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mimxrt/machine_i2c: Add hardware-based machine.I2C to machine module.
It uses non-blocking transfer of data. Advantage over SoftI2C: - Higher data rate up to ~3 MHZ. - Full protocol support.
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| /* | ||
| * This file is part of the MicroPython project, http://micropython.org/ | ||
| * | ||
| * The MIT License (MIT) | ||
| * | ||
| * Copyright (c) 2020-2021 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. | ||
| */ | ||
|
|
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| #include "py/runtime.h" | ||
| #include "py/mphal.h" | ||
| #include "py/mperrno.h" | ||
| #include "extmod/machine_i2c.h" | ||
| #include "modmachine.h" | ||
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|
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| #include "fsl_iomuxc.h" | ||
| #include "fsl_lpi2c.h" | ||
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|
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| #define DEFAULT_I2C_FREQ (400000) | ||
| #define DEFAULT_I2C_DRIVE (6) | ||
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| // Select USB1 PLL (480 MHz) as master lpi2c clock source | ||
| #define LPI2C_CLOCK_SOURCE_SELECT (0U) | ||
| // Clock divider for master lpi2c clock source | ||
| #define LPI2C_CLOCK_SOURCE_DIVIDER (1U) | ||
| // Get frequency of lpi2c clock = 30 MHz | ||
| #define LPI2C_CLOCK_FREQUENCY ((CLOCK_GetFreq(kCLOCK_Usb1PllClk) / 8) / (LPI2C_CLOCK_SOURCE_DIVIDER + 1U)) | ||
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| typedef struct _machine_i2c_obj_t { | ||
| mp_obj_base_t base; | ||
| LPI2C_Type *i2c_inst; | ||
| uint8_t i2c_id; | ||
| uint8_t i2c_hw_id; | ||
| bool transfer_busy; | ||
| status_t transfer_status; | ||
| lpi2c_master_config_t *master_config; | ||
| } machine_i2c_obj_t; | ||
|
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| typedef struct _iomux_table_t { | ||
| uint32_t muxRegister; | ||
| uint32_t muxMode; | ||
| uint32_t inputRegister; | ||
| uint32_t inputDaisy; | ||
| uint32_t configRegister; | ||
| } iomux_table_t; | ||
|
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| STATIC const uint8_t i2c_index_table[] = MICROPY_HW_I2C_INDEX; | ||
| STATIC LPI2C_Type *i2c_base_ptr_table[] = LPI2C_BASE_PTRS; | ||
| 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]) | ||
| #define SDA (iomux_table[index + 1]) | ||
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| bool lpi2c_set_iomux(int8_t hw_i2c, uint8_t drive) { | ||
| int index = (hw_i2c - 1) * 2; | ||
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| if (SCL.muxRegister != 0) { | ||
| IOMUXC_SetPinMux(SCL.muxRegister, SCL.muxMode, SCL.inputRegister, SCL.inputDaisy, SCL.configRegister, 1U); | ||
| IOMUXC_SetPinConfig(SCL.muxRegister, SCL.muxMode, SCL.inputRegister, SCL.inputDaisy, SCL.configRegister, | ||
| 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); | ||
| IOMUXC_SetPinConfig(SDA.muxRegister, SDA.muxMode, SDA.inputRegister, SDA.inputDaisy, SDA.configRegister, | ||
| 0xF880u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT); | ||
| return true; | ||
| } else { | ||
| return false; | ||
| } | ||
| } | ||
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| STATIC void machine_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { | ||
| machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); | ||
| mp_printf(print, "I2C(%u, freq=%u)", | ||
| self->i2c_id, self->master_config->baudRate_Hz); | ||
| } | ||
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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) { | ||
| enum { ARG_id, ARG_freq, ARG_drive}; | ||
| static const mp_arg_t allowed_args[] = { | ||
| { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ }, | ||
| { MP_QSTR_freq, MP_ARG_INT, {.u_int = DEFAULT_I2C_FREQ} }, | ||
| { MP_QSTR_drive, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_I2C_DRIVE} }, | ||
| }; | ||
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| static bool clk_init = true; | ||
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| // Parse args. | ||
| 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); | ||
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| // Get I2C bus. | ||
| int i2c_id = mp_obj_get_int(args[ARG_id].u_obj); | ||
| if (i2c_id < 0 || i2c_id >= MICROPY_HW_I2C_NUM) { | ||
| mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("I2C(%d) doesn't exist"), i2c_id); | ||
