zephyr/drivers/bluetooth/nrf51_pm.c

117 lines
2.7 KiB
C

/* nrf51-pm.c Power Management for nrf51 chip */
/*
* Copyright (c) 2016 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <gpio.h>
#include <uart.h>
#include <bluetooth/log.h>
#include <errno.h>
#define NBLE_SWDIO_PIN 6
#define NBLE_RESET_PIN NBLE_SWDIO_PIN
#define NBLE_BTWAKE_PIN 5
static struct device *nrf51_gpio;
int nrf51_wakeup(void)
{
return gpio_pin_write(nrf51_gpio, NBLE_BTWAKE_PIN, 1);
}
int nrf51_allow_sleep(void)
{
return gpio_pin_write(nrf51_gpio, NBLE_BTWAKE_PIN, 0);
}
static inline void sleep_ms(unsigned int ms)
{
switch (sys_execution_context_type_get()) {
case NANO_CTX_FIBER:
fiber_sleep(MSEC(ms));
return;
case NANO_CTX_TASK:
task_sleep(MSEC(ms));
return;
default:
BT_ERR("ISR context is not supported");
return;
}
}
int nrf51_init(struct device *dev)
{
uint8_t c;
int ret;
nrf51_gpio = device_get_binding("GPIO_0");
if (!nrf51_gpio) {
BT_ERR("Cannot find GPIO_0");
return -ENODEV;
}
ret = gpio_pin_configure(nrf51_gpio, NBLE_RESET_PIN, GPIO_DIR_OUT);
if (ret) {
BT_ERR("Error configuring pin %d", NBLE_RESET_PIN);
return -ENODEV;
}
/* Reset hold time is 0.2us (normal) or 100us (SWD debug) */
ret = gpio_pin_write(nrf51_gpio, NBLE_RESET_PIN, 0);
if (ret) {
BT_ERR("Error pin write %d", NBLE_RESET_PIN);
return -EINVAL;
}
/* Drain the fifo */
while (uart_fifo_read(dev, &c, 1)) {
continue;
}
/**
* NBLE reset is achieved by asserting low the SWDIO pin.
* However, the BLE Core chip can be in SWD debug mode,
* and NRF_POWER->RESET = 0 due to, other constraints: therefore,
* this reset might not work everytime, especially after
* flashing or debugging.
*/
/* sleep 1ms depending on context */
sleep_ms(1);
ret = gpio_pin_write(nrf51_gpio, NBLE_RESET_PIN, 1);
if (ret) {
BT_ERR("Error pin write %d", NBLE_RESET_PIN);
return -EINVAL;
}
/* Set back GPIO to input to avoid interfering with external debugger */
ret = gpio_pin_configure(nrf51_gpio, NBLE_RESET_PIN, GPIO_DIR_IN);
if (ret) {
BT_ERR("Error configuring pin %d", NBLE_RESET_PIN);
return -ENODEV;
}
ret = gpio_pin_configure(nrf51_gpio, NBLE_BTWAKE_PIN, GPIO_DIR_OUT);
if (ret) {
BT_ERR("Error configuring pin %d", NBLE_BTWAKE_PIN);
return -ENODEV;
}
return nrf51_wakeup();
}