/* * MIT License * * Copyright (c) 2017 David Antliff * Copyright (c) 2017 Chris Morgan * * 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. */ /** * @file */ #include #include #include #include #include #include "freertos/FreeRTOS.h" #include "freertos/task.h" #include "esp_log.h" #include "sdkconfig.h" #include "driver/gpio.h" #include "owb.h" #include "owb_gpio.h" static const char * TAG = "owb_gpio"; // Define PHY_DEBUG to enable GPIO output around when the bus is sampled // by the master (this library). This GPIO output makes it possible to // validate the master's sampling using an oscilloscope. // // For the debug GPIO the idle state is low and made high before the 1-wire sample // point and low again after the sample point #undef PHY_DEBUG #ifdef PHY_DEBUG // Update these defines to a pin that you can access #define PHY_DEBUG_GPIO GPIO_NUM_27 #define PHY_DEBUG_GPIO_MASK GPIO_SEL_27 #endif /// @cond ignore struct _OneWireBus_Timing { uint32_t A, B, C, D, E, F, G, H, I, J; }; /// @endcond // 1-Wire timing delays (standard) in microseconds. // Labels and values are from https://www.maximintegrated.com/en/app-notes/index.mvp/id/126 static const struct _OneWireBus_Timing _StandardTiming = { 6, // A - read/write "1" master pull DQ low duration 64, // B - write "0" master pull DQ low duration 60, // C - write "1" master pull DQ high duration 10, // D - write "0" master pull DQ high duration 9, // E - read master pull DQ high duration 55, // F - complete read timeslot + 10ms recovery 0, // G - wait before reset 480, // H - master pull DQ low duration 70, // I - master pull DQ high duration 410, // J - complete presence timeslot + recovery }; static void _us_delay(uint32_t time_us) { ets_delay_us(time_us); } /// @cond ignore #define info_from_bus(owb) container_of(owb, owb_gpio_driver_info, bus) /// @endcond /** * @brief Generate a 1-Wire reset (initialization). * @param[in] bus Initialised bus instance. * @param[out] is_present true if device is present, otherwise false. * @return status */ static owb_status _reset(const OneWireBus * bus, bool * is_present) { bool present = false; portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; portENTER_CRITICAL(&timeCriticalMutex); owb_gpio_driver_info *i = info_from_bus(bus); gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); _us_delay(bus->timing->G); gpio_set_level(i->gpio, 0); // Drive DQ low _us_delay(bus->timing->H); gpio_set_direction(i->gpio, GPIO_MODE_INPUT); // Release the bus gpio_set_level(i->gpio, 1); // Reset the output level for the next output _us_delay(bus->timing->I); #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 1); #endif int level1 = gpio_get_level(i->gpio); #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 0); #endif _us_delay(bus->timing->J); // Complete the reset sequence recovery #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 1); #endif int level2 = gpio_get_level(i->gpio); #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 0); #endif portEXIT_CRITICAL(&timeCriticalMutex); present = (level1 == 0) && (level2 == 1); // Sample for presence pulse from slave ESP_LOGD(TAG, "reset: level1 0x%x, level2 0x%x, present %d", level1, level2, present); *is_present = present; return OWB_STATUS_OK; } /** * @brief Send a 1-Wire write bit, with recovery time. * @param[in] bus Initialised bus instance. * @param[in] bit The value to send. */ static void _write_bit(const OneWireBus * bus, int bit) { int delay1 = bit ? bus->timing->A : bus->timing->C; int delay2 = bit ? bus->timing->B : bus->timing->D; owb_gpio_driver_info *i = info_from_bus(bus); portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; portENTER_CRITICAL(&timeCriticalMutex); gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); gpio_set_level(i->gpio, 0); // Drive DQ low _us_delay(delay1); gpio_set_level(i->gpio, 1); // Release the bus _us_delay(delay2); portEXIT_CRITICAL(&timeCriticalMutex); } /** * @brief Read a bit from the 1-Wire bus and return the value, with recovery time. * @param[in] bus Initialised bus instance. */ static int _read_bit(const OneWireBus * bus) { int result = 0; owb_gpio_driver_info *i = info_from_bus(bus); portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; portENTER_CRITICAL(&timeCriticalMutex); gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); gpio_set_level(i->gpio, 0); // Drive DQ low _us_delay(bus->timing->A); gpio_set_direction(i->gpio, GPIO_MODE_INPUT); // Release the bus gpio_set_level(i->gpio, 1); // Reset the output level for the next output _us_delay(bus->timing->E); #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 1); #endif int level = gpio_get_level(i->gpio); #ifdef PHY_DEBUG gpio_set_level(PHY_DEBUG_GPIO, 0); #endif _us_delay(bus->timing->F); // Complete the timeslot and 10us recovery portEXIT_CRITICAL(&timeCriticalMutex); result = level & 0x01; return result; } /** * @brief Write 1-Wire data byte. * NOTE: The data is shifted out of the low bits, eg. it is written in the order of lsb to msb * @param[in] bus Initialised bus instance. * @param[in] data Value to write. * @param[in] number_of_bits_to_read bits to write */ static owb_status _write_bits(const OneWireBus * bus, uint8_t data, int number_of_bits_to_write) { ESP_LOGD(TAG, "write 0x%02x", data); for (int i = 0; i < number_of_bits_to_write; ++i) { _write_bit(bus, data & 0x01); data >>= 1; } return OWB_STATUS_OK; } /** * @brief Read 1-Wire data byte from bus. * NOTE: Data is read into the high bits, eg. each bit read is shifted down before the next bit is read * @param[in] bus Initialised bus instance. * @return Byte value read from bus. */ static owb_status _read_bits(const OneWireBus * bus, uint8_t *out, int number_of_bits_to_read) { uint8_t result = 0; for (int i = 0; i < number_of_bits_to_read; ++i) { result >>= 1; if (_read_bit(bus)) { result |= 0x80; } } ESP_LOGD(TAG, "read 0x%02x", result); *out = result; return OWB_STATUS_OK; } static owb_status _uninitialize(const OneWireBus * bus) { // Nothing to do here for this driver_info return OWB_STATUS_OK; } static const struct owb_driver gpio_function_table = { .name = "owb_gpio", .uninitialize = _uninitialize, .reset = _reset, .write_bits = _write_bits, .read_bits = _read_bits }; OneWireBus* owb_gpio_initialize(owb_gpio_driver_info * driver_info, int gpio) { ESP_LOGD(TAG, "%s(): gpio %d\n", __func__, gpio); driver_info->gpio = gpio; driver_info->bus.driver = &gpio_function_table; driver_info->bus.timing = &_StandardTiming; driver_info->bus.strong_pullup_gpio = GPIO_NUM_NC; // platform specific: gpio_pad_select_gpio(driver_info->gpio); #ifdef PHY_DEBUG gpio_config_t io_conf; io_conf.intr_type = GPIO_INTR_DISABLE; io_conf.mode = GPIO_MODE_OUTPUT; io_conf.pin_bit_mask = PHY_DEBUG_GPIO_MASK; io_conf.pull_down_en = GPIO_PULLDOWN_ENABLE; io_conf.pull_up_en = GPIO_PULLUP_DISABLE; ESP_ERROR_CHECK(gpio_config(&io_conf)); #endif return &(driver_info->bus); }