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Usage scenarios
In addition to using GPIO in the application layer, the fact is to call in other more complex driving. Such as SD card driver to be used to monitor the GPIO insert a card and the extractor, the card requires the use of a GPIO driver to control the phy chip hard reset, some cases need to simulate GPIO like the I2C bus. When the drive is used GPIO, in order to improve efficiency is not calling GPIO device file, but the use of GPIO call interface SylixOS provided.
GPIO API
/*********************************************************************************************************
GPIO API (以下 API 仅供驱动程序内部使用, 应用程序不可使用)
*********************************************************************************************************/
LW_API VOID API_GpioInit(VOID);
LW_API INT API_GpioChipAdd(PLW_GPIO_CHIP pgchip);
LW_API INT API_GpioChipDelete(PLW_GPIO_CHIP pgchip);
LW_API PLW_GPIO_CHIP API_GpioChipFind(PVOID pvData, BOOL (*pfuncMatch)(PLW_GPIO_CHIP pgchip, PVOID pvData));
LW_API INT API_GpioIsValid(UINT uiGpio);
LW_API INT API_GpioHasDrv(UINT uiGpio);
LW_API INT API_GpioRequest(UINT uiGpio, CPCHAR pcLabel);
LW_API INT API_GpioRequestOne(UINT uiGpio, ULONG ulFlags, CPCHAR pcLabel);
LW_API VOID API_GpioFree(UINT uiGpio);
LW_API INT API_GpioRequestArray(PLW_GPIO pgArray, size_t stNum);
LW_API VOID API_GpioFreeArray(PLW_GPIO pgArray, size_t stNum);
LW_API INT API_GpioGetFlags(UINT uiGpio, ULONG *pulFlags);
LW_API VOID API_GpioOpenDrain(UINT uiGpio, BOOL bOpenDrain);
LW_API VOID API_GpioOpenSource(UINT uiGpio, BOOL bOpenSource);
LW_API INT API_GpioSetDebounce(UINT uiGpio, UINT uiDebounce);
LW_API INT API_GpioSetPull(UINT uiGpio, UINT uiType);
LW_API INT API_GpioDirectionInput(UINT uiGpio);
LW_API INT API_GpioDirectionOutput(UINT uiGpio, INT iValue);
LW_API INT API_GpioGetValue(UINT uiGpio);
LW_API VOID API_GpioSetValue(UINT uiGpio, INT iValue);
LW_API ULONG API_GpioGetIrq(UINT uiGpio, BOOL bIsLevel, UINT uiType);
LW_API ULONG API_GpioSetupIrq(UINT uiGpio, BOOL bIsLevel, UINT uiType);
LW_API VOID API_GpioClearIrq(UINT uiGpio);
LW_API irqreturn_t API_GpioSvrIrq(UINT uiGpio);
While the system also for these API functions have been defined macros
#define gpioInit API_GpioInit
#define gpioChipAdd API_GpioChipAdd
#define gpioChipDelete API_GpioChipDelete
#define gpioChipFind API_GpioChipFind
#define gpioIsValid API_GpioIsValid
#define gpioHasDrv API_GpioHasDrv
#define gpioRequest API_GpioRequest
#define gpioRequestOne API_GpioRequestOne
#define gpioFree API_GpioFree
#define gpioRequestArray API_GpioRequestArray
#define gpioFreeArray API_GpioFreeArray
#define gpioGetFlags API_GpioGetFlags
#define gpioOpenDrain API_GpioOpenDrain
#define gpioOpenSource API_GpioOpenSource
#define gpioSetDebounce API_GpioSetDebounce
#define gpioSetPull API_GpioSetPull
#define gpioDirectionInput API_GpioDirectionInput
#define gpioDirectionOutput API_GpioDirectionOutput
#define gpioGetValue API_GpioGetValue
#define gpioSetValue API_GpioSetValue
#define gpioGetIrq API_GpioGetIrq
#define gpioSetupIrq API_GpioSetupIrq
#define gpioClearIrq API_GpioClearIrq
#define gpioSvrIrq API_GpioSvrIrq
Common Interface
GPIO is generally used to read or control the input level at the output level, not too complicated operation, only the following four functions can be invoked.
/*********************************************************************************************************
** 函数名称: API_GpioRequestOne
** 功能描述: 请求使用一个 GPIO
** 输 入 : uiGpio 请求 GPIO 号
** ulFlags 需要设置的属性
** pcLabel 标签
** 输 出 : ERROR_NONE or PX_ERROR
*********************************************************************************************************/
LW_API INT API_GpioRequestOne(UINT uiGpio, ULONG ulFlags, CPCHAR pcLabel);
/*********************************************************************************************************
** 函数名称: API_GpioGetValue
** 功能描述: 获取指定 GPIO 的值
** 输 入 : uiGpio GPIO 号
** 输 出 : GPIO 当前电平状态 1: 高电平 0: 低电平
** 注 意 : 此函数不做任何参数有效性判断, 所以用户必须保证 uiGpio 已经请求成功, 方向与其他参数设置正确.
*********************************************************************************************************/
LW_API INT API_GpioGetValue(UINT uiGpio);
/*********************************************************************************************************
** 函数名称: API_GpioSetValue
** 功能描述: 设置指定 GPIO 的值
** 输 入 : uiGpio GPIO 号
** iValue 1: 高电平 0: 低电平
** 输 出 : NONE
** 注 意 : 此函数不做任何参数有效性判断, 所以用户必须保证 uiGpio 已经请求成功, 方向与其他参数设置正确.
*********************************************************************************************************/
LW_API VOID API_GpioSetValue(UINT uiGpio, INT iValue);
/*********************************************************************************************************
** 函数名称: API_GpioFree
** 功能描述: 释放使用一个 GPIO
** 输 入 : uiGpio GPIO 号
** 输 出 : NONE
*********************************************************************************************************/
LW_API VOID API_GpioFree(UINT uiGpio);
These interfaces are API can only use the internal driver in the kernel mode, user mode application are not available. Before use need to include "SylixOS.h" header file.
First call API_GpioRequestOnefunction, turn on and follow the ulFlagsGPIO initialization parameters. Other functions can be called only after the interface opens GPIO. The GPIO can later be input or output, respectively, to call mode API_GpioGetValueor API_GpioSetValuefunction is operated. If the GPIO no longer in use, need to call API_GpioFreethe function to be released.
ulFlagsParameters and gpiofdfunctions flagssimilar to the parameters used to configure some GPIO related properties. Specific options are as follows:
#define LW_GPIOF_DIR_OUT (0 << 0)
#define LW_GPIOF_DIR_IN (1 << 0)
#define LW_GPIOF_INIT_LOW (0 << 1)
#define LW_GPIOF_INIT_HIGH (1 << 1)
#define LW_GPIOF_IN (LW_GPIOF_DIR_IN)
#define LW_GPIOF_OUT_INIT_LOW (LW_GPIOF_DIR_OUT | LW_GPIOF_INIT_LOW)
#define LW_GPIOF_OUT_INIT_HIGH (LW_GPIOF_DIR_OUT | LW_GPIOF_INIT_HIGH)
#define LW_GPIOF_OPEN_DRAIN (1 << 2)
#define LW_GPIOF_OPEN_SOURCE (1 << 3)
Demonstration routine
/*********************************************************************************************************
**
** 中国软件开源组织
**
** 嵌入式实时操作系统
**
** SylixOS(TM) LW : long wing
**
** Copyright All Rights Reserved
**
**--------------文件信息--------------------------------------------------------------------------------
**
** 文 件 名: gpioDrvExample1.c
**
** 创 建 人: Hou.JinYu (侯进宇)
**
** 文件创建日期: 2017 年 12 月 13 日
**
** 描 述: gpio 在驱动中的调用例程,针对NXP i.MX-RT1050 EVK开发版。
** 因为连接板载 LED01 的引脚同时也连接了 enet 的复位脚，硬件冲突故不能使用。
** LED02 只是一个空闲的gpio（为J22.7）,需要用户连接LED或万用表来检测电平变化。
*********************************************************************************************************/
#define __SYLIXOS_KERNEL
#include "stdio.h"
#include "SylixOS.h"
#include "gpio/gpio.h"
/*********************************************************************************************************
引脚宏定义
********************************************************************************************************/
#define KEY08 GPIO_E_00 /* GPIO5--00 */
#define LED01 GPIO_A_09 /* GPIO1--09 */
#define LED02 GPIO_A_18 /* GPIO1--18 */
/*********************************************************************************************************
** 函数名称: gpioDrvExample1
** 功能描述: gpio 轮询读取例程
** 输 入: NONE
** 输 出: ERROR_CODE
*********************************************************************************************************/
INT gpioDrvExample1 (VOID)
{
UINT8 ucValue;
printf("Gpio poll example. Waiting press the key SW8.\n");
API_GpioRequestOne(KEY08, LW_GPIOF_IN, "KEY08");
API_GpioRequestOne(LED02, LW_GPIOF_OUT_INIT_LOW, "LED02");
while (1) {
ucValue = API_GpioGetValue(KEY08); /* 读取当前按键值 */
printf("The key value = %d\n", ucValue);
API_GpioSetValue(LED02, ucValue); /* 设置LED引脚输出 */
sleep(1);
}
API_GpioFree(KEY08);
API_GpioFree(LED02);
return (ERROR_NONE);
}
/*********************************************************************************************************
END
*********************************************************************************************************/
And achieve the effect of " used in the application layer GPIO as" the gpioExample1 routine.