summaryrefslogtreecommitdiff
path: root/bsp/ht32/libraries/ht32_drivers/drv_soft_i2c.c
blob: 269eaf5eee08ec921c647da4fedf8d70a2ce7bca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
 * Copyright (c) 2006-2024, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2024-05-29     QT-one       first version
 */
#include <rtdbg.h>
#include "drv_soft_i2c.h"

#ifdef RT_USING_I2C
#if !defined(BSP_USING_I2C0_SW) && !defined(BSP_USING_I2C1_SW) && !defined(BSP_USING_I2C2_SW)
    #error "Please define at least one BSP_USING_I2Cx_SW"
    /* this driver can be disabled at menuconfig RT-Thread Components Device Drivers */
#endif

/* ht32 software i2c config class */
struct ht32_soft_i2c_config
{
    rt_uint8_t scl;
    rt_uint8_t sda;
    const char *bus_name;
};
/* ht32 software i2c dirver class */
struct ht32_soft_i2c
{
    struct rt_i2c_bit_ops ops;
    struct rt_i2c_bus_device i2c_bus;
};

static rt_uint8_t scl_rw_flag = 0;
static rt_uint8_t sda_rw_flag = 0;

static const struct ht32_soft_i2c_config soft_i2c_config[] =
{
#ifdef BSP_USING_I2C0_SW
    {
        .scl        = BSP_I2C0_SLC_PIN,
        .sda        = BSP_I2C0_SDA_PIN,
        .bus_name   = BSP_USING_I2C0_SW_NAME,
    },
#endif
#ifdef BSP_USING_I2C1_SW
    {
        .scl        = BSP_I2C1_SLC_PIN,
        .sda        = BSP_I2C1_SDA_PIN,
        .bus_name   = BSP_USING_I2C1_SW_NAME,
    },
#endif
#ifdef BSP_USING_I2C2_SW
    {
        .scl        = BSP_I2C2_SLC_PIN,
        .sda        = BSP_I2C2_SDA_PIN,
        .bus_name   = BSP_USING_I2C2_SW_NAME,
    },
#endif
};

static struct ht32_soft_i2c i2c_obj[sizeof(soft_i2c_config) / sizeof(soft_i2c_config[0])];

/* this function initializes the software i2c pin */
static void ht32_soft_i2c_gpio_init(struct ht32_soft_i2c *i2c)
{
    struct ht32_soft_i2c_config* cfg = (struct ht32_soft_i2c_config*)i2c->ops.data;

    rt_pin_mode(cfg->scl, PIN_MODE_OUTPUT_OD);
    rt_pin_mode(cfg->sda, PIN_MODE_OUTPUT_OD);

    rt_pin_write(cfg->scl, PIN_HIGH);
    rt_pin_write(cfg->sda, PIN_HIGH);
}
/* this function sets the sda pin */
void ht32_set_sda(void *data, rt_int32_t state)
{
    struct ht32_soft_i2c_config* cfg = (struct ht32_soft_i2c_config*)data;
    if(sda_rw_flag != 0)
    {
        sda_rw_flag = 0;
        rt_pin_mode(cfg->sda, PIN_MODE_OUTPUT_OD);
    }
    if (state)
    {
        rt_pin_write(cfg->sda, PIN_HIGH);
    }
    else
    {
        rt_pin_write(cfg->sda, PIN_LOW);
    }
}
/* this function sets the scl pin */
void ht32_set_scl(void *data, rt_int32_t state)
{
    struct ht32_soft_i2c_config* cfg = (struct ht32_soft_i2c_config*)data;
    if(scl_rw_flag != 0)
    {
        scl_rw_flag = 0;
        rt_pin_mode(cfg->scl, PIN_MODE_OUTPUT_OD);
    }
    if (state)
    {
        rt_pin_write(cfg->scl, PIN_HIGH);
    }
    else
    {
        rt_pin_write(cfg->scl, PIN_LOW);
    }
}
/* this function gets the sda pin state */
rt_int32_t ht32_get_sda(void *data)
{
    struct ht32_soft_i2c_config* cfg = (struct ht32_soft_i2c_config*)data;

