change to new 1-wire platform (#6860)

Co-authored-by: Samuel Sieb <samuel@sieb.net>
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/gpio/one_wire/gpio_one_wire.cpp

@@ -0,0 +1,199 @@
+#include "gpio_one_wire.h"
+#include "esphome/core/log.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome {
+namespace gpio {
+
+static const char *const TAG = "gpio.one_wire";
+
+void GPIOOneWireBus::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up 1-wire bus...");
+  this->search();
+}
+
+void GPIOOneWireBus::dump_config() {
+  ESP_LOGCONFIG(TAG, "GPIO 1-wire bus:");
+  LOG_PIN("  Pin: ", this->t_pin_);
+  this->dump_devices_(TAG);
+}
+
+bool HOT IRAM_ATTR GPIOOneWireBus::reset() {
+  // See reset here:
+  // https://www.maximintegrated.com/en/design/technical-documents/app-notes/1/126.html
+  // Wait for communication to clear (delay G)
+  pin_.pin_mode(gpio::FLAG_INPUT | gpio::FLAG_PULLUP);
+  uint8_t retries = 125;
+  do {
+    if (--retries == 0)
+      return false;
+    delayMicroseconds(2);
+  } while (!pin_.digital_read());
+
+  bool r;
+
+  // Send 480µs LOW TX reset pulse (drive bus low, delay H)
+  pin_.pin_mode(gpio::FLAG_OUTPUT);
+  pin_.digital_write(false);
+  delayMicroseconds(480);
+
+  // Release the bus, delay I
+  pin_.pin_mode(gpio::FLAG_INPUT | gpio::FLAG_PULLUP);
+  delayMicroseconds(70);
+
+  // sample bus, 0=device(s) present, 1=no device present
+  r = !pin_.digital_read();
+  // delay J
+  delayMicroseconds(410);
+  return r;
+}
+
+void HOT IRAM_ATTR GPIOOneWireBus::write_bit_(bool bit) {
+  // drive bus low
+  pin_.pin_mode(gpio::FLAG_OUTPUT);
+  pin_.digital_write(false);
+
+  // from datasheet:
+  // write 0 low time: t_low0: min=60µs, max=120µs
+  // write 1 low time: t_low1: min=1µs, max=15µs
+  // time slot: t_slot: min=60µs, max=120µs
+  // recovery time: t_rec: min=1µs
+  // ds18b20 appears to read the bus after roughly 14µs
+  uint32_t delay0 = bit ? 6 : 60;
+  uint32_t delay1 = bit ? 54 : 5;
+
+  // delay A/C
+  delayMicroseconds(delay0);
+  // release bus
+  pin_.digital_write(true);
+  // delay B/D
+  delayMicroseconds(delay1);
+}
+
+bool HOT IRAM_ATTR GPIOOneWireBus::read_bit_() {
+  // drive bus low
+  pin_.pin_mode(gpio::FLAG_OUTPUT);
+  pin_.digital_write(false);
+
+  // note: for reading we'll need very accurate timing, as the
+  // timing for the digital_read() is tight; according to the datasheet,
+  // we should read at the end of 16µs starting from the bus low
+  // typically, the ds18b20 pulls the line high after 11µs for a logical 1
+  // and 29µs for a logical 0
+
+  uint32_t start = micros();
+  // datasheet says >1µs
+  delayMicroseconds(2);
+
+  // release bus, delay E
+  pin_.pin_mode(gpio::FLAG_INPUT | gpio::FLAG_PULLUP);
+
+  // measure from start value directly, to get best accurate timing no matter
+  // how long pin_mode/delayMicroseconds took
+  delayMicroseconds(12 - (micros() - start));
+
+  // sample bus to read bit from peer
+  bool r = pin_.digital_read();
+
+  // read slot is at least 60µs; get as close to 60µs to spend less time with interrupts locked
+  uint32_t now = micros();
+  if (now - start < 60)
+    delayMicroseconds(60 - (now - start));
+
+  return r;
+}
+
+void IRAM_ATTR GPIOOneWireBus::write8(uint8_t val) {
+  for (uint8_t i = 0; i < 8; i++) {
+    this->write_bit_(bool((1u << i) & val));
+  }
+}
+
+void IRAM_ATTR GPIOOneWireBus::write64(uint64_t val) {
+  for (uint8_t i = 0; i < 64; i++) {
+    this->write_bit_(bool((1ULL << i) & val));
+  }
+}
+
+uint8_t IRAM_ATTR GPIOOneWireBus::read8() {
+  uint8_t ret = 0;
+  for (uint8_t i = 0; i < 8; i++) {
+    ret |= (uint8_t(this->read_bit_()) << i);
+  }
+  return ret;
+}
+
+uint64_t IRAM_ATTR GPIOOneWireBus::read64() {
+  uint64_t ret = 0;
+  for (uint8_t i = 0; i < 8; i++) {
+    ret |= (uint64_t(this->read_bit_()) << i);
+  }
+  return ret;
+}
+
+void GPIOOneWireBus::reset_search() {
+  this->last_discrepancy_ = 0;
+  this->last_device_flag_ = false;
+  this->address_ = 0;
+}
+
+uint64_t IRAM_ATTR GPIOOneWireBus::search_int() {
+  if (this->last_device_flag_)
+    return 0u;
+
+  uint8_t last_zero = 0;
+  uint64_t bit_mask = 1;
+  uint64_t address = this->address_;
+
+  // Initiate search
+  for (int bit_number = 1; bit_number <= 64; bit_number++, bit_mask <<= 1) {
+    // read bit
+    bool id_bit = this->read_bit_();
+    // read its complement
+    bool cmp_id_bit = this->read_bit_();
+
+    if (id_bit && cmp_id_bit) {
+      // No devices participating in search
+      return 0;
+    }
+
+    bool branch;
+
+    if (id_bit != cmp_id_bit) {
+      // only chose one branch, the other one doesn't have any devices.
+      branch = id_bit;
+    } else {
+      // there are devices with both 0s and 1s at this bit
+      if (bit_number < this->last_discrepancy_) {
+        branch = (address & bit_mask) > 0;
+      } else {
+        branch = bit_number == this->last_discrepancy_;
+      }
+
+      if (!branch) {
+        last_zero = bit_number;
+      }
+    }
+
+    if (branch) {
+      address |= bit_mask;
+    } else {
+      address &= ~bit_mask;
+    }
+
+    // choose/announce branch
+    this->write_bit_(branch);
+  }
+
+  this->last_discrepancy_ = last_zero;
+  if (this->last_discrepancy_ == 0) {
+    // we're at root and have no choices left, so this was the last one.
+    this->last_device_flag_ = true;
+  }
+
+  this->address_ = address;
+  return address;
+}
+
+}  // namespace gpio
+}  // namespace esphome