1 /*
2 * Copyright (c) 2023, Nordic Semiconductor ASA
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include "spi_nrfx_common.h"
8 #include <zephyr/kernel.h>
9
spi_nrfx_wake_init(const nrfx_gpiote_t * gpiote,uint32_t wake_pin)10 int spi_nrfx_wake_init(const nrfx_gpiote_t *gpiote, uint32_t wake_pin)
11 {
12 nrf_gpio_pin_pull_t pull_config = NRF_GPIO_PIN_PULLDOWN;
13 uint8_t ch;
14 nrfx_gpiote_trigger_config_t trigger_config = {
15 .trigger = NRFX_GPIOTE_TRIGGER_HITOLO,
16 .p_in_channel = &ch,
17 };
18 nrfx_gpiote_input_pin_config_t input_config = {
19 .p_pull_config = &pull_config,
20 .p_trigger_config = &trigger_config,
21 .p_handler_config = NULL,
22 };
23 nrfx_err_t res;
24
25 res = nrfx_gpiote_channel_alloc(gpiote, &ch);
26 if (res != NRFX_SUCCESS) {
27 return -ENODEV;
28 }
29
30 res = nrfx_gpiote_input_configure(gpiote, wake_pin, &input_config);
31 if (res != NRFX_SUCCESS) {
32 nrfx_gpiote_channel_free(gpiote, ch);
33 return -EIO;
34 }
35
36 return 0;
37 }
38
spi_nrfx_wake_request(const nrfx_gpiote_t * gpiote,uint32_t wake_pin)39 int spi_nrfx_wake_request(const nrfx_gpiote_t *gpiote, uint32_t wake_pin)
40 {
41 nrf_gpiote_event_t trigger_event = nrfx_gpiote_in_event_get(gpiote, wake_pin);
42 uint32_t start_cycles;
43 uint32_t max_wait_cycles =
44 DIV_ROUND_UP(CONFIG_SPI_NRFX_WAKE_TIMEOUT_US *
45 CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC,
46 1000000);
47 int err = 0;
48
49 /* Enable the trigger (a high-to-low transition) without its interrupt.
50 * The expected time to wait is quite short so it is not worth paying
51 * the overhead of context switching to handle the interrupt.
52 */
53 nrfx_gpiote_trigger_enable(gpiote, wake_pin, false);
54 /* Enable pull-up on the WAKE line. After the slave device sees the
55 * WAKE line going high, it will force the line to go low. This will
56 * be caught by the enabled trigger and the loop below waits for that.
57 */
58 nrf_gpio_cfg_input(wake_pin, NRF_GPIO_PIN_PULLUP);
59
60 start_cycles = k_cycle_get_32();
61 while (!nrf_gpiote_event_check(gpiote->p_reg, trigger_event)) {
62 uint32_t elapsed_cycles = k_cycle_get_32() - start_cycles;
63
64 if (elapsed_cycles >= max_wait_cycles) {
65 err = -ETIMEDOUT;
66 break;
67 }
68 }
69
70 nrfx_gpiote_trigger_disable(gpiote, wake_pin);
71 nrf_gpio_cfg_input(wake_pin, NRF_GPIO_PIN_PULLDOWN);
72
73 return err;
74 }
75
