diff options
Diffstat (limited to 'drivers/of/fdt.c')
| -rw-r--r-- | drivers/of/fdt.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index a6f83ea107ae..1fbeab27075f 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -21,6 +21,7 @@ #include <linux/slab.h> #include <linux/libfdt.h> #include <linux/debugfs.h> +#include <linux/serial_core.h> #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ #include <asm/page.h> @@ -696,6 +697,61 @@ static inline void early_init_dt_check_for_initrd(unsigned long node) } #endif /* CONFIG_BLK_DEV_INITRD */ +#ifdef CONFIG_SERIAL_EARLYCON +extern struct of_device_id __earlycon_of_table[]; + +int __init early_init_dt_scan_chosen_serial(void) +{ + int offset; + const char *p; + int l; + const struct of_device_id *match = __earlycon_of_table; + const void *fdt = initial_boot_params; + + offset = fdt_path_offset(fdt, "/chosen"); + if (offset < 0) + offset = fdt_path_offset(fdt, "/chosen@0"); + if (offset < 0) + return -ENOENT; + + p = fdt_getprop(fdt, offset, "stdout-path", &l); + if (!p) + p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); + if (!p || !l) + return -ENOENT; + + /* Get the node specified by stdout-path */ + offset = fdt_path_offset(fdt, p); + if (offset < 0) + return -ENODEV; + + while (match->compatible) { + unsigned long addr; + if (fdt_node_check_compatible(fdt, offset, match->compatible)) { + match++; + continue; + } + + addr = fdt_translate_address(fdt, offset); + if (!addr) + return -ENXIO; + + of_setup_earlycon(addr, match->data); + return 0; + } + return -ENODEV; +} + +static int __init setup_of_earlycon(char *buf) +{ + if (buf) + return 0; + + return early_init_dt_scan_chosen_serial(); +} +early_param("earlycon", setup_of_earlycon); +#endif + /** * early_init_dt_scan_root - fetch the top level address and size cells */ |