/* * This file is part of the Micro Python 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 MICROPY_HAL_H #include "py/runtime.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" /// \moduleref pyb /// \class I2C - a two-wire serial protocol /// /// I2C is a two-wire protocol for communicating between devices. At the physical /// level it consists of 2 wires: SCL and SDA, the clock and data lines respectively. /// /// I2C objects are created attached to a specific bus. They can be initialised /// when created, or initialised later on: /// /// from pyb import I2C /// /// i2c = I2C(1) # create /// i2c = I2C(1, 50000) # create and init with a 50KHz baudrate /// i2c.init(100000) # init with a 100KHz baudrate /// i2c.deinit() # turn off the peripheral /// /// Printing the i2c object gives you information about its configuration. /// /// Basic methods for slave are send and recv: /// /// i2c.send('abc') # send 3 bytes /// i2c.send(0x42) # send a single byte, given by the number /// data = i2c.recv(3) # receive 3 bytes /// /// To receive inplace, first create a bytearray: /// /// data = bytearray(3) # create a buffer /// i2c.recv(data) # receive 3 bytes, writing them into data /// /// A master must specify the recipient's address: /// /// i2c.init(1, 100000) /// i2c.send('123', 0x42) # send 3 bytes to slave with address 0x42 /// i2c.send(b'456', addr=0x42) # keyword for address /// /// Master also has other methods: /// /// i2c.is_ready(0x42) # check if slave 0x42 is ready /// i2c.scan() # scan for slaves on the bus, returning /// # a list of valid addresses /// i2c.mem_read(3, 0x42, 2) # read 3 bytes from memory of slave 0x42, /// # starting at address 2 in the slave /// i2c.mem_write('abc', 0x42, 2) # write 3 bytes to memory of slave 0x42, /// # starting at address 2 in the slave typedef struct _pyb_i2c_obj_t { mp_obj_base_t base; uint baudrate; } pyb_i2c_obj_t; /****************************************************************************** DEFINE CONSTANTS ******************************************************************************/ #define PYBI2C_MASTER (0) #define PYBI2C_MIN_BAUD_RATE_HZ (50000) #define PYBI2C_MAX_BAUD_RATE_HZ (400000) #define PYBI2C_TRANSC_TIMEOUT_MS (10) #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}; /****************************************************************************** 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) { // wait for a few microseconds UtilsDelay(UTILS_DELAY_US_TO_COUNT(PYBI2C_TRANSAC_WAIT_DELAY_US)); timeout -= PYBI2C_TRANSAC_WAIT_DELAY_US; if (timeout < 0) { // the peripheral is not responding, so stop return false; } } // 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 bool pyb_i2c_write(byte devAddr, byte *data, uint len, bool stop) { // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, devAddr, 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, send it. if (stop) { RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_BURST_SEND_STOP)); } return true; } STATIC bool pyb_i2c_read(byte devAddr, byte *data, uint len) { uint cmd; // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, devAddr, true); // Check if its a single receive or burst receive if (len > 1) { // Initiate a burst receive sequence cmd = I2C_MASTER_CMD_BURST_RECEIVE_START; } else { // Configure for a single receive cmd = I2C_MASTER_CMD_SINGLE_RECEIVE; } // Initiate the transfer. RET_IF_ERR(pyb_i2c_transaction(cmd)); // Decrement the count len--; // 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 bool pyb_i2c_scan_device(byte devAddr) { // Set I2C codec slave address MAP_I2CMasterSlaveAddrSet(I2CA0_BASE, devAddr, true); // Initiate the transfer. RET_IF_ERR(pyb_i2c_transaction(I2C_MASTER_CMD_SINGLE_RECEIVE)); // Since this is a hack, send the stop bit anyway MAP_I2CMasterControl(I2CA0_BASE, I2C_MASTER_CMD_BURST_SEND_ERROR_STOP); return true; } /******************************************************************************/ /* Micro Python 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, ")", self->baudrate); } else { mp_print_str(print, ""); } } /// \method init(mode, *, baudrate=100000) /// /// Initialise the I2C bus with the given parameters: /// /// - `mode` must be either `I2C.MASTER` or `I2C.SLAVE` /// - `baudrate` is the SCL clock rate (only sensible for a master) STATIC const mp_arg_t