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Diffstat (limited to 'stmhal/machine_i2c.c')
| -rw-r--r-- | stmhal/machine_i2c.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/stmhal/machine_i2c.c b/stmhal/machine_i2c.c new file mode 100644 index 0000000000..f4ed7128fc --- /dev/null +++ b/stmhal/machine_i2c.c @@ -0,0 +1,151 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2016 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 <stdio.h> +#include <string.h> + +#include "py/runtime.h" +#include "py/mphal.h" +#include "extmod/machine_i2c.h" +#include "genhdr/pins.h" + +// for now we use the SW I2C implementation for the HW peripheral I2C blocks +typedef mp_machine_soft_i2c_obj_t machine_hard_i2c_obj_t; + +STATIC const mp_obj_type_t machine_hard_i2c_type; + +STATIC machine_hard_i2c_obj_t machine_hard_i2c_obj[] = { + #if defined(MICROPY_HW_I2C1_SCL) + {{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C1_SCL, &MICROPY_HW_I2C1_SDA}, + #else + {{NULL}, 0, 0, NULL, NULL}, + #endif + #if defined(MICROPY_HW_I2C2_SCL) + {{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C2_SCL, &MICROPY_HW_I2C2_SDA}, + #else + {{NULL}, 0, 0, NULL, NULL}, + #endif + #if defined(MICROPY_HW_I2C3_SCL) + {{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C3_SCL, &MICROPY_HW_I2C3_SDA}, + #else + {{NULL}, 0, 0, NULL, NULL}, + #endif +}; + +STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { + machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timeout=%u)", + self - &machine_hard_i2c_obj[0] + 1, + self->scl->name, self->sda->name, 500000 / self->us_delay, self->us_timeout); +} + +mp_obj_t machine_hard_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 = -1} }, + { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} }, + }; + 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); + + // work out i2c bus + int i2c_id = 0; + if (MP_OBJ_IS_STR(args[ARG_id].u_obj)) { + const char *port = mp_obj_str_get_str(args[ARG_id].u_obj); + if (0) { + #ifdef MICROPY_HW_I2C1_NAME + } else if (strcmp(port, MICROPY_HW_I2C1_NAME) == 0) { + i2c_id = 1; + #endif + #ifdef MICROPY_HW_I2C2_NAME + } else if (strcmp(port, MICROPY_HW_I2C2_NAME) == 0) { + i2c_id = 2; + #endif + #ifdef MICROPY_HW_I2C3_NAME + } else if (strcmp(port, MICROPY_HW_I2C3_NAME) == 0) { + i2c_id = 3; + #endif + } else { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, + "I2C(%s) does not exist", port)); + } + } else { + i2c_id = mp_obj_get_int(args[ARG_id].u_obj); + if (i2c_id < 1 || i2c_id > MP_ARRAY_SIZE(machine_hard_i2c_obj) + || machine_hard_i2c_obj[i2c_id - 1].base.type == NULL) { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, + "I2C(%d) does not exist", i2c_id)); + } + } + + // get static peripheral object + machine_hard_i2c_obj_t *self = &machine_hard_i2c_obj[i2c_id - 1]; + + // here we would check the scl/sda pins and configure them, but it's not implemented + if (args[ARG_scl].u_obj != MP_OBJ_NULL || args[ARG_sda].u_obj != MP_OBJ_NULL) { + mp_raise_ValueError("explicit choice of scl/sda is not implemented"); + } + + // set parameters + if (args[ARG_freq].u_int != -1) { + if (args[ARG_freq].u_int >= 1000000) { + // allow fastest possible bit-bang rate + self->us_delay = 0; + } else { + self->us_delay = 500000 / args[ARG_freq].u_int; + if (self->us_delay == 0) { + self->us_delay = 1; + } + } + } + if (args[ARG_timeout].u_int != -1) { + self->us_timeout = args[ARG_timeout].u_int; + } + + // init pins + mp_hal_pin_open_drain(self->scl); + mp_hal_pin_open_drain(self->sda); + + return MP_OBJ_FROM_PTR(self); +} + +STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = { + .readfrom = mp_machine_soft_i2c_readfrom, + .writeto = mp_machine_soft_i2c_writeto, +}; + +STATIC const mp_obj_type_t machine_hard_i2c_type = { + { &mp_type_type }, + .name = MP_QSTR_I2C, + .print = machine_hard_i2c_print, + .make_new = machine_hard_i2c_make_new, + .protocol = &machine_hard_i2c_p, + .locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict, +}; |