From 94d27ae28fd4b815b3ace7dd91643aa0d1b620cd Mon Sep 17 00:00:00 2001 From: robert-hh Date: Sun, 5 Jun 2022 18:11:06 +0200 Subject: [PATCH] samd/machine_i2c: Add the machine.I2C class. Using the common API. Tested with SAMD21 and SAMD51 boards. --- ports/samd/Makefile | 2 + ports/samd/machine_i2c.c | 270 ++++++++++++++++++++++++++++++++++++++ ports/samd/modmachine.c | 1 + ports/samd/modmachine.h | 1 + ports/samd/mpconfigport.h | 1 + ports/samd/samd_isr.c | 4 +- 6 files changed, 277 insertions(+), 2 deletions(-) create mode 100644 ports/samd/machine_i2c.c diff --git a/ports/samd/Makefile b/ports/samd/Makefile index ca0309fa6..c5d36adda 100644 --- a/ports/samd/Makefile +++ b/ports/samd/Makefile @@ -91,6 +91,7 @@ SRC_C = \ clock_config.c \ help.c \ machine_adc.c \ + machine_i2c.c \ machine_led.c \ machine_pin.c \ machine_spi.c \ @@ -143,6 +144,7 @@ endif # List of sources for qstr extraction SRC_QSTR += \ machine_adc.c \ + machine_i2c.c \ machine_led.c \ machine_pin.c \ machine_pwm.c \ diff --git a/ports/samd/machine_i2c.c b/ports/samd/machine_i2c.c new file mode 100644 index 000000000..4d1b03f7d --- /dev/null +++ b/ports/samd/machine_i2c.c @@ -0,0 +1,270 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2020-2021 Damien P. George + * Copyright (c) 2022 Robert Hammelrath + * + * 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 "py/runtime.h" +#include "py/mphal.h" +#include "py/mperrno.h" +#include "extmod/machine_i2c.h" +#include "modmachine.h" +#include "samd_soc.h" +#include "pin_af.h" +#include "clock_config.h" + +#define DEFAULT_I2C_FREQ (400000) +#define RISETIME_NS (300) +#define I2C_TIMEOUT (100) + +#define IS_BUS_BUSY (i2c->I2CM.STATUS.bit.BUSSTATE == 3) +#define NACK_RECVD (i2c->I2CM.STATUS.bit.RXNACK == 1) +#define IRQ_DATA_SENT (i2c->I2CM.INTFLAG.bit.MB == 1) +#define IRQ_DATA_RECVD (i2c->I2CM.INTFLAG.bit.SB == 1) +#define READ_MODE ((flags & MP_MACHINE_I2C_FLAG_READ) != 0) + +#define PREPARE_ACK i2c->I2CM.CTRLB.bit.ACKACT = 0 +#define PREPARE_NACK i2c->I2CM.CTRLB.bit.ACKACT = 1 +#define SET_STOP_STATE i2c_send_command(i2c, 0x03) + +enum state_t { + state_done = 0, + state_busy, + state_buserr, + state_nack +}; + +typedef struct _machine_i2c_obj_t { + mp_obj_base_t base; + Sercom *instance; + uint8_t id; + uint8_t scl; + uint8_t sda; + uint8_t state; + uint32_t freq; + uint32_t timeout; + size_t len; + uint8_t *buf; +} machine_i2c_obj_t; + +extern Sercom *sercom_instance[]; +extern void *sercom_table[SERCOM_INST_NUM]; + +STATIC void i2c_send_command(Sercom *i2c, uint8_t command) { + i2c->I2CM.CTRLB.bit.CMD = command; + while (i2c->I2CM.SYNCBUSY.bit.SYSOP) { + } +} + +void common_i2c_irq_handler(int i2c_id) { + // handle Sercom I2C IRQ + machine_i2c_obj_t *self = sercom_table[i2c_id]; + // Handle IRQ + if (self != NULL) { + Sercom *i2c = self->instance; + // For now, clear all interrupts + if (IRQ_DATA_RECVD) { + if (self->len > 0) { + *(self->buf)++ = i2c->I2CM.DATA.reg; + self->len--; + self->timeout = I2C_TIMEOUT; + } + if (self->len > 0) { // no ACK at the last byte + PREPARE_ACK; // Send ACK + i2c_send_command(i2c, 0x02); + } else { + PREPARE_NACK; // Send NACK after the last byte + self->state = state_done; + i2c->I2CM.INTFLAG.reg |= SERCOM_I2CM_INTFLAG_SB; + } + } else if (IRQ_DATA_SENT) { + if (NACK_RECVD) { // e.g. NACK after adress for both read and write. + self->state = state_nack; // force stop of transmission + i2c->I2CM.INTFLAG.reg |= SERCOM_I2CM_INTFLAG_MB; + } else if (self->len > 0) { // data to be sent + i2c->I2CM.DATA.bit.DATA = *(self->buf)++; + self->len--; + self->timeout = I2C_TIMEOUT; + } else { // No data left, if there was any. + self->state = state_done; + i2c->I2CM.INTFLAG.reg |= SERCOM_I2CM_INTFLAG_MB; + } + } else { // On any error, e.g. ARBLOST or BUSERROR, stop the transmission + self->len = 0; + self->state = state_buserr; + i2c->I2CM.INTFLAG.reg |= SERCOM_I2CM_INTFLAG_ERROR; + } + } +} + +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, scl=%u, sda=%u)", + self->id, self->freq, self->scl, self->sda); +} + +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_scl, ARG_sda }; + 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_scl, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} }, + { MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} }, + }; + + // 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); + + // Get I2C bus. + int id = mp_obj_get_int(args[ARG_id].u_obj); + if (id < 0 || id >= SERCOM_INST_NUM) { + mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("I2C(%d) doesn't exist"), id); + } + + // Get the peripheral object. + machine_i2c_obj_t *self = mp_obj_malloc(machine_i2c_obj_t, &machine_hw_i2c_type); + self->id = id; + self->instance = sercom_instance[self->id]; + + // Set SCL/SDA pins. + sercom_pad_config_t scl_pad_config; + self->scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj); + scl_pad_config = get_sercom_config(self->scl, self->id); + + sercom_pad_config_t sda_pad_config; + self->sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj); + sda_pad_config = get_sercom_config(self->sda, self->id); + if (sda_pad_config.pad_nr != 0 || scl_pad_config.pad_nr != 1) { + mp_raise_ValueError(MP_ERROR_TEXT("invalid pin for sda or scl")); + } + sercom_table[self->id] = self; + self->freq = args[ARG_freq].u_int; + + // Configure the Pin mux. + mp_hal_set_pin_mux(self->scl, scl_pad_config.alt_fct); + mp_hal_set_pin_mux(self->sda, sda_pad_config.alt_fct); + + // Set up the clocks + enable_sercom_clock(self->id); + + // Initialise the I2C peripheral + Sercom *i2c = self->instance; + + // Reset the device + i2c->I2CM.CTRLA.reg = SERCOM_I2CM_CTRLA_SWRST; + while (i2c->I2CM.SYNCBUSY.bit.SWRST == 1) { + } + // Set to master mode, inactivity timeout of 20 SCL cycles and speed. + i2c->I2CM.CTRLA.reg = SERCOM_I2CM_CTRLA_MODE(0x05) + | SERCOM_I2CM_CTRLA_INACTOUT(3) + | SERCOM_I2CM_CTRLA_SPEED(self->freq > 400000 ? 1 : 0); + + // I2C is driven by the clock of GCLK Generator 2, with it's freq in variable bus_freq + // baud = peripheral_freq / (2 * baudrate) - 5 - (rise_time * peripheral_freq) / 2 + // Just set the minimal configuration for standard and fast mode. + // Set Baud. Assume ~300ns rise time. Maybe set later by a keyword argument. + i2c->I2CM.BAUD.reg = get_apb_freq() / (2 * self->freq) - 5 - (get_apb_freq() / 1000000) * RISETIME_NS / 2000; + + // Enable interrupts + sercom_register_irq(self->id, SERCOM_IRQ_TYPE_SPI); + #if defined(MCU_SAMD21) + NVIC_EnableIRQ(SERCOM0_IRQn + self->id); + #elif defined(MCU_SAMD51) + NVIC_EnableIRQ(SERCOM0_0_IRQn + 4 * self->id); // MB interrupt + NVIC_EnableIRQ(SERCOM0_0_IRQn + 4 * self->id + 1); // SB interrupt + NVIC_EnableIRQ(SERCOM0_0_IRQn + 4 * self->id + 3); // ERRROR interrupt + #endif + + // Now enable I2C. + sercom_enable(i2c, 1); + + // Force the bus state to idle + i2c->I2CM.STATUS.bit.BUSSTATE = 1; + + return MP_OBJ_FROM_PTR(self); +} + +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; + Sercom *i2c = self->instance; + + self->timeout = I2C_TIMEOUT; + self->len = len; + self->buf = buf; + // Wait a while if the bus