nvmem: brcm_nvram: new driver exposing Broadcom's NVRAM

This driver provides access to Broadcom's NVRAM.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210330111241.19401-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 75d2594c16e19aa64f6bc7119ae8beab87e31064..642ddc699fd161f6e6c41d0b1f200ca4730cdaaf 100644 (file)
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -278,4 +278,13 @@ config NVMEM_RMEM
 
          This driver can also be built as a module. If so, the module
          will be called nvmem-rmem.
+
+config NVMEM_BRCM_NVRAM
+       tristate "Broadcom's NVRAM support"
+       depends on ARCH_BCM_5301X || COMPILE_TEST
+       depends on HAS_IOMEM
+       help
+         This driver provides support for Broadcom's NVRAM that can be accessed
+         using I/O mapping.
+
 endif

diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 5376b8e0dae5a9da24cf957407a37c5bfe0ba011..bbea1410240a887d42b8d959fa2606fd569c2b30 100644 (file)
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -57,3 +57,5 @@ 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
+obj-$(CONFIG_NVMEM_BRCM_NVRAM) += nvmem_brcm_nvram.o
+nvmem_brcm_nvram-y             := brcm_nvram.o

diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
new file mode 100644 (file)
index 0000000..bd2ecaa
--- /dev/null
+++ b/drivers/nvmem/brcm_nvram.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+
+struct brcm_nvram {
+       struct device *dev;
+       void __iomem *base;
+};
+
+static int brcm_nvram_read(void *context, unsigned int offset, void *val,
+                          size_t bytes)
+{
+       struct brcm_nvram *priv = context;
+       u8 *dst = val;
+
+       while (bytes--)
+               *dst++ = readb(priv->base + offset++);
+
+       return 0;
+}
+
+static int brcm_nvram_probe(struct platform_device *pdev)
+{
+       struct nvmem_config config = {
+               .name = "brcm-nvram",
+               .reg_read = brcm_nvram_read,
+       };
+       struct device *dev = &pdev->dev;
+       struct resource *res;
+       struct brcm_nvram *priv;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+       priv->dev = dev;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       priv->base = devm_ioremap_resource(dev, res);
+       if (IS_ERR(priv->base))
+               return PTR_ERR(priv->base);
+
+       config.dev = dev;
+       config.priv = priv;
+       config.size = resource_size(res);
+
+       return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+}
+
+static const struct of_device_id brcm_nvram_of_match_table[] = {
+       { .compatible = "brcm,nvram", },
+       {},
+};
+
+static struct platform_driver brcm_nvram_driver = {
+       .probe = brcm_nvram_probe,
+       .driver = {
+               .name = "brcm_nvram",
+               .of_match_table = brcm_nvram_of_match_table,
+       },
+};
+
+static int __init brcm_nvram_init(void)
+{
+       return platform_driver_register(&brcm_nvram_driver);
+}
+
+subsys_initcall_sync(brcm_nvram_init);
+
+MODULE_AUTHOR("Rafał Miłecki");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);