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power: reset: nvmem-reboot-mode: use NVMEM as reboot mode write interface 

Add a new reboot mode write interface that is using an NVMEM cell
to store the reboot mode magic.

Signed-off-by: Nandor Han <nandor.han@vaisala.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
This commit is contained in:
Han Nandor 2019-05-15 10:47:14 +00:00 committed by Sebastian Reichel
parent cba155e50a
commit 7a78a7f769
3 changed files with 86 additions and 0 deletions
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9
drivers/power/reset/Kconfig
View File

@ -245,5 +245,14 @@ config POWER_RESET_SC27XX
PMICs includes the SC2720, SC2721, SC2723, SC2730
and SC2731 chips.
config NVMEM_REBOOT_MODE
tristate "Generic NVMEM reboot mode driver"
select REBOOT_MODE
help
Say y here will enable reboot mode driver. This will
get reboot mode arguments and store it in a NVMEM cell,
then the bootloader can read it and take different
action according to the mode.
endif

1
drivers/power/reset/Makefile
View File

@ -29,3 +29,4 @@ obj-$(CONFIG_POWER_RESET_ZX) += zx-reboot.o
obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o

76
drivers/power/reset/nvmem-reboot-mode.c Normal file
View File

@ -0,0 +1,76 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) Vaisala Oyj. All rights reserved.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/nvmem-consumer.h>
#include <linux/platform_device.h>
#include <linux/reboot-mode.h>
struct nvmem_reboot_mode {
struct reboot_mode_driver reboot;
struct nvmem_cell *cell;
};
static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
unsigned int magic)
{
int ret;
struct nvmem_reboot_mode *nvmem_rbm;
nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
if (ret < 0)
dev_err(reboot->dev, "update reboot mode bits failed\n");
return ret;
}
static int nvmem_reboot_mode_probe(struct platform_device *pdev)
{
int ret;
struct nvmem_reboot_mode *nvmem_rbm;
nvmem_rbm = devm_kzalloc(&pdev->dev, sizeof(*nvmem_rbm), GFP_KERNEL);
if (!nvmem_rbm)
return -ENOMEM;
nvmem_rbm->reboot.dev = &pdev->dev;
nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
if (IS_ERR(nvmem_rbm->cell)) {
dev_err(&pdev->dev, "failed to get the nvmem cell reboot-mode\n");
return PTR_ERR(nvmem_rbm->cell);
}
ret = devm_reboot_mode_register(&pdev->dev, &nvmem_rbm->reboot);
if (ret)
dev_err(&pdev->dev, "can't register reboot mode\n");
return ret;
}
static const struct of_device_id nvmem_reboot_mode_of_match[] = {
{ .compatible = "nvmem-reboot-mode" },
{}
};
MODULE_DEVICE_TABLE(of, nvmem_reboot_mode_of_match);
static struct platform_driver nvmem_reboot_mode_driver = {
.probe = nvmem_reboot_mode_probe,
.driver = {
.name = "nvmem-reboot-mode",
.of_match_table = nvmem_reboot_mode_of_match,
},
};
module_platform_driver(nvmem_reboot_mode_driver);
MODULE_AUTHOR("Nandor Han <nandor.han@vaisala.com>");
MODULE_DESCRIPTION("NVMEM reboot mode driver");
MODULE_LICENSE("GPL");