RTC devices could provide battery-backed memory that can be used for storing the reboot mode magic value.
Add a new reboot-mode back-end that uses RTC to store the reboot-mode magic value. The driver also supports both endianness modes.
Signed-off-by: Nandor Han nandor.han@vaisala.com --- .../reboot-mode/reboot-mode-rtc.txt | 22 +++ drivers/reboot-mode/Kconfig | 9 ++ drivers/reboot-mode/Makefile | 1 + drivers/reboot-mode/reboot-mode-rtc.c | 132 ++++++++++++++++++ include/reboot-mode/reboot-mode-rtc.h | 16 +++ 5 files changed, 180 insertions(+) create mode 100644 doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt create mode 100644 drivers/reboot-mode/reboot-mode-rtc.c create mode 100644 include/reboot-mode/reboot-mode-rtc.h
diff --git a/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt b/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt new file mode 100644 index 0000000000..23aa12c88c --- /dev/null +++ b/doc/device-tree-bindings/reboot-mode/reboot-mode-rtc.txt @@ -0,0 +1,22 @@ +RTC Reboot Mode Configuration + +Required Properties: +- compatible: must be "reboot-mode-rtc". +- rtc: reference to the rtc device used. +- reg: start register and the number of bytes used. Maximum 4 bytes supported. +- modes: list of properties that define the modes and associated unique ids. + +Optional Properties: +- u-boot,env-variable: used to save the reboot mode (default: reboot-mode). +- big-endian: if the magic value is stored in big-endian. (default: false). + +Example: + reboot-mode-rtc { + compatible = "reboot-mode-rtc"; + rtc = <&rtc_0>; + reg = <0x14 4>; + u-boot,env-variable = "bootstatus"; + big-endian; + modes-test = <0x21969147>; + modes-download = <0x51939147>; + }; diff --git a/drivers/reboot-mode/Kconfig b/drivers/reboot-mode/Kconfig index ff65e2031a..ac67bfcef6 100644 --- a/drivers/reboot-mode/Kconfig +++ b/drivers/reboot-mode/Kconfig @@ -24,4 +24,13 @@ config DM_REBOOT_MODE_GPIO a device in a specific mode by using a GPIO that can be controlled outside U-Boot.
+config DM_REBOOT_MODE_RTC + bool "Use RTC as reboot mode backend" + depends on DM_REBOOT_MODE + default n + help + Use RTC non volatile memory to control the reboot mode. This will allow users to boot + a device in a specific mode by using a register(s) that can be controlled + outside U-Boot (e.g. Kernel). + endmenu diff --git a/drivers/reboot-mode/Makefile b/drivers/reboot-mode/Makefile index 04917be4f4..2c13780ced 100644 --- a/drivers/reboot-mode/Makefile +++ b/drivers/reboot-mode/Makefile @@ -6,3 +6,4 @@
obj-$(CONFIG_DM_REBOOT_MODE) += reboot-mode-uclass.o obj-$(CONFIG_DM_REBOOT_MODE_GPIO) += reboot-mode-gpio.o +obj-$(CONFIG_DM_REBOOT_MODE_RTC) += reboot-mode-rtc.o diff --git a/drivers/reboot-mode/reboot-mode-rtc.c b/drivers/reboot-mode/reboot-mode-rtc.c new file mode 100644 index 0000000000..db11acc75a --- /dev/null +++ b/drivers/reboot-mode/reboot-mode-rtc.