1 files changed, 56 insertions, 46 deletions

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 1c1c7348972b..250cf7f40b85 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -365,6 +365,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val)
 	if (ret)
 		dev_err(pci->dev, "write DBI address failed\n");
 }
+EXPORT_SYMBOL_GPL(dw_pcie_write_dbi2);
 
 static inline void __iomem *dw_pcie_select_atu(struct dw_pcie *pci, u32 dir,
 					       u32 index)
@@ -732,6 +733,53 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
 
 }
 
+static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
+{
+	u32 lnkcap, lwsc, plc;
+	u8 cap;
+
+	if (!num_lanes)
+		return;
+
+	/* Set the number of lanes */
+	plc = dw_pcie_readl_dbi(pci, PCIE_PORT_LINK_CONTROL);
+	plc &= ~PORT_LINK_FAST_LINK_MODE;
+	plc &= ~PORT_LINK_MODE_MASK;
+
+	/* Set link width speed control register */
+	lwsc = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+	lwsc &= ~PORT_LOGIC_LINK_WIDTH_MASK;
+	switch (num_lanes) {
+	case 1:
+		plc |= PORT_LINK_MODE_1_LANES;
+		lwsc |= PORT_LOGIC_LINK_WIDTH_1_LANES;
+		break;
+	case 2:
+		plc |= PORT_LINK_MODE_2_LANES;
+		lwsc |= PORT_LOGIC_LINK_WIDTH_2_LANES;
+		break;
+	case 4:
+		plc |= PORT_LINK_MODE_4_LANES;
+		lwsc |= PORT_LOGIC_LINK_WIDTH_4_LANES;
+		break;
+	case 8:
+		plc |= PORT_LINK_MODE_8_LANES;
+		lwsc |= PORT_LOGIC_LINK_WIDTH_8_LANES;
+		break;
+	default:
+		dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes);
+		return;
+	}
+	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc);
+	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc);
+
+	cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
+	lnkcap &= ~PCI_EXP_LNKCAP_MLW;
+	lnkcap |= FIELD_PREP(PCI_EXP_LNKCAP_MLW, num_lanes);
+	dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap);
+}
+
 void dw_pcie_iatu_detect(struct dw_pcie *pci)
 {
 	int max_region, ob, ib;
@@ -840,8 +888,14 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
 	 * Indirect eDMA CSRs access has been completely removed since v5.40a
 	 * thus no space is now reserved for the eDMA channels viewport and
 	 * former DMA CTRL register is no longer fixed to FFs.
+	 *
+	 * Note that Renesas R-Car S4-8's PCIe controllers for unknown reason
+	 * have zeros in the eDMA CTRL register even though the HW-manual
+	 * explicitly states there must FFs if the unrolled mapping is enabled.
+	 * For such cases the low-level drivers are supposed to manually
+	 * activate the unrolled mapping to bypass the auto-detection procedure.
 	 */
-	if (dw_pcie_ver_is_ge(pci, 540A))
+	if (dw_pcie_ver_is_ge(pci, 540A) || dw_pcie_cap_is(pci, EDMA_UNROLL))
 		val = 0xFFFFFFFF;
 	else
 		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
@@ -1013,49 +1067,5 @@ void dw_pcie_setup(struct dw_pcie *pci)
 	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_FAST_LINK_MODE;
-	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);
-
-	/* Set link width speed control register */
-	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
-	val &= ~PORT_LOGIC_LINK_WIDTH_MASK;
-	switch (pci->num_lanes) {
-	case 1:
-		val |= PORT_LOGIC_LINK_WIDTH_1_LANES;
-		break;
-	case 2:
-		val |= PORT_LOGIC_LINK_WIDTH_2_LANES;
-		break;
-	case 4:
-		val |= PORT_LOGIC_LINK_WIDTH_4_LANES;
-		break;
-	case 8:
-		val |= PORT_LOGIC_LINK_WIDTH_8_LANES;
-		break;
-	}
-	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+	dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
 }