nvmem: uniphier: add UniPhier eFuse driver

Add eFuse driver for Socionext UniPhier series SoC.
Note that eFuse device is under soc-glue and this register
implements as read only.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 110 insertions, 0 deletions

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index eb09916744bf..ff505af064ba 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -123,6 +123,17 @@ config NVMEM_SUNXI_SID
           This driver can also be built as a module. If so, the module
           will be called nvmem_sunxi_sid.
 
+config UNIPHIER_EFUSE
+        tristate "UniPhier SoCs eFuse support"
+        depends on ARCH_UNIPHIER || COMPILE_TEST
+        depends on HAS_IOMEM
+        help
+          This is a simple driver to dump specified values of UniPhier SoC
+          from eFuse.
+
+          This driver can also be built as a module. If so, the module
+          will be called nvmem-uniphier-efuse.
+
 config NVMEM_VF610_OCOTP
         tristate "VF610 SoC OCOTP support"
         depends on SOC_VF610 || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 362f394da65d..64849e946d50 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -26,6 +26,8 @@ obj-$(CONFIG_ROCKCHIP_EFUSE)	+= nvmem_rockchip_efuse.o
 nvmem_rockchip_efuse-y          := rockchip-efuse.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)   += nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y               := sunxi_sid.o
+obj-$(CONFIG_UNIPHIER_EFUSE)    += nvmem-uniphier-efuse.o
+nvmem-uniphier-efuse-y          := uniphier-efuse.o
 obj-$(CONFIG_NVMEM_VF610_OCOTP) += nvmem-vf610-ocotp.o
 nvmem-vf610-ocotp-y             := vf610-ocotp.o
 obj-$(CONFIG_MESON_EFUSE)       += nvmem_meson_efuse.o
diff --git a/drivers/nvmem/uniphier-efuse.c b/drivers/nvmem/uniphier-efuse.c
new file mode 100644
index 000000000000..9d278b4e1dc7
--- /dev/null
+++ b/drivers/nvmem/uniphier-efuse.c
@@ -0,0 +1,97 @@
+/*
+ * UniPhier eFuse driver
+ *
+ * Copyright (C) 2017 Socionext Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+
+struct uniphier_efuse_priv {
+        void __iomem *base;
+};
+
+static int uniphier_reg_read(void *context,
+                             unsigned int reg, void *_val, size_t bytes)
+{
+        struct uniphier_efuse_priv *priv = context;
+        u32 *val = _val;
+        int offs;
+
+        for (offs = 0; offs < bytes; offs += sizeof(u32))
+                *val++ = readl(priv->base + reg + offs);
+
+        return 0;
+}
+
+static int uniphier_efuse_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct resource *res;
+        struct nvmem_device *nvmem;
+        struct nvmem_config econfig = {};
+        struct uniphier_efuse_priv *priv;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        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);
+
+        econfig.stride = 4;
+        econfig.word_size = 4;
+        econfig.read_only = true;
+        econfig.reg_read = uniphier_reg_read;
+        econfig.size = resource_size(res);
+        econfig.priv = priv;
+        econfig.dev = dev;
+        nvmem = nvmem_register(&econfig);
+        if (IS_ERR(nvmem))
+                return PTR_ERR(nvmem);
+
+        platform_set_drvdata(pdev, nvmem);
+
+        return 0;
+}
+
+static int uniphier_efuse_remove(struct platform_device *pdev)
+{
+        struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+        return nvmem_unregister(nvmem);
+}
+
+static const struct of_device_id uniphier_efuse_of_match[] = {
+        { .compatible = "socionext,uniphier-efuse",},
+        {/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
+
+static struct platform_driver uniphier_efuse_driver = {
+        .probe = uniphier_efuse_probe,
+        .remove = uniphier_efuse_remove,
+        .driver = {
+                .name = "uniphier-efuse",
+                .of_match_table = uniphier_efuse_of_match,
+        },
+};
+module_platform_driver(uniphier_efuse_driver);
+
+MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
+MODULE_DESCRIPTION("UniPhier eFuse driver");
+MODULE_LICENSE("GPL v2");