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It uses non-blocking transfer of data. Advantage over SoftI2C: - Higher data rate up to ~3 MHZ. - Full protocol support.pull/7544/head
robert-hh
3 years ago
committed by
Damien George
Damien George
11 changed files with 313 additions and 1 deletions
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/*
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* This file is part of the MicroPython project, http://micropython.org/
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* |
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* The MIT License (MIT) |
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* |
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* Copyright (c) 2020-2021 Damien P. George |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a copy |
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* of this software and associated documentation files (the "Software"), to deal |
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* in the Software without restriction, including without limitation the rights |
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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* copies of the Software, and to permit persons to whom the Software is |
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* furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice shall be included in |
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* all copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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* THE SOFTWARE. |
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*/ |
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#include "py/runtime.h" |
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#include "py/mphal.h" |
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#include "py/mperrno.h" |
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#include "extmod/machine_i2c.h" |
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#include "modmachine.h" |
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#include "fsl_iomuxc.h" |
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#include "fsl_lpi2c.h" |
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#define DEFAULT_I2C_FREQ (400000) |
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#define DEFAULT_I2C_DRIVE (6) |
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// Select USB1 PLL (480 MHz) as master lpi2c clock source
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#define LPI2C_CLOCK_SOURCE_SELECT (0U) |
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// Clock divider for master lpi2c clock source
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#define LPI2C_CLOCK_SOURCE_DIVIDER (1U) |
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// Get frequency of lpi2c clock = 30 MHz
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#define LPI2C_CLOCK_FREQUENCY ((CLOCK_GetFreq(kCLOCK_Usb1PllClk) / 8) / (LPI2C_CLOCK_SOURCE_DIVIDER + 1U)) |
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typedef struct _machine_i2c_obj_t { |
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mp_obj_base_t base; |
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LPI2C_Type *i2c_inst; |
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uint8_t i2c_id; |
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uint8_t i2c_hw_id; |
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bool transfer_busy; |
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status_t transfer_status; |
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lpi2c_master_config_t *master_config; |
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} machine_i2c_obj_t; |
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typedef struct _iomux_table_t { |
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uint32_t muxRegister; |
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uint32_t muxMode; |
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uint32_t inputRegister; |
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uint32_t inputDaisy; |
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uint32_t configRegister; |
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} iomux_table_t; |
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STATIC const uint8_t i2c_index_table[] = MICROPY_HW_I2C_INDEX; |
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STATIC LPI2C_Type *i2c_base_ptr_table[] = LPI2C_BASE_PTRS; |
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static const iomux_table_t iomux_table[] = { IOMUX_TABLE_I2C }; |
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#define MICROPY_HW_I2C_NUM ARRAY_SIZE(i2c_index_table) |
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#define SCL (iomux_table[index]) |
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#define SDA (iomux_table[index + 1]) |
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bool lpi2c_set_iomux(int8_t hw_i2c, uint8_t drive) { |
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int index = (hw_i2c - 1) * 2; |
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if (SCL.muxRegister != 0) { |
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IOMUXC_SetPinMux(SCL.muxRegister, SCL.muxMode, SCL.inputRegister, SCL.inputDaisy, SCL.configRegister, 1U); |
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IOMUXC_SetPinConfig(SCL.muxRegister, SCL.muxMode, SCL.inputRegister, SCL.inputDaisy, SCL.configRegister, |
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0xF880u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT); |
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IOMUXC_SetPinMux(SDA.muxRegister, SDA.muxMode, SDA.inputRegister, SDA.inputDaisy, SDA.configRegister, 1U); |
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IOMUXC_SetPinConfig(SDA.muxRegister, SDA.muxMode, SDA.inputRegister, SDA.inputDaisy, SDA.configRegister, |
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0xF880u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT); |
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return true; |
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} else { |
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return false; |
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} |
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} |
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STATIC void machine_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { |
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machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); |
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mp_printf(print, "I2C(%u, freq=%u)", |
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self->i2c_id, self->master_config->baudRate_Hz); |
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} |
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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 *all_args) { |
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enum { ARG_id, ARG_freq, ARG_drive}; |
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static const mp_arg_t allowed_args[] = { |
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{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ }, |
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{ MP_QSTR_freq, MP_ARG_INT, {.u_int = DEFAULT_I2C_FREQ} }, |
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{ MP_QSTR_drive, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_I2C_DRIVE} }, |
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}; |
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static bool clk_init = true; |
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// Parse args.
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; |
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mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); |
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// Get I2C bus.
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int i2c_id = mp_obj_get_int(args[ARG_id].u_obj); |
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if (i2c_id < 0 || i2c_id >= MICROPY_HW_I2C_NUM) { |
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mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("I2C(%d) doesn't exist"), i2c_id); |
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} |
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// Get I2C Object.
