aboutsummaryrefslogtreecommitdiff
path: root/ports/esp32/machine_i2c.c
blob: 61a68074ca115d1922ffb7718a15e9b1240bb049 (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
/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "py/runtime.h"
#include "py/mphal.h"
#include "py/mperrno.h"
#include "extmod/machine_i2c.h"

#include "driver/i2c.h"

#define I2C_0_DEFAULT_SCL (GPIO_NUM_18)
#define I2C_0_DEFAULT_SDA (GPIO_NUM_19)
#define I2C_1_DEFAULT_SCL (GPIO_NUM_25)
#define I2C_1_DEFAULT_SDA (GPIO_NUM_26)

#define I2C_DEFAULT_TIMEOUT_US (10000) // 10ms

typedef struct _machine_hw_i2c_obj_t {
    mp_obj_base_t base;
    i2c_port_t port : 8;
    gpio_num_t scl : 8;
    gpio_num_t sda : 8;
} machine_hw_i2c_obj_t;

STATIC const mp_obj_type_t machine_hw_i2c_type;
STATIC machine_hw_i2c_obj_t machine_hw_i2c_obj[I2C_NUM_MAX];

STATIC void machine_hw_i2c_init(machine_hw_i2c_obj_t *self, uint32_t freq, uint32_t timeout_us, bool first_init) {
    if (!first_init) {
        i2c_driver_delete(self->port);
    }
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = self->sda,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_io_num = self->scl,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = freq,
    };
    i2c_param_config(self->port, &conf);
    i2c_set_timeout(self->port, I2C_APB_CLK_FREQ / 1000000 * timeout_us);
    i2c_driver_install(self->port, I2C_MODE_MASTER, 0, 0, 0);
}

int machine_hw_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
    machine_hw_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);

    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, addr << 1 | (flags & MP_MACHINE_I2C_FLAG_READ), true);

    int data_len = 0;
    for (; n--; ++bufs) {
        if (flags & MP_MACHINE_I2C_FLAG_READ) {
            i2c_master_read(cmd, bufs->buf, bufs->len, n == 0 ? I2C_MASTER_LAST_NACK : I2C_MASTER_ACK);
        } else {
            if (bufs->len != 0) {
                i2c_master_write(cmd, bufs->buf, bufs->len, true);
            }
        }
        data_len += bufs->len;
    }

    if (flags & MP_MACHINE_I2C_FLAG_STOP) {
        i2c_master_stop(cmd);
    }

    // TODO proper timeout
    esp_err_t err = i2c_master_cmd_begin(self->port, cmd, 100 * (1 + data_len) / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    if (err == ESP_FAIL) {
        return -MP_ENODEV;
    } else if (err == ESP_ERR_TIMEOUT) {
        return -MP_ETIMEDOUT;
    } else if (err != ESP_OK) {
        return -abs(err);
    }

    return data_len;
}

/******************************************************************************/
// MicroPython bindings for machine API

STATIC void machine_hw_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    machine_hw_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
    int h, l;
    i2c_get_period(self->port, &h, &l);
    mp_printf(print, "I2C(%u, scl=%u, sda=%u, freq=%u)",
        self->port, self->scl, self->sda, I2C_APB_CLK_FREQ / (h + l));
}

mp_obj_t machine_hw_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
    // Parse args
    enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
        { MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
        { MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
        { MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = I2C_DEFAULT_TIMEOUT_US} },
    };
    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    // Get I2C bus
    mp_int_t i2c_id = mp_obj_get_int(args[ARG_id].u_obj);
    if (!(I2C_NUM_0 <= i2c_id && i2c_id < I2C_NUM_MAX)) {
        mp_raise_msg_varg(&mp_type_ValueError, "I2C(%d) doesn't exist", i2c_id);
    }

    // Get static peripheral object
    machine_hw_i2c_obj_t *self = (machine_hw_i2c_obj_t*)&machine_hw_i2c_obj[i2c_id];

    bool first_init = false;
    if (self->base.type == NULL) {
        // Created for the first time, set default pins
        self->base.type = &machine_hw_i2c_type;
        self->port = i2c_id;
        if (self->port == I2C_NUM_0) {
            self->scl = I2C_0_DEFAULT_SCL;
            self->sda = I2C_0_DEFAULT_SDA;
        } else {
            self->scl = I2C_1_DEFAULT_SCL;
            self->sda = I2C_1_DEFAULT_SDA;
        }
        first_init = true;
    }

    // Set SCL/SDA pins if given
    if (args[ARG_scl].u_obj != MP_OBJ_NULL) {
        self->scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj);
    }
    if (args[ARG_sda].u_obj != MP_OBJ_NULL) {
        self->sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj);
    }

    // Initialise the I2C peripheral
    machine_hw_i2c_init(self, args[ARG_freq].u_int, args[ARG_timeout].u_int, first_init);

    return MP_OBJ_FROM_PTR(self);
}

STATIC const mp_machine_i2c_p_t machine_hw_i2c_p = {
    .transfer = machine_hw_i2c_transfer,
};

STATIC const mp_obj_type_t machine_hw_i2c_type = {
    { &mp_type_type },
    .name = MP_QSTR_I2C,
    .print = machine_hw_i2c_print,
    .make_new = machine_hw_i2c_make_new,
    .protocol = &machine_hw_i2c_p,
    .locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict,
};