fdt: Add ft_system_setup() function for system device tree additions

Add an additional function for adding information to the device tree before
booting. This permits additions which are not board-specific.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>

README

@@ -669,6 +669,13 @@ The following options need to be configured:
 		Board code has addition modification that it wants to make
 		to the flat device tree before handing it off to the kernel
 
+		CONFIG_OF_SYSTEM_SETUP
+
+		Other code has addition modification that it wants to make
+		to the flat device tree before handing it off to the kernel.
+		This causes ft_system_setup() to be called before booting
+		the kernel.
+
 		CONFIG_OF_BOOT_CPU
 
 		This define fills in the correct boot CPU in the boot
@@ -3407,7 +3414,7 @@ FIT uImage format:
 		to 128 or 256, although it does not have to be power of 2).
 
 		default: 4096
-		
+
 		CONFIG_MTD_UBI_BEB_LIMIT
 		This option specifies the maximum bad physical eraseblocks UBI
 		expects on the MTD device (per 1024 eraseblocks). If the

common/cmd_fdt.c

@@ -576,6 +576,18 @@ static int do_fdt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		}
 	}
 #endif
+#ifdef CONFIG_OF_SYSTEM_SETUP
+	/* Call the board-specific fixup routine */
+	else if (strncmp(argv[1], "sys", 3) == 0) {
+		int err = ft_system_setup(working_fdt, gd->bd);
+
+		if (err) {
+			printf("Failed to add system information to FDT: %s\n",
+			       fdt_strerror(err));
+			return CMD_RET_FAILURE;
+		}
+	}
+#endif
 	/* Create a chosen node */
 	else if (strncmp(argv[1], "cho", 3) == 0) {
 		unsigned long initrd_start = 0, initrd_end = 0;
@@ -1015,6 +1027,9 @@ static char fdt_help_text[] =
 #ifdef CONFIG_OF_BOARD_SETUP
 	"fdt boardsetup                      - Do board-specific set up\n"
 #endif
+#ifdef CONFIG_OF_SYSTEM_SETUP
+	"fdt systemsetup                     - Do system-specific set up\n"
+#endif
 	"fdt move   <fdt> <newaddr> <length> - Copy the fdt to <addr> and make it active\n"
 	"fdt resize                          - Resize fdt to size + padding to 4k addr\n"
 	"fdt print  <path> [<prop>]          - Recursive print starting at <path>\n"

common/image-fdt.c

@@ -479,6 +479,13 @@ int image_setup_libfdt(bootm_headers_t *images, void *blob,
 			goto err;
 		}
 	}
+	if (IMAGE_OF_SYSTEM_SETUP) {
+		if (ft_system_setup(blob, gd->bd)) {
+			printf("ERROR: system-specific fdt fixup failed: %s\n",
+			       fdt_strerror(fdt_ret));
+			goto err;
+		}
+	}
 	fdt_fixup_ethernet(blob);
 
 	/* Delete the old LMB reservation */

include/fdt_support.h

@@ -88,6 +88,18 @@ void ft_board_setup_ex(void *blob, bd_t *bd);
 void ft_cpu_setup(void *blob, bd_t *bd);
 void ft_pci_setup(void *blob, bd_t *bd);
 
+/**
+ * Add system-specific data to the FDT before booting the OS.
+ *
+ * Use CONFIG_SYS_FDT_PAD to ensure there is sufficient space.
+ * This function is called if CONFIG_OF_SYSTEM_SETUP is defined
+ *
+ * @param blob		FDT blob to update
+ * @param bd_t		Pointer to board data
+ * @return 0 if ok, or -FDT_ERR_... on error
+ */
+int ft_system_setup(void *blob, bd_t *bd);
+
 void set_working_fdt_addr(void *addr);
 int fdt_shrink_to_minimum(void *blob);
 int fdt_increase_size(void *fdt, int add_len);

include/image.h

@@ -119,6 +119,12 @@ struct lmb;
 # define IMAGE_OF_BOARD_SETUP		0
 #endif
 
+#ifdef CONFIG_OF_SYSTEM_SETUP
+# define IMAGE_OF_SYSTEM_SETUP	1
+#else
+# define IMAGE_OF_SYSTEM_SETUP	0
+#endif
+
 /*
  * Operating System Codes
  */