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eeprom_i2c driver: added EXTERNAL_EEPROM_WP_PIN configuration option. (#12617)

master
Purdea Andrei 2021-06-22 05:34:28 +03:00 committed by GitHub
parent 0e3ae2cde0
commit dd16d3cc7e
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 25 additions and 1 deletions
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3
docs/eeprom_driver.md
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@ -31,6 +31,9 @@ Currently QMK supports 24xx-series chips over I2C. As such, requires a working i
`#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
`#define EXTERNAL_EEPROM_WP_PIN` | If defined the WP pin will be toggled appropriately when writing to the EEPROM. | _none_
Some I2C EEPROM manufacturers explicitly recommend against hardcoding the WP pin to ground. This is in order to protect the eeprom memory content during power-up/power-down/brown-out conditions at low voltage where the eeprom is still operational, but the i2c master output might be unpredictable. If a WP pin is configured, then having an external pull-up on the WP pin is recommended.
Default values and extended descriptions can be found in `drivers/eeprom/eeprom_i2c.h`.

23
drivers/eeprom/eeprom_i2c.c
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@ -16,6 +16,9 @@
#include <stdint.h>
#include <string.h>
#if defined(EXTERNAL_EEPROM_WP_PIN)
# include "gpio.h"
#endif
/*
Note that the implementations of eeprom_XXXX_YYYY on AVR are normally
@ -50,7 +53,14 @@ static inline void fill_target_address(uint8_t *buffer, const void *addr) {
}
}
void eeprom_driver_init(void) { i2c_init(); }
void eeprom_driver_init(void) {
i2c_init();
#if defined(EXTERNAL_EEPROM_WP_PIN)
/* We are setting the WP pin to high in a way that requires at least two bit-flips to change back to 0 */
writePin(EXTERNAL_EEPROM_WP_PIN, 1);
setPinInputHigh(EXTERNAL_EEPROM_WP_PIN);
#endif
}
void eeprom_driver_erase(void) {
#if defined(CONSOLE_ENABLE) && defined(DEBUG_EEPROM_OUTPUT)
@ -89,6 +99,11 @@ void eeprom_write_block(const void *buf, void *addr, size_t len) {
uint8_t * read_buf = (uint8_t *)buf;
uintptr_t target_addr = (uintptr_t)addr;
#if defined(EXTERNAL_EEPROM_WP_PIN)
setPinOutput(EXTERNAL_EEPROM_WP_PIN);
writePin(EXTERNAL_EEPROM_WP_PIN, 0);
#endif
while (len > 0) {
uintptr_t page_offset = target_addr % EXTERNAL_EEPROM_PAGE_SIZE;
int write_length = EXTERNAL_EEPROM_PAGE_SIZE - page_offset;
@ -116,4 +131,10 @@ void eeprom_write_block(const void *buf, void *addr, size_t len) {
target_addr += write_length;
len -= write_length;
}
#if defined(EXTERNAL_EEPROM_WP_PIN)
/* We are setting the WP pin to high in a way that requires at least two bit-flips to change back to 0 */
writePin(EXTERNAL_EEPROM_WP_PIN, 1);
setPinInputHigh(EXTERNAL_EEPROM_WP_PIN);
#endif
}