staging: mt7621-pci: fix io space and properly set resource limits

Function 'mt7621_pci_parse_request_of_pci_ranges' is using
'of_pci_range_to_resource' to get both mem and io resources.
Internally this function calls to 'pci_address_to_pio' which
returns -1 if io space address is an address > IO_SPACE_LIMIT
which is 0xFFFF for mips. This mt7621 soc has io space in physical
address 0x1e160000. In order to fix this, overwrite invalid io
0xffffffff  with properly values from the device tree and set
mapped address of this resource as io port base memory address
calling 'set_io_port_base' function. There is also need to properly
setup resource limits and io and memory windows with properly
parsed values instead of set them as 'no limit' which it is wrong.
For any reason I don't really know legacy driver sets up mem window
as 0xFFFFFFFF and any other value seems to does not work as expected,
so set up also here with same values.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20200318094445.19669-1-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-pci/pci-mt7621.c

@@ -118,6 +118,7 @@ struct mt7621_pcie_port {
  * @busn: bus range
  * @offset: IO / Memory offset
  * @dev: Pointer to PCIe device
+ * @io_map_base: virtual memory base address for io
  * @ports: pointer to PCIe port information
  * @resets_inverted: depends on chip revision
  * reset lines are inverted.
@@ -132,6 +133,7 @@ struct mt7621_pcie {
 		resource_size_t mem;
 		resource_size_t io;
 	} offset;
+	unsigned long io_map_base;
 	struct list_head ports;
 	bool resets_inverted;
 };
@@ -291,22 +293,21 @@ static int mt7621_pci_parse_request_of_pci_ranges(struct mt7621_pcie *pcie)
 	}
 
 	for_each_of_pci_range(&parser, &range) {
-		struct resource *res = NULL;
-
 		switch (range.flags & IORESOURCE_TYPE_BITS) {
 		case IORESOURCE_IO:
-			ioremap(range.cpu_addr, range.size);
-			res = &pcie->io;
+			pcie->io_map_base =
+				(unsigned long)ioremap(range.cpu_addr,
+						       range.size);
+			of_pci_range_to_resource(&range, node, &pcie->io);
+			pcie->io.start = range.cpu_addr;
+			pcie->io.end = range.cpu_addr + range.size - 1;
 			pcie->offset.io = 0x00000000UL;
 			break;
 		case IORESOURCE_MEM:
-			res = &pcie->mem;
+			of_pci_range_to_resource(&range, node, &pcie->mem);
 			pcie->offset.mem = 0x00000000UL;
 			break;
 		}
-
-		if (res)
-			of_pci_range_to_resource(&range, node, res);
 	}
 
 	err = of_pci_parse_bus_range(node, &pcie->busn);
@@ -318,6 +319,8 @@ static int mt7621_pci_parse_request_of_pci_ranges(struct mt7621_pcie *pcie)
 		pcie->busn.flags = IORESOURCE_BUS;
 	}
 
+	set_io_port_base(pcie->io_map_base);
+
 	return 0;
 }
 
@@ -548,6 +551,10 @@ static void mt7621_pcie_enable_ports(struct mt7621_pcie *pcie)
 	u32 slot;
 	u32 val;
 
+	/* Setup MEMWIN and IOWIN */
+	pcie_write(pcie, 0xffffffff, RALINK_PCI_MEMBASE);
+	pcie_write(pcie, pcie->io.start, RALINK_PCI_IOBASE);
+
 	list_for_each_entry(port, &pcie->ports, list) {
 		if (port->enabled) {
 			mt7621_pcie_port_clk_enable(port);
@@ -668,11 +675,17 @@ static int mt7621_pci_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	err = mt7621_pci_parse_request_of_pci_ranges(pcie);
+	if (err) {
+		dev_err(dev, "Error requesting pci resources from ranges");
+		goto out_release_gpios;
+	}
+
 	/* set resources limits */
-	iomem_resource.start = 0;
-	iomem_resource.end = ~0UL; /* no limit */
-	ioport_resource.start = 0;
-	ioport_resource.end = ~0UL; /* no limit */
+	iomem_resource.start = pcie->mem.start;
+	iomem_resource.end = pcie->mem.end;
+	ioport_resource.start = pcie->io.start;
+	ioport_resource.end = pcie->io.end;
 
 	mt7621_pcie_init_ports(pcie);
 
@@ -685,12 +698,6 @@ static int mt7621_pci_probe(struct platform_device *pdev)
 
 	mt7621_pcie_enable_ports(pcie);
 
-	err = mt7621_pci_parse_request_of_pci_ranges(pcie);
-	if (err) {
-		dev_err(dev, "Error requesting pci resources from ranges");
-		goto out_release_gpios;
-	}
-
 	setup_cm_memory_region(pcie);
 
 	err = mt7621_pcie_request_resources(pcie, &res);