reboot-mode: Add NVMEM reboot mode
This adds an NVMEM reboot mode driver, similar to Linux's
implementation. This allows using the same device tree binding for Linux
and U-Boot in most cases.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 237f394..b2de50c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1198,6 +1198,7 @@
S: Maintained
F: doc/api/nvmem.rst
F: drivers/misc/nvmem.c
+F: drivers/reboot-mode/reboot-mode-nvmem.c
F: include/nvmem.h
NXP C45 TJA11XX PHY DRIVER
diff --git a/drivers/reboot-mode/Kconfig b/drivers/reboot-mode/Kconfig
index 63ea18c..d57baac 100644
--- a/drivers/reboot-mode/Kconfig
+++ b/drivers/reboot-mode/Kconfig
@@ -30,4 +30,11 @@
a device in a specific mode by using a register(s) that can be controlled
outside U-Boot (e.g. Kernel).
+config REBOOT_MODE_NVMEM
+ bool "Use NVMEM reboot mode"
+ depends on DM_REBOOT_MODE && NVMEM
+ help
+ Use any kind of non-volatile memory (EEPROM, RTC, etc) to control the
+ reboot mode.
+
endmenu
diff --git a/drivers/reboot-mode/Makefile b/drivers/reboot-mode/Makefile
index 2c13780..48c8ab7 100644
--- a/drivers/reboot-mode/Makefile
+++ b/drivers/reboot-mode/Makefile
@@ -7,3 +7,4 @@
obj-$(CONFIG_DM_REBOOT_MODE) += reboot-mode-uclass.o
obj-$(CONFIG_DM_REBOOT_MODE_GPIO) += reboot-mode-gpio.o
obj-$(CONFIG_DM_REBOOT_MODE_RTC) += reboot-mode-rtc.o
+obj-$(CONFIG_REBOOT_MODE_NVMEM) += reboot-mode-nvmem.o
diff --git a/drivers/reboot-mode/reboot-mode-nvmem.c b/drivers/reboot-mode/reboot-mode-nvmem.c
new file mode 100644
index 0000000..da41ca4
--- /dev/null
+++ b/drivers/reboot-mode/reboot-mode-nvmem.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <nvmem.h>
+#include <reboot-mode/reboot-mode.h>
+
+/**
+ * struct nvmem_reboot_mode_priv - Private data for the nvmem reboot mode device
+ * @cell: The nvmem cell to store the mode in
+ */
+struct nvmem_reboot_mode_priv {
+ struct nvmem_cell cell;
+};
+
+static int reboot_mode_get(struct udevice *dev, u32 *mode)
+{
+ struct nvmem_reboot_mode_priv *priv = dev_get_priv(dev);
+
+ return nvmem_cell_read(&priv->cell, mode, sizeof(*mode));
+}
+
+static int reboot_mode_set(struct udevice *dev, u32 mode)
+{
+ struct nvmem_reboot_mode_priv *priv = dev_get_priv(dev);
+
+ return nvmem_cell_write(&priv->cell, &mode, sizeof(mode));
+}
+
+static const struct reboot_mode_ops nvmem_reboot_mode_ops = {
+ .get = reboot_mode_get,
+ .set = reboot_mode_set,
+};
+
+static int reboot_mode_probe(struct udevice *dev)
+{
+ struct nvmem_reboot_mode_priv *priv = dev_get_priv(dev);
+
+ return nvmem_cell_get_by_name(dev, "reboot-mode", &priv->cell);
+}
+
+static const struct udevice_id nvmem_reboot_mode_ids[] = {
+ { .compatible = "nvmem-reboot-mode" },
+ { }
+};
+
+U_BOOT_DRIVER(nvmem_reboot_mode) = {
+ .name = "nvmem-reboot-mode",
+ .id = UCLASS_REBOOT_MODE,
+ .of_match = nvmem_reboot_mode_ids,
+ .probe = reboot_mode_probe,
+ .priv_auto = sizeof(struct nvmem_reboot_mode_priv),
+ .ops = &nvmem_reboot_mode_ops,
+};