172 lines
4.0 KiB
C
172 lines
4.0 KiB
C
/*
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* Copyright (c) 2019 Antmicro <www.antmicro.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <device.h>
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#include <drivers/i2c.h>
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#include "i2c_bitbang.h"
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#define SCL_BIT_POS 0
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#define SDA_DIR_BIT_POS 1
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#define SDA_BIT_W_POS 2
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#define SDA_BIT_R_POS 0
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#define SDA_DIR_OUTPUT 1
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#define SDA_DIR_INPUT 0
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#define HIGH_STATE_ON_I2C_LINES 0x7
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struct i2c_litex_cfg {
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volatile u32_t *w_reg;
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volatile const u32_t *r_reg;
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};
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#define GET_I2C_CFG(dev) \
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((const struct i2c_litex_cfg *) dev->config->config_info)
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#define GET_I2C_BITBANG(dev) \
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((struct i2c_bitbang *) dev->driver_data)
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static inline void set_bit(volatile u32_t *reg, u32_t bit, u32_t val)
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{
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u32_t mask = BIT(bit);
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if (val) {
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*reg |= mask;
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} else {
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*reg &= ~mask;
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}
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}
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static inline int get_bit(volatile const u32_t *reg, u32_t bit)
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{
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u32_t mask = BIT(bit);
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return !!((*reg) & mask);
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}
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static void i2c_litex_bitbang_set_scl(void *context, int state)
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{
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const struct i2c_litex_cfg *config =
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(const struct i2c_litex_cfg *) context;
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set_bit(config->w_reg, SCL_BIT_POS, state);
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}
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static void i2c_litex_bitbang_set_sda(void *context, int state)
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{
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const struct i2c_litex_cfg *config =
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(const struct i2c_litex_cfg *) context;
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set_bit(config->w_reg, SDA_DIR_BIT_POS, SDA_DIR_OUTPUT);
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set_bit(config->w_reg, SDA_BIT_W_POS, state);
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}
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static int i2c_litex_bitbang_get_sda(void *context)
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{
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const struct i2c_litex_cfg *config =
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(const struct i2c_litex_cfg *) context;
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set_bit(config->w_reg, SDA_DIR_BIT_POS, SDA_DIR_INPUT);
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return get_bit(config->r_reg, SDA_BIT_R_POS);
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}
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static const struct i2c_bitbang_io i2c_litex_bitbang_io = {
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.set_scl = i2c_litex_bitbang_set_scl,
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.set_sda = i2c_litex_bitbang_set_sda,
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.get_sda = i2c_litex_bitbang_get_sda,
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};
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static int i2c_litex_init(struct device *dev)
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{
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const struct i2c_litex_cfg *config = GET_I2C_CFG(dev);
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struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
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*(config->w_reg) |= HIGH_STATE_ON_I2C_LINES;
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i2c_bitbang_init(bitbang, &i2c_litex_bitbang_io, (void *)config);
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return 0;
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}
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static int i2c_litex_configure(struct device *dev, u32_t dev_config)
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{
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struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
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return i2c_bitbang_configure(bitbang, dev_config);
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}
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static int i2c_litex_transfer(struct device *dev, struct i2c_msg *msgs,
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u8_t num_msgs, u16_t addr)
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{
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struct i2c_bitbang *bitbang = GET_I2C_BITBANG(dev);
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return i2c_bitbang_transfer(bitbang, msgs, num_msgs, addr);
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}
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static const struct i2c_driver_api i2c_litex_driver_api = {
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.configure = i2c_litex_configure,
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.transfer = i2c_litex_transfer,
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.slave_register = NULL,
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.slave_unregister = NULL,
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};
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/* Device Instantiation */
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#define I2C_LITEX_INIT(n) \
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static const struct i2c_litex_cfg i2c_litex_cfg_##n = { \
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.w_reg = \
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(volatile u32_t *) DT_INST_##n##_LITEX_I2C_WRITE_BASE_ADDRESS,\
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.r_reg = \
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(volatile u32_t *) DT_INST_##n##_LITEX_I2C_READ_BASE_ADDRESS, \
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}; \
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\
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static struct i2c_bitbang i2c_bitbang_##n; \
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\
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DEVICE_AND_API_INIT(litex_i2c_##n, \
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DT_INST_##n##_LITEX_I2C_LABEL, \
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i2c_litex_init, \
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&i2c_bitbang_##n, \
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&i2c_litex_cfg_##n, \
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POST_KERNEL, \
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CONFIG_I2C_INIT_PRIORITY, \
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&i2c_litex_driver_api \
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)
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#ifdef DT_INST_0_LITEX_I2C_LABEL
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I2C_LITEX_INIT(0);
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#endif
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#ifdef DT_INST_1_LITEX_I2C_LABEL
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I2C_LITEX_INIT(1);
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#endif
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#ifdef DT_INST_2_LITEX_I2C_LABEL
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I2C_LITEX_INIT(2);
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#endif
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#ifdef DT_INST_3_LITEX_I2C_LABEL
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I2C_LITEX_INIT(3);
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#endif
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#ifdef DT_INST_4_LITEX_I2C_LABEL
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I2C_LITEX_INIT(4);
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#endif
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#ifdef DT_INST_5_LITEX_I2C_LABEL
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I2C_LITEX_INIT(5);
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#endif
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#ifdef DT_INST_6_LITEX_I2C_LABEL
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I2C_LITEX_INIT(6);
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#endif
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#ifdef DT_INST_7_LITEX_I2C_LABEL
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I2C_LITEX_INIT(7);
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#endif
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#ifdef DT_INST_8_LITEX_I2C_LABEL
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I2C_LITEX_INIT(8);
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#endif
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