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author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2020-09-28 16:45:07 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2020-09-29 10:25:02 +0200 |
commit | b42bf25c5bd4baffac1a4f3b40ec0ba10cc13504 (patch) | |
tree | 95bdbfff4e833b180677eb86184ce492e1272289 /drivers/power | |
parent | fc8511d20ab32a31e9502c54a28a3f7f55223f39 (diff) | |
download | barebox-b42bf25c5bd4baffac1a4f3b40ec0ba10cc13504.tar.gz barebox-b42bf25c5bd4baffac1a4f3b40ec0ba10cc13504.tar.xz |
power: reset: reboot-mode: port syscon-reboot-mode support
Reboot modes are one-shot information that should be valid for only a
single reset. Syscons that survive a warm reset are one way to implement
this. This is used by many BootROMs to allow falling into a recovery
mode on the next boot. This ports the Linux syscon-reboot-mode support.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/power')
-rw-r--r-- | drivers/power/reset/Kconfig | 11 | ||||
-rw-r--r-- | drivers/power/reset/Makefile | 1 | ||||
-rw-r--r-- | drivers/power/reset/syscon-reboot-mode.c | 85 |
3 files changed, 97 insertions, 0 deletions
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index 5554fc122d..f65e1f67fd 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -3,3 +3,14 @@ config REBOOT_MODE bool + +config SYSCON_REBOOT_MODE + bool "Generic SYSCON regmap reboot mode driver" + depends on OFDEVICE + depends on MFD_SYSCON + select REBOOT_MODE + help + Say y here will enable reboot mode driver. This will + get reboot mode arguments and store it in SYSCON mapped + register, then the bootloader can read it to take different + action according to the mode. diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile index 68231f044a..56feec78cf 100644 --- a/drivers/power/reset/Makefile +++ b/drivers/power/reset/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o +obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c new file mode 100644 index 0000000000..5e4aed943d --- /dev/null +++ b/drivers/power/reset/syscon-reboot-mode.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd + */ + +#include <common.h> +#include <init.h> +#include <driver.h> +#include <of.h> +#include <regmap.h> +#include <mfd/syscon.h> +#include <linux/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 device_d *dev) +{ + int ret; + struct syscon_reboot_mode *syscon_rbm; + struct device_node *np = dev->device_node; + u32 magic; + + syscon_rbm = xzalloc(sizeof(*syscon_rbm)); + + syscon_rbm->reboot.dev = dev; + syscon_rbm->reboot.write = syscon_reboot_mode_write; + syscon_rbm->mask = 0xffffffff; + + syscon_rbm->map = syscon_node_to_regmap(dev->parent->device_node); + if (IS_ERR(syscon_rbm->map)) + return PTR_ERR(syscon_rbm->map); + + if (of_property_read_u32(np, "offset", &syscon_rbm->offset)) + return -EINVAL; + + of_property_read_u32(np, "mask", &syscon_rbm->mask); + + ret = regmap_read(syscon_rbm->map, syscon_rbm->offset, &magic); + if (ret) { + dev_err(dev, "error reading reboot mode: %s\n", + strerror(-ret)); + return ret; + } + + magic &= syscon_rbm->mask; + + ret = reboot_mode_register(&syscon_rbm->reboot, magic); + if (ret) + dev_err(dev, "can't register reboot mode\n"); + + return ret; +} + +static const struct of_device_id syscon_reboot_mode_of_match[] = { + { .compatible = "syscon-reboot-mode" }, + { /* sentinel */ } +}; + +static struct driver_d syscon_reboot_mode_driver = { + .probe = syscon_reboot_mode_probe, + .name = "syscon-reboot-mode", + .of_compatible = syscon_reboot_mode_of_match, +}; +coredevice_platform_driver(syscon_reboot_mode_driver); |