pyb_i2c_init_args[] = { { MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT, }, { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 100000} }, }; #define PYB_I2C_INIT_NUM_ARGS MP_ARRAY_SIZE(pyb_i2c_init_args) STATIC mp_obj_t pyb_i2c_init_helper(pyb_i2c_obj_t *self, mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args mp_arg_val_t vals[PYB_I2C_INIT_NUM_ARGS]; mp_arg_parse_all(n_args, args, kw_args, PYB_I2C_INIT_NUM_ARGS, pyb_i2c_init_args, vals); // verify that mode is master if (vals[0].u_int != PYBI2C_MASTER) { nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments)); } // make sure the baudrate is between the valid range self->baudrate = MIN(MAX(vals[1].u_int, PYBI2C_MIN_BAUD_RATE_HZ), PYBI2C_MAX_BAUD_RATE_HZ); // init the I2C bus i2c_init(self); // register it with the sleep module pybsleep_add ((const mp_obj_t)self, (WakeUpCB_t)i2c_init); return mp_const_none; } /// \classmethod \constructor(bus, ...) /// /// Construct an I2C object on the given bus. `bus` can only be 1. /// With no additional parameters, the I2C object is created but not /// initialised (it has the settings from the last initialisation of /// the bus, if any). If extra arguments are given, the bus is initialised. /// See `init` for parameters of initialisation. STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) { // check arguments mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true); // setup the object pyb_i2c_obj_t *self = &pyb_i2c_obj; self->base.type = &pyb_i2c_type; if (n_args > 1 || n_kw > 0) { // start the peripheral mp_map_t kw_args; mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); pyb_i2c_init_helper(self, n_args - 1, args + 1, &kw_args); } return (mp_obj_t)self; } STATIC mp_obj_t pyb_i2c_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { return pyb_i2c_init_helper(args[0], n_args - 1, args + 1, kw_args); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_init_obj, 1, pyb_i2c_init); /// \method deinit() /// Turn off the I2C bus. 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 pybsleep_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); /// \method is_ready(addr) /// Check if an I2C device responds to the given address. Only valid when in master mode. STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) { mp_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o); for (int i = 0; i < 7; i++) { if (pyb_i2c_scan_device(i2c_addr)) { return mp_const_true; } } return mp_const_false; } STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready); /// \method scan() /// Scan all I2C addresses from 0x01 to 0x7f and return a list of those that respond. /// Only valid when in master mode. STATIC mp_obj_t pyb_i2c_scan(mp_obj_t self_in) { mp_obj_t list = mp_obj_new_list(0, NULL); for (uint addr = 1; addr <= 127; addr++) { for (int i = 0; i < 7; 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); /// \method send(send, addr=0x00) /// Send data on the bus: /// /// - `send` is the data to send (an integer to send, or a buffer object) /// - `addr` is the address to send to (only required in master mode) /// Return value: `None`. STATIC const mp_arg_t pyb_i2c_send_args[] = { { MP_QSTR_send, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_INT, {.u_int = 0} }, }; #define PYB_I2C_SEND_NUM_ARGS MP_ARRAY_SIZE(pyb_i2c_send_args) STATIC mp_obj_t pyb_i2c_send(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args mp_arg_val_t vals[PYB_I2C_SEND_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_SEND_NUM_ARGS, pyb_i2c_send_args, vals); // get the buffer to send from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data); // send the data if (!pyb_i2c_write(vals[1].u_int, bufinfo.buf, bufinfo.len, true)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, mpexception_os_operation_failed)); } return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_send_obj, 1, pyb_i2c_send); /// \method recv(recv, addr=0x00) /// /// Receive data on the bus: /// /// - `recv` can be an integer, which is the number of bytes to receive, /// or a mutable buffer, which will be filled with received bytes /// - `addr` is the address to receive from (only required in master mode) /// /// Return value: if `recv` is an integer then a new buffer of the bytes received, /// otherwise the same buffer that was passed in to `recv`. STATIC const mp_arg_t pyb_i2c_recv_args[] = { { MP_QSTR_recv, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_INT, {.u_int = 0} }, }; #define