Fri, 05 Jul 2019 20:22:05 +0200
Version 0.3.6
0 | 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 | } |