cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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i2c-boardinfo.c (2695B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * i2c-boardinfo.c - collect pre-declarations of I2C devices
      4 */
      5
      6#include <linux/export.h>
      7#include <linux/i2c.h>
      8#include <linux/kernel.h>
      9#include <linux/property.h>
     10#include <linux/rwsem.h>
     11#include <linux/slab.h>
     12
     13#include "i2c-core.h"
     14
     15
     16/* These symbols are exported ONLY FOR the i2c core.
     17 * No other users will be supported.
     18 */
     19DECLARE_RWSEM(__i2c_board_lock);
     20EXPORT_SYMBOL_GPL(__i2c_board_lock);
     21
     22LIST_HEAD(__i2c_board_list);
     23EXPORT_SYMBOL_GPL(__i2c_board_list);
     24
     25int __i2c_first_dynamic_bus_num;
     26EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num);
     27
     28
     29/**
     30 * i2c_register_board_info - statically declare I2C devices
     31 * @busnum: identifies the bus to which these devices belong
     32 * @info: vector of i2c device descriptors
     33 * @len: how many descriptors in the vector; may be zero to reserve
     34 *	the specified bus number.
     35 *
     36 * Systems using the Linux I2C driver stack can declare tables of board info
     37 * while they initialize.  This should be done in board-specific init code
     38 * near arch_initcall() time, or equivalent, before any I2C adapter driver is
     39 * registered.  For example, mainboard init code could define several devices,
     40 * as could the init code for each daughtercard in a board stack.
     41 *
     42 * The I2C devices will be created later, after the adapter for the relevant
     43 * bus has been registered.  After that moment, standard driver model tools
     44 * are used to bind "new style" I2C drivers to the devices.  The bus number
     45 * for any device declared using this routine is not available for dynamic
     46 * allocation.
     47 *
     48 * The board info passed can safely be __initdata, but be careful of embedded
     49 * pointers (for platform_data, functions, etc) since that won't be copied.
     50 */
     51int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len)
     52{
     53	int status;
     54
     55	down_write(&__i2c_board_lock);
     56
     57	/* dynamic bus numbers will be assigned after the last static one */
     58	if (busnum >= __i2c_first_dynamic_bus_num)
     59		__i2c_first_dynamic_bus_num = busnum + 1;
     60
     61	for (status = 0; len; len--, info++) {
     62		struct i2c_devinfo	*devinfo;
     63
     64		devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL);
     65		if (!devinfo) {
     66			pr_debug("i2c-core: can't register boardinfo!\n");
     67			status = -ENOMEM;
     68			break;
     69		}
     70
     71		devinfo->busnum = busnum;
     72		devinfo->board_info = *info;
     73
     74		if (info->resources) {
     75			devinfo->board_info.resources =
     76				kmemdup(info->resources,
     77					info->num_resources *
     78						sizeof(*info->resources),
     79					GFP_KERNEL);
     80			if (!devinfo->board_info.resources) {
     81				status = -ENOMEM;
     82				kfree(devinfo);
     83				break;
     84			}
     85		}
     86
     87		list_add_tail(&devinfo->list, &__i2c_board_list);
     88	}
     89
     90	up_write(&__i2c_board_lock);
     91
     92	return status;
     93}