#ifdef USE_ESP32 #include "i2c_bus_esp_idf.h" #include #include #include #include "esphome/core/application.h" #include "esphome/core/hal.h" #include "esphome/core/helpers.h" #include "esphome/core/log.h" namespace esphome { namespace i2c { static const char *const TAG = "i2c.idf"; void IDFI2CBus::setup() { static i2c_port_t next_hp_port = I2C_NUM_0; #if SOC_LP_I2C_SUPPORTED static i2c_port_t next_lp_port = LP_I2C_NUM_0; #endif if (this->timeout_ > 13000) { ESP_LOGW(TAG, "Using max allowed timeout: 13 ms"); this->timeout_ = 13000; } this->recover_(); i2c_master_bus_config_t bus_conf{}; memset(&bus_conf, 0, sizeof(bus_conf)); bus_conf.sda_io_num = gpio_num_t(sda_pin_); bus_conf.scl_io_num = gpio_num_t(scl_pin_); bus_conf.glitch_ignore_cnt = 7; #if SOC_LP_I2C_SUPPORTED if (this->lp_mode_) { if ((next_lp_port - LP_I2C_NUM_0) == SOC_LP_I2C_NUM) { ESP_LOGE(TAG, "No more than %u LP buses supported", SOC_LP_I2C_NUM); this->mark_failed(); return; } this->port_ = next_lp_port; next_lp_port = (i2c_port_t) (next_lp_port + 1); bus_conf.lp_source_clk = LP_I2C_SCLK_DEFAULT; } else { #endif if (next_hp_port == SOC_HP_I2C_NUM) { ESP_LOGE(TAG, "No more than %u HP buses supported", SOC_HP_I2C_NUM); this->mark_failed(); return; } this->port_ = next_hp_port; next_hp_port = (i2c_port_t) (next_hp_port + 1); bus_conf.clk_source = I2C_CLK_SRC_DEFAULT; #if SOC_LP_I2C_SUPPORTED } #endif bus_conf.i2c_port = this->port_; bus_conf.flags.enable_internal_pullup = sda_pullup_enabled_ || scl_pullup_enabled_; esp_err_t err = i2c_new_master_bus(&bus_conf, &this->bus_); if (err != ESP_OK) { ESP_LOGW(TAG, "i2c_new_master_bus failed: %s", esp_err_to_name(err)); this->mark_failed(); return; } i2c_device_config_t dev_conf{}; memset(&dev_conf, 0, sizeof(dev_conf)); dev_conf.dev_addr_length = I2C_ADDR_BIT_LEN_7; dev_conf.device_address = I2C_DEVICE_ADDRESS_NOT_USED; dev_conf.scl_speed_hz = this->frequency_; dev_conf.scl_wait_us = this->timeout_; err = i2c_master_bus_add_device(this->bus_, &dev_conf, &this->dev_); if (err != ESP_OK) { ESP_LOGW(TAG, "i2c_master_bus_add_device failed: %s", esp_err_to_name(err)); this->mark_failed(); return; } this->initialized_ = true; if (this->scan_) { ESP_LOGV(TAG, "Scanning for devices"); this->i2c_scan_(); } } void IDFI2CBus::dump_config() { ESP_LOGCONFIG(TAG, "I2C Bus:"); ESP_LOGCONFIG(TAG, " SDA Pin: GPIO%u\n" " SCL Pin: GPIO%u\n" " Frequency: %" PRIu32 " Hz", this->sda_pin_, this->scl_pin_, this->frequency_); if (timeout_ > 0) { ESP_LOGCONFIG(TAG, " Timeout: %" PRIu32 "us", this->timeout_); } switch (this->recovery_result_) { case RECOVERY_COMPLETED: ESP_LOGCONFIG(TAG, " Recovery: bus successfully recovered"); break; case RECOVERY_FAILED_SCL_LOW: ESP_LOGCONFIG(TAG, " Recovery: failed, SCL is held low on the bus"); break; case RECOVERY_FAILED_SDA_LOW: ESP_LOGCONFIG(TAG, " Recovery: failed, SDA is held low on the bus"); break; } if (this->scan_) { ESP_LOGCONFIG(TAG, "Results from bus scan:"); if (scan_results_.empty()) { ESP_LOGCONFIG(TAG, "Found no devices"); } else { for (const auto &s : scan_results_) { if (s.second) { ESP_LOGCONFIG(TAG, "Found device at address 0x%02X", s.first); } else { ESP_LOGE(TAG, "Unknown error at address 0x%02X", s.first); } } } } } ErrorCode IDFI2CBus::write_readv(uint8_t address, const uint8_t *write_buffer, size_t write_count, uint8_t *read_buffer, size_t read_count) { // logging is only enabled with v level, if warnings are shown the caller // should log them if (!initialized_) { ESP_LOGW(TAG, "i2c bus not initialized!"); return ERROR_NOT_INITIALIZED; } i2c_operation_job_t jobs[8]{}; size_t num_jobs = 0; uint8_t write_addr = (address << 1) | I2C_MASTER_WRITE; uint8_t read_addr = (address << 1) | I2C_MASTER_READ; ESP_LOGV(TAG, "Writing %zu bytes, reading %zu bytes", write_count, read_count); if (read_count == 0 && write_count == 0) { // basically just a bus probe. Send a start, address and stop ESP_LOGV(TAG, "0x%02X BUS PROBE", address); jobs[num_jobs++].command = I2C_MASTER_CMD_START; jobs[num_jobs].command = I2C_MASTER_CMD_WRITE; jobs[num_jobs].write.ack_check = true; jobs[num_jobs].write.data = &write_addr; jobs[num_jobs++].write.total_bytes = 1; } else { if (write_count != 0) { ESP_LOGV(TAG, "0x%02X TX %s", address, format_hex_pretty(write_buffer, write_count).c_str()); jobs[num_jobs++].command = I2C_MASTER_CMD_START; jobs[num_jobs].command = I2C_MASTER_CMD_WRITE; jobs[num_jobs].write.ack_check = true; jobs[num_jobs].write.data = &write_addr; jobs[num_jobs++].write.total_bytes = 1; jobs[num_jobs].command = I2C_MASTER_CMD_WRITE; jobs[num_jobs].write.ack_check = true; jobs[num_jobs].write.data = (uint8_t *) write_buffer; jobs[num_jobs++].write.total_bytes = write_count; } if (read_count != 0) { ESP_LOGV(TAG, "0x%02X RX bytes %zu", address, read_count); jobs[num_jobs++].command = I2C_MASTER_CMD_START; jobs[num_jobs].command = I2C_MASTER_CMD_WRITE; jobs[num_jobs].write.ack_check = true; jobs[num_jobs].write.data = &read_addr; jobs[num_jobs++].write.total_bytes = 1; if (read_count > 1) { jobs[num_jobs].command = I2C_MASTER_CMD_READ; jobs[num_jobs].read.ack_value = I2C_ACK_VAL; jobs[num_jobs].read.data = read_buffer; jobs[num_jobs++].read.total_bytes = read_count - 1; } jobs[num_jobs].command = I2C_MASTER_CMD_READ; jobs[num_jobs].read.ack_value = I2C_NACK_VAL; jobs[num_jobs].read.data = read_buffer + read_count - 1; jobs[num_jobs++].read.total_bytes = 1; } } jobs[num_jobs++].command = I2C_MASTER_CMD_STOP; ESP_LOGV(TAG, "Sending %zu jobs", num_jobs); esp_err_t err = i2c_master_execute_defined_operations(this->dev_, jobs, num_jobs, 20); if (err == ESP_ERR_INVALID_STATE) { ESP_LOGV(TAG, "TX to %02X failed: not acked", address); return ERROR_NOT_ACKNOWLEDGED; } else if (err == ESP_ERR_TIMEOUT) { ESP_LOGV(TAG, "TX to %02X failed: timeout", address); return ERROR_TIMEOUT; } else if (err != ESP_OK) { ESP_LOGV(TAG, "TX to %02X failed: %s", address, esp_err_to_name(err)); return ERROR_UNKNOWN; } return ERROR_OK; } /// Perform I2C bus recovery, see: /// https://www.nxp.com/docs/en/user-guide/UM10204.pdf /// https://www.analog.com/media/en/technical-documentation/application-notes/54305147357414AN686_0.pdf void IDFI2CBus::recover_() { ESP_LOGI(TAG, "Performing bus recovery"); const auto scl_pin = static_cast(scl_pin_); const auto sda_pin = static_cast(sda_pin_); // For the upcoming operations, target for a 60kHz toggle frequency. // 1000kHz is the maximum frequency for I2C running in standard-mode, // but lower frequencies are not a problem. // Note: the timing that is used here is chosen manually, to get // results that are close to the timing that can be archieved by the // implementation for the Arduino framework. const auto half_period_usec = 7; // Configure SCL pin for open drain input/output, with a pull up resistor. gpio_set_level(scl_pin, 1); gpio_config_t scl_config{}; scl_config.pin_bit_mask = 1ULL << scl_pin_; scl_config.mode = GPIO_MODE_INPUT_OUTPUT_OD; scl_config.pull_up_en = GPIO_PULLUP_ENABLE; scl_config.pull_down_en = GPIO_PULLDOWN_DISABLE; scl_config.intr_type = GPIO_INTR_DISABLE; gpio_config(&scl_config); // Configure SDA pin for open drain input/output, with a pull up resistor. gpio_set_level(sda_pin, 1); gpio_config_t sda_conf{}; sda_conf.pin_bit_mask = 1ULL << sda_pin_; sda_conf.mode = GPIO_MODE_INPUT_OUTPUT_OD; sda_conf.pull_up_en = GPIO_PULLUP_ENABLE; sda_conf.pull_down_en = GPIO_PULLDOWN_DISABLE; sda_conf.intr_type = GPIO_INTR_DISABLE; gpio_config(&sda_conf); // If SCL is pulled low on the I2C bus, then some device is interfering // with the SCL line. In that case, the I2C bus cannot be recovered. delayMicroseconds(half_period_usec); if (gpio_get_level(scl_pin) == 0) { ESP_LOGE(TAG, "Recovery failed: SCL is held LOW on the bus"); recovery_result_ = RECOVERY_FAILED_SCL_LOW; return; } // From the specification: // "If the data line (SDA) is stuck LOW, send nine clock pulses. The // device that held the bus LOW should release it sometime within // those nine clocks." // We don't really have to detect if SDA is stuck low. We'll simply send // nine clock pulses here, just in case SDA is stuck. Actual checks on // the SDA line status will be done after the clock pulses. for (auto i = 0; i < 9; i++) { gpio_set_level(scl_pin, 0); delayMicroseconds(half_period_usec); gpio_set_level(scl_pin, 1); delayMicroseconds(half_period_usec); // When SCL is kept LOW at this point, we might be looking at a device // that applies clock stretching. Wait for the release of the SCL line, // but not forever. There is no specification for the maximum allowed // time. We yield and reset the WDT, so as to avoid triggering reset. // No point in trying to recover the bus by forcing a uC reset. Bus // should recover in a few ms or less else not likely to recovery at // all. auto wait = 250; while (wait-- && gpio_get_level(scl_pin) == 0) { App.feed_wdt(); delayMicroseconds(half_period_usec * 2); } if (gpio_get_level(scl_pin) == 0) { ESP_LOGE(TAG, "Recovery failed: SCL is held LOW during clock pulse cycle"); recovery_result_ = RECOVERY_FAILED_SCL_LOW; return; } } // By now, any stuck device ought to have sent all remaining bits of its // transaction, meaning that it should have freed up the SDA line, resulting // in SDA being pulled up. if (gpio_get_level(sda_pin) == 0) { ESP_LOGE(TAG, "Recovery failed: SDA is held LOW after clock pulse cycle"); recovery_result_ = RECOVERY_FAILED_SDA_LOW; return; } // From the specification: // "I2C-bus compatible devices must reset their bus logic on receipt of // a START or repeated START condition such that they all anticipate // the sending of a target address, even if these START conditions are // not positioned according to the proper format." // While the 9 clock pulses from above might have drained all bits of a // single byte within a transaction, a device might have more bytes to // transmit. So here we'll generate a START condition to snap the device // out of this state. // SCL and SDA are already high at this point, so we can generate a START // condition by making the SDA signal LOW. delayMicroseconds(half_period_usec); gpio_set_level(sda_pin, 0); // From the specification: // "A START condition immediately followed by a STOP condition (void // message) is an illegal format. Many devices however are designed to // operate properly under this condition." // Finally, we'll bring the I2C bus into a starting state by generating // a STOP condition. delayMicroseconds(half_period_usec); gpio_set_level(sda_pin, 1); recovery_result_ = RECOVERY_COMPLETED; } } // namespace i2c } // namespace esphome #endif // USE_ESP32