~ruther/qmk_firmware

f2f2afe13ba3ae1da8a546ad85eb9e69ddc70a8a — Nick Brassel 5 years ago 3a3ea03
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>
M common_features.mk => common_features.mk +4 -0
@@ 141,6 141,10 @@ else
        SRC += $(PLATFORM_COMMON_DIR)/flash_stm32.c
        OPT_DEFS += -DEEPROM_EMU_STM32F072xB
        OPT_DEFS += -DSTM32_EEPROM_ENABLE
      else ifneq ($(filter $(MCU_SERIES),STM32L0xx STM32L1xx),)
        OPT_DEFS += -DEEPROM_DRIVER
        COMMON_VPATH += $(DRIVER_PATH)/eeprom
        SRC += eeprom_driver.c eeprom_stm32_L0_L1.c
      else
        # This will effectively work the same as "transient" if not supported by the chip
        SRC += $(PLATFORM_COMMON_DIR)/eeprom_teensy.c

M docs/eeprom_driver.md => docs/eeprom_driver.md +7 -5
@@ 2,14 2,16 @@

The EEPROM driver can be swapped out depending on the needs of the keyboard, or whether extra hardware is present.

Driver                      | Description
--------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
`EEPROM_DRIVER = vendor`    | Uses the on-chip driver provided by the chip manufacturer. For AVR, this is provided by avr-libc. This is supported on ARM for a subset of chips -- STM32F3xx, STM32F1xx, and STM32F072xB will be emulated by writing to flash. Other chips will generally act as "transient" below.
`EEPROM_DRIVER = i2c`       | Supports writing to I2C-based 24xx EEPROM chips. See the driver section below.
`EEPROM_DRIVER = transient` | Fake EEPROM driver -- supports reading/writing to RAM, and will be discarded when power is lost.
Driver                             | Description
-----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
`EEPROM_DRIVER = vendor` (default) | Uses the on-chip driver provided by the chip manufacturer. For AVR, this is provided by avr-libc. This is supported on ARM for a subset of chips -- STM32F3xx, STM32F1xx, and STM32F072xB will be emulated by writing to flash. STM32L0xx and STM32L1xx will use the onboard dedicated true EEPROM. Other chips will generally act as "transient" below.
`EEPROM_DRIVER = i2c`              | Supports writing to I2C-based 24xx EEPROM chips. See the driver section below.
`EEPROM_DRIVER = transient`        | Fake EEPROM driver -- supports reading/writing to RAM, and will be discarded when power is lost.

## Vendor Driver Configuration

!> Resetting EEPROM using an STM32L0/L1 device takes up to 1 second for every 1kB of internal EEPROM used.

No configurable options are available.

## I2C Driver Configuration

A drivers/eeprom/eeprom_stm32_L0_L1.c => drivers/eeprom/eeprom_stm32_L0_L1.c +96 -0
@@ 0,0 1,96 @@
/* 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/>.
 */

#include <stdint.h>
#include <string.h>

#include "hal.h"
#include "eeprom_driver.h"
#include "eeprom_stm32_L0_L1.h"

#define EEPROM_BASE_ADDR 0x08080000
#define EEPROM_ADDR(offset) (EEPROM_BASE_ADDR + (offset))
#define EEPROM_PTR(offset) ((__IO uint8_t *)EEPROM_ADDR(offset))
#define EEPROM_BYTE(location, offset) (*(EEPROM_PTR(((uint32_t)location) + ((uint32_t)offset))))

#define BUFFER_BYTE(buffer, offset) (*(((uint8_t *)buffer) + offset))

#define FLASH_PEKEY1 0x89ABCDEF
#define FLASH_PEKEY2 0x02030405

static inline void STM32_L0_L1_EEPROM_WaitNotBusy(void) {
    while (FLASH->SR & FLASH_SR_BSY) {
        __WFI();
    }
}

static inline void STM32_L0_L1_EEPROM_Unlock(void) {
    STM32_L0_L1_EEPROM_WaitNotBusy();
    if (FLASH->PECR & FLASH_PECR_PELOCK) {
        FLASH->PEKEYR = FLASH_PEKEY1;
        FLASH->PEKEYR = FLASH_PEKEY2;
    }
}

static inline void STM32_L0_L1_EEPROM_Lock(void) {
    STM32_L0_L1_EEPROM_WaitNotBusy();
    FLASH->PECR |= FLASH_PECR_PELOCK;
}

void eeprom_driver_init(void) {}

void eeprom_driver_erase(void) {
    STM32_L0_L1_EEPROM_Unlock();

    for (size_t offset = 0; offset < STM32_ONBOARD_EEPROM_SIZE; offset += sizeof(uint32_t)) {
        FLASH->PECR |= FLASH_PECR_ERASE | FLASH_PECR_DATA;

        *(__IO uint32_t *)EEPROM_ADDR(offset) = (uint32_t)0;

        STM32_L0_L1_EEPROM_WaitNotBusy();
        FLASH->PECR &= ~(FLASH_PECR_ERASE | FLASH_PECR_DATA);
    }

    STM32_L0_L1_EEPROM_Lock();
}

void eeprom_read_block(void *buf, const void *addr, size_t len) {
    for (size_t offset = 0; offset < len; ++offset) {
        // Drop out if we've hit the limit of the EEPROM
        if ((((uint32_t)addr) + offset) >= STM32_ONBOARD_EEPROM_SIZE) {
            break;
        }

        STM32_L0_L1_EEPROM_WaitNotBusy();
        BUFFER_BYTE(buf, offset) = EEPROM_BYTE(addr, offset);
    }
}

void eeprom_write_block(const void *buf, void *addr, size_t len) {
    STM32_L0_L1_EEPROM_Unlock();

    for (size_t offset = 0; offset < len; ++offset) {
        // Drop out if we've hit the limit of the EEPROM
        if ((((uint32_t)addr) + offset) >= STM32_ONBOARD_EEPROM_SIZE) {
            break;
        }

        STM32_L0_L1_EEPROM_WaitNotBusy();
        EEPROM_BYTE(addr, offset) = BUFFER_BYTE(buf, offset);
    }

    STM32_L0_L1_EEPROM_Lock();
}

A drivers/eeprom/eeprom_stm32_L0_L1.h => drivers/eeprom/eeprom_stm32_L0_L1.h +33 -0
@@ 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