PYB_I2C_RECV_NUM_ARGS MP_ARRAY_SIZE(pyb_i2c_recv_args) STATIC mp_obj_t pyb_i2c_recv(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args mp_arg_val_t vals[PYB_I2C_RECV_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_RECV_NUM_ARGS, pyb_i2c_recv_args, vals); // get the buffer to receive into vstr_t vstr; mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &vstr); // receive the data if (!pyb_i2c_read(vals[1].u_int, (byte *)vstr.buf, vstr.len)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, mpexception_os_operation_failed)); } // return the received data if (o_ret != MP_OBJ_NULL) { return o_ret; } else { return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); } } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_recv_obj, 1, pyb_i2c_recv); /// \method mem_read(data, addr, memaddr, addr_size=8) /// /// Read from the memory of an I2C device: /// /// - `data` can be an integer or a buffer to read into /// - `addr` is the I2C device address /// - `memaddr` is the memory location within the I2C device /// - `addr_size` selects the width of memaddr: 8 or 16 bits /// /// Returns the read data. /// This is only valid in master mode. STATIC const mp_arg_t pyb_i2c_mem_read_args[] = { { MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_addr_size, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, }; #define PYB_I2C_MEM_READ_NUM_ARGS MP_ARRAY_SIZE(pyb_i2c_mem_read_args) STATIC mp_obj_t pyb_i2c_mem_read(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args mp_arg_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_args, vals); // get the buffer to read into vstr_t vstr; mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &vstr); // get the addresses mp_uint_t i2c_addr = vals[1].u_int; mp_uint_t mem_addr = vals[2].u_int; // determine the width of mem_addr (1 or 2 bytes) mp_uint_t mem_addr_size = vals[3].u_int >> 3; // Write the register address to be read from. if (pyb_i2c_write (i2c_addr, (byte *)&mem_addr, mem_addr_size, false)) { // Read the specified length of data if (pyb_i2c_read (i2c_addr, (byte *)vstr.buf, vstr.len)) { // return the read data if (o_ret != MP_OBJ_NULL) { return o_ret; } else { return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr); } } } nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, mpexception_os_operation_failed)); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_read_obj, 1, pyb_i2c_mem_read); /// \method mem_write(data, addr, memaddr, addr_size=8) /// /// Write to the memory of an I2C device: /// /// - `data` can be an integer or a buffer to write from /// - `addr` is the I2C device address /// - `memaddr` is the memory location within the I2C device /// - `addr_size` selects the width of memaddr: 8 or 16 bits /// /// Returns `None`. /// This is only valid in master mode. STATIC mp_obj_t pyb_i2c_mem_write(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args (same as mem_read) mp_arg_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_args, vals); // get the buffer to write from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data); // get the addresses mp_uint_t i2c_addr = vals[1].u_int; mp_uint_t mem_addr = vals[2].u_int; // determine the width of mem_addr (1 or 2 bytes) mp_uint_t mem_addr_size = vals[3].u_int >> 3; // Write the register address to write to. if (pyb_i2c_write (i2c_addr, (byte *)&mem_addr, mem_addr_size, false)) { // Write the specified length of data if (pyb_i2c_write (i2c_addr, bufinfo.buf, bufinfo.len, true)) { return mp_const_none; } } nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, mpexception_os_operation_failed)); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_write_obj, 1, pyb_i2c_mem_write); 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_is_ready), (mp_obj_t)&pyb_i2c_is_ready_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_scan), (mp_obj_t)&pyb_i2c_scan_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_i2c_send_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_i2c_recv_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_mem_read), (mp_obj_t)&pyb_i2c_mem_read_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_mem_write), (mp_obj_t)&pyb_i2c_mem_write_obj }, // class constants /// \constant MASTER - for initialising the bus to master mode { MP_OBJ_NEW_QSTR(MP_QSTR_MASTER), MP_OBJ_NEW_SMALL_INT(PYBI2C_MASTER) }, }; 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, };