PCI: rcar: Allow DT to override default window settings

If the DTB specifies dma-ranges, use those values.  Otherwise, default to
the values that were previously hardcoded into the driver.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt b/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
index 7fab84b335313bbd8abc668f347f06c8d0cfe87d..891463cb09c237dbb049f49290c834cd7902343c 100644 (file)
--- a/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
+++ b/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
@@ -24,6 +24,11 @@ Required properties:
 - interrupt-map-mask: standard property that helps to define the interrupt
   mapping.
 
+Optional properties:
+- dma-ranges: a single range for the inbound memory region. If not supplied,
+  defaults to 1GiB at 0x40000000. Note there are hardware restrictions on the
+  allowed combinations of address and size.
+
 Example SoC configuration:
 
        pci0: pci@ee090000  {
@@ -38,6 +43,7 @@ Example SoC configuration:
                #address-cells = <3>;
                #size-cells = <2>;
                #interrupt-cells = <1>;
+               dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000>;
                interrupt-map-mask = <0xff00 0 0 0x7>;
                interrupt-map = <0x0000 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
                                 0x0800 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH

diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
index c4f64bfee551b6cd46c50dabb05cbb5d7b4f5c48..62951165dcbb84065f81d9f186274d1bf3fd9aa1 100644 (file)
--- a/drivers/pci/host/pci-rcar-gen2.c
+++ b/drivers/pci/host/pci-rcar-gen2.c
@@ -15,6 +15,7 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_address.h>
 #include <linux/of_pci.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
@@ -102,6 +103,8 @@ struct rcar_pci_priv {
        unsigned busnr;
        int irq;
        unsigned long window_size;
+       unsigned long window_addr;
+       unsigned long window_pci;
 };
 
 /* PCI configuration space operations */
@@ -239,8 +242,8 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
               RCAR_PCI_ARBITER_PCIBP_MODE;
        iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);
 
-       /* PCI-AHB mapping: 0x40000000 base */
-       iowrite32(0x40000000 | RCAR_PCIAHB_PREFETCH16,
+       /* PCI-AHB mapping */
+       iowrite32(priv->window_addr | RCAR_PCIAHB_PREFETCH16,
                  reg + RCAR_PCIAHB_WIN1_CTR_REG);
 
        /* AHB-PCI mapping: OHCI/EHCI registers */
@@ -251,7 +254,7 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
        iowrite32(RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG,
                  reg + RCAR_AHBPCI_WIN1_CTR_REG);
        /* Set PCI-AHB Window1 address */
-       iowrite32(0x40000000 | PCI_BASE_ADDRESS_MEM_PREFETCH,
+       iowrite32(priv->window_pci | PCI_BASE_ADDRESS_MEM_PREFETCH,
                  reg + PCI_BASE_ADDRESS_1);
        /* Set AHB-PCI bridge PCI communication area address */
        val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
@@ -284,6 +287,64 @@ static struct pci_ops rcar_pci_ops = {
        .write  = pci_generic_config_write,
 };
 
+static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
+                                    struct device_node *node)
+{
+       const int na = 3, ns = 2;
+       int rlen;
+
+       parser->node = node;
+       parser->pna = of_n_addr_cells(node);
+       parser->np = parser->pna + na + ns;
+
+       parser->range = of_get_property(node, "dma-ranges", &rlen);
+       if (!parser->range)
+               return -ENOENT;
+
+       parser->end = parser->range + rlen / sizeof(__be32);
+       return 0;
+}
+
+static int rcar_pci_parse_map_dma_ranges(struct rcar_pci_priv *pci,
+                                        struct device_node *np)
+{
+       struct of_pci_range range;
+       struct of_pci_range_parser parser;
+       int index = 0;
+
+       /* Failure to parse is ok as we fall back to defaults */
+       if (pci_dma_range_parser_init(&parser, np))
+               return 0;
+
+       /* Get the dma-ranges from DT */
+       for_each_of_pci_range(&parser, &range) {
+               /* Hardware only allows one inbound 32-bit range */
+               if (index)
+                       return -EINVAL;
+
+               pci->window_addr = (unsigned long)range.cpu_addr;
+               pci->window_pci = (unsigned long)range.pci_addr;
+               pci->window_size = (unsigned long)range.size;
+
+               /* Catch HW limitations */
+               if (!(range.flags & IORESOURCE_PREFETCH)) {
+                       dev_err(pci->dev, "window must be prefetchable\n");
+                       return -EINVAL;
+               }
+               if (pci->window_addr) {
+                       u32 lowaddr = 1 << (ffs(pci->window_addr) - 1);
+
+                       if (lowaddr < pci->window_size) {
+                               dev_err(pci->dev, "invalid window size/addr\n");
+                               return -EINVAL;
+                       }
+               }
+               index++;
+       }
+
+       return 0;
+}
+
 static int rcar_pci_probe(struct platform_device *pdev)
 {
        struct resource *cfg_res, *mem_res;
@@ -329,6 +390,9 @@ static int rcar_pci_probe(struct platform_device *pdev)
                return priv->irq;
        }
 
+       /* default window addr and size if not specified in DT */
+       priv->window_addr = 0x40000000;
+       priv->window_pci = 0x40000000;
        priv->window_size = SZ_1G;
 
        if (pdev->dev.of_node) {
@@ -344,6 +408,12 @@ static int rcar_pci_probe(struct platform_device *pdev)
                priv->busnr = busnr.start;
                if (busnr.end != busnr.start)
                        dev_warn(&pdev->dev, "only one bus number supported\n");
+
+               ret = rcar_pci_parse_map_dma_ranges(priv, pdev->dev.of_node);
+               if (ret < 0) {
+                       dev_err(&pdev->dev, "failed to parse dma-range\n");
+                       return ret;
+               }
        } else {
                priv->busnr = pdev->id;
        }