    if(sda_rw_flag == 0)
    {
        sda_rw_flag = 1;
        rt_pin_mode(cfg->sda, PIN_MODE_INPUT);
    }
    return rt_pin_read(cfg->sda);
}
/* this function gets the scl pin state */
rt_int32_t ht32_get_scl(void *data)
{
    struct ht32_soft_i2c_config* cfg = (struct ht32_soft_i2c_config*)data;
    if(scl_rw_flag == 0)
    {
        scl_rw_flag = 1;
        rt_pin_mode(cfg->scl, PIN_MODE_INPUT);
    }
    return rt_pin_read(cfg->scl);
}

void ht32_udelay(rt_uint32_t us)
{
    rt_uint32_t ticks;
    rt_uint32_t told, tnow, tcnt = 0;
    rt_uint32_t reload = SysTick->LOAD;

    ticks = us * reload / (1000000 / RT_TICK_PER_SECOND);
    told = SysTick->VAL;
    while (1)
    {
        tnow = SysTick->VAL;
        if (tnow != told)
        {
            if (tnow < told)
            {
                tcnt += told - tnow;
            }
            else
            {
                tcnt += reload - tnow + told;
            }
            told = tnow;
            if (tcnt >= ticks)
            {
                break;
            }
        }
    }
}

static const struct rt_i2c_bit_ops ht32_bit_ops_default =
{
    .data     = RT_NULL,
    .set_sda  = ht32_set_sda,
    .set_scl  = ht32_set_scl,
    .get_sda  = ht32_get_sda,
    .get_scl  = ht32_get_scl,
    .udelay   = ht32_udelay,
    .delay_us = 1,
    .timeout  = 100
};

/* if i2c is locked, this function will unlock it */
static rt_err_t ht32_soft_i2c_bus_unlock(const struct ht32_soft_i2c_config *cfg)
{
    rt_int32_t i = 0;
    rt_pin_mode(cfg->sda, PIN_MODE_INPUT_PULLUP);
    if (PIN_LOW == rt_pin_read(cfg->sda))
    {
        while (i++ < 9)
        {
            rt_pin_write(cfg->scl, PIN_HIGH);
            ht32_udelay(100);
            rt_pin_write(cfg->scl, PIN_LOW);
            ht32_udelay(100);
        }
    }
    if (PIN_LOW == rt_pin_read(cfg->sda))
    {
        return -RT_ERROR;
    }
    rt_pin_mode(cfg->sda, PIN_MODE_OUTPUT_OD);
    return RT_EOK;
}

/* i2c initialization function */
int rt_sw_i2c_init(void)
{
    rt_size_t obj_num = sizeof(i2c_obj) / sizeof(struct ht32_soft_i2c);
    rt_err_t result;

    for (int i = 0; i < obj_num; i++)
    {
        i2c_obj[i].ops = ht32_bit_ops_default;
        i2c_obj[i].ops.data = (void*)&soft_i2c_config[i];
        i2c_obj[i].i2c_bus.priv = &i2c_obj[i].ops;
        ht32_soft_i2c_gpio_init(&i2c_obj[i]);

        result = rt_i2c_bit_add_bus(&i2c_obj[i].i2c_bus, soft_i2c_config[i].bus_name);

        RT_ASSERT(result == RT_EOK);
        ht32_soft_i2c_bus_unlock(&soft_i2c_config[i]);

        LOG_D("software simulation %s init done, pin scl: %d, pin sda %d",
        soft_i2c_config[i].bus_name,
        soft_i2c_config[i].scl,
        soft_i2c_config[i].sda);
    }
    return result;
}

INIT_BOARD_EXPORT(rt_sw_i2c_init);


#endif /* RT_USING_I2C */