drivers/at24cxxx: add MTD wrapper for at24cxxx EEPROMs

drivers/Makefile.dep

@@ -510,6 +510,10 @@ endif
 ifneq (,$(filter mtd_%,$(USEMODULE)))
   USEMODULE += mtd
 
+  ifneq (,$(filter mtd_at24cxxx,$(USEMODULE)))
+    USEMODULE += at24cxxx
+  endif
+
   ifneq (,$(filter mtd_at25xxx,$(USEMODULE)))
     USEMODULE += at25xxx
   endif

drivers/at24cxxx/Makefile

@@ -1 +1,5 @@
+ifneq (,$(filter mtd_at24cxxx,$(USEMODULE)))
+  DIRS += mtd
+endif
+
 include $(RIOTBASE)/Makefile.base

drivers/at24cxxx/mtd/Makefile

@@ -0,0 +1,10 @@
+MODULE := mtd_at24cxxx
+BASE_MODULE := at24cxxx
+
+# at24cxxx_mtd files
+SRC := mtd.c
+
+# enable submodules
+SUBMODULES := 1
+
+include $(RIOTBASE)/Makefile.base

drivers/at24cxxx/mtd/mtd.c

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2020 Otto-von-Guericke-Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ *
+ */
+
+/**
+ * @ingroup     drivers_at24cxxx
+ * @{
+ *
+ * @file
+ * @brief       MTD EEPROM driver implementation for at24cxxx EEPROM
+ *
+ * @author      Fabian Hüßler <fabian.huessler@ovgu.de>
+ *
+ * @}
+ */
+
+#include <errno.h>
+#include <assert.h>
+
+#include "mtd_at24cxxx.h"
+
+#define DEV(mtd_ptr)        (((mtd_at24cxxx_t *)(mtd_ptr))->at24cxxx_eeprom)
+#define PARAMS(mtd_ptr)     (((mtd_at24cxxx_t *)(mtd_ptr))->params)
+
+static int _mtd_at24cxxx_init(mtd_dev_t *mtd)
+{
+    assert(mtd);
+    assert(mtd->driver == &mtd_at24cxxx_driver);
+    assert(DEV(mtd));
+    assert(PARAMS(mtd));
+    int init = at24cxxx_init(DEV(mtd), PARAMS(mtd));
+    if (init != AT24CXXX_OK) {
+        return init;
+    }
+    mtd->page_size = DEV(mtd)->params.page_size;
+    mtd->pages_per_sector = 1;
+    mtd->sector_count = DEV(mtd)->params.eeprom_size /
+                        DEV(mtd)->params.page_size;
+    return 0;
+}
+
+static int _mtd_at24cxxx_read(mtd_dev_t *mtd, void *dest, uint32_t addr,
+                              uint32_t size)
+{
+    return at24cxxx_read(DEV(mtd), addr, dest, size) == AT24CXXX_OK ? 0 : -EIO;
+}
+
+static int _mtd_at24cxxx_write(mtd_dev_t *mtd, const void *src, uint32_t addr,
+                               uint32_t size)
+{
+    return at24cxxx_write(DEV(mtd), addr, src, size) == AT24CXXX_OK ? 0 : -EIO;
+}
+
+static int _mtd_at24cxxx_erase(mtd_dev_t *mtd, uint32_t addr, uint32_t size)
+{
+    return at24cxxx_clear(DEV(mtd), addr, size) == AT24CXXX_OK ? 0 : -EIO;
+}
+
+static int _mtd_at24cxxx_power(mtd_dev_t *mtd, enum mtd_power_state power)
+{
+    (void)mtd;
+    (void)power;
+    return -ENOTSUP;
+}
+
+const mtd_desc_t mtd_at24cxxx_driver = {
+    .init = _mtd_at24cxxx_init,
+    .read = _mtd_at24cxxx_read,
+    .write = _mtd_at24cxxx_write,
+    .erase = _mtd_at24cxxx_erase,
+    .power = _mtd_at24cxxx_power
+};

drivers/include/mtd_at24cxxx.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2020 Otto-von-Guericke Universität
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    drivers_mtd_at24cxxx MTD wrapper for AT24cxxx family of I2C-EEPROMs
+ * @ingroup     drivers_storage
+ * @brief       MTD wrapper for AT24XXX I2C based EEPROMs
+ *
+ * @{
+ *
+ * @file
+ * @brief       Interface definition for at24cxxx MTD wrapper
+ *
+ *
+ * @author      Fabian Hüßler <fabian.huessler@ovgu.de>
+ */
+
+#ifndef MTD_AT24CXXX_H
+#define MTD_AT24CXXX_H
+
+#include "at24cxxx.h"
+#include "mtd.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/**
+ * @brief   Device descriptor for mtd at24cxxx device
+ *
+ * This is an extension of the @c mtd_dev_t struct
+ */
+typedef struct {
+    mtd_dev_t base;                     /**< inherit from mtd_dev_t object */
+    at24cxxx_t *at24cxxx_eeprom;        /**< at24cxxx device descriptor */
+    const at24cxxx_params_t* params;    /**< at24cxxx parameters */
+} mtd_at24cxxx_t;
+
+/**
+ * @brief Shortcut initializer for @ref mtd_at24cxxx_t
+ */
+#define MTD_AT24CXXX_INIT(dev_p, params_p)          \
+(mtd_at24cxxx_t) {                                  \
+    .base = {                                       \
+        .driver = &mtd_at24cxxx_driver              \
+    },                                              \
+    .at24cxxx_eeprom = (dev_p),                     \
+    .params = (params_p)                            \
+}
+
+/**
+ * @brief MTD EEPROM driver for at24cxxx EEPROM
+ */
+extern const mtd_desc_t mtd_at24cxxx_driver;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MTD_AT24CXXX_H */
+/** @} */