v4.19.13 snapshot.
diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c
new file mode 100644
index 0000000..509a600
--- /dev/null
+++ b/drivers/i2c/i2c-boardinfo.c
@@ -0,0 +1,113 @@
+/*
+ * i2c-boardinfo.c - collect pre-declarations of I2C devices
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/export.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/property.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+
+#include "i2c-core.h"
+
+
+/* These symbols are exported ONLY FOR the i2c core.
+ * No other users will be supported.
+ */
+DECLARE_RWSEM(__i2c_board_lock);
+EXPORT_SYMBOL_GPL(__i2c_board_lock);
+
+LIST_HEAD(__i2c_board_list);
+EXPORT_SYMBOL_GPL(__i2c_board_list);
+
+int __i2c_first_dynamic_bus_num;
+EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
+
+
+/**
+ * i2c_register_board_info - statically declare I2C devices
+ * @busnum: identifies the bus to which these devices belong
+ * @info: vector of i2c device descriptors
+ * @len: how many descriptors in the vector; may be zero to reserve
+ * the specified bus number.
+ *
+ * Systems using the Linux I2C driver stack can declare tables of board info
+ * while they initialize. This should be done in board-specific init code
+ * near arch_initcall() time, or equivalent, before any I2C adapter driver is
+ * registered. For example, mainboard init code could define several devices,
+ * as could the init code for each daughtercard in a board stack.
+ *
+ * The I2C devices will be created later, after the adapter for the relevant
+ * bus has been registered. After that moment, standard driver model tools
+ * are used to bind "new style" I2C drivers to the devices. The bus number
+ * for any device declared using this routine is not available for dynamic
+ * allocation.
+ *
+ * The board info passed can safely be __initdata, but be careful of embedded
+ * pointers (for platform_data, functions, etc) since that won't be copied.
+ * Device properties are deep-copied though.
+ */
+int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
+{
+ int status;
+
+ down_write(&__i2c_board_lock);
+
+ /* dynamic bus numbers will be assigned after the last static one */
+ if (busnum >= __i2c_first_dynamic_bus_num)
+ __i2c_first_dynamic_bus_num = busnum + 1;
+
+ for (status = 0; len; len--, info++) {
+ struct i2c_devinfo *devinfo;
+
+ devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
+ if (!devinfo) {
+ pr_debug("i2c-core: can't register boardinfo!\n");
+ status = -ENOMEM;
+ break;
+ }
+
+ devinfo->busnum = busnum;
+ devinfo->board_info = *info;
+
+ if (info->properties) {
+ devinfo->board_info.properties =
+ property_entries_dup(info->properties);
+ if (IS_ERR(devinfo->board_info.properties)) {
+ status = PTR_ERR(devinfo->board_info.properties);
+ kfree(devinfo);
+ break;
+ }
+ }
+
+ if (info->resources) {
+ devinfo->board_info.resources =
+ kmemdup(info->resources,
+ info->num_resources *
+ sizeof(*info->resources),
+ GFP_KERNEL);
+ if (!devinfo->board_info.resources) {
+ status = -ENOMEM;
+ kfree(devinfo);
+ break;
+ }
+ }
+
+ list_add_tail(&devinfo->list, &__i2c_board_list);
+ }
+
+ up_write(&__i2c_board_lock);
+
+ return status;
+}