From 4fcd504edbf7c793325511c2df8dcd083958e28a Mon Sep 17 00:00:00 2001 From: Andy Yan Date: Wed, 6 Jul 2016 21:27:26 +0800 Subject: power: reset: add reboot mode driver This driver parses the reboot commands like "reboot bootloader" and "reboot recovery" to get a boot mode described in the device tree , then call the write interfae to store the boot mode in some place like special register or sram, which can be read by the bootloader after system reboot, then the bootloader can take different action according to the mode stored. This is commonly used on Android based devices, in order to reboot the device into fastboot or recovery mode. Reviewed-by: Matthias Brugger Reviewed-by: Moritz Fischer Tested-by: John Stultz Acked-by: John Stultz Signed-off-by: Andy Yan Reviewed-by: Krzysztof Kozlowski Signed-off-by: Sebastian Reichel --- drivers/power/reset/syscon-reboot-mode.c | 99 ++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 drivers/power/reset/syscon-reboot-mode.c (limited to 'drivers/power/reset/syscon-reboot-mode.c') diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c new file mode 100644 index 000000000000..9e1cba5dd58e --- /dev/null +++ b/drivers/power/reset/syscon-reboot-mode.c @@ -0,0 +1,99 @@ +/* + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "reboot-mode.h" + +struct syscon_reboot_mode { + struct regmap *map; + struct reboot_mode_driver reboot; + u32 offset; + u32 mask; +}; + +static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot, + unsigned int magic) +{ + struct syscon_reboot_mode *syscon_rbm; + int ret; + + syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot); + + ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset, + syscon_rbm->mask, magic); + if (ret < 0) + dev_err(reboot->dev, "update reboot mode bits failed\n"); + + return ret; +} + +static int syscon_reboot_mode_probe(struct platform_device *pdev) +{ + int ret; + struct syscon_reboot_mode *syscon_rbm; + + syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL); + if (!syscon_rbm) + return -ENOMEM; + + syscon_rbm->reboot.dev = &pdev->dev; + syscon_rbm->reboot.write = syscon_reboot_mode_write; + syscon_rbm->mask = 0xffffffff; + + dev_set_drvdata(&pdev->dev, syscon_rbm); + + syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node); + if (IS_ERR(syscon_rbm->map)) + return PTR_ERR(syscon_rbm->map); + + if (of_property_read_u32(pdev->dev.of_node, "offset", + &syscon_rbm->offset)) + return -EINVAL; + + of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask); + + ret = reboot_mode_register(&syscon_rbm->reboot); + if (ret) + dev_err(&pdev->dev, "can't register reboot mode\n"); + + return ret; +} + +static int syscon_reboot_mode_remove(struct platform_device *pdev) +{ + struct syscon_reboot_mode *syscon_rbm = dev_get_drvdata(&pdev->dev); + + return reboot_mode_unregister(&syscon_rbm->reboot); +} + +static const struct of_device_id syscon_reboot_mode_of_match[] = { + { .compatible = "syscon-reboot-mode" }, + {} +}; + +static struct platform_driver syscon_reboot_mode_driver = { + .probe = syscon_reboot_mode_probe, + .remove = syscon_reboot_mode_remove, + .driver = { + .name = "syscon-reboot-mode", + .of_match_table = syscon_reboot_mode_of_match, + }, +}; +module_platform_driver(syscon_reboot_mode_driver); + +MODULE_AUTHOR("Andy Yan