Add support for STM32L0/L1 onboard EEPROM. (#8002)

* Add support for STM32L0/L1 onboard EEPROM.

* Update docs/eeprom_driver.md

Co-Authored-By: Joel Challis <git@zvecr.com>

Co-authored-by: Joel Challis <git@zvecr.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/eeprom/eeprom_stm32_L0_L1.h b/drivers/eeprom/eeprom_stm32_L0_L1.h
new file mode 100644
index 0000000000..a35defca8b
--- /dev/null
+++ b/drivers/eeprom/eeprom_stm32_L0_L1.h
@@ -0,0 +1,33 @@
+/* Copyright 2020 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/>.
+ */
+
+#pragma once
+
+/*
+    The size used by the STM32 L0/L1 EEPROM driver.
+*/
+#ifndef STM32_ONBOARD_EEPROM_SIZE
+#    ifdef VIA_ENABLE
+#        define STM32_ONBOARD_EEPROM_SIZE 1024
+#    else
+#        include "eeconfig.h"
+#        define STM32_ONBOARD_EEPROM_SIZE (((EECONFIG_SIZE + 3) / 4) * 4)  // based off eeconfig's current usage, aligned to 4-byte sizes, to deal with LTO and EEPROM page sizing
+#    endif
+#endif
+
+#if STM32_ONBOARD_EEPROM_SIZE > 128
+#    pragma message("Please note: resetting EEPROM using an STM32L0/L1 device takes up to 1 second for every 1kB of internal EEPROM used.")
+#endif