK,
-				   IMX6SX_GPR12_PCIE_RX_EQ_2);
-		fallthrough;
-	default:
+
+	return 0;
+}
+
+static int imx7d_pcie_init_phy(struct imx6_pcie *imx6_pcie)
+{
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
+
+	return 0;
+}
+
+static int imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
+{
 	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
 
@@ -388,10 +377,15 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
 	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
 			   IMX6Q_GPR8_TX_SWING_LOW,
 			   imx6_pcie->tx_swing_low << 25);
-		break;
-	}
+	return 0;
+}
 
-	imx6_pcie_configure_type(imx6_pcie);
+static int imx6sx_pcie_init_phy(struct imx6_pcie *imx6_pcie)
+{
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			   IMX6SX_GPR12_PCIE_RX_EQ_MASK, IMX6SX_GPR12_PCIE_RX_EQ_2);
+
+	return imx6_pcie_init_phy(imx6_pcie);
 }
 
 static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
@@ -902,7 +896,11 @@ static int imx6_pcie_host_init(struct dw_pcie_rp *pp)
 	}
 
 	imx6_pcie_assert_core_reset(imx6_pcie);
-	imx6_pcie_init_phy(imx6_pcie);
+
+	if (imx6_pcie->drvdata->init_phy)
+		imx6_pcie->drvdata->init_phy(imx6_pcie);
+
+	imx6_pcie_configure_type(imx6_pcie);
 
 	ret = imx6_pcie_clk_enable(imx6_pcie);
 	if (ret) {
@@ -1381,6 +1379,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
+		.init_phy = imx6_pcie_init_phy,
 	},
 	[IMX6SX] = {
 		.variant = IMX6SX,
@@ -1394,6 +1393,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
+		.init_phy = imx6sx_pcie_init_phy,
 	},
 	[IMX6QP] = {
 		.variant = IMX6QP,
@@ -1408,6 +1408,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2,
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
+		.init_phy = imx6_pcie_init_phy,
 	},
 	[IMX7D] = {
 		.variant = IMX7D,
@@ -1419,6 +1420,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.clks_cnt = ARRAY_SIZE(imx6q_clks),
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
+		.init_phy = imx7d_pcie_init_phy,
 	},
 	[IMX8MQ] = {
 		.variant = IMX8MQ,
@@ -1431,6 +1433,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.mode_off[1] = IOMUXC_GPR12,
 		.mode_mask[1] = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
+		.init_phy = imx8mq_pcie_init_phy,
 	},
 	[IMX8MM] = {
 		.variant = IMX8MM,
@@ -1466,6 +1469,7 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.mode_off[1] = IOMUXC_GPR12,
 		.mode_mask[1] = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
+		.init_phy = imx8mq_pcie_init_phy,
 	},
 	[IMX8MM_EP] = {
 		.variant = IMX8MM_EP,