pcie: designware: mvebu: do not configure ATU for IO when not used

The pcie_dw_mvebu configure ATU regions for memory, configuration
and IO space types. However the latter is not obligatory
and when not specified in the device tree, causes wrong
ATU configuration. Fix that by adding a dependency on the
detected PCIE regions count.

Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-on: https://sj1git1.cavium.com/18136
Reviewed-by: Kostya Porotchkin <kostap@marvell.com>
Tested-by: Kostya Porotchkin <kostap@marvell.com>
diff --git a/drivers/pci/pcie_dw_mvebu.c b/drivers/pci/pcie_dw_mvebu.c
index 93e57cf..0490fd3 100644
--- a/drivers/pci/pcie_dw_mvebu.c
+++ b/drivers/pci/pcie_dw_mvebu.c
@@ -115,6 +115,7 @@
 	int first_busno;
 
 	/* IO and MEM PCI regions */
+	int region_count;
 	struct pci_region io;
 	struct pci_region mem;
 };
@@ -267,9 +268,10 @@
 	debug("(addr,val)=(0x%04x, 0x%08lx)\n", offset, value);
 	*valuep = pci_conv_32_to_size(value, offset, size);
 
-	pcie_dw_prog_outbound_atu(pcie, PCIE_ATU_REGION_INDEX0,
-				  PCIE_ATU_TYPE_IO, pcie->io.phys_start,
-				  pcie->io.bus_start, pcie->io.size);
+	if (pcie->region_count > 1)
+		pcie_dw_prog_outbound_atu(pcie, PCIE_ATU_REGION_INDEX0,
+					  PCIE_ATU_TYPE_IO, pcie->io.phys_start,
+					  pcie->io.bus_start, pcie->io.size);
 
 	return 0;
 }
@@ -312,9 +314,10 @@
 	value = pci_conv_size_to_32(old, value, offset, size);
 	writel(value, va_address);
 
-	pcie_dw_prog_outbound_atu(pcie, PCIE_ATU_REGION_INDEX0,
-				  PCIE_ATU_TYPE_IO, pcie->io.phys_start,
-				  pcie->io.bus_start, pcie->io.size);
+	if (pcie->region_count > 1)
+		pcie_dw_prog_outbound_atu(pcie, PCIE_ATU_REGION_INDEX0,
+					  PCIE_ATU_TYPE_IO, pcie->io.phys_start,
+					  pcie->io.bus_start, pcie->io.size);
 
 	return 0;
 }
@@ -513,14 +516,24 @@
 		       hose->first_busno);
 	}
 
+	pcie->region_count = hose->region_count - CONFIG_NR_DRAM_BANKS;
+
 	/* Store the IO and MEM windows settings for future use by the ATU */
-	pcie->io.phys_start = hose->regions[0].phys_start; /* IO base */
-	pcie->io.bus_start  = hose->regions[0].bus_start;  /* IO_bus_addr */
-	pcie->io.size	    = hose->regions[0].size;	   /* IO size */
+	if (pcie->region_count > 1) {
+		/* IO base */
+		pcie->io.phys_start = hose->regions[0].phys_start;
+		/* IO_bus_addr */
+		pcie->io.bus_start  = hose->regions[0].bus_start;
+		/* IO size */
+		pcie->io.size       = hose->regions[0].size;
+	}
 
-	pcie->mem.phys_start = hose->regions[1].phys_start; /* MEM base */
-	pcie->mem.bus_start  = hose->regions[1].bus_start;  /* MEM_bus_addr */
-	pcie->mem.size	     = hose->regions[1].size;	    /* MEM size */
+	/* MEM base */
+	pcie->mem.phys_start = hose->regions[pcie->region_count - 1].phys_start;
+	/* MEM_bus_addr */
+	pcie->mem.bus_start  = hose->regions[pcie->region_count - 1].bus_start;
+	/* MEM size */
+	pcie->mem.size       = hose->regions[pcie->region_count - 1].size;
 
 	pcie_dw_prog_outbound_atu(pcie, PCIE_ATU_REGION_INDEX1,
 				  PCIE_ATU_TYPE_MEM, pcie->mem.phys_start,