toradex: tdx-cfg-block: add EEPROM read/store wrappers

These functions wrap functionality for storing config blocks in EEPROM.

Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>

board/toradex/common/Makefile

@@ -8,4 +8,5 @@ obj- := __dummy__.o
 else
 obj-$(CONFIG_TDX_CFG_BLOCK) += tdx-cfg-block.o
 obj-y += tdx-common.o
+obj-y += tdx-eeprom.o
 endif

board/toradex/common/tdx-eeprom.c

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2020 Toradex
+ */
+
+#include <dm.h>
+#include <i2c_eeprom.h>
+#include <linux/errno.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int get_tdx_eeprom(u32 eeprom_id, struct udevice **devp)
+{
+	int ret = 0;
+	int node;
+	ofnode eeprom;
+	char eeprom_str[16];
+	const char *path;
+
+	if (!gd->fdt_blob) {
+		printf("%s: don't have a valid gd->fdt_blob!\n", __func__);
+		return -EFAULT;
+	}
+
+	node = fdt_path_offset(gd->fdt_blob, "/aliases");
+	if (node < 0)
+		return -ENODEV;
+
+	sprintf(eeprom_str, "eeprom%d", eeprom_id);
+
+	path = fdt_getprop(gd->fdt_blob, node, eeprom_str, NULL);
+	if (!path) {
+		printf("%s: no alias for %s\n", __func__, eeprom_str);
+		return -ENODEV;
+	}
+
+	eeprom = ofnode_path(path);
+	if (!ofnode_valid(eeprom)) {
+		printf("%s: invalid hardware path to EEPROM\n", __func__);
+		return -ENODEV;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_I2C_EEPROM, eeprom, devp);
+	if (ret) {
+		printf("%s: cannot find EEPROM by node\n", __func__);
+		return ret;
+	}
+
+	return ret;
+}
+
+int read_tdx_eeprom_data(u32 eeprom_id, int offset, u8 *buf,
+			 int size)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = get_tdx_eeprom(eeprom_id, &dev);
+	if (ret)
+		return ret;
+
+	ret = i2c_eeprom_read(dev, 0x0, buf, size);
+	if (ret) {
+		printf("%s: error reading data from EEPROM id: %d!, ret = %d\n",
+		       __func__, eeprom_id, ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+int write_tdx_eeprom_data(u32 eeprom_id, int offset, u8 *buf,
+			  int size)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = get_tdx_eeprom(eeprom_id, &dev);
+	if (ret)
+		return ret;
+
+	ret = i2c_eeprom_write(dev, 0x0, buf, size);
+	if (ret) {
+		printf("%s: error writing data to EEPROM id: %d, ret = %d\n",
+		       __func__, eeprom_id, ret);
+		return ret;
+	}
+
+	return ret;
+}

board/toradex/common/tdx-eeprom.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2020 Toradex
+ */
+
+#ifndef _TDX_EEPROM_H
+#define _TDX_EEPROM_H
+
+#include <i2c_eeprom.h>
+
+int read_tdx_eeprom_data(u32 eeprom_id, int offset, uint8_t *buf, int size);
+int write_tdx_eeprom_data(u32 eeprom_id, int offset, uint8_t *buf, int size);
+
+#endif /* _TDX_EEPROM_H */