1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/nvmem/regmap.c b/drivers/nvmem/regmap.c
new file mode 100644
index 0000000000..24712fbb0f
--- /dev/null
+++ b/drivers/nvmem/regmap.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <common.h>
+#include <driver.h>
+#include <malloc.h>
+#include <xfuncs.h>
+#include <errno.h>
+#include <init.h>
+#include <io.h>
+#include <linux/regmap.h>
+#include <linux/nvmem-provider.h>
+
+static int nvmem_regmap_write(void *ctx, unsigned offset, const void *val, size_t bytes)
+{
+	struct regmap *map = ctx;
+
+	/*
+	 * eFuse writes going through this function may be irreversible,
+	 * so expect users to observe alignment.
+	 */
+	if (bytes % regmap_get_val_bytes(map))
+		return -EINVAL;
+
+	return regmap_bulk_write(map, offset, val,
+				 bytes / regmap_get_val_bytes(map));
+}
+
+static int nvmem_regmap_read(void *ctx, unsigned offset, void *buf, size_t bytes)
+{
+	struct regmap *map = ctx;
+	size_t rbytes, stride, skip_bytes;
+	u32 roffset, val;
+	u8 *buf8 = buf, *val8 = (u8 *)&val;
+	int i, j = 0, ret, size;
+
+	stride = regmap_get_reg_stride(map);
+
+	roffset = rounddown(offset, stride);
+	skip_bytes = offset & (stride - 1);
+	rbytes = roundup(bytes + skip_bytes, stride);
+
+	if (roffset + rbytes > regmap_size_bytes(map))
+		return -EINVAL;
+
+	for (i = roffset; i < roffset + rbytes; i += stride) {
+		ret = regmap_read(map, i, &val);
+		if (ret) {
+			dev_err(regmap_get_device(map), "Can't read data%d (%d)\n", i, ret);
+			return ret;
+		}
+
+		/* skip first bytes in case of unaligned read */
+		if (skip_bytes)
+			size = min(bytes, stride - skip_bytes);
+		else
+			size = min(bytes, stride);
+
+		memcpy(&buf8[j], &val8[skip_bytes], size);
+		bytes -= size;
+		j += size;
+		skip_bytes = 0;
+	}
+
+	return 0;
+}
+
+struct nvmem_device *
+nvmem_regmap_register_with_pp(struct regmap *map, const char *name,
+			      nvmem_cell_post_process_t cell_post_process)
+{
+	struct nvmem_config config = {};
+
+	/* Can be retrofitted if needed */
+	if (regmap_get_reg_stride(map) != regmap_get_val_bytes(map))
+		return ERR_PTR(-EINVAL);
+
+	config.name = name;
+	config.dev = regmap_get_device(map);
+	config.priv = map;
+	config.stride = 1;
+	config.word_size = 1;
+	config.size = regmap_size_bytes(map);
+	config.cell_post_process = cell_post_process;
+	config.reg_write = nvmem_regmap_write;
+	config.reg_read = nvmem_regmap_read;
+
+	return nvmem_register(&config);
+}
+
+struct nvmem_device *nvmem_regmap_register(struct regmap *map, const char *name)
+{
+	return nvmem_regmap_register_with_pp(map, name, NULL);
+}