diff -r 000000000000 -r b74b0e4902c3 components/esp32-owb/owb_gpio.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/components/esp32-owb/owb_gpio.c Sat Oct 20 13:23:15 2018 +0200 @@ -0,0 +1,284 @@ +/* + * 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); +} + +#define info_from_bus(owb) container_of(owb, owb_gpio_driver_info, bus) + +/** + * @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_LOGI(TAG, "%s(): gpio %d\n", __func__, gpio); + + driver_info->gpio = gpio; + driver_info->bus.driver = &gpio_function_table; + driver_info->bus.timing = &_StandardTiming; + + // 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); +}