devicetree/fdt_pci: implement the fdt_pci_ecam_register()

So the borad level do not need implement the
pci_ecam_register_from_fdt() again and again.

Signed-off-by: Bowen Wang <wangbowen6@xiaomi.com>

drivers/devicetree/CMakeLists.txt

@@ -20,6 +20,10 @@
 if(CONFIG_DEVICE_TREE)
   set(SRCS fdt.c)
 
+  if(CONFIG_PCI)
+    list(APPEND SRCS fdt_pci.c)
+  endif()
+
   target_include_directories(drivers
                              PRIVATE ${NUTTX_DIR}/libs/libc/fdt/dtc/libfdt)
   target_sources(drivers PRIVATE ${SRCS})

drivers/devicetree/Make.defs

@@ -22,6 +22,10 @@ ifeq ($(CONFIG_DEVICE_TREE),y)
 
 CSRCS += fdt.c
 
+ifeq ($(CONFIG_PCI),y)
+  CSRCS += fdt_pci.c
+endif
+
 CFLAGS += ${INCDIR_PREFIX}$(TOPDIR)$(DELIM)libs$(DELIM)libc$(DELIM)fdt$(DELIM)dtc$(DELIM)libfdt
 
 DEPPATH += --dep-path devicetree

drivers/devicetree/fdt_pci.c

@@ -0,0 +1,139 @@
+/****************************************************************************
+ * drivers/devicetree/fdt_pci.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <errno.h>
+
+#include <nuttx/pci/pci_ecam.h>
+#include <nuttx/fdt.h>
+
+#include <libfdt.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define FDT_PCI_TYPE_IO       0x01000000
+#define FDT_PCI_TYPE_MEM32    0x02000000
+#define FDT_PCI_TYPE_MEM64    0x03000000
+#define FDT_PCI_TYPE_MASK     0x03000000
+#define FDT_PCI_PREFTCH       0x40000000
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: fdt_pci_ecam_register
+ *
+ * Description:
+ *   This function is used to register an ecam driver from the device tree
+ *
+ * Input Parameters:
+ *   fdt      - Device tree handle
+ *
+ * Returned Value:
+ *   Return 0 if success, nageative if failed
+ *
+ ****************************************************************************/
+
+int fdt_pci_ecam_register(FAR const void *fdt)
+{
+  struct pci_resource_s prefetch;
+  struct pci_resource_s cfg;
+  struct pci_resource_s mem;
+  struct pci_resource_s io;
+  FAR const fdt32_t *ranges;
+  int offset;
+
+  /* #address-size must be 3
+   * defined in the PCI Bus Binding to IEEE Std 1275-1994 :
+   * Bit#
+   *
+   * phys.hi cell:  npt000ss bbbbbbbb dddddfff rrrrrrrr
+   * phys.mid cell: hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
+   * phys.lo cell:  llllllll llllllll llllllll llllllll
+   */
+
+  const int na = 3;
+
+  /* #size-cells must be 2 */
+
+  const int ns = 2;
+  int rlen;
+  int pna;
+
+  memset(&prefetch, 0, sizeof(prefetch));
+  memset(&cfg, 0, sizeof(cfg));
+  memset(&mem, 0, sizeof(mem));
+  memset(&io, 0, sizeof(io));
+
+  offset = fdt_node_offset_by_compatible(fdt, -1,
+                                         "pci-host-ecam-generic");
+  if (offset < 0)
+    {
+      return offset;
+    }
+
+  /* Get the reg address, 64 or 32 */
+
+  cfg.start = fdt_get_reg_base(fdt, offset);
+  cfg.end = cfg.start + fdt_get_reg_size(fdt, offset);
+
+  /* Get the ranges address */
+
+  ranges = fdt_getprop(fdt, offset, "ranges", &rlen);
+  if (ranges == NULL)
+    {
+      return -EINVAL;
+    }
+
+  pna = fdt_get_parent_address_cells(fdt, offset);
+
+  for (rlen /= 4; (rlen -= na + pna + ns) >= 0; ranges += na + pna + ns)
+    {
+      uint32_t type = fdt32_ld(ranges);
+
+      if ((type & FDT_PCI_TYPE_MASK) == FDT_PCI_TYPE_IO)
+        {
+          io.start = fdt_ld_by_cells(ranges + na, pna);
+          io.end = io.start + fdt_ld_by_cells(ranges + na + pna, ns);
+        }
+      else if ((type & FDT_PCI_PREFTCH) == FDT_PCI_PREFTCH)
+        {
+          prefetch.start = fdt_ld_by_cells(ranges + na, pna);
+          prefetch.end = prefetch.start +
+                         fdt_ld_by_cells(ranges + na + pna, ns);
+        }
+      else if (((type & FDT_PCI_TYPE_MEM32) == FDT_PCI_TYPE_MEM32 &&
+                sizeof(uintptr_t) == 4) ||
+               ((type & FDT_PCI_TYPE_MEM64) == FDT_PCI_TYPE_MEM64 &&
+                sizeof(uintptr_t) == 8))
+        {
+          mem.start = fdt_ld_by_cells(ranges + na, pna);
+          mem.end = mem.start + fdt_ld_by_cells(ranges + na + pna, ns);
+        }
+    }
+
+  return pci_ecam_register(&cfg, &io, &mem, &prefetch);
+}

include/nuttx/fdt.h

@@ -409,4 +409,22 @@ int fdt_load_prop_u32(FAR const void *fdt, int offset,
                       FAR const char *property, int index,
                       FAR uint32_t *value);
 
+/****************************************************************************
+ * Name: pci_ecam_register_from_fdt
+ *
+ * Description:
+ *   This function is used to register an ecam driver from the device tree
+ *
+ * Input Parameters:
+ *   fdt      - Device tree handle
+ *
+ * Returned Value:
+ *   Return 0 if success, nageative if failed
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_PCI
+int fdt_pci_ecam_register(FAR const void *fdt);
+#endif
+
 #endif /* __INCLUDE_NUTTX_FDT_H */