zephyr/drivers/eeprom/eeprom_mb85rcxx.c

234 lines
6.3 KiB
C

/*
* Copyright (c) 2023 Antmicro <www.antmicro.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT fujitsu_mb85rcxx
#include <zephyr/device.h>
#include <zephyr/drivers/eeprom.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(EEPROM_MB85RCXX, CONFIG_EEPROM_LOG_LEVEL);
struct mb85rcxx_config {
struct i2c_dt_spec i2c;
struct gpio_dt_spec wp_gpio;
size_t size;
size_t pagesize;
uint8_t addr_width;
bool readonly;
};
struct mb85rcxx_data {
struct k_mutex lock;
};
static int mb85rcxx_write_protect_set(const struct device *dev, int value)
{
const struct mb85rcxx_config *cfg = dev->config;
if (!cfg->wp_gpio.port) {
return 0;
}
return gpio_pin_set_dt(&cfg->wp_gpio, value);
}
static uint16_t mb85rcxx_translate_address(const struct device *dev, off_t offset, uint8_t *addr)
{
const struct mb85rcxx_config *cfg = dev->config;
off_t page_offset = offset % cfg->pagesize;
if (cfg->addr_width > 8) {
sys_put_be16(page_offset, addr);
addr[0] &= BIT_MASK(cfg->addr_width - 8);
} else {
addr[0] = page_offset & BIT_MASK(cfg->addr_width);
}
return cfg->i2c.addr + (offset >> cfg->addr_width);
}
static size_t mb85rcxx_remaining_len_in_page(const struct device *dev, off_t offset, size_t len)
{
const struct mb85rcxx_config *cfg = dev->config;
off_t page_offset = offset % cfg->pagesize;
size_t rem = cfg->pagesize - page_offset;
if (rem > len) {
rem = len;
}
return rem;
}
static int mb85rcxx_init(const struct device *dev)
{
const struct mb85rcxx_config *cfg = dev->config;
struct mb85rcxx_data *data = dev->data;
k_mutex_init(&data->lock);
if (!i2c_is_ready_dt(&cfg->i2c)) {
LOG_ERR("i2c bus device not ready");
return -EINVAL;
}
if (cfg->wp_gpio.port) {
if (!gpio_is_ready_dt(&cfg->wp_gpio)) {
LOG_ERR("wp gpio device not ready");
return -EINVAL;
}
int err = gpio_pin_configure_dt(&cfg->wp_gpio, GPIO_OUTPUT_ACTIVE);
if (err) {
LOG_ERR("failed to configure WP GPIO pin (err %d)", err);
return err;
}
}
return 0;
}
static int mb85rcxx_read(const struct device *dev, off_t offset, void *buf, size_t len)
{
const struct mb85rcxx_config *cfg = dev->config;
struct mb85rcxx_data *data = dev->data;
uint8_t addr[2];
uint16_t i2c_addr;
size_t len_in_page;
int ret;
if (offset + len > cfg->size) {
LOG_ERR("attempt to read past device boundary");
return -EINVAL;
}
k_mutex_lock(&data->lock, K_FOREVER);
while (len) {
i2c_addr = mb85rcxx_translate_address(dev, offset, addr);
len_in_page = mb85rcxx_remaining_len_in_page(dev, offset, len);
ret = i2c_write_read(cfg->i2c.bus, i2c_addr, addr, DIV_ROUND_UP(cfg->addr_width, 8),
buf, len_in_page);
if (ret < 0) {
LOG_ERR("failed to read FRAM (err %d)", ret);
k_mutex_unlock(&data->lock);
return ret;
}
len -= len_in_page;
*(char *)&buf += len_in_page;
offset += len_in_page;
}
k_mutex_unlock(&data->lock);
return 0;
}
static int mb85rcxx_i2c_write(const struct device *dev, uint16_t i2c_addr, uint8_t *addr,
const void *buf, size_t len)
{
const struct mb85rcxx_config *cfg = dev->config;
struct i2c_msg msgs[2];
msgs[0].buf = addr;
msgs[0].len = DIV_ROUND_UP(cfg->addr_width, 8);
msgs[0].flags = I2C_MSG_WRITE;
msgs[1].buf = (void *)buf;
msgs[1].len = len;
msgs[1].flags = I2C_MSG_WRITE | I2C_MSG_STOP;
return i2c_transfer(cfg->i2c.bus, &msgs[0], 2, i2c_addr);
}
static int mb85rcxx_write(const struct device *dev, off_t offset, const void *buf, size_t len)
{
const struct mb85rcxx_config *cfg = dev->config;
struct mb85rcxx_data *data = dev->data;
uint8_t addr[2];
uint16_t i2c_addr;
size_t len_in_page;
int ret;
if (cfg->readonly) {
LOG_ERR("attempt to write to read-only device");
return -EACCES;
}
if (offset + len > cfg->size) {
LOG_ERR("attempt to write past device boundary");
return -EINVAL;
}
ret = mb85rcxx_write_protect_set(dev, 0);
if (ret) {
LOG_ERR("failed to write-enable FRAM (err %d)", ret);
return ret;
}
k_mutex_lock(&data->lock, K_FOREVER);
while (len) {
i2c_addr = mb85rcxx_translate_address(dev, offset, addr);
len_in_page = mb85rcxx_remaining_len_in_page(dev, offset, len);
ret = mb85rcxx_i2c_write(dev, i2c_addr, addr, buf, len);
if (ret < 0) {
LOG_ERR("failed to write to FRAM (err %d)", ret);
k_mutex_unlock(&data->lock);
return ret;
}
len -= len_in_page;
*(char *)&buf += len_in_page;
offset += len_in_page;
}
k_mutex_unlock(&data->lock);
mb85rcxx_write_protect_set(dev, 1);
return ret;
}
static size_t mb85rcxx_get_size(const struct device *dev)
{
const struct mb85rcxx_config *cfg = dev->config;
return cfg->size;
}
static const struct eeprom_driver_api mb85rcxx_driver_api = {
.read = &mb85rcxx_read,
.write = &mb85rcxx_write,
.size = &mb85rcxx_get_size,
};
#define MB85RCXX_DEFINE(inst) \
static struct mb85rcxx_data mb85rcxx_data_##inst; \
\
static const struct mb85rcxx_config mb85rcxx_config_##inst = { \
.i2c = I2C_DT_SPEC_INST_GET(inst), \
IF_ENABLED(DT_INST_NODE_HAS_PROP(inst, wp_gpios), \
(.wp_gpio = GPIO_DT_SPEC_INST_GET(inst, wp_gpios),)) \
.size = DT_INST_PROP(inst, size), \
.pagesize = \
COND_CODE_1(DT_INST_NODE_HAS_PROP(inst, pagesize), \
(DT_INST_PROP(inst, pagesize)), (DT_INST_PROP(inst, size))), \
.addr_width = DT_INST_PROP(inst, address_width), \
.readonly = DT_INST_PROP(inst, read_only)}; \
\
DEVICE_DT_INST_DEFINE(inst, mb85rcxx_init, NULL, &mb85rcxx_data_##inst, \
&mb85rcxx_config_##inst, POST_KERNEL, CONFIG_EEPROM_INIT_PRIORITY, \
&mb85rcxx_driver_api);
DT_INST_FOREACH_STATUS_OKAY(MB85RCXX_DEFINE)