pxa255_GPIO.c

#include "pxa255_GPIO.h"
#include "mem.h"


static void pxa255gpioPrvRecalcValues(Pxa255gpio* gpio, UInt32 which){

	UInt8 i;
	UInt32 val, bit;

	val = gpio->dirs[which];
	gpio->levels[which] = (gpio->latches[which] & val) | (gpio->inputs[which] & (~val));

	val = 3;
	bit = 1;
	for(i = 0 ; i < 16; i++, val <<= 2, bit <<= 1) if(gpio->AFRs[(which << 1) + 0] & val) gpio->levels[which] &=~ bit;	//all AFRs read as zero to CPU
	for(i = 16; i < 32; i++, val <<= 2, bit <<= 1) if(gpio->AFRs[(which << 1) + 1] & val) gpio->levels[which] &=~ bit;	//all AFRs read as zero to CPU
}

static void pxa255gpioPrvRecalcIntrs(Pxa255gpio* gpio){

	pxa255icInt(gpio->ic, PXA255_I_GPIO_all, gpio->levels[1] || gpio->levels[2] || (gpio->levels[0] &~ 3));
	pxa255icInt(gpio->ic, PXA255_I_GPIO_1, (gpio->levels[0] & 2) != 0);
	pxa255icInt(gpio->ic, PXA255_I_GPIO_0, (gpio->levels[0] & 1) != 0);
}

static Boolean pxa255gpioPrvMemAccessF(void* userData, UInt32 pa, UInt8 size, Boolean write, void* buf){

	Pxa255gpio* gpio = userData;
	UInt32 val = 0;

	if(size != 4) {
		err_str(__FILE__ ": Unexpected ");
	//	err_str(write ? "write" : "read");
	//	err_str(" of ");
	//	err_dec(size);
	//	err_str(" bytes to 0x");
	//	err_hex(pa);
	//	err_str("\r\n");
		return true;		//we do not support non-word accesses
	}

	pa = (pa - PXA255_GPIO_BASE) >> 2;

	if(write){
		val = *(UInt32*)buf;

		switch(pa){
			case 0:
			case 1:
			case 2:

				break;

			case 3:
			case 4:
			case 5:
				pa -= 3;
				gpio->dirs[pa] = val;
				goto recalc;

			case 6:
			case 7:
			case 8:
				pa -= 6;
				gpio->levels[pa] |= val;
				goto recalc;

			case 9:
			case 10:
			case 11:
				pa -= 9;
				gpio->levels[pa] &=~ val;
				goto recalc;

			case 12:
			case 13:
			case 14:
				gpio->riseDet[pa - 12] = val;
				break;

			case 15:
			case 16:
			case 17:
				gpio->fallDet[pa - 15] = val;
				break;

			case 18:
			case 19:
			case 20:
				gpio->detStatus[pa - 18] &=~ val;
				goto trigger_intrs;

			case 21:
			case 22:
			case 23:
			case 24:
			case 25:
			case 26:
				gpio->AFRs[pa - 21] = val;
				goto recalc;
		}

		goto done;

recalc:
		pxa255gpioPrvRecalcValues(gpio, pa);

trigger_intrs:
		pxa255gpioPrvRecalcIntrs(gpio);
	}
	else{
		switch(pa){
			case 0:
			case 1:
			case 2:
				val = gpio->levels[pa - 0];
				break;

			case 3:
			case 4:
			case 5:
				val = gpio->dirs[pa - 3];
				break;

			case 6:
			case 7:
			case 8:
			case 9:
			case 10:
			case 11:
				val = 0;
				break;

			case 12:
			case 13:
			case 14:
				val = gpio->riseDet[pa - 12];
				break;

			case 15:
			case 16:
			case 17:
				val = gpio->fallDet[pa - 15];
				break;

			case 18:
			case 19:
			case 20:
				val = gpio->detStatus[pa - 18];
				break;

			case 21:
			case 22:
			case 23:
			case 24:
			case 25:
			case 26:
				val = gpio->AFRs[pa - 21];
				break;

		}
		*(UInt32*)buf = val;
	}

done:
	return true;
}


Boolean pxa255gpioInit(Pxa255gpio* gpio, ArmMem* physMem, Pxa255ic* ic){

	__mem_zero(gpio, sizeof(Pxa255gpio));
	gpio->ic = ic;

	return memRegionAdd(physMem, PXA255_GPIO_BASE, PXA255_GPIO_SIZE, pxa255gpioPrvMemAccessF, gpio);
}

void pxa255gpioSetState(Pxa255gpio* gpio, UInt8 gpioNum, Boolean on){

	UInt32 set = gpioNum >> 5;
	UInt32 v = 1UL << (gpioNum & 0x1F);
	UInt32* p;

	if(gpioNum >= 85) return;

	p =  gpio->inputs + set;
	if(on) *p |= v;
	else *p &=~ v;

	pxa255gpioPrvRecalcValues(gpio, set);
	pxa255gpioPrvRecalcIntrs(gpio);
}

UInt8 pxa255gpioGetState(Pxa255gpio* gpio, UInt8 gpioNum){

	UInt32 sSet = gpioNum >> 5;
	UInt32 bSet = gpioNum >> 4;
	UInt32 sV = 1UL << (gpioNum & 0x1F);
	UInt32 bV = 3UL << (gpioNum & 0x0F);


	if(gpioNum >= 85) return PXA255_GPIO_NOT_PRESENT;
	if(gpio->AFRs[bSet] & bV) return ((gpio->AFRs[bSet] & bV) >> (gpioNum & 0x0F)) + PXA255_GPIO_AFR1;
	if(gpio->dirs[sSet] & sV) return (gpio->latches[sSet] & sV) ? PXA255_GPIO_HIGH : PXA255_GPIO_LOW;
	return PXA255_GPIO_HiZ;
}