Add customisable EEPROM driver selection (qmk#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.

common_features.mk

@@ -102,6 +102,57 @@ ifeq ($(strip $(UNICODE_COMMON)), yes)
     SRC += $(QUANTUM_DIR)/process_keycode/process_unicode_common.c
 endif
 
+VALID_EEPROM_DRIVER_TYPES := vendor custom transient i2c
+EEPROM_DRIVER ?= vendor
+ifeq ($(filter $(EEPROM_DRIVER),$(VALID_EEPROM_DRIVER_TYPES)),)
+  $(error EEPROM_DRIVER="$(EEPROM_DRIVER)" is not a valid EEPROM driver)
+else
+  OPT_DEFS += -DEEPROM_ENABLE
+  ifeq ($(strip $(EEPROM_DRIVER)), custom)
+    OPT_DEFS += -DEEPROM_DRIVER -DEEPROM_CUSTOM
+    COMMON_VPATH += $(DRIVER_PATH)/eeprom
+    SRC += eeprom_driver.c
+  else ifeq ($(strip $(EEPROM_DRIVER)), i2c)
+    OPT_DEFS += -DEEPROM_DRIVER -DEEPROM_I2C
+    COMMON_VPATH += $(DRIVER_PATH)/eeprom
+    QUANTUM_LIB_SRC += i2c_master.c
+    SRC += eeprom_driver.c eeprom_i2c.c
+  else ifeq ($(strip $(EEPROM_DRIVER)), transient)
+    OPT_DEFS += -DEEPROM_DRIVER -DEEPROM_TRANSIENT
+    COMMON_VPATH += $(DRIVER_PATH)/eeprom
+    SRC += eeprom_driver.c eeprom_transient.c
+  else ifeq ($(strip $(EEPROM_DRIVER)), vendor)
+    OPT_DEFS += -DEEPROM_VENDOR
+    ifeq ($(PLATFORM),AVR)
+      # Automatically provided by avr-libc, nothing required
+    else ifeq ($(PLATFORM),CHIBIOS)
+      ifeq ($(MCU_SERIES), STM32F3xx)
+        SRC += $(PLATFORM_COMMON_DIR)/eeprom_stm32.c
+        SRC += $(PLATFORM_COMMON_DIR)/flash_stm32.c
+        OPT_DEFS += -DEEPROM_EMU_STM32F303xC
+        OPT_DEFS += -DSTM32_EEPROM_ENABLE
+      else ifeq ($(MCU_SERIES), STM32F1xx)
+        SRC += $(PLATFORM_COMMON_DIR)/eeprom_stm32.c
+        SRC += $(PLATFORM_COMMON_DIR)/flash_stm32.c
+        OPT_DEFS += -DEEPROM_EMU_STM32F103xB
+        OPT_DEFS += -DSTM32_EEPROM_ENABLE
+      else ifeq ($(MCU_SERIES)_$(MCU_LDSCRIPT), STM32F0xx_STM32F072xB)
+        SRC += $(PLATFORM_COMMON_DIR)/eeprom_stm32.c
+        SRC += $(PLATFORM_COMMON_DIR)/flash_stm32.c
+        OPT_DEFS += -DEEPROM_EMU_STM32F072xB
+        OPT_DEFS += -DSTM32_EEPROM_ENABLE
+      else
+        # This will effectively work the same as "transient" if not supported by the chip
+        SRC += $(PLATFORM_COMMON_DIR)/eeprom_teensy.c
+      endif
+    else ifeq ($(PLATFORM),ARM_ATSAM)
+      SRC += $(PLATFORM_COMMON_DIR)/eeprom.c
+    else ifeq ($(PLATFORM),TEST)
+      SRC += $(PLATFORM_COMMON_DIR)/eeprom.c
+    endif
+  endif
+endif
+
 ifeq ($(strip $(RGBLIGHT_ENABLE)), yes)
     POST_CONFIG_H += $(QUANTUM_DIR)/rgblight_post_config.h
     OPT_DEFS += -DRGBLIGHT_ENABLE

docs/_summary.md

@@ -104,6 +104,7 @@
   * [ADC Driver](adc_driver.md)
   * [I2C Driver](i2c_driver.md)
   * [WS2812 Driver](ws2812_driver.md)
+  * [EEPROM Driver](eeprom_driver.md)
   * [GPIO Controls](internals_gpio_control.md)
   * [Custom Matrix](custom_matrix.md)
   * [Proton C Conversion](proton_c_conversion.md)

