1 /*
2 * Copyright (c) 2019 - 2020, Nordic Semiconductor ASA
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its
16 * contributors may be used to endorse or promote products derived from this
17 * software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
23 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <nrfx_twi_twim.h>
33
34 #if NRFX_CHECK(NRFX_TWI_ENABLED) || NRFX_CHECK(NRFX_TWIM_ENABLED)
35
36 #include <hal/nrf_gpio.h>
37
38 #define TWI_TWIM_PIN_CONFIGURE(_pin) nrf_gpio_cfg((_pin), \
39 NRF_GPIO_PIN_DIR_OUTPUT, \
40 NRF_GPIO_PIN_INPUT_CONNECT, \
41 NRF_GPIO_PIN_PULLUP, \
42 NRF_GPIO_PIN_S0D1, \
43 NRF_GPIO_PIN_NOSENSE)
44
nrfx_twi_twim_bus_recover(uint32_t scl_pin,uint32_t sda_pin)45 nrfx_err_t nrfx_twi_twim_bus_recover(uint32_t scl_pin, uint32_t sda_pin)
46 {
47 nrf_gpio_pin_set(scl_pin);
48 nrf_gpio_pin_set(sda_pin);
49
50 TWI_TWIM_PIN_CONFIGURE(scl_pin);
51 TWI_TWIM_PIN_CONFIGURE(sda_pin);
52 NRFX_DELAY_US(4);
53
54 for (uint8_t i = 0; i < 9; i++)
55 {
56 if (nrf_gpio_pin_read(sda_pin))
57 {
58 break;
59 }
60 else
61 {
62 // Pulse CLOCK signal
63 nrf_gpio_pin_clear(scl_pin);
64 NRFX_DELAY_US(4);
65 nrf_gpio_pin_set(scl_pin);
66 NRFX_DELAY_US(4);
67 }
68 }
69
70 // Generate a STOP condition on the bus
71 nrf_gpio_pin_clear(sda_pin);
72 NRFX_DELAY_US(4);
73 nrf_gpio_pin_set(sda_pin);
74 NRFX_DELAY_US(4);
75
76 if (nrf_gpio_pin_read(sda_pin))
77 {
78 return NRFX_SUCCESS;
79 }
80 else
81 {
82 return NRFX_ERROR_INTERNAL;
83 }
84 }
85
86 #endif // NRFX_CHECK(NRFX_TWI_ENABLED) || NRFX_CHECK(NRFX_TWIM_ENABLED)
87