How to read GPIO direction using HAL?

[Spaghetto]

Hello world,

I'm developing a FW for STM32F107VCT6 which can change GPIO direction programmatically: there is a terminal command which can switch individually 7 pins* mapped on different ports between GPIO_MODE_OUTPUT_PP \ GPIO_MODE_INPUT.

I'm wondering if is there a way to read GPIO direction using STM32 HAL the same way I use HAL_GPIO_ReadPin for the status.

Since the code is completely written pointing the resources with an header file which defines are used to feed HAL drivers calls, I don't want to write just for this code which dive down to GPIOx_CRL/H MODEx pins....is there a more straightforward way?

Thanks

*: Pin listed below

#define EXP6_Pin GPIO_PIN_8
#define EXP6_GPIO_Port GPIOB
#define EXP5_Pin GPIO_PIN_9
#define EXP5_GPIO_Port GPIOB
#define EXP4_Pin GPIO_PIN_10
#define EXP4_GPIO_Port GPIOC
#define EXP3_Pin GPIO_PIN_11
#define EXP3_GPIO_Port GPIOC
#define EXP2_Pin GPIO_PIN_5
#define EXP2_GPIO_Port GPIOA
#define EXP1_Pin GPIO_PIN_6
#define EXP1_GPIO_Port GPIOA
#define EXP0_Pin GPIO_PIN_7
#define EXP0_GPIO_Port GPIOA

[Peter BENSCH]

Welcome, @Luca Gallucci​, to the community!

Well, compared to reading a GPIO, querying the current data flow direction occurs rather rarely. However, it should be easy to query via GPIO->CTL or GPIO->CTH and branch accordingly, even for several pins at the same time.

Regards

/Peter

[TDK]

> is there a more straightforward way?

A global variable which keeps track of how the pins have been defined, perhaps. STM32Cube doesn't really support changing pin functionality so it's not surprising there isn't an appropriate HAL call.

[Spaghetto · Accepted solution]

Uhm, thanks for the answer. After about half an hour of very hard coding I solved the way below.

I don't like that manual define of EXPx_Dir (where I extract the MODE values) in particular I don'ìt like the fact that can't be derived from the .ioc automatically generated code in a straightforward way, i could spare some time to use EXPx_Pin and EXPx_GPIO_Port to displace automatically the EXPx_Dir read but the reuse of that code is not to high to justify the effort.

Thanks for your support,

LG

.H:

...
#define EXP6_Pin GPIO_PIN_8
#define EXP6_GPIO_Port GPIOB
#define EXP5_Pin GPIO_PIN_9
#define EXP5_GPIO_Port GPIOB
#define EXP4_Pin GPIO_PIN_10
#define EXP4_GPIO_Port GPIOC
#define EXP3_Pin GPIO_PIN_11
#define EXP3_GPIO_Port GPIOC
#define EXP2_Pin GPIO_PIN_5
#define EXP2_GPIO_Port GPIOA
#define EXP1_Pin GPIO_PIN_6
#define EXP1_GPIO_Port GPIOA
#define EXP0_Pin GPIO_PIN_7
#define EXP0_GPIO_Port GPIOA
...
#define EXP0_Dir	(GPIOA->CRL>>28) 	& 0b11	//GPIOA.7
#define EXP1_Dir	(GPIOA->CRL>>24) 	& 0b11	//GPIOA.6
#define EXP2_Dir	(GPIOA->CRL>>20) 	& 0b11	//GPIOA.5
#define EXP3_Dir	(GPIOC->CRH>>12) 	& 0b11	//GPIOC.11
#define EXP4_Dir	(GPIOC->CRH>>8) 	& 0b11	//GPIOC.10
#define EXP5_Dir	(GPIOB->CRH>>4) 	& 0b11	//GPIOB.9
#define EXP6_Dir	(GPIOB->CRH)		& 0b11	//GPIOB.8
 ...

.C:

...
struct expbus_struct{
	GPIO_TypeDef* 	port[7];
	uint16_t	 	pin[7];
	uint8_t			dir[7];
} expbus =  {{EXP0_GPIO_Port,EXP1_GPIO_Port,EXP2_GPIO_Port,EXP3_GPIO_Port,EXP4_GPIO_Port,EXP5_GPIO_Port,EXP6_GPIO_Port},{EXP0_Pin,EXP1_Pin,EXP2_Pin,EXP3_Pin,EXP4_Pin,EXP5_Pin,EXP6_Pin}};
...
char expr (uint8_t ch){
	uint8_t	dir=0, val=0;
 
	switch(ch){
		case 0:
			if (EXP0_Dir) dir=1;
			break;
		case 1:
			if (EXP1_Dir) dir=1;
			break;
		case 2:
			if (EXP2_Dir) dir=1;
			break;
		case 3:
			if (EXP3_Dir) dir=1;
			break;
		case 4:
			if (EXP4_Dir) dir=1;
			break;
		case 5:
			if (EXP5_Dir) dir=1;
			break;
		case 6:
			if (EXP6_Dir) dir=1;
			break;
	}
 
	if(HAL_GPIO_ReadPin(expbus.port[ch],expbus.pin[ch])==GPIO_PIN_SET) val=1;
 
	if (dir && val) 	return 'H'; //out hi
	else if (dir && !val) 	return 'L'; //out lo
	else if (!dir && !val) 	return '0'; //in lo
	else return '1'; //in hi (default)
}