docs/eeprom_driver.md

@@ -0,0 +1,50 @@
+# EEPROM Driver Configuration
+
+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.
+
+## Vendor Driver Configuration
+
+No configurable options are available.
+
+## I2C Driver Configuration
+
+Currently QMK supports 24xx-series chips over I2C. As such, requires a working i2c_master driver configuration. You can override the driver configuration via your config.h:
+
+`config.h` override                         | Description                                                                         | Default Value
+------------------------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------
+`#define EXTERNAL_EEPROM_I2C_BASE_ADDRESS`  | Base I2C address for the EEPROM -- shifted left by 1 as per i2c_master requirements | 0b10100000
+`#define EXTERNAL_EEPROM_I2C_ADDRESS(addr)` | Calculated I2C address for the EEPROM                                               | `(EXTERNAL_EEPROM_I2C_BASE_ADDRESS)`
+`#define EXTERNAL_EEPROM_BYTE_COUNT`        | Total size of the EEPROM in bytes                                                   | 8192
+`#define EXTERNAL_EEPROM_PAGE_SIZE`         | Page size of the EEPROM in bytes, as specified in the datasheet                     | 32
+`#define EXTERNAL_EEPROM_ADDRESS_SIZE`      | The number of bytes to transmit for the memory location within the EEPROM           | 2
+`#define EXTERNAL_EEPROM_WRITE_TIME`        | Write cycle time of the EEPROM, as specified in the datasheet                       | 5
+
+Default values and extended descriptions can be found in `drivers/eeprom/eeprom_i2c.h`.
+
+Alternatively, there are pre-defined hardware configurations for available chips/modules:
+
+Module           | Equivalent `#define`            | Source
+-----------------|---------------------------------|------------------------------------------
+CAT24C512 EEPROM | `#define EEPROM_I2C_CAT24C512`  | <https://www.sparkfun.com/products/14764>
+RM24C512C EEPROM | `#define EEPROM_I2C_RM24C512C`  | <https://www.sparkfun.com/products/14764>
+24LC128 EEPROM   | `#define EEPROM_I2C_24LC128`    | <https://www.microchip.com/wwwproducts/en/24LC128>
+24LC256 EEPROM   | `#define EEPROM_I2C_24LC256`    | <https://www.sparkfun.com/products/525>
+MB85RC256V FRAM  | `#define EEPROM_I2C_MB85RC256V` | <https://www.adafruit.com/product/1895>
+
+?> If you find that the EEPROM is not cooperating, ensure you've correctly shifted up your EEPROM address by 1. For example, the datasheet might state the address as `0b01010000` -- the correct value of `EXTERNAL_EEPROM_I2C_BASE_ADDRESS` needs to be `0b10100000`.
+
+## Transient Driver configuration
+
+The only configurable item for the transient EEPROM driver is its size:
+
+`config.h` override             | Description                               | Default Value
+------------------------------- | ----------------------------------------- | -------------
+`#define TRANSIENT_EEPROM_SIZE` | Total size of the EEPROM storage in bytes | 64
+
+Default values and extended descriptions can be found in `drivers/eeprom/eeprom_transient.h`.

docs/hardware_drivers.md

@@ -33,3 +33,7 @@ Support for up to 2 drivers. Each driver impliments 2 charlieplex matrices to in
 ## IS31FL3733
 
 Support for up to a single driver with room for expansion. Each driver can control 192 individual LEDs or 64 RGB LEDs. For more information on how to setup the driver see the [RGB Matrix](feature_rgb_matrix.md) page.
+
+## 24xx series external I2C EEPROM
+
+Support for an external I2C-based EEPROM instead of using the on-chip EEPROM. For more information on how to setup the driver see the [EEPROM Driver](eeprom_driver.md) page.

drivers/eeprom/eeprom_custom.c-template

@@ -0,0 +1,46 @@
+/* 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"
+
+void eeprom_driver_init(void) {
+    /* Any initialisation code */
+ }
+
+void eeprom_driver_erase(void) {
+    /* Wipe out the EEPROM, setting values to zero */
+}
+
+void eeprom_read_block(void *buf, const void *addr, size_t len) {
+    /*
+        Read a block of data:
+            buf: target buffer
+            addr: 0-based offset within the EEPROM
+            len: length to read
+     */
+}
+
+void eeprom_write_block(const void *buf, void *addr, size_t len) {
+    /*
+        Write a block of data:
+            buf: target buffer
+            addr: 0-based offset within the EEPROM
+            len: length to write
+     */
+}