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machine_i2c_obj_t *self = m_new_obj(machine_i2c_obj_t); |
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self->base.type = &machine_i2c_type; |
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self->i2c_id = i2c_id; |
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self->i2c_hw_id = i2c_index_table[i2c_id]; // the hw i2c number 1..n
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self->i2c_inst = i2c_base_ptr_table[self->i2c_hw_id]; |
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uint8_t drive = args[ARG_drive].u_int; |
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if (drive < 1 || drive > 7) { |
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drive = DEFAULT_I2C_DRIVE; |
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} |
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if (clk_init) { |
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clk_init = false; |
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// Set clock source for LPI2C
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CLOCK_SetMux(kCLOCK_Lpi2cMux, LPI2C_CLOCK_SOURCE_SELECT); // USB1 PLL (480 MHz)
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CLOCK_SetDiv(kCLOCK_Lpi2cDiv, LPI2C_CLOCK_SOURCE_DIVIDER); |
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} |
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// Initialise the I2C peripheral if any arguments given, or it was not initialised previously.
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lpi2c_set_iomux(self->i2c_hw_id, drive); |
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self->master_config = m_new_obj(lpi2c_master_config_t); |
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LPI2C_MasterGetDefaultConfig(self->master_config); |
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// Initialise the I2C peripheral.
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self->master_config->baudRate_Hz = args[ARG_freq].u_int; |
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LPI2C_MasterInit(self->i2c_inst, self->master_config, LPI2C_CLOCK_FREQUENCY); |
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return MP_OBJ_FROM_PTR(self); |
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} |
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static void lpi2c_master_callback(LPI2C_Type *base, lpi2c_master_handle_t *handle, status_t status, void *self_in) { |
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machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in; |
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self->transfer_busy = false; |
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self->transfer_status = status; |
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} |
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STATIC int machine_i2c_transfer_single(mp_obj_base_t *self_in, uint16_t addr, size_t len, uint8_t *buf, unsigned int flags) { |
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machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in; |
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status_t ret; |
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lpi2c_master_handle_t g_master_handle; |
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lpi2c_master_transfer_t masterXfer = {0}; |
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LPI2C_MasterTransferCreateHandle(self->i2c_inst, &g_master_handle, lpi2c_master_callback, self); |
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if (flags & MP_MACHINE_I2C_FLAG_READ) { |
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masterXfer.direction = kLPI2C_Read; |
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} else { |
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masterXfer.direction = kLPI2C_Write; |
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} |
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if (addr < 0x80) { // 7 or 10 bit address?
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masterXfer.slaveAddress = addr; |
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} else { |
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masterXfer.slaveAddress = 0x78 | ((addr >> 8) & 0x03); |
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masterXfer.subaddress = addr & 0xff; |
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masterXfer.subaddressSize = 1; |
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} |
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masterXfer.data = buf; |
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masterXfer.dataSize = len; |
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if (flags & MP_MACHINE_I2C_FLAG_STOP) { |
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masterXfer.flags = kLPI2C_TransferDefaultFlag; |
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} else { |
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masterXfer.flags = kLPI2C_TransferNoStopFlag; |
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} |
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self->transfer_busy = true; |
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// Send master data to slave in non-blocking mode
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ret = LPI2C_MasterTransferNonBlocking(self->i2c_inst, &g_master_handle, &masterXfer); |
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if (ret != kStatus_Success) { |
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return -MP_EIO; |
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} |
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// Wait for the transfer to complete
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while (self->transfer_busy) { |
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MICROPY_EVENT_POLL_HOOK |
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} |
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// Transfer will not send a stop in case of errors like NAK. So it's done here.
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if (flags & MP_MACHINE_I2C_FLAG_STOP && self->transfer_status != kStatus_Success) { |
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LPI2C_MasterStop(self->i2c_inst); |
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} |
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if (self->transfer_status == kStatus_Success) { |
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return len; |
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} else if (self->transfer_status == kStatus_LPI2C_Nak) { |
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return -MP_ENODEV; |
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} else { |
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return -MP_EIO; |
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} |
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} |
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STATIC const mp_machine_i2c_p_t machine_i2c_p = { |
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.transfer = mp_machine_i2c_transfer_adaptor, |
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.transfer_single = machine_i2c_transfer_single, |
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}; |
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const mp_obj_type_t machine_i2c_type = { |
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{ &mp_type_type }, |
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.name = MP_QSTR_I2C, |
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.print = machine_i2c_print, |
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.make_new = machine_i2c_make_new, |
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.protocol = &machine_i2c_p, |
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.locals_dict = (mp_obj_dict_t *)&mp_machine_i2c_locals_dict, |
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}; |
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