is busy + while (IS_BUS_BUSY && self->timeout) { + MICROPY_EVENT_POLL_HOOK + if (--self->timeout == 0) { + return -MP_ETIMEDOUT; + } + } + // Enable interrupts and set the state + i2c->I2CM.INTENSET.reg = SERCOM_I2CM_INTENSET_MB | SERCOM_I2CM_INTENSET_SB | SERCOM_I2CM_INTENSET_ERROR; + self->state = state_busy; + + // Send the adress, which kicks off the transfer + i2c->I2CM.ADDR.bit.ADDR = (addr << 1) | READ_MODE; + + // Transfer the data + self->timeout = I2C_TIMEOUT; + while (self->state == state_busy && self->timeout) { + self->timeout--; + MICROPY_EVENT_POLL_HOOK + } + i2c->I2CM.INTENCLR.reg = SERCOM_I2CM_INTENSET_MB | SERCOM_I2CM_INTENSET_SB | SERCOM_I2CM_INTENSET_ERROR; + + // Check the error states after the transfer is stopped + if (self->state == state_nack) { + SET_STOP_STATE; + return self->len == len ? -MP_ENODEV : -MP_EIO; + } else if (self->state == state_buserr) { + SET_STOP_STATE; + return -MP_EIO; + } else if (self->timeout == 0) { + SET_STOP_STATE; + return -MP_ETIMEDOUT; + } + + if (flags & MP_MACHINE_I2C_FLAG_STOP) { + SET_STOP_STATE; + } + + return len; +} + +STATIC const mp_machine_i2c_p_t machine_i2c_p = { + .transfer = mp_machine_i2c_transfer_adaptor, + .transfer_single = machine_i2c_transfer_single, +}; + +MP_DEFINE_CONST_OBJ_TYPE( + machine_hw_i2c_type, + MP_QSTR_I2C, + MP_TYPE_FLAG_NONE, + make_new, machine_i2c_make_new, + print, machine_i2c_print, + protocol, &machine_i2c_p, + locals_dict, &mp_machine_i2c_locals_dict + ); diff --git a/ports/samd/modmachine.c b/ports/samd/modmachine.c index 712b520f5..acd672faf 100644 --- a/ports/samd/modmachine.c +++ b/ports/samd/modmachine.c @@ -154,6 +154,7 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = { { MP_ROM_QSTR(MP_QSTR_Pin), MP_ROM_PTR(&machine_pin_type) }, { MP_ROM_QSTR(MP_QSTR_PWM), MP_ROM_PTR(&machine_pwm_type) }, { MP_ROM_QSTR(MP_QSTR_SoftI2C), MP_ROM_PTR(&mp_machine_soft_i2c_type) }, + { MP_ROM_QSTR(MP_QSTR_I2C), MP_ROM_PTR(&machine_hw_i2c_type) }, { MP_ROM_QSTR(MP_QSTR_SoftSPI), MP_ROM_PTR(&mp_machine_soft_spi_type) }, { MP_ROM_QSTR(MP_QSTR_SPI), MP_ROM_PTR(&machine_spi_type) }, { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&machine_uart_type) }, diff --git a/ports/samd/modmachine.h b/ports/samd/modmachine.h index 143e3488f..431986719 100644 --- a/ports/samd/modmachine.h +++ b/ports/samd/modmachine.h @@ -29,6 +29,7 @@ #include "py/obj.h" extern const mp_obj_type_t machine_adc_type; +extern const mp_obj_type_t machine_hw_i2c_type; extern const mp_obj_type_t machine_led_type; extern const mp_obj_type_t machine_pin_type; extern const mp_obj_type_t machine_pwm_type; diff --git a/ports/samd/mpconfigport.h b/ports/samd/mpconfigport.h index 22fed00b2..425ecc597 100644 --- a/ports/samd/mpconfigport.h +++ b/ports/samd/mpconfigport.h @@ -98,6 +98,7 @@ #define MICROPY_PY_URANDOM (1) #define MICROPY_PY_UZLIB (1) #define MICROPY_PY_UASYNCIO (1) +#define MICROPY_PY_MACHINE_I2C (1) #define MICROPY_PY_MACHINE_SOFTI2C (1) #define MICROPY_PY_MACHINE_SPI (1) #define MICROPY_PY_MACHINE_SOFTSPI (1) diff --git a/ports/samd/samd_isr.c b/ports/samd/samd_isr.c index 2a5a3e042..5cb0668c2 100644 --- a/ports/samd/samd_isr.c +++ b/ports/samd/samd_isr.c @@ -109,11 +109,11 @@ void PendSV_Handler(void) { static uint8_t sercom_irq_type[SERCOM_INST_NUM] = {}; -// Temporarily commented until the module is added + void (*sercom_irq_handler_table[])(int num) = { common_uart_irq_handler, common_spi_irq_handler, - NULL // common_i2c_irq_handler + common_i2c_irq_handler }; void sercom_register_irq(int sercom_id, int mode) {