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);
+    }
+}

drivers/eeprom/eeprom_driver.h

@@ -0,0 +1,22 @@
+/* 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/>.
+ */
+
+#pragma once
+
+#include "eeprom.h"
+
+void eeprom_driver_init(void);
+void eeprom_driver_erase(void);

drivers/eeprom/eeprom_i2c.c

@@ -0,0 +1,120 @@
+/* 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>
+
+/*
+    Note that the implementations of eeprom_XXXX_YYYY on AVR are normally
+    provided by avr-libc. The same functions are reimplemented below and are
+    rerouted to the external i2c equivalent.
+
+    Seemingly, as this is compiled from within QMK, the object file generated
+    during the build overrides the avr-libc implementation during the linking
+    stage.
+
+    On other platforms such as ARM, there are no provided implementations, so
+    there is nothing to override during linkage.
+*/
+
+#include "wait.h"
+#include "i2c_master.h"
+#include "eeprom.h"
+#include "eeprom_i2c.h"
+
+// #define DEBUG_EEPROM_OUTPUT
+
+#ifdef DEBUG_EEPROM_OUTPUT
+#    include "print.h"
+#endif  // DEBUG_EEPROM_OUTPUT
+
+static inline void init_i2c_if_required(void) {
+    static int done = 0;
+    if (!done) {
+        i2c_init();
+        done = 1;
+    }
+}
+
+static inline void fill_target_address(uint8_t *buffer, const void *addr) {
+    intptr_t p = (intptr_t)addr;
+    for (int i = 0; i < EXTERNAL_EEPROM_ADDRESS_SIZE; ++i) {
+        buffer[EXTERNAL_EEPROM_ADDRESS_SIZE - 1 - i] = p & 0xFF;
+        p >>= 8;
+    }
+}
+
+void eeprom_driver_init(void) {}
+
+void eeprom_driver_erase(void) {
+    uint8_t buf[EXTERNAL_EEPROM_PAGE_SIZE];
+    memset(buf, 0x00, EXTERNAL_EEPROM_PAGE_SIZE);
+    for (intptr_t addr = 0; addr < EXTERNAL_EEPROM_BYTE_COUNT; addr += EXTERNAL_EEPROM_PAGE_SIZE) {
+        eeprom_write_block(buf, (void *)addr, EXTERNAL_EEPROM_PAGE_SIZE);
+    }
+}
+
+void eeprom_read_block(void *buf, const void *addr, size_t len) {
+    uint8_t complete_packet[EXTERNAL_EEPROM_ADDRESS_SIZE];
+    fill_target_address(complete_packet, addr);
+
+    init_i2c_if_required();
+    i2c_transmit(EXTERNAL_EEPROM_I2C_ADDRESS((intptr_t)addr), complete_packet, EXTERNAL_EEPROM_ADDRESS_SIZE, 100);
+    i2c_receive(EXTERNAL_EEPROM_I2C_ADDRESS((intptr_t)addr), buf, len, 100);
+
+#ifdef DEBUG_EEPROM_OUTPUT
+    dprintf("[EEPROM R] 0x%04X: ", ((int)addr));
+    for (size_t i = 0; i < len; ++i) {
+        dprintf(" %02X", (int)(((uint8_t *)buf)[i]));
+    }
+    dprintf("\n");
+#endif  // DEBUG_EEPROM_OUTPUT
+}
+
+void eeprom_write_block(const void *buf, void *addr, size_t len) {
+    uint8_t  complete_packet[EXTERNAL_EEPROM_ADDRESS_SIZE + EXTERNAL_EEPROM_PAGE_SIZE];
+    uint8_t *read_buf    = (uint8_t *)buf;
+    intptr_t target_addr = (intptr_t)addr;
+
+    init_i2c_if_required();
+    while (len > 0) {
+        intptr_t page_offset  = target_addr % EXTERNAL_EEPROM_PAGE_SIZE;
+        int      write_length = EXTERNAL_EEPROM_PAGE_SIZE - page_offset;
+        if (write_length > len) {
+            write_length = len;
+        }
+
+        fill_target_address(complete_packet, (const void *)target_addr);
+        for (uint8_t i = 0; i < write_length; i++) {
+            complete_packet[EXTERNAL_EEPROM_ADDRESS_SIZE + i] = read_buf[i];
+        }
+
+#ifdef DEBUG_EEPROM_OUTPUT
+        dprintf("[EEPROM W] 0x%04X: ", ((int)target_addr));
+        for (uint8_t i = 0; i < write_length; i++) {
+            dprintf(" %02X", (int)(read_buf[i]));
+        }
+        dprintf("\n");
+#endif  // DEBUG_EEPROM_OUTPUT
+
+        i2c_transmit(EXTERNAL_EEPROM_I2C_ADDRESS((intptr_t)addr), complete_packet, EXTERNAL_EEPROM_ADDRESS_SIZE + write_length, 100);
+        wait_ms(EXTERNAL_EEPROM_WRITE_TIME);
+
+        read_buf += write_length;
+        target_addr += write_length;
+        len -= write_length;
+    }
+}