drivers/of/of_pci.c

   1 #include <linux/kernel.h>
   2 #include <linux/export.h>
   3 #include <linux/of.h>
   4 #include <linux/of_pci.h>
   5 #include <asm/prom.h>
   6
   7 static inline int __of_pci_pci_compare(struct device_node *node,
   8                                        unsigned int data)
   9 {
  10         int devfn;
  11
  12         devfn = of_pci_get_devfn(node);
  13         if (devfn < 0)
  14                 return 0;
  15
  16         return devfn == data;
  17 }
  18
  19 struct device_node *of_pci_find_child_device(struct device_node *parent,
  20                                              unsigned int devfn)
  21 {
  22         struct device_node *node, *node2;
  23
  24         for_each_child_of_node(parent, node) {
  25                 if (__of_pci_pci_compare(node, devfn))
  26                         return node;
  27                 /*
  28                  * Some OFs create a parent node "multifunc-device" as
  29                  * a fake root for all functions of a multi-function
  30                  * device we go down them as well.
  31                  */
  32                 if (!strcmp(node->name, "multifunc-device")) {
  33                         for_each_child_of_node(node, node2) {
  34                                 if (__of_pci_pci_compare(node2, devfn)) {
  35                                         of_node_put(node);
  36                                         return node2;
  37                                 }
  38                         }
  39                 }
  40         }
  41         return NULL;
  42 }
  43 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
  44
  45 /**
  46  * of_pci_get_devfn() - Get device and function numbers for a device node
  47  * @np: device node
  48  *
  49  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
  50  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
  51  * and function numbers respectively. On error a negative error code is
  52  * returned.
  53  */
  54 int of_pci_get_devfn(struct device_node *np)
  55 {
  56         unsigned int size;
  57         const __be32 *reg;
  58
  59         reg = of_get_property(np, "reg", &size);
  60
  61         if (!reg || size < 5 * sizeof(__be32))
  62                 return -EINVAL;
  63
  64         return (be32_to_cpup(reg) >> 8) & 0xff;
  65 }
  66 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
  67
  68 /**
  69  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
  70  * @node: device node
  71  * @res: address to a struct resource to return the bus-range
  72  *
  73  * Returns 0 on success or a negative error-code on failure.
  74  */
  75 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
  76 {
  77         const __be32 *values;
  78         int len;
  79
  80         values = of_get_property(node, "bus-range", &len);
  81         if (!values || len < sizeof(*values) * 2)
  82                 return -EINVAL;
  83
  84         res->name = node->name;
  85         res->start = be32_to_cpup(values++);
  86         res->end = be32_to_cpup(values);
  87         res->flags = IORESOURCE_BUS;
  88
  89         return 0;
  90 }
  91 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);