src/patches/kernel/wandboard/imx/0013-of-pci-Provide-support-for-parsing-PCI-DT-ranges-pro.patch

   1 From: Andrew Murray <Andrew.Murray@arm.com>
   2 Subject: [PATCH] of/pci: Provide support for parsing PCI DT ranges property
   3
   4 This patch factors out common implementation patterns to reduce overall kernel
   5 code and provide a means for host bridge drivers to directly obtain struct
   6 resources from the DT's ranges property without relying on architecture specific
   7 DT handling. This will make it easier to write archiecture independent host bridge
   8 drivers and mitigate against further duplication of DT parsing code.
   9
  10 This patch can be used in the following way:
  11
  12         struct of_pci_range_parser parser;
  13         struct of_pci_range range;
  14
  15         if (of_pci_range_parser_init(&parser, np))
  16                 ; //no ranges property
  17
  18         for_each_of_pci_range(&parser, &range) {
  19
  20                 /*
  21                         directly access properties of the address range, e.g.:
  22                         range.pci_space, range.pci_addr, range.cpu_addr,
  23                         range.size, range.flags
  24
  25                         alternatively obtain a struct resource, e.g.:
  26                         struct resource res;
  27                         of_pci_range_to_resource(&range, np, &res);
  28                 */
  29         }
  30
  31 Additionally the implementation takes care of adjacent ranges and merges them
  32 into a single range (as was the case with powerpc and microblaze).
  33
  34 Signed-off-by: Andrew Murray <Andrew.Murray@arm.com>
  35 Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
  36 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  37 Reviewed-by: Rob Herring <rob.herring@calxeda.com>
  38 Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  39 Tested-by: Linus Walleij <linus.walleij@linaro.org>
  40 Tested-by: Jingoo Han <jg1.han@samsung.com>
  41 Acked-by: Grant Likely <grant.likely@secretlab.ca>
  42 Signed-off-by: Jason Cooper <jason@lakedaemon.net>
  43 ---
  44  drivers/of/address.c       | 67 ++++++++++++++++++++++++++++++++++++++++++++++
  45  include/linux/of_address.h | 48 +++++++++++++++++++++++++++++++++
  46  2 files changed, 115 insertions(+)
  47
  48 --- a/drivers/of/address.c
  49 +++ b/drivers/of/address.c
  50 @@ -231,6 +231,73 @@ int of_pci_address_to_resource(struct de
  51         return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
  52  }
  53  EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
  54 +
  55 +int of_pci_range_parser_init(struct of_pci_range_parser *parser,
  56 +                               struct device_node *node)
  57 +{
  58 +       const int na = 3, ns = 2;
  59 +       int rlen;
  60 +
  61 +       parser->node = node;
  62 +       parser->pna = of_n_addr_cells(node);
  63 +       parser->np = parser->pna + na + ns;
  64 +
  65 +       parser->range = of_get_property(node, "ranges", &rlen);
  66 +       if (parser->range == NULL)
  67 +               return -ENOENT;
  68 +
  69 +       parser->end = parser->range + rlen / sizeof(__be32);
  70 +
  71 +       return 0;
  72 +}
  73 +EXPORT_SYMBOL_GPL(of_pci_range_parser_init);
  74 +
  75 +struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
  76 +                                               struct of_pci_range *range)
  77 +{
  78 +       const int na = 3, ns = 2;
  79 +
  80 +       if (!range)
  81 +               return NULL;
  82 +
  83 +       if (!parser->range || parser->range + parser->np > parser->end)
  84 +               return NULL;
  85 +
  86 +       range->pci_space = parser->range[0];
  87 +       range->flags = of_bus_pci_get_flags(parser->range);
  88 +       range->pci_addr = of_read_number(parser->range + 1, ns);
  89 +       range->cpu_addr = of_translate_address(parser->node,
  90 +                               parser->range + na);
  91 +       range->size = of_read_number(parser->range + parser->pna + na, ns);
  92 +
  93 +       parser->range += parser->np;
  94 +
  95 +       /* Now consume following elements while they are contiguous */
  96 +       while (parser->range + parser->np <= parser->end) {
  97 +               u32 flags, pci_space;
  98 +               u64 pci_addr, cpu_addr, size;
  99 +
 100 +               pci_space = be32_to_cpup(parser->range);
 101 +               flags = of_bus_pci_get_flags(parser->range);
 102 +               pci_addr = of_read_number(parser->range + 1, ns);
 103 +               cpu_addr = of_translate_address(parser->node,
 104 +                               parser->range + na);
 105 +               size = of_read_number(parser->range + parser->pna + na, ns);
 106 +
 107 +               if (flags != range->flags)
 108 +                       break;
 109 +               if (pci_addr != range->pci_addr + range->size ||
 110 +                   cpu_addr != range->cpu_addr + range->size)
 111 +                       break;
 112 +
 113 +               range->size += size;
 114 +               parser->range += parser->np;
 115 +       }
 116 +
 117 +       return range;
 118 +}
 119 +EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
 120 +
 121  #endif /* CONFIG_PCI */
 122
 123  /*
 124 --- a/include/linux/of_address.h
 125 +++ b/include/linux/of_address.h
 126 @@ -4,6 +4,36 @@
 127  #include <linux/errno.h>
 128  #include <linux/of.h>
 129
 130 +struct of_pci_range_parser {
 131 +       struct device_node *node;
 132 +       const __be32 *range;
 133 +       const __be32 *end;
 134 +       int np;
 135 +       int pna;
 136 +};
 137 +
 138 +struct of_pci_range {
 139 +       u32 pci_space;
 140 +       u64 pci_addr;
 141 +       u64 cpu_addr;
 142 +       u64 size;
 143 +       u32 flags;
 144 +};
 145 +
 146 +#define for_each_of_pci_range(parser, range) \
 147 +       for (; of_pci_range_parser_one(parser, range);)
 148 +
 149 +static inline void of_pci_range_to_resource(struct of_pci_range *range,
 150 +                                           struct device_node *np,
 151 +                                           struct resource *res)
 152 +{
 153 +       res->flags = range->flags;
 154 +       res->start = range->cpu_addr;
 155 +       res->end = range->cpu_addr + range->size - 1;
 156 +       res->parent = res->child = res->sibling = NULL;
 157 +       res->name = np->full_name;
 158 +}
 159 +
 160  #ifdef CONFIG_OF_ADDRESS
 161  extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
 162  extern bool of_can_translate_address(struct device_node *dev);
 163 @@ -27,6 +57,11 @@ static inline unsigned long pci_address_
 164  #define pci_address_to_pio pci_address_to_pio
 165  #endif
 166
 167 +extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,
 168 +                       struct device_node *node);
 169 +extern struct of_pci_range *of_pci_range_parser_one(
 170 +                                       struct of_pci_range_parser *parser,
 171 +                                       struct of_pci_range *range);
 172  #else /* CONFIG_OF_ADDRESS */
 173  #ifndef of_address_to_resource
 174  static inline int of_address_to_resource(struct device_node *dev, int index,
 175 @@ -53,6 +88,19 @@ static inline const __be32 *of_get_addre
 176  {
 177         return NULL;
 178  }
 179 +
 180 +static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,
 181 +                       struct device_node *node)
 182 +{
 183 +       return -1;
 184 +}
 185 +
 186 +static inline struct of_pci_range *of_pci_range_parser_one(
 187 +                                       struct of_pci_range_parser *parser,
 188 +                                       struct of_pci_range *range)
 189 +{
 190 +       return NULL;
 191 +}
 192  #endif /* CONFIG_OF_ADDRESS */
 193
 194