1 files changed, 125 insertions, 0 deletions
diff --git a/drivers/nvmem/airoha-smc-efuses.c b/drivers/nvmem/airoha-smc-efuses.c
new file mode 100644
index 000000000..e56a99f4a
--- /dev/null
+++ b/drivers/nvmem/airoha-smc-efuses.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Author: Christian Marangi <ansuelsmth@gmail.com>
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#define AIROHA_SMC_EFUSE_FID		0x82000001
+#define AIROHA_SMC_EFUSE_SUB_ID_READ	0x44414552
+
+#define AIROHA_EFUSE_CELLS		64
+
+struct airoha_efuse_bank_priv {
+	u32 bank_index;
+};
+
+static int airoha_efuse_read(void *context, unsigned int offset,
+			     void *val, size_t bytes)
+{
+	struct regmap *regmap = context;
+
+	return regmap_bulk_read(regmap, offset,
+				val, bytes / sizeof(u32));
+}
+
+static int airoha_efuse_reg_read(void *context, unsigned int offset,
+				 unsigned int *val)
+{
+	struct airoha_efuse_bank_priv *priv = context;
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(AIROHA_SMC_EFUSE_FID,
+			     AIROHA_SMC_EFUSE_SUB_ID_READ,
+			     priv->bank_index, offset, 0, 0, 0, 0, &res);
+
+	/* check if SMC reported an error */
+	if (res.a0)
+		return -EIO;
+
+	*val = res.a1;
+	return 0;
+}
+
+static int airoha_efuse_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	for_each_child_of_node_scoped(dev->of_node, child) {
+		struct nvmem_config nvmem_config = {
+			.size = AIROHA_EFUSE_CELLS * sizeof(u32),
+			.stride = sizeof(u32),
+			.word_size = sizeof(u32),
+			.reg_read = airoha_efuse_read,
+		};
+		struct regmap_config regmap_config = {
+			.reg_read = airoha_efuse_reg_read,
+			.reg_bits = 32,
+			.val_bits = 32,
+			.reg_stride = 4,
+		};
+		struct airoha_efuse_bank_priv *priv;
+		struct nvmem_device *nvmem;
+		struct regmap *regmap;
+		const char *name;
+		u32 bank;
+
+		ret = of_property_read_u32(child, "reg", &bank);
+		if (ret)
+			return ret;
+
+		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+		if (!priv)
+			return -ENOMEM;
+
+		name = devm_kasprintf(dev, GFP_KERNEL, "airoha-efuse-%u",
+				      bank);
+		if (!name)
+			return -ENOMEM;
+
+		priv->bank_index = bank;
+
+		regmap_config.name = name;
+		regmap = devm_regmap_init(dev, NULL, priv,
+					  &regmap_config);
+		if (IS_ERR(regmap))
+			return PTR_ERR(regmap);
+
+		nvmem_config.name = name;
+		nvmem_config.priv = regmap;
+		nvmem_config.dev = dev;
+		nvmem_config.id = bank;
+		nvmem_config.of_node = child;
+		nvmem = devm_nvmem_register(dev, &nvmem_config);
+		if (IS_ERR(nvmem))
+			return PTR_ERR(nvmem);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id airoha_efuse_of_match[] = {
+	{ .compatible = "airoha,an7581-efuses", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, airoha_efuse_of_match);
+
+static struct platform_driver airoha_efuse_driver = {
+	.probe = airoha_efuse_probe,
+	.driver = {
+		.name = "airoha-efuse",
+		.of_match_table = airoha_efuse_of_match,
+	},
+};
+module_platform_driver(airoha_efuse_driver);
+
+MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
+MODULE_DESCRIPTION("Driver for Airoha SMC eFUSEs");
+MODULE_LICENSE("GPL");