comparison: components/esp32-owb/owb_gpio.c
components/esp32-owb/owb_gpio.c
- changeset 0
- 88d965579617
- child 72
- acc1904cd70d
equal
deleted
inserted
replaced
| -1:000000000000 | 0:88d965579617 |
|---|---|
| 1 /* | |
| 2 * MIT License | |
| 3 * | |
| 4 * Copyright (c) 2017 David Antliff | |
| 5 * Copyright (c) 2017 Chris Morgan <chmorgan@gmail.com> | |
| 6 * | |
| 7 * Permission is hereby granted, free of charge, to any person obtaining a copy | |
| 8 * of this software and associated documentation files (the "Software"), to deal | |
| 9 * in the Software without restriction, including without limitation the rights | |
| 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
| 11 * copies of the Software, and to permit persons to whom the Software is | |
| 12 * furnished to do so, subject to the following conditions: | |
| 13 * | |
| 14 * The above copyright notice and this permission notice shall be included in all | |
| 15 * copies or substantial portions of the Software. | |
| 16 * | |
| 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
| 20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
| 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
| 23 * SOFTWARE. | |
| 24 */ | |
| 25 | |
| 26 /** | |
| 27 * @file | |
| 28 */ | |
| 29 | |
| 30 #include <stddef.h> | |
| 31 #include <stdbool.h> | |
| 32 #include <inttypes.h> | |
| 33 #include <string.h> | |
| 34 #include <stdlib.h> | |
| 35 | |
| 36 #include "freertos/FreeRTOS.h" | |
| 37 #include "freertos/task.h" | |
| 38 #include "esp_log.h" | |
| 39 #include "sdkconfig.h" | |
| 40 #include "driver/gpio.h" | |
| 41 | |
| 42 #include "owb.h" | |
| 43 #include "owb_gpio.h" | |
| 44 | |
| 45 static const char * TAG = "owb_gpio"; | |
| 46 | |
| 47 // Define PHY_DEBUG to enable GPIO output around when the bus is sampled | |
| 48 // by the master (this library). This GPIO output makes it possible to | |
| 49 // validate the master's sampling using an oscilloscope. | |
| 50 // | |
| 51 // For the debug GPIO the idle state is low and made high before the 1-wire sample | |
| 52 // point and low again after the sample point | |
| 53 #undef PHY_DEBUG | |
| 54 | |
| 55 #ifdef PHY_DEBUG | |
| 56 // Update these defines to a pin that you can access | |
| 57 #define PHY_DEBUG_GPIO GPIO_NUM_27 | |
| 58 #define PHY_DEBUG_GPIO_MASK GPIO_SEL_27 | |
| 59 #endif | |
| 60 | |
| 61 /// @cond ignore | |
| 62 struct _OneWireBus_Timing | |
| 63 { | |
| 64 uint32_t A, B, C, D, E, F, G, H, I, J; | |
| 65 }; | |
| 66 //// @endcond | |
| 67 | |
| 68 // 1-Wire timing delays (standard) in microseconds. | |
| 69 // Labels and values are from https://www.maximintegrated.com/en/app-notes/index.mvp/id/126 | |
| 70 static const struct _OneWireBus_Timing _StandardTiming = { | |
| 71 6, // A - read/write "1" master pull DQ low duration | |
| 72 64, // B - write "0" master pull DQ low duration | |
| 73 60, // C - write "1" master pull DQ high duration | |
| 74 10, // D - write "0" master pull DQ high duration | |
| 75 9, // E - read master pull DQ high duration | |
| 76 55, // F - complete read timeslot + 10ms recovery | |
| 77 0, // G - wait before reset | |
| 78 480, // H - master pull DQ low duration | |
| 79 70, // I - master pull DQ high duration | |
| 80 410, // J - complete presence timeslot + recovery | |
| 81 }; | |
| 82 | |
| 83 static void _us_delay(uint32_t time_us) | |
| 84 { | |
| 85 ets_delay_us(time_us); | |
| 86 } | |
| 87 | |
| 88 #define info_from_bus(owb) container_of(owb, owb_gpio_driver_info, bus) | |
