138 lines
3.5 KiB
C
138 lines
3.5 KiB
C
/*
|
|
* Copyright (c) 2019 Antmicro <www.antmicro.com>
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#define DT_DRV_COMPAT litex_i2c
|
|
|
|
#include <device.h>
|
|
#include <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 {
|
|
volatile uint32_t *w_reg;
|
|
volatile const uint32_t *r_reg;
|
|
};
|
|
|
|
#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(volatile uint32_t *reg, uint32_t bit, uint32_t val)
|
|
{
|
|
uint32_t mask = BIT(bit);
|
|
|
|
if (val) {
|
|
*reg |= mask;
|
|
} else {
|
|
*reg &= ~mask;
|
|
}
|
|
}
|
|
|
|
static inline int get_bit(volatile const uint32_t *reg, uint32_t bit)
|
|
{
|
|
uint32_t mask = BIT(bit);
|
|
|
|
return !!((*reg) & 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->w_reg, 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->w_reg, SDA_DIR_BIT_POS, SDA_DIR_OUTPUT);
|
|
set_bit(config->w_reg, 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->w_reg, SDA_DIR_BIT_POS, SDA_DIR_INPUT);
|
|
return get_bit(config->r_reg, 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);
|
|
|
|
*(config->w_reg) |= HIGH_STATE_ON_I2C_LINES;
|
|
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 = { \
|
|
.w_reg = \
|
|
(volatile uint32_t *) DT_INST_REG_ADDR_BY_NAME(n, write),\
|
|
.r_reg = \
|
|
(volatile uint32_t *) 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)
|