| } | ||
|
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| // Get I2C Object. | ||
| machine_i2c_obj_t *self = m_new_obj(machine_i2c_obj_t); | ||
| self->base.type = &machine_i2c_type; | ||
| self->i2c_id = i2c_id; | ||
| self->i2c_hw_id = i2c_index_table[i2c_id]; // the hw i2c number 1..n | ||
| self->i2c_inst = i2c_base_ptr_table[self->i2c_hw_id]; | ||
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| uint8_t drive = args[ARG_drive].u_int; | ||
| if (drive < 1 || drive > 7) { | ||
| drive = DEFAULT_I2C_DRIVE; | ||
| } | ||
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| if (clk_init) { | ||
| clk_init = false; | ||
| // Set clock source for LPI2C | ||
| CLOCK_SetMux(kCLOCK_Lpi2cMux, LPI2C_CLOCK_SOURCE_SELECT); // USB1 PLL (480 MHz) | ||
| CLOCK_SetDiv(kCLOCK_Lpi2cDiv, LPI2C_CLOCK_SOURCE_DIVIDER); | ||
| } | ||
|
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| // Initialise the I2C peripheral if any arguments given, or it was not initialised previously. | ||
| lpi2c_set_iomux(self->i2c_hw_id, drive); | ||
| self->master_config = m_new_obj(lpi2c_master_config_t); | ||
| LPI2C_MasterGetDefaultConfig(self->master_config); | ||
| // Initialise the I2C peripheral. | ||
| self->master_config->baudRate_Hz = args[ARG_freq].u_int; | ||
| 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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| static void lpi2c_master_callback(LPI2C_Type *base, lpi2c_master_handle_t *handle, status_t status, void *self_in) { | ||
| machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in; | ||
|
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| self->transfer_busy = false; | ||
| self->transfer_status = status; | ||
| } | ||
|
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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) { | ||
| machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in; | ||
| status_t ret; | ||
| lpi2c_master_handle_t g_master_handle; | ||
| lpi2c_master_transfer_t masterXfer = {0}; | ||
| LPI2C_MasterTransferCreateHandle(self->i2c_inst, &g_master_handle, lpi2c_master_callback, self); | ||
|
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| if (flags & MP_MACHINE_I2C_FLAG_READ) { | ||
| masterXfer.direction = kLPI2C_Read; | ||
| } else { | ||
| masterXfer.direction = kLPI2C_Write; | ||
| } | ||
| if (addr < 0x80) { // 7 or 10 bit address? | ||
| masterXfer.slaveAddress = addr; | ||
| } else { | ||
| masterXfer.slaveAddress = 0x78 | ((addr >> 8) & 0x03); | ||
| masterXfer.subaddress = addr & 0xff; | ||
| masterXfer.subaddressSize = 1; | ||
| } | ||
| masterXfer.data = buf; | ||
| masterXfer.dataSize = len; | ||
| if (flags & MP_MACHINE_I2C_FLAG_STOP) { | ||
| masterXfer.flags = kLPI2C_TransferDefaultFlag; | ||
| } else { | ||
| masterXfer.flags = kLPI2C_TransferNoStopFlag; | ||
| } | ||
| self->transfer_busy = true; | ||
|
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| // Send master data to slave in non-blocking mode | ||
| ret = LPI2C_MasterTransferNonBlocking(self->i2c_inst, &g_master_handle, &masterXfer); | ||
| if (ret != kStatus_Success) { | ||
| return -MP_EIO; | ||
| } | ||
| // Wait for the transfer to complete | ||
| while (self->transfer_busy) { | ||
| MICROPY_EVENT_POLL_HOOK | ||
| } | ||
|
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| // Transfer will not send a stop in case of errors like NAK. So it's done here. | ||
| if (flags & MP_MACHINE_I2C_FLAG_STOP && self->transfer_status != kStatus_Success) { | ||
| LPI2C_MasterStop(self->i2c_inst); | ||
| } | ||
|
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| if (self->transfer_status == kStatus_Success) { | ||
| return len; | ||
| } else if (self->transfer_status == kStatus_LPI2C_Nak) { | ||
| return -MP_ENODEV; | ||
| } else { | ||
| return -MP_EIO; | ||
| } | ||
| } | ||
|
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| STATIC const mp_machine_i2c_p_t machine_i2c_p = { | ||
| .transfer = mp_machine_i2c_transfer_adaptor, | ||
| .transfer_single = machine_i2c_transfer_single, | ||
| }; | ||
|
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| const mp_obj_type_t machine_i2c_type = { | ||
| { &mp_type_type }, | ||
| .name = MP_QSTR_I2C, | ||
| .print = machine_i2c_print, | ||
| .make_new = machine_i2c_make_new, | ||
| .protocol = &machine_i2c_p, | ||
| .locals_dict = (mp_obj_dict_t *)&mp_machine_i2c_locals_dict, | ||
| }; |
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