| 89 | |
| 90 /** | |
| 91 * @brief Generate a 1-Wire reset (initialization). | |
| 92 * @param[in] bus Initialised bus instance. | |
| 93 * @param[out] is_present true if device is present, otherwise false. | |
| 94 * @return status | |
| 95 */ | |
| 96 static owb_status _reset(const OneWireBus * bus, bool * is_present) | |
| 97 { | |
| 98 bool present = false; | |
| 99 portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; | |
| 100 portENTER_CRITICAL(&timeCriticalMutex); | |
| 101 | |
| 102 owb_gpio_driver_info *i = info_from_bus(bus); | |
| 103 | |
| 104 gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); | |
| 105 _us_delay(bus->timing->G); | |
| 106 gpio_set_level(i->gpio, 0); // Drive DQ low | |
| 107 _us_delay(bus->timing->H); | |
| 108 gpio_set_direction(i->gpio, GPIO_MODE_INPUT); // Release the bus | |
| 109 gpio_set_level(i->gpio, 1); // Reset the output level for the next output | |
| 110 _us_delay(bus->timing->I); | |
| 111 | |
| 112 #ifdef PHY_DEBUG | |
| 113 gpio_set_level(PHY_DEBUG_GPIO, 1); | |
| 114 #endif | |
| 115 | |
| 116 int level1 = gpio_get_level(i->gpio); | |
| 117 | |
| 118 #ifdef PHY_DEBUG | |
| 119 gpio_set_level(PHY_DEBUG_GPIO, 0); | |
| 120 #endif | |
| 121 | |
| 122 _us_delay(bus->timing->J); // Complete the reset sequence recovery | |
| 123 | |
| 124 #ifdef PHY_DEBUG | |
| 125 gpio_set_level(PHY_DEBUG_GPIO, 1); | |
| 126 #endif | |
| 127 | |
| 128 int level2 = gpio_get_level(i->gpio); | |
| 129 | |
| 130 #ifdef PHY_DEBUG | |
| 131 gpio_set_level(PHY_DEBUG_GPIO, 0); | |
| 132 #endif | |
| 133 | |
| 134 portEXIT_CRITICAL(&timeCriticalMutex); | |
| 135 | |
| 136 present = (level1 == 0) && (level2 == 1); // Sample for presence pulse from slave | |
| 137 ESP_LOGD(TAG, "reset: level1 0x%x, level2 0x%x, present %d", level1, level2, present); | |
| 138 | |
| 139 *is_present = present; | |
| 140 | |
| 141 return OWB_STATUS_OK; | |
| 142 } | |
| 143 | |
| 144 /** | |
| 145 * @brief Send a 1-Wire write bit, with recovery time. | |
| 146 * @param[in] bus Initialised bus instance. | |
| 147 * @param[in] bit The value to send. | |
| 148 */ | |
| 149 static void _write_bit(const OneWireBus * bus, int bit) | |
| 150 { | |
| 151 int delay1 = bit ? bus->timing->A : bus->timing->C; | |
| 152 int delay2 = bit ? bus->timing->B : bus->timing->D; | |
| 153 owb_gpio_driver_info *i = info_from_bus(bus); | |
| 154 | |
| 155 portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; | |
| 156 portENTER_CRITICAL(&timeCriticalMutex); | |
| 157 | |
| 158 gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); | |
| 159 gpio_set_level(i->gpio, 0); // Drive DQ low | |
| 160 _us_delay(delay1); | |
| 161 gpio_set_level(i->gpio, 1); // Release the bus | |
| 162 _us_delay(delay2); | |
| 163 | |
| 164 portEXIT_CRITICAL(&timeCriticalMutex); | |
| 165 } | |
| 166 | |
| 167 /** | |
| 168 * @brief Read a bit from the 1-Wire bus and return the value, with recovery time. | |
| 169 * @param[in] bus Initialised bus instance. | |
| 170 */ | |
| 171 static int _read_bit(const OneWireBus * bus) | |
| 172 { | |
| 173 int result = 0; | |
| 174 owb_gpio_driver_info *i = info_from_bus(bus); | |
| 175 | |
| 176 portMUX_TYPE timeCriticalMutex = portMUX_INITIALIZER_UNLOCKED; | |
| 177 portENTER_CRITICAL(&timeCriticalMutex); | |
| 178 | |
| 179 gpio_set_direction(i->gpio, GPIO_MODE_OUTPUT); | |
| 180 gpio_set_level(i->gpio, 0); // Drive DQ low | |
| 181 _us_delay(bus->timing->A); | |
