[PATCH v12 05/19] PCI: dwc: Add dw_pcie_link_set_max_width()

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>]

To improve code readability, add dw_pcie_link_set_max_width().
The original code writes the PCIE_PORT_LINK_CONTROL register twice
if the pci->num_lanes is not zero. But, it should avoid to write
the register twice. So, refactor it.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware.c | 65 ++++++++++----------
 1 file changed, 34 insertions(+), 31 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 09e43c2fb247..354e83352398 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -731,6 +731,39 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
 	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed);
 }
 
+static void dw_pcie_link_set_max_width(struct dw_pcie *pci, u32 num_lanes)
+{
+	u32 val;
+
+	/* Set the number of lanes */
+	val = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
+	val &= ~PORT_LINK_FAST_LINK_MODE;
+	val |= PORT_LINK_DLL_LINK_EN;
+
+	/* Mask LINK_MODE if num_lanes is not zero */
+	if (num_lanes)
+		val &= ~PORT_LINK_MODE_MASK;
+
+	switch (num_lanes) {
+	case 1:
+		val |= PORT_LINK_MODE_1_LANES;
+		break;
+	case 2:
+		val |= PORT_LINK_MODE_2_LANES;
+		break;
+	case 4:
+		val |= PORT_LINK_MODE_4_LANES;
+		break;
+	case 8:
+		val |= PORT_LINK_MODE_8_LANES;
+		break;
+	default:
+		dev_dbg(pci->dev, "Using h/w default number of lanes\n");
+		return;
+	}
+	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
+}
+
 static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 {
 	u32 val;
@@ -1034,36 +1067,6 @@ void dw_pcie_setup(struct dw_pcie *pci)
 		dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val);
 	}
 
-	val = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
-	val &= ~PORT_LINK_FAST_LINK_MODE;
-	val |= PORT_LINK_DLL_LINK_EN;
-	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
-
-	if (!pci->num_lanes) {
-		dev_dbg(pci->dev, "Using h/w default number of lanes\n");
-		return;
-	}
-
-	/* Set the number of lanes */
-	val &= ~PORT_LINK_MODE_MASK;
-	switch (pci->num_lanes) {
-	case 1:
-		val |= PORT_LINK_MODE_1_LANES;
-		break;
-	case 2:
-		val |= PORT_LINK_MODE_2_LANES;
-		break;
-	case 4:
-		val |= PORT_LINK_MODE_4_LANES;
-		break;
-	case 8:
-		val |= PORT_LINK_MODE_8_LANES;
-		break;
-	default:
-		dev_err(pci->dev, "num-lanes %u: invalid value\n", pci->num_lanes);
-		return;
-	}
-	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, val);
-
+	dw_pcie_link_set_max_width(pci, pci->num_lanes);
 	dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
 }
-- 
2.25.1