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imx8/gpio: allow 0 as "no-op" gpio pin

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as the gpio controller number starts at 1,
we can use 0 to mean "no pin", so passing
0 to gpioout() or gpioin() pin argument
will have no effect.