Add customisable EEPROM driver selection (#7274)

- uprintf -> dprintf
- Fix atsam "vendor" eeprom.
- Bump Kinetis K20x to 64 bytes, too.
- Rollback Kinetis to 32 bytes as partitioning can only be done once. Add warning about changing the value.
- Change RAM-backed "fake" EEPROM implementations to match eeconfig's current usage.
- Add 24LC128 by request.

drivers/eeprom/eeprom_driver.c

@@ -0,0 +1,73 @@
+/* Copyright 2019 Nick Brassel (tzarc)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "eeprom_driver.h"
+
+uint8_t eeprom_read_byte(const uint8_t *addr) {
+    uint8_t ret;
+    eeprom_read_block(&ret, addr, 1);
+    return ret;
+}
+
+uint16_t eeprom_read_word(const uint16_t *addr) {
+    uint16_t ret;
+    eeprom_read_block(&ret, addr, 2);
+    return ret;
+}
+
+uint32_t eeprom_read_dword(const uint32_t *addr) {
+    uint32_t ret;
+    eeprom_read_block(&ret, addr, 4);
+    return ret;
+}
+
+void eeprom_write_byte(uint8_t *addr, uint8_t value) { eeprom_write_block(&value, addr, 1); }
+
+void eeprom_write_word(uint16_t *addr, uint16_t value) { eeprom_write_block(&value, addr, 2); }
+
+void eeprom_write_dword(uint32_t *addr, uint32_t value) { eeprom_write_block(&value, addr, 4); }
+
+void eeprom_update_block(const void *buf, void *addr, size_t len) {
+    uint8_t read_buf[len];
+    eeprom_read_block(read_buf, addr, len);
+    if (memcmp(buf, read_buf, len) != 0) {
+        eeprom_write_block(buf, addr, len);
+    }
+}
+
+void eeprom_update_byte(uint8_t *addr, uint8_t value) {
+    uint8_t orig = eeprom_read_byte(addr);
+    if (orig != value) {
+        eeprom_write_byte(addr, value);
+    }
+}
+
+void eeprom_update_word(uint16_t *addr, uint16_t value) {
+    uint16_t orig = eeprom_read_word(addr);
+    if (orig != value) {
+        eeprom_write_word(addr, value);
+    }
+}
+
+void eeprom_update_dword(uint32_t *addr, uint32_t value) {
+    uint32_t orig = eeprom_read_dword(addr);
+    if (orig != value) {
+        eeprom_write_dword(addr, value);
+    }
+}