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c), Vaisala Oyj + */ + +#include <common.h> +#include <rtc.h> +#include <dm.h> +#include <errno.h> +#include <reboot-mode/reboot-mode-rtc.h> +#include <reboot-mode/reboot-mode.h> + +DECLARE_GLOBAL_DATA_PTR; + +static int reboot_mode_get(struct udevice *dev, u32 *buf) +{ + if (!buf) + return -EINVAL; + + int ret; + u8 *val = (u8 *)buf; + struct reboot_mode_rtc_platdata *plat_data; + + plat_data = dev_get_platdata(dev); + if (!plat_data) + return -EINVAL; + + for (int i = 0; i < plat_data->size; i++) { + ret = rtc_read8(plat_data->rtc, plat_data->addr + i); + if (ret < 0) + return ret; + + val[i] = ret; + } + + if (plat_data->is_big_endian) + *buf = __be32_to_cpu(*buf); + else + *buf = __le32_to_cpu(*buf); + + return 0; +} + +static int reboot_mode_set(struct udevice *dev, u32 buf) +{ + int ret; + u8 *val; + struct reboot_mode_rtc_platdata *plat_data; + + plat_data = dev_get_platdata(dev); + if (!plat_data) + return -EINVAL; + + if (plat_data->is_big_endian) + buf = __cpu_to_be32(buf); + else + buf = __cpu_to_le32(buf); + + val = (u8 *)&buf; + + for (int i = 0; i < plat_data->size; i++) { + ret = rtc_write8(plat_data->rtc, (plat_data->addr + i), val[i]); + if (ret < 0) + return ret; + } + + return 0; +} + +#if CONFIG_IS_ENABLED(OF_CONTROL) +static int reboot_mode_ofdata_to_platdata(struct udevice *dev) +{ + struct ofnode_phandle_args phandle_args; + struct reboot_mode_rtc_platdata *plat_data; + + plat_data = dev_get_platdata(dev); + if (!plat_data) + return -EINVAL; + + if (dev_read_phandle_with_args(dev, "rtc", NULL, 0, 0, &phandle_args)) { + dev_err(dev, "RTC device not specified\n"); + return -ENOENT; + } + + if (uclass_get_device_by_ofnode(UCLASS_RTC, + phandle_args.node, &plat_data->rtc)) { + dev_err(dev, "could not get the RTC device\n"); + return -ENODEV; + } + + plat_data->addr = fdtdec_get_addr_size_auto_noparent(gd->fdt_blob, + dev_of_offset(dev), + "reg", + 0, + (fdt_size_t *)&plat_data->size, + false); + if (plat_data->addr == FDT_ADDR_T_NONE) { + dev_err(dev, "Invalid RTC address\n"); + return -EINVAL; + } + + if (plat_data->size > sizeof(u32)) { + dev_err(dev, "Invalid reg size\n"); + return -EINVAL; + } + + plat_data->is_big_endian = ofnode_read_bool(dev->node, "big-endian"); + + return 0; +} + +static const struct udevice_id reboot_mode_ids[] = { + { .compatible = "reboot-mode-rtc", 0 }, + { } +}; +#endif + +static const struct reboot_mode_ops reboot_mode_rtc_ops = { + .get = reboot_mode_get, + .set = reboot_mode_set, +}; + +U_BOOT_DRIVER(reboot_mode_rtc) = { + .name = "reboot-mode-rtc", + .id = UCLASS_REBOOT_MODE, +#if CONFIG_IS_ENABLED(OF_CONTROL) + .of_match = reboot_mode_ids, + .ofdata_to_platdata = reboot_mode_ofdata_to_platdata, +#endif + .platdata_auto_alloc_size = sizeof(struct reboot_mode_rtc_platdata), + .ops = &reboot_mode_rtc_ops, +}; diff --git a/include/reboot-mode/reboot-mode-rtc.h b/include/reboot-mode/reboot-mode-rtc.h new file mode 100644 index 0000000000..3613678f63 --- /dev/null +++ b/include/reboot-mode/reboot-mode-rtc.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c), Vaisala Oyj + */ + +#ifndef REBOOT_MODE_REBOOT_MODE_RTC_H_ +#define REBOOT_MODE_REBOOT_MODE_RTC_H_ + +struct reboot_mode_rtc_platdata { + struct udevice *rtc; + bool is_big_endian; + int addr; + size_t size; +}; + +#endif /* REBOOT_MODE_REBOOT_MODE_RTC_H_ */