From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/i2c/i2c-boardinfo.c | 93 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 drivers/i2c/i2c-boardinfo.c (limited to 'drivers/i2c/i2c-boardinfo.c') diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c new file mode 100644 index 000000000..4df8ad092 --- /dev/null +++ b/drivers/i2c/i2c-boardinfo.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * i2c-boardinfo.c - collect pre-declarations of I2C devices + */ + +#include +#include +#include +#include +#include +#include + +#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. + */ +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->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; +} -- cgit v1.2.3