| 182 gpio_set_direction(i->gpio, GPIO_MODE_INPUT); // Release the bus | |
| 183 gpio_set_level(i->gpio, 1); // Reset the output level for the next output | |
| 184 _us_delay(bus->timing->E); | |
| 185 | |
| 186 #ifdef PHY_DEBUG | |
| 187 gpio_set_level(PHY_DEBUG_GPIO, 1); | |
| 188 #endif | |
| 189 | |
| 190 int level = gpio_get_level(i->gpio); | |
| 191 | |
| 192 #ifdef PHY_DEBUG | |
| 193 gpio_set_level(PHY_DEBUG_GPIO, 0); | |
| 194 #endif | |
| 195 | |
| 196 _us_delay(bus->timing->F); // Complete the timeslot and 10us recovery | |
| 197 | |
| 198 portEXIT_CRITICAL(&timeCriticalMutex); | |
| 199 | |
| 200 result = level & 0x01; | |
| 201 | |
| 202 return result; | |
| 203 } | |
| 204 | |
| 205 /** | |
| 206 * @brief Write 1-Wire data byte. | |
| 207 * NOTE: The data is shifted out of the low bits, eg. it is written in the order of lsb to msb | |
| 208 * @param[in] bus Initialised bus instance. | |
| 209 * @param[in] data Value to write. | |
| 210 * @param[in] number_of_bits_to_read bits to write | |
| 211 */ | |
| 212 static owb_status _write_bits(const OneWireBus * bus, uint8_t data, int number_of_bits_to_write) | |
| 213 { | |
| 214 ESP_LOGD(TAG, "write 0x%02x", data); | |
| 215 for (int i = 0; i < number_of_bits_to_write; ++i) | |
| 216 { | |
| 217 _write_bit(bus, data & 0x01); | |
| 218 data >>= 1; | |
| 219 } | |
| 220 | |
| 221 return OWB_STATUS_OK; | |
| 222 } | |
| 223 | |
| 224 /** | |
| 225 * @brief Read 1-Wire data byte from bus. | |
| 226 * NOTE: Data is read into the high bits, eg. each bit read is shifted down before the next bit is read | |
| 227 * @param[in] bus Initialised bus instance. | |
| 228 * @return Byte value read from bus. | |
| 229 */ | |
| 230 static owb_status _read_bits(const OneWireBus * bus, uint8_t *out, int number_of_bits_to_read) | |
| 231 { | |
| 232 uint8_t result = 0; | |
| 233 for (int i = 0; i < number_of_bits_to_read; ++i) | |
| 234 { | |
| 235 result >>= 1; | |
| 236 if (_read_bit(bus)) | |
| 237 { | |
| 238 result |= 0x80; | |
| 239 } | |
| 240 } | |
| 241 ESP_LOGD(TAG, "read 0x%02x", result); | |
| 242 *out = result; | |
| 243 | |
| 244 return OWB_STATUS_OK; | |
| 245 } | |
| 246 | |
| 247 static owb_status _uninitialize(const OneWireBus * bus) | |
| 248 { | |
| 249 // Nothing to do here for this driver_info | |
| 250 return OWB_STATUS_OK; | |
| 251 } | |
| 252 | |
| 253 static const struct owb_driver gpio_function_table = | |
| 254 { | |
| 255 .name = "owb_gpio", | |
| 256 .uninitialize = _uninitialize, | |
| 257 .reset = _reset, | |
| 258 .write_bits = _write_bits, | |
| 259 .read_bits = _read_bits | |
| 260 }; | |
| 261 | |
| 262 OneWireBus* owb_gpio_initialize(owb_gpio_driver_info *driver_info, int gpio) | |
| 263 { | |
| 264 ESP_LOGI(TAG, "%s(): gpio %d\n", __func__, gpio); | |
| 265 | |
| 266 driver_info->gpio = gpio; | |
| 267 driver_info->bus.driver = &gpio_function_table; | |
| 268 driver_info->bus.timing = &_StandardTiming; | |
| 269 | |
| 270 // platform specific: | |
| 271 gpio_pad_select_gpio(driver_info->gpio); | |
| 272 | |
| 273 #ifdef PHY_DEBUG | |
| 274 gpio_config_t io_conf; | |
| 275 io_conf.intr_type = GPIO_INTR_DISABLE; | |
| 276 io_conf.mode = GPIO_MODE_OUTPUT; | |
| 277 io_conf.pin_bit_mask = PHY_DEBUG_GPIO_MASK; | |
| 278 io_conf.pull_down_en = GPIO_PULLDOWN_ENABLE; | |
| 279 io_conf.pull_up_en = GPIO_PULLUP_DISABLE; | |
| 280 ESP_ERROR_CHECK(gpio_config(&io_conf)); | |
| 281 #endif | |
| 282 | |
| 283 return &(driver_info->bus); | |
| 284 } |
