/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2013, 2014 Damien P. George * Copyright (c) 2015 Daniel Campora * * 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 "py/mpstate.h" #include "py/runtime.h" #include "py/mperrno.h" #include "py/mphal.h" #include "bufhelper.h" #include "inc/hw_types.h" #include "inc/hw_i2c.h" #include "inc/hw_ints.h" #include "inc/hw_memmap.h" #include "rom_map.h" #include "pin.h" #include "prcm.h" #include "i2c.h" #include "pybi2c.h" #include "mpexception.h" #include "pybsleep.h" #include "utils.h" #include "pybpin.h" #include "pins.h" /// \moduleref pyb /// \class I2C - a two-wire serial protocol typedef struct _pyb_i2c_obj_t { mp_obj_base_t base; uint baudrate; } pyb_i2c_obj_t; /****************************************************************************** DEFINE CONSTANTS ******************************************************************************/ #define PYBI2C_MIN_BAUD_RATE_HZ (50000) #define PYBI2C_MAX_BAUD_RATE_HZ (400000) #define PYBI2C_TRANSC_TIMEOUT_MS (20) #define PYBI2C_TRANSAC_WAIT_DELAY_US (10) #define PYBI2C_TIMEOUT_TO_COUNT(to_us, baud) (((baud) * to_us) / 16000000) #define RET_IF_ERR(Func) { \ if (!Func) { \ return false; \ } \ } /****************************************************************************** DECLARE PRIVATE DATA ******************************************************************************/ STATIC pyb_i2c_obj_t pyb_i2c_obj = {.baudrate = 0}; /****************************************************************************** DECLARE PRIVATE FUNCTIONS ******************************************************************************/ STATIC bool pyb_i2c_write(byte addr, byte *data, uint len, bool stop); /****************************************************************************** DEFINE PRIVATE FUNCTIONS ******************************************************************************/ // only master mode is available for the moment STATIC void i2c_init (pyb_i2c_obj_t *self) { // Enable the I2C Peripheral MAP_PRCMPeripheralClkEnable(PRCM_I2CA0, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK); MAP_PRCMPeripheralReset(PRCM_I2CA0); // Configure I2C module with the specified baudrate MAP_I2CMasterInitExpClk(I2CA0_BASE, self->baudrate); } STATIC bool pyb_i2c_transaction(uint cmd) { // Convert the timeout to microseconds int32_t timeout = PYBI2C_TRANSC_TIMEOUT_MS * 1000; // Sanity check, t_timeout must be between 1 and 255 uint t_timeout = MIN(PYBI2C_TIMEOUT_TO_COUNT(timeout, pyb_i2c_obj.baudrate), 255); // Clear all interrupts MAP_I2CMasterIntClearEx(I2CA0_BASE, MAP_I2CMasterIntStatusEx(I2CA0_BASE, false)); // Set the time-out in terms of clock cycles. Not to be used with breakpoints. MAP_I2CMasterTimeoutSet(I2CA0_BASE, t_timeout); // Initiate the transfer. MAP_I2CMasterControl(I2CA0_BASE, cmd); // Wait until the current byte has been transferred. // Poll on the raw interrupt status. while ((MAP_I2CMasterIntStatusEx(I2CA0_BASE, false) & (I2C_MASTER_INT_DATA | I2C_MASTER_INT_TIMEOUT)) == 0) { if (timeout < 0) { // the peripheral is not responding, so stop return false; } // wait for a few microseconds UtilsDelay(UTILS_DELAY_US_TO_COUNT(PYBI2C_TRANSAC_WAIT_DELAY_US)); timeout -= PYBI2C_TRANSAC_WAIT_DELAY_US; } // Check for any errors in the transfer if (MAP_I2CMasterErr(I2CA0_BASE) != I2C_MASTER_ERR_NONE) { switch(cmd) { case I2C_MASTER_CMD_BURST_SEND_START: case I2C_MASTER_CMD_BURST_SEND_CONT: case I2C_MASTER_CMD_BURST_SEND_STOP: MAP_I2CMasterControl(I2CA0_BASE, I2C_MASTER_CMD_BURST_SEND_ERROR_STOP); break; case I2C_MASTER_CMD_BURST_RECEIVE_START: case I2C_MASTER_CMD_BURST_RECEIVE_CONT: case I2C_MASTER_CMD_BURST_RECEIVE_FINISH: MAP_I2CMasterControl(I2CA0_BASE, I2C_MASTER_CMD_BURST_RECEIVE_ERROR_STOP); break; default: break; } return false; } return true; } STATIC void pyb_i2c_check_init(pyb_i2c_obj_t *self) { // not initialized if (!self->baudrate) { mp_raise_OSError(MP_EPERM); } } STATIC bool pyb_i2c_scan_device(byte devAddr) { bool ret = false; // Set the I2C slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, devAddr, true); // Initiate the transfer. if (pyb_i2c_transaction(I2C_MASTER_CMD_SINGLE_RECEIVE)) { ret = true; } // Send the stop bit to cancel the read transaction MAP_I2CMasterControl(I2CA0_BASE, I2C_MASTER_CMD_BURST_SEND_ERROR_STOP); if (!ret) { uint8_t data = 0; if (pyb_i2c_write(devAddr, &data, sizeof(data), true)) { ret = true; } } return ret; } STATIC bool pyb_i2c_mem_addr_write (byte addr, byte *mem_addr, uint mem_addr_len) { // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, addr, false); // Write the first byte to the controller. MAP_I2CMasterDataPut(I2CA0_BASE, *mem_addr++); // Initiate the transfer. RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_START)); // Loop until the completion of transfer or error while (--mem_addr_len) { // Write the next byte of data MAP_I2CMasterDataPut(I2CA0_BASE, *mem_addr++); // Transact over I2C to send the next byte RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_CONT)); } return true; } STATIC bool pyb_i2c_mem_write (byte addr, byte *mem_addr, uint mem_addr_len, byte *data, uint data_len) { if (pyb_i2c_mem_addr_write (addr, mem_addr, mem_addr_len)) { // Loop until the completion of transfer or error while (data_len--) { // Write the next byte of data MAP_I2CMasterDataPut(I2CA0_BASE, *data++); // Transact over I2C to send the byte RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_CONT)); } // send the stop bit RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_STOP)); return true; } return false; } STATIC bool pyb_i2c_write(byte addr, byte *data, uint len, bool stop) { // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, addr, false); // Write the first byte to the controller. MAP_I2CMasterDataPut(I2CA0_BASE, *data++); // Initiate the transfer. RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_START)); // Loop until the completion of transfer or error while (--len) { // Write the next byte of data MAP_I2CMasterDataPut(I2CA0_BASE, *data++); // Transact over I2C to send the byte RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_CONT)); } // If a stop bit is to be sent, do it. if (stop) { RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_STOP)); } return true; } STATIC bool pyb_i2c_read(byte addr, byte *data, uint len) { // Initiate a burst or single receive sequence uint cmd = --len > 0 ? I2C_MASTER_CMD_BURST_RECEIVE_START : I2C_MASTER_CMD_SINGLE_RECEIVE; // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, addr, true); // Initiate the transfer. RET_IF_ERR(pyb_i2c_transaction(cmd)); // Loop until the completion of reception or error while (len) { // Receive the byte over I2C *data++ = MAP_I2CMasterDataGet(I2CA0_BASE); if (--len) { // Continue with reception RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_RECEIVE_CONT)); } else { // Complete the last reception RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_RECEIVE_FINISH)); } } // Receive the last byte over I2C *data = MAP_I2CMasterDataGet(I2CA0_BASE); return true; } STATIC void pyb_i2c_read_into (mp_arg_val_t *args, vstr_t *vstr) { pyb_i2c_check_init(&pyb_i2c_obj); // get the buffer to receive into pyb_buf_get_for_recv(args[1].u_obj, vstr); // receive the data if (!pyb_i2c_read(args[0].u_int, (byte *)vstr->buf, vstr->len)) { mp_raise_OSError(MP_EIO); } } STATIC void pyb_i2c_readmem_into (mp_arg_val_t *args, vstr_t *vstr) { pyb_i2c_check_init(&pyb_i2c_obj); // get the buffer to receive into pyb_buf_get_for_recv(args[2].u_obj, vstr); // get the addresses mp_uint_t i2c_addr = args[0].u_int; mp_uint_t mem_addr = args[1].u_int; // determine the width of mem_addr (1 or 2 bytes) mp_uint_t mem_addr_size = args[3].u_int >> 3; // write the register address to be read from if (pyb_i2c_mem_addr_write (i2c_addr, (byte *)&mem_addr, mem_addr_size)) { // Read the specified length of data if (!pyb_i2c_read (i2c_addr, (byte *)vstr->buf, vstr->len)) { mp_raise_OSError(MP_EIO); } } else { mp_raise_OSError(MP_EIO); } } /******************************************************************************/ /* MicroPython bindings */ /******************************************************************************/ STATIC void pyb_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { pyb_i2c_obj_t *self = self_in; if (self->baudrate > 0) { mp_printf(print, "I2C(0, baudrate=%u)", self->baudrate); } else { mp_print_str(print, "I2C(0)"); } } STATIC mp_obj_t pyb_i2c_init_helper(pyb_i2c_obj_t *self, size_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_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 = 100000} }, }; 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); // make sure the baudrate is between the valid range self->baudrate = MIN(MAX(args[ARG_freq].u_int, PYBI2C_MIN_BAUD_RATE_HZ), PYBI2C_MAX_BAUD_RATE_HZ); // assign the pins mp_obj_t pins[2] = {&pin_GP13, &pin_GP23}; // default (SDA, SCL) pins if (args[ARG_scl].u_obj != MP_OBJ_NULL) { pins[1] = args[ARG_scl].u_obj; } if (args[ARG_sda].u_obj != MP_OBJ_NULL) { pins[0] = args[ARG_sda].u_obj; } pin_assign_pins_af(pins, 2, PIN_TYPE_STD_PU, PIN_FN_I2C, 0); // init the I2C bus i2c_init(self); // register it with the sleep module pyb_sleep_add ((const mp_obj_t)self, (WakeUpCB_t)i2c_init); return mp_const_none; } STATIC mp_obj_t pyb_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) { // check the id argument, if given if (n_args > 0) { if (all_args[0] != MP_OBJ_NEW_SMALL_INT(0)) { mp_raise_OSError(MP_ENODEV); } --n_args; ++all_args; } // parse args mp_map_t kw_args; mp_map_init_fixed_table(&kw_args, n_kw, all_args + n_args); // setup the object pyb_i2c_obj_t *self = &pyb_i2c_obj; self->base.type = &pyb_i2c_type; // start the peripheral pyb_i2c_init_helper(self, n_args, all_args, &kw_args); return (mp_obj_t)self; } STATIC mp_obj_t pyb_i2c_init(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { return pyb_i2c_init_helper(pos_args[0], n_args - 1, pos_args + 1, kw_args); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_init_obj, 1, pyb_i2c_init); STATIC mp_obj_t pyb_i2c_deinit(mp_obj_t self_in) { // disable the peripheral MAP_I2CMasterDisable(I2CA0_BASE); MAP_PRCMPeripheralClkDisable(PRCM_I2CA0, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK); // invalidate the baudrate pyb_i2c_obj.baudrate = 0; // unregister it with the sleep module pyb_sleep_remove ((const mp_obj_t)self_in); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_deinit_obj, pyb_i2c_deinit); STATIC mp_obj_t pyb_i2c_scan(mp_obj_t self_in) { pyb_i2c_check_init(&pyb_i2c_obj); mp_obj_t list = mp_obj_new_list(0, NULL); for (uint addr = 0x08; addr <= 0x77; addr++) { for (int i = 0; i < 3; i++) { if (pyb_i2c_scan_device(addr)) { mp_obj_list_append(list, mp_obj_new_int(addr)); break; } } } return list; } STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_scan_obj, pyb_i2c_scan); STATIC mp_obj_t pyb_i2c_readfrom(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { STATIC const mp_arg_t pyb_i2c_readfrom_args[] = { { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_nbytes, MP_ARG_REQUIRED | MP_ARG_OBJ, }, }; // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_readfrom_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(args), pyb_i2c_readfrom_args, args); vstr_t vstr; pyb_i2c_read_into(args, &vstr); // return the received data return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_readfrom_obj, 3, pyb_i2c_readfrom); STATIC mp_obj_t pyb_i2c_readfrom_into(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { STATIC const mp_arg_t pyb_i2c_readfrom_into_args[] = { { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, }, }; // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_readfrom_into_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(args), pyb_i2c_readfrom_into_args, args); vstr_t vstr; pyb_i2c_read_into(args, &vstr); // return the number of bytes received return mp_obj_new_int(vstr.len); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_readfrom_into_obj, 1, pyb_i2c_readfrom_into); STATIC mp_obj_t pyb_i2c_writeto(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { STATIC const mp_arg_t pyb_i2c_writeto_args[] = { { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, }, { MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} }, }; // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_writeto_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(args), pyb_i2c_writeto_args, args); pyb_i2c_check_init(&pyb_i2c_obj); // get the buffer to send from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(args[1].u_obj, &bufinfo, data); // send the data if (!pyb_i2c_write(args[0].u_int, bufinfo.buf, bufinfo.len, args[2].u_bool)) { mp_raise_OSError(MP_EIO); } // return the number of bytes written return mp_obj_new_int(bufinfo.len); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_writeto_obj, 1, pyb_i2c_writeto); STATIC mp_obj_t pyb_i2c_readfrom_mem(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { STATIC const mp_arg_t pyb_i2c_readfrom_mem_args[] = { { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_nbytes, MP_ARG_REQUIRED | MP_ARG_OBJ, }, { MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, }; // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_readfrom_mem_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(args), pyb_i2c_readfrom_mem_args, args); vstr_t vstr; pyb_i2c_readmem_into (args, &vstr); return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_readfrom_mem_obj, 1, pyb_i2c_readfrom_mem); STATIC const mp_arg_t pyb_i2c_readfrom_mem_into_args[] = { { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, }, { MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, }; STATIC mp_obj_t pyb_i2c_readfrom_mem_into(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_readfrom_mem_into_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(args), pyb_i2c_readfrom_mem_into_args, args); // get the buffer to read into vstr_t vstr; pyb_i2c_readmem_into (args, &vstr); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_readfrom_mem_into_obj, 1, pyb_i2c_readfrom_mem_into); STATIC mp_obj_t pyb_i2c_writeto_mem(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { // parse args mp_arg_val_t args[MP_ARRAY_SIZE(pyb_i2c_readfrom_mem_into_args)]; mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(pyb_i2c_readfrom_mem_into_args), pyb_i2c_readfrom_mem_into_args, args); pyb_i2c_check_init(&pyb_i2c_obj); // get the buffer to write from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(args[2].u_obj, &bufinfo, data); // get the addresses mp_uint_t i2c_addr = args[0].u_int; mp_uint_t mem_addr = args[1].u_int; // determine the width of mem_addr (1 or 2 bytes) mp_uint_t mem_addr_size = args[3].u_int >> 3; // write the register address to write to. if (pyb_i2c_mem_write (i2c_addr, (byte *)&mem_addr, mem_addr_size, bufinfo.buf, bufinfo.len)) { return mp_const_none; } mp_raise_OSError(MP_EIO); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_writeto_mem_obj, 1, pyb_i2c_writeto_mem); STATIC const mp_map_elem_t pyb_i2c_locals_dict_table[] = { // instance methods { MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_i2c_init_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_i2c_deinit_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_scan), (mp_obj_t)&pyb_i2c_scan_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_readfrom), (mp_obj_t)&pyb_i2c_readfrom_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_readfrom_into), (mp_obj_t)&pyb_i2c_readfrom_into_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_writeto), (mp_obj_t)&pyb_i2c_writeto_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_readfrom_mem), (mp_obj_t)&pyb_i2c_readfrom_mem_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_readfrom_mem_into), (mp_obj_t)&pyb_i2c_readfrom_mem_into_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_writeto_mem), (mp_obj_t)&pyb_i2c_writeto_mem_obj }, }; STATIC MP_DEFINE_CONST_DICT(pyb_i2c_locals_dict, pyb_i2c_locals_dict_table); const mp_obj_type_t pyb_i2c_type = { { &mp_type_type }, .name = MP_QSTR_I2C, .print = pyb_i2c_print, .make_new = pyb_i2c_make_new, .locals_dict = (mp_obj_t)&pyb_i2c_locals_dict, };