drivers/mtd_mci: add MTD wrapper for MCI driver

drivers/mtd_mci/Makefile

@@ -0,0 +1 @@
+include $(RIOTBASE)/Makefile.base

drivers/mtd_mci/Makefile.dep

@@ -0,0 +1 @@
+USEMODULE += mci

drivers/mtd_mci/mtd_mci.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2020 Beuth Hochschule für Technik Berlin
+ *
+ * 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_mtd
+ * @{
+ *
+ * @file
+ * @brief       Driver for using lpc23xx-mci via mtd interface
+ *
+ * @author      Benjamin Valentin <benpicco@beuth-hochschule.de>
+ *
+ * @}
+ */
+
+#include <errno.h>
+#include <string.h>
+
+#include "diskio.h"
+#include "mtd.h"
+#include "sdcard_spi.h"
+
+#define ENABLE_DEBUG    (0)
+#include "debug.h"
+
+#define min(a, b) ((a) > (b) ? (b) : (a))
+
+/* MCI driver only suports whole page reads / writes */
+static uint8_t _page_buffer[SD_HC_BLOCK_SIZE];
+
+static int mtd_mci_init(mtd_dev_t *dev)
+{
+    if (mci_initialize()) {
+        return -EIO;
+    }
+
+    if (ENABLE_DEBUG) {
+        uint32_t block_size;
+        mci_ioctl(GET_BLOCK_SIZE, &block_size);
+        DEBUG("block size: %lu\n", block_size);
+    }
+
+    dev->pages_per_sector = 1;
+    dev->page_size = SD_HC_BLOCK_SIZE;
+    mci_ioctl(GET_SECTOR_COUNT, &dev->sector_count);
+
+    DEBUG("sector size: %lu\n", dev->page_size);
+    DEBUG("sector count: %lu\n", dev->sector_count);
+    DEBUG("pages / sector: %lu\n", dev->pages_per_sector);
+
+    return 0;
+}
+
+static int mtd_mci_read_page(mtd_dev_t *dev, void *buff, uint32_t page,
+                             uint32_t offset, uint32_t size)
+{
+    (void)dev;
+    uint8_t pages = size / SD_HC_BLOCK_SIZE;
+
+    DEBUG("%s(%lu, %lu, %lu)\n", __func__, page, offset, size);
+
+    /* emulate unaligned / sub-page read */
+    if (pages == 0 || offset) {
+        size = min(SD_HC_BLOCK_SIZE - offset, size);
+
+        if (mci_read(_page_buffer, page, 1)) {
+            return -EIO;
+        }
+
+        memcpy(buff, _page_buffer + offset, size);
+
+        return size;
+    }
+
+    if (mci_read(buff, page, pages)) {
+        return -EIO;
+    }
+
+    return pages * SD_HC_BLOCK_SIZE;
+}
+
+static int mtd_mci_write_page(mtd_dev_t *dev, const void *buff, uint32_t page,
+                              uint32_t offset, uint32_t size)
+{
+    (void)dev;
+    uint8_t pages = size / SD_HC_BLOCK_SIZE;
+
+    DEBUG("%s(%lu, %lu, %lu)\n", __func__, page, offset, size);
+
+    /* emulate unaligned / sub-page write */
+    if (pages == 0 || offset) {
+        size = min(SD_HC_BLOCK_SIZE - offset, size);
+
+        if (mci_read(_page_buffer, page, 1)) {
+            return -EIO;
+        }
+
+        memcpy(_page_buffer + offset, buff, size);
+
+        buff  = _page_buffer;
+        pages = 1;
+    }
+
+    if (mci_write(buff, page, pages)) {
+        return -EIO;
+    }
+
+    return pages * SD_HC_BLOCK_SIZE;
+}
+
+static int mtd_mci_erase_sector(mtd_dev_t *dev, uint32_t sector, uint32_t count)
+{
+    (void)dev;
+
+    while (count--) {
+        mci_ioctl(CTRL_ERASE_SECTOR, &sector);
+        ++sector;
+    }
+    return 0;
+}
+
+static int mtd_mci_power(mtd_dev_t *dev, enum mtd_power_state power)
+{
+    (void)dev;
+
+    unsigned char on = power == MTD_POWER_UP ? 1 : 0;
+    if (mci_ioctl(CTRL_POWER, &on)) {
+        return -EIO;
+    }
+
+    return 0;
+}
+
+const mtd_desc_t mtd_mci_driver = {
+    .init           = mtd_mci_init,
+    .read_page      = mtd_mci_read_page,
+    .write_page     = mtd_mci_write_page,
+    .erase_sector   = mtd_mci_erase_sector,
+    .power          = mtd_mci_power,
+};