GPIO in DLPS - Automatic Configuration

This sample uses the auto-configuration wake-up feature of the GPIO to detect GPIO input signals in low power mode.

Users can modify pin information through different macro configurations. For specific macro configurations, refer to Configurations.

Requirements

For hardware requirements, please refer to the Requirements.

Configurations

The following macros can be configured to modify GPIO pin definitions.
```
#define TEST_Pin                      P0_0
```
The entry function is as follows, call this function in main() to run this sample code. For more details, please refer to the Initialization.
```
dlps_gpio_wk_auto_config_demo();
```

Building and Downloading

For building and downloading, please refer to the Building and Downloading.

Experimental Verification

Press the Reset button on the EVB and the following message is printed in the Debug Analyzer.
```
gpio_test: gpio_level 1
```
After initialization is complete, the system is in idle state, it will enter DLPS mode. Observe the entering DLPS message displayed in the Debug Analyzer.
```
dlps_store: enter dlps
```
When a low level input is detected on P0_0, the system will be awakened and the interrupt function of the GPIO will be called. The following message is printed in the Debug Analyzer.
```
gpio_handler: gpio_level 0
dlps_restore: exit dlps
```

Code Overview

This section introduces the code and process description for initialization and corresponding function implementation in the sample.

Source Code Directory

The directory for project file and source code are as follows.

For project directory, please refer to Source Code Directory.
Source code directory: sdk\sample\io_demo\dlps\dlps_gpio_wk_auto_config_demo.c.

GPIO Initialization

The initialization flow for peripherals can refer to Initialization Flow.

Call hal_gpio_init() to enable GPIO clock.
```
hal_gpio_init();
```
Call hal_gpio_int_init() to initialize GPIO interrupt.
```
hal_gpio_int_init();
```
Call hal_gpio_set_debounce_time() to set GPIO debounce time.
```
hal_gpio_set_debounce_time(30);
```
Call hal_gpio_init_pin() to initialize the GPIO peripheral and call hal_gpio_set_up_irq() to initialize interrupt-related parameters. The GPIO initialization parameters are configured as shown in the table below.

GPIO Input Initialization Parameters
GPIO Hardware Parameters	GPIO
Pin Number	`TEST_Pin`
GPIO Type	`GPIO_TYPE_AUTO`
GPIO Mode	`GPIO_DIR_INPUT`
GPIO Pull Value	`GPIO_PULL_UP`
Interrupt Type	`GPIO_IRQ_EDGE`
Interrupt Polarity	`GPIO_IRQ_ACTIVE_LOW`
Debounce Enable	`true`

Call hal_gpio_register_isr_callback() to register gpio interrupt callback.
Call hal_gpio_irq_enable() to enable gpio interrupt.

DLPS Mode Initialization

Call io_dlps_register() to initialize IO store/restore and do not need to worry about which IO peripheral requires specific handling.
Call io_dlps_register_enter_cb() to register callbacks to DLPS enter stage. Function dlps_store will be executed while entering DLPS.
1. No action is needed.

Call io_dlps_register_exit_cb() to register callbacks to DLPS exit stage. Function dlps_restore will be executed while exiting from DLPS.
1. No action is needed.
Call bt_power_mode_set() to set Bluetooth MAC deep sleep mode.
Call power_mode_set() to switch the system to DLPS mode.

Functional Implementation

When connecting P0_0 to GND, detecting a low level of P0_0 triggers a GPIO interrupt. The interrupt handler function gpio_handler prints interrupt information.

static void gpio_handler(uint32_t context)
{
    uint8_t pin_index = (uint32_t)context;
    T_GPIO_LEVEL gpio_level = hal_gpio_get_input_level(pin_index);

    IO_PRINT_INFO1("gpio_handler: gpio_level %d", gpio_level);

    // add user code here
}