diff --git a/extmod/machine_i2c.c b/extmod/machine_i2c.c new file mode 100644 index 000000000..3d3fa5136 --- /dev/null +++ b/extmod/machine_i2c.c @@ -0,0 +1,357 @@ +/* + * 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 +#include +#include + +#include "py/mphal.h" +#include "py/runtime.h" +#include "extmod/machine_i2c.h" + +#if MICROPY_PY_MACHINE_I2C + +typedef struct _machine_i2c_obj_t { + mp_obj_base_t base; + uint32_t us_delay; + mp_hal_pin_obj_t *scl; + mp_hal_pin_obj_t *sda; +} machine_i2c_obj_t; + +STATIC void mp_hal_i2c_delay(machine_i2c_obj_t *self) { + // We need to use an accurate delay to get acceptable I2C + // speeds (eg 1us should be not much more than 1us). + mp_hal_delay_us_fast(self->us_delay); +} + +STATIC void mp_hal_i2c_scl_low(machine_i2c_obj_t *self) { + mp_hal_pin_low(self->scl); +} + +STATIC void mp_hal_i2c_scl_release(machine_i2c_obj_t *self) { + mp_hal_pin_od_high(self->scl); +} + +STATIC void mp_hal_i2c_sda_low(machine_i2c_obj_t *self) { + mp_hal_pin_low(self->sda); +} + +STATIC void mp_hal_i2c_sda_release(machine_i2c_obj_t *self) { + mp_hal_pin_od_high(self->sda); +} + +STATIC int mp_hal_i2c_sda_read(machine_i2c_obj_t *self) { + return mp_hal_pin_read(self->sda); +} + +STATIC void mp_hal_i2c_start(machine_i2c_obj_t *self) { + mp_hal_i2c_sda_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_sda_low(self); + mp_hal_i2c_delay(self); +} + +STATIC void mp_hal_i2c_stop(machine_i2c_obj_t *self) { + mp_hal_i2c_delay(self); + mp_hal_i2c_sda_low(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_sda_release(self); + mp_hal_i2c_delay(self); +} + +STATIC void mp_hal_i2c_init(machine_i2c_obj_t *self, uint32_t freq) { + self->us_delay = 500000 / freq; + if (self->us_delay == 0) { + self->us_delay = 1; + } + mp_hal_pin_config_od(self->scl); + mp_hal_pin_config_od(self->sda); + mp_hal_i2c_stop(self); +} + +STATIC int mp_hal_i2c_write_byte(machine_i2c_obj_t *self, uint8_t val) { + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_low(self); + + for (int i = 7; i >= 0; i--) { + if ((val >> i) & 1) { + mp_hal_i2c_sda_release(self); + } else { + mp_hal_i2c_sda_low(self); + } + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_low(self); + } + + mp_hal_i2c_sda_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + + int ret = mp_hal_i2c_sda_read(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_low(self); + + return !ret; +} + +STATIC void mp_hal_i2c_write(machine_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len) { + mp_hal_i2c_start(self); + if (!mp_hal_i2c_write_byte(self, addr << 1)) { + goto er; + } + while (len--) { + if (!mp_hal_i2c_write_byte(self, *data++)) { + goto er; + } + } + return; + +er: + mp_hal_i2c_stop(self); + nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error")); +} + +STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val) { + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_low(self); + mp_hal_i2c_delay(self); + + uint8_t data = 0; + for (int i = 7; i >= 0; i--) { + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + data = (data << 1) | mp_hal_i2c_sda_read(self); + mp_hal_i2c_scl_low(self); + mp_hal_i2c_delay(self); + } + *val = data; + + mp_hal_i2c_scl_release(self); + mp_hal_i2c_delay(self); + mp_hal_i2c_scl_low(self); + mp_hal_i2c_delay(self); + + return 1; // success +} + +STATIC void mp_hal_i2c_read(machine_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len) { + mp_hal_i2c_start(self); + if (!mp_hal_i2c_write_byte(self, (addr << 1) | 1)) { + goto er; + } + while (len--) { + if (!mp_hal_i2c_read_byte(self, data++)) { + goto er; + } + } + return; + +er: + mp_hal_i2c_stop(self); + nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error")); +} + +/******************************************************************************/ +// MicroPython bindings for I2C + +STATIC void machine_i2c_obj_init_helper(machine_i2c_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_scl, ARG_sda, ARG_freq }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ }, + { MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ }, + { MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} }, + }; + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + self->scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj); + self->sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj); + mp_hal_i2c_init(self, args[ARG_freq].u_int); +} + +STATIC mp_obj_t machine_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) { + mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true); + machine_i2c_obj_t *self = m_new_obj(machine_i2c_obj_t); + self->base.type = &machine_i2c_type; + mp_map_t kw_args; + mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); + machine_i2c_obj_init_helper(self, n_args, args, &kw_args); + return (mp_obj_t)self; +} + +STATIC mp_obj_t machine_i2c_obj_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { + machine_i2c_obj_init_helper(args[0], n_args - 1, args + 1, kw_args); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_init_obj, 1, machine_i2c_obj_init); + +STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_obj_t list = mp_obj_new_list(0, NULL); + // 7-bit addresses 0b0000xxx and 0b1111xxx are reserved + for (int addr = 0x08; addr < 0x78; ++addr) { + mp_hal_i2c_start(self); + int ack = mp_hal_i2c_write_byte(self, (addr << 1) | 1); + if (ack) { + mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr)); + } + mp_hal_i2c_stop(self); + } + return list; +} +MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_scan_obj, machine_i2c_scan); + +STATIC mp_obj_t machine_i2c_start(mp_obj_t self_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_hal_i2c_start(self); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_start_obj, machine_i2c_start); + +STATIC mp_obj_t machine_i2c_stop(mp_obj_t self_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_hal_i2c_stop(self); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(machine_i2c_stop_obj, machine_i2c_stop); + +STATIC mp_obj_t machine_i2c_readinto(mp_obj_t self_in, mp_obj_t buf_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + + // get the buffer to read into + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_WRITE); + + // do the read + uint8_t *dest = bufinfo.buf; + while (bufinfo.len--) { + if (!mp_hal_i2c_read_byte(self, dest++)) { + nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error")); + } + } + + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_2(machine_i2c_readinto_obj, machine_i2c_readinto); + +STATIC mp_obj_t machine_i2c_write(mp_obj_t self_in, mp_obj_t buf_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + + // get the buffer to write from + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ); + + // do the write + uint8_t *src = bufinfo.buf; + while (bufinfo.len--) { + if (!mp_hal_i2c_write_byte(self, *src++)) { + nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error")); + } + } + + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_2(machine_i2c_write_obj, machine_i2c_write); + +STATIC mp_obj_t machine_i2c_readfrom(mp_obj_t self_in, mp_obj_t addr_in, mp_obj_t nbytes_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + vstr_t vstr; + vstr_init_len(&vstr, mp_obj_get_int(nbytes_in)); + mp_hal_i2c_read(self, mp_obj_get_int(addr_in), (uint8_t*)vstr.buf, vstr.len); + return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); +} +MP_DEFINE_CONST_FUN_OBJ_3(machine_i2c_readfrom_obj, machine_i2c_readfrom); + +STATIC mp_obj_t machine_i2c_readfrom_into(mp_obj_t self_in, mp_obj_t addr_in, mp_obj_t buf_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_WRITE); + mp_hal_i2c_read(self, mp_obj_get_int(addr_in), (uint8_t*)bufinfo.buf, bufinfo.len); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_3(machine_i2c_readfrom_into_obj, machine_i2c_readfrom_into); + +STATIC mp_obj_t machine_i2c_writeto(mp_obj_t self_in, mp_obj_t addr_in, mp_obj_t buf_in) { + machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ); + mp_hal_i2c_write(self, mp_obj_get_int(addr_in), bufinfo.buf, bufinfo.len); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_3(machine_i2c_writeto_obj, machine_i2c_writeto); + +STATIC mp_obj_t machine_i2c_readfrom_mem(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { + mp_not_implemented("I2C.readfrom_mem"); +} +MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_obj, 1, machine_i2c_readfrom_mem); + +STATIC mp_obj_t machine_i2c_readfrom_mem_into(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { + mp_not_implemented("I2C.readfrom_mem_into"); +} +MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_into_obj, 1, machine_i2c_readfrom_mem_into); + +STATIC mp_obj_t machine_i2c_writeto_mem(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { + mp_not_implemented("I2C.writeto_mem"); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_writeto_mem_obj, 1, machine_i2c_writeto_mem); + +STATIC const mp_rom_map_elem_t machine_i2c_locals_dict_table[] = { + { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_i2c_init_obj) }, + { MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&machine_i2c_scan_obj) }, + + // primitive I2C operations + { MP_ROM_QSTR(MP_QSTR_start), MP_ROM_PTR(&machine_i2c_start_obj) }, + { MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&machine_i2c_stop_obj) }, + { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&machine_i2c_readinto_obj) }, + { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&machine_i2c_write_obj) }, + + // standard bus operations + { MP_ROM_QSTR(MP_QSTR_readfrom), MP_ROM_PTR(&machine_i2c_readfrom_obj) }, + { MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&machine_i2c_readfrom_into_obj) }, + { MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&machine_i2c_writeto_obj) }, + + // memory operations + { MP_ROM_QSTR(MP_QSTR_readfrom_mem), MP_ROM_PTR(&machine_i2c_readfrom_mem_obj) }, + { MP_ROM_QSTR(MP_QSTR_readfrom_mem_into), MP_ROM_PTR(&machine_i2c_readfrom_mem_into_obj) }, + { MP_ROM_QSTR(MP_QSTR_writeto_mem), MP_ROM_PTR(&machine_i2c_writeto_mem_obj) }, +}; + +STATIC MP_DEFINE_CONST_DICT(machine_i2c_locals_dict, machine_i2c_locals_dict_table); + +const mp_obj_type_t machine_i2c_type = { + { &mp_type_type }, + .name = MP_QSTR_I2C, + .make_new = machine_i2c_make_new, + .locals_dict = (mp_obj_dict_t*)&machine_i2c_locals_dict, +}; + +#endif // MICROPY_PY_MACHINE_I2C diff --git a/extmod/machine_i2c.h b/extmod/machine_i2c.h new file mode 100644 index 000000000..03fa6422a --- /dev/null +++ b/extmod/machine_i2c.h @@ -0,0 +1,34 @@ +/* + * 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. + */ + +#ifndef __MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H__ +#define __MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H__ + +#include "py/obj.h" + +extern const mp_obj_type_t machine_i2c_type; + +#endif // __MICROPY_INCLUDED_EXTMOD_MACHINE_I2C_H__ diff --git a/py/mpconfig.h b/py/mpconfig.h index bbf055513..017030b0f 100644 --- a/py/mpconfig.h +++ b/py/mpconfig.h @@ -837,6 +837,10 @@ typedef double mp_float_t; #define MICROPY_PY_MACHINE (0) #endif +#ifndef MICROPY_PY_MACHINE_I2C +#define MICROPY_PY_MACHINE_I2C (0) +#endif + #ifndef MICROPY_PY_USSL #define MICROPY_PY_USSL (0) #endif diff --git a/py/py.mk b/py/py.mk index 3cfc6712a..599850e3d 100644 --- a/py/py.mk +++ b/py/py.mk @@ -167,6 +167,7 @@ PY_O_BASENAME = \ ../extmod/moduhashlib.o \ ../extmod/modubinascii.o \ ../extmod/machine_mem.o \ + ../extmod/machine_i2c.o \ ../extmod/modussl.o \ ../extmod/modurandom.o \ ../extmod/modwebsocket.o \ diff --git a/py/qstrdefs.h b/py/qstrdefs.h index d8c7ccc42..a2717d256 100644 --- a/py/qstrdefs.h +++ b/py/qstrdefs.h @@ -681,6 +681,26 @@ Q(mem16) Q(mem32) #endif +#if MICROPY_PY_MACHINE_I2C +Q(I2C) +Q(init) +Q(scl) +Q(sda) +Q(freq) +Q(scan) +Q(start) +Q(stop) +Q(read) +Q(readinto) +Q(write) +Q(readfrom) +Q(readfrom_into) +Q(writeto) +Q(readfrom_mem) +Q(readfrom_mem_into) +Q(writeto_mem) +#endif + #if MICROPY_PY_USSL Q(ussl) Q(wrap_socket)