diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 954d3b4a52ab..fecc19b884bf 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -270,4 +270,12 @@ config SPRD_EFUSE
This driver can also be built as a module. If so, the module
will be called nvmem-sprd-efuse.
+config NVMEM_RMEM
+ tristate "Reserved Memory Based Driver Support"
+ help
+ This drivers maps reserved memory into an nvmem device. It might be
+ useful to expose information left by firmware in memory.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-rmem.
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index a7c377218341..5376b8e0dae5 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -55,3 +55,5 @@ obj-$(CONFIG_NVMEM_ZYNQMP) += nvmem_zynqmp_nvmem.o
nvmem_zynqmp_nvmem-y := zynqmp_nvmem.o
obj-$(CONFIG_SPRD_EFUSE) += nvmem_sprd_efuse.o
nvmem_sprd_efuse-y := sprd-efuse.o
+obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o
+nvmem-rmem-y := rmem.o
diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
new file mode 100644
index 000000000000..b11c3c974b3d
--- /dev/null
+++ b/drivers/nvmem/rmem.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+
+struct rmem {
+ struct device *dev;
+ struct nvmem_device *nvmem;
+ struct reserved_mem *mem;
+
+ phys_addr_t size;
+};
+
+static int rmem_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rmem *priv = context;
+ size_t available = priv->mem->size;
+ loff_t off = offset;
+ void *addr;
+ int count;
+
+ /*
+ * Only map the reserved memory at this point to avoid potential rogue
+ * kernel threads inadvertently modifying it. Based on the current
+ * uses-cases for this driver, the performance hit isn't a concern.
+ * Nor is likely to be, given the nature of the subsystem. Most nvmem
+ * devices operate over slow buses to begin with.
+ *
+ * An alternative would be setting the memory as RO, set_memory_ro(),
+ * but as of Dec 2020 this isn't possible on arm64.
+ */
+ addr = memremap(priv->mem->base, available, MEMREMAP_WB);
+ if (IS_ERR(addr)) {
+ dev_err(priv->dev, "Failed to remap memory region\n");
+ return PTR_ERR(addr);
+ }
+
+ count = memory_read_from_buffer(val, bytes, &off, addr, available);
+
+ memunmap(addr);
+
+ return count;
+}
+
+static int rmem_probe(struct platform_device *pdev)
+{
+ struct nvmem_config config = { };
+ struct device *dev = &pdev->dev;
+ struct reserved_mem *mem;
+ struct rmem *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = dev;
+
+ mem = of_reserved_mem_lookup(dev->of_node);
+ if (!mem) {
+ dev_err(dev, "Failed to lookup reserved memory\n");
+ return -EINVAL;
+ }
+ priv->mem = mem;
+
+ config.dev = dev;
+ config.priv = priv;
+ config.name = "rmem";
+ config.size = mem->size;
+ config.reg_read = rmem_read;
+
+ return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+}
+
+static const struct of_device_id rmem_match[] = {
+ { .compatible = "nvmem-rmem", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rmem_match);
+
+static struct platform_driver rmem_driver = {
+ .probe = rmem_probe,
+ .driver = {
+ .name = "rmem",
+ .of_match_table = rmem_match,
+ },
+};
+module_platform_driver(rmem_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Reserved Memory Based nvmem Driver");
+MODULE_LICENSE("GPL");diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 79bd5f5a1bf1..6699cdbe58b6 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -511,6 +511,7 @@ static const struct of_device_id reserved_mem_matches[] = {
{ .compatible = "qcom,rmtfs-mem" },
{ .compatible = "qcom,cmd-db" },
{ .compatible = "ramoops" },
+ { .compatible = "nvmem-rmem" },
{}
};
--
2.29.2