--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/components/esp32-owb/owb_gpio.c Tue Oct 08 12:00:31 2019 +0200
@@ -0,0 +1,284 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 David Antliff
+ * Copyright (c) 2017 Chris Morgan <chmorgan@gmail.com>
+ *
+ * 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 <stddef.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+
+#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);
+}