[PATCH v9 08/16] PCI: imx6: Simplify switch-case logic by involve init_phy callback

From: Frank Li <Frank.Li@nxp.com>
Date: 2024-01-19 17:12:27
Also in: imx, linux-devicetree, linux-pci, lkml
Subsystem: pci driver for imx6, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers: Richard Zhu, Lucas Stach, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

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. This simplifies the code.

Reviewed-by: Manivannan Sadhasivam <redacted>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v7 to v8:
    - rework commit message
    - wrap comments to 100 chars
    - return 0 at imx7d_pcie_init_phy()
    
    change from v1 to v4:
    - none

 drivers/pci/controller/dwc/pci-imx6.c | 134 +++++++++++++-------------
 1 file changed, 69 insertions(+), 65 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 8df07b71c93e5..dad192f38e702 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/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 {

@@ -322,76 +326,66 @@ 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.
+	 */
+	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_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.
-		 */
-		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:
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX8MQ_GPR_PCIE_VREG_BYPASS,
+				   0);
+
+	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);
 
-		/* configure constant input signal to the pcie ctrl and phy */
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				   IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
-
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-				   IMX6Q_GPR8_TX_DEEMPH_GEN1,
-				   imx6_pcie->tx_deemph_gen1 << 0);
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-				   IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
-				   imx6_pcie->tx_deemph_gen2_3p5db << 6);
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-				   IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
-				   imx6_pcie->tx_deemph_gen2_6db << 12);
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-				   IMX6Q_GPR8_TX_SWING_FULL,
-				   imx6_pcie->tx_swing_full << 18);
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-				   IMX6Q_GPR8_TX_SWING_LOW,
-				   imx6_pcie->tx_swing_low << 25);
-		break;
-	}
+	/* configure constant input signal to the pcie ctrl and phy */
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			   IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
+
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			   IMX6Q_GPR8_TX_DEEMPH_GEN1,
+			   imx6_pcie->tx_deemph_gen1 << 0);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			   IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
+			   imx6_pcie->tx_deemph_gen2_3p5db << 6);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			   IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
+			   imx6_pcie->tx_deemph_gen2_6db << 12);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			   IMX6Q_GPR8_TX_SWING_FULL,
+			   imx6_pcie->tx_swing_full << 18);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			   IMX6Q_GPR8_TX_SWING_LOW,
+			   imx6_pcie->tx_swing_low << 25);
+	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) {

@@ -1382,6 +1380,7 @@ 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,

@@ -1395,6 +1394,7 @@ 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,

@@ -1409,6 +1409,7 @@ 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,

@@ -1420,6 +1421,7 @@ 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,

@@ -1432,6 +1434,7 @@ 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,

@@ -1467,6 +1470,7 @@ 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,

-- 
2.34.1


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