blob: 8f429ba5e5962e34682a5ae75f73f047711a09da [file] [log] [blame] [edit]
/*
* Copyright (c) 2019 Antmicro <www.antmicro.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT litex_i2c
#include <zephyr/device.h>
#include <zephyr/drivers/i2c.h>
#include "i2c_bitbang.h"
#define SCL_BIT_POS 0
#define SDA_DIR_BIT_POS 1
#define SDA_BIT_W_POS 2
#define SDA_BIT_R_POS 0
#define SDA_DIR_OUTPUT 1
#define SDA_DIR_INPUT 0
#define HIGH_STATE_ON_I2C_LINES 0x7
struct i2c_litex_cfg {
uint32_t write_addr;
uint32_t read_addr;
};
#define GET_I2C_CFG(dev) \
((const struct i2c_litex_cfg *) dev->config)
#define GET_I2C_BITBANG(dev) \
((struct i2c_bitbang *) dev->data)
static inline void set_bit(uint32_t addr, uint32_t bit, uint32_t val)
{
uint32_t mask = BIT(bit);
if (val) {
litex_write8(litex_read8(addr) | mask, addr);
} else {
litex_write8(litex_read8(addr) & ~mask, addr);
}
}
static inline int get_bit(uint32_t addr, uint32_t bit)
{
uint32_t mask = BIT(bit);
return !!(litex_read8(addr) & mask);
}
static void i2c_litex_bitbang_set_scl(void *context, int state)
{
const struct i2c_litex_cfg *config =
(const struct i2c_litex_cfg *) context;
set_bit(config->write_addr, SCL_BIT_POS, state);
}
static void i2c_litex_bitbang_set_sda(void *context, int state)
{
const struct i2c_litex_cfg *config =
(const struct i2c_litex_cfg *) context;
set_bit(config->write_addr, SDA_DIR_BIT_POS, SDA_DIR_OUTPUT);
set_bit(config->write_addr, SDA_BIT_W_POS, state);
}
static int i2c_litex_bitbang_get_sda(void *context)
{
const struct i2c_litex_cfg *config =
(const struct i2c_litex_cfg *) context;
set_bit(config->write_addr, SDA_DIR_BIT_POS, SDA_DIR_INPUT);
return get_bit(config->read_addr, SDA_BIT_R_POS);
}
static const struct i2c_bitbang_io i2c_litex_bitbang_io = {
.set_scl = i2c_litex_bitbang_set_scl,
.set_sda = i2c_litex_bitbang_set_sda,
.get_sda = i2c_litex_bitbang_get_sda,
};
static int i2c_litex_init(const struct device *dev)
{
const struct i2c_litex_cfg *config = GET_I2C_CFG(dev);
struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
litex_write8(litex_read8(config->write_addr) | HIGH_STATE_ON_I2C_LINES, config->write_addr);
i2c_bitbang_init(bitbang, &i2c_litex_bitbang_io, (void *)config);
return 0;
}
static int i2c_litex_configure(const struct device *dev, uint32_t dev_config)
{
struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
return i2c_bitbang_configure(bitbang, dev_config);
}
static int i2c_litex_transfer(const struct device *dev, struct i2c_msg *msgs,
uint8_t num_msgs, uint16_t addr)
{
struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
return i2c_bitbang_transfer(bitbang, msgs, num_msgs, addr);
}
static const struct i2c_driver_api i2c_litex_driver_api = {
.configure = i2c_litex_configure,
.transfer = i2c_litex_transfer,
};
/* Device Instantiation */
#define I2C_LITEX_INIT(n) \
static const struct i2c_litex_cfg i2c_litex_cfg_##n = { \
.write_addr = DT_INST_REG_ADDR_BY_NAME(n, write), \
.read_addr = DT_INST_REG_ADDR_BY_NAME(n, read), \
}; \
\
static struct i2c_bitbang i2c_bitbang_##n; \
\
I2C_DEVICE_DT_INST_DEFINE(n, \
i2c_litex_init, \
NULL, \
&i2c_bitbang_##n, \
&i2c_litex_cfg_##n, \
POST_KERNEL, \
CONFIG_I2C_INIT_PRIORITY, \
&i2c_litex_driver_api \
);
DT_INST_FOREACH_STATUS_OKAY(I2C_LITEX_INIT)