Refine EEPROM types / flags (#17772)

Marlin/src/HAL/shared/eeprom_if_i2c.cpp

@@ -0,0 +1,128 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * 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 3 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/>.
+ *
+ */
+
+/**
+ * Platform-independent Arduino functions for I2C EEPROM.
+ * Enable USE_SHARED_EEPROM if not supplied by the framework.
+ */
+
+#include "../../inc/MarlinConfig.h"
+
+#if BOTH(USE_SHARED_EEPROM, I2C_EEPROM)
+
+#include "../HAL.h"
+#include <Wire.h>
+
+#include "eeprom_if.h"
+
+#ifndef EEPROM_WRITE_DELAY
+  #define EEPROM_WRITE_DELAY    5
+#endif
+
+// ------------------------
+// Private Variables
+// ------------------------
+
+#ifndef EEPROM_DEVICE_ADDRESS
+  #define EEPROM_DEVICE_ADDRESS  0x50
+#endif
+
+static constexpr uint8_t eeprom_device_address = I2C_ADDRESS(EEPROM_DEVICE_ADDRESS);
+
+// ------------------------
+// Public functions
+// ------------------------
+
+static void eeprom_init() { Wire.begin(); }
+
+void eeprom_write_byte(uint8_t *pos, unsigned char value) {
+  const unsigned eeprom_address = (unsigned)pos;
+
+  Wire.beginTransmission(eeprom_device_address);
+  Wire.write(int(eeprom_address >> 8));   // MSB
+  Wire.write(int(eeprom_address & 0xFF)); // LSB
+  Wire.write(value);
+  Wire.endTransmission();
+
+  // wait for write cycle to complete
+  // this could be done more efficiently with "acknowledge polling"
+  delay(EEPROM_WRITE_DELAY);
+}
+
+// WARNING: address is a page address, 6-bit end will wrap around
+// also, data can be maximum of about 30 bytes, because the Wire library has a buffer of 32 bytes
+void eeprom_update_block(const void *pos, void *__dst, size_t n) {
+  const unsigned eeprom_address = (unsigned)__dst;
+
+  eeprom_init();
+
+  Wire.beginTransmission(eeprom_device_address);
+  Wire.write(int(eeprom_address >> 8));   // MSB
+  Wire.write(int(eeprom_address & 0xFF)); // LSB
+  Wire.endTransmission();
+
+  uint8_t *ptr = (uint8_t*)pos;
+  uint8_t flag = 0;
+  Wire.requestFrom(eeprom_device_address, (byte)n);
+  for (byte c = 0; c < n && Wire.available(); c++)
+    flag |= Wire.read() ^ ptr[c];
+
+  if (flag) {
+    Wire.beginTransmission(eeprom_device_address);
+    Wire.write(int(eeprom_address >> 8));   // MSB
+    Wire.write(int(eeprom_address & 0xFF)); // LSB
+    Wire.write((uint8_t*)pos, n);
+    Wire.endTransmission();
+
+    // wait for write cycle to complete
+    // this could be done more efficiently with "acknowledge polling"
+    delay(EEPROM_WRITE_DELAY);
+  }
+}
+
+uint8_t eeprom_read_byte(uint8_t *pos) {
+  const unsigned eeprom_address = (unsigned)pos;
+
+  Wire.beginTransmission(eeprom_device_address);
+  Wire.write(int(eeprom_address >> 8));   // MSB
+  Wire.write(int(eeprom_address & 0xFF)); // LSB
+  Wire.endTransmission();
+  Wire.requestFrom(eeprom_device_address, (byte)1);
+  return Wire.available() ? Wire.read() : 0xFF;
+}
+
+// Don't read more than 30..32 bytes at a time!
+void eeprom_read_block(void* pos, const void *__dst, size_t n) {
+  const unsigned eeprom_address = (unsigned)__dst;
+
+  eeprom_init();
+
+  Wire.beginTransmission(eeprom_device_address);
+  Wire.write(int(eeprom_address >> 8));   // MSB
+  Wire.write(int(eeprom_address & 0xFF)); // LSB
+  Wire.endTransmission();
+  Wire.requestFrom(eeprom_device_address, (byte)n);
+  for (byte c = 0; c < n; c++ )
+    if (Wire.available()) *((uint8_t*)pos + c) = Wire.read();
+}
+
+#endif // USE_SHARED_EEPROM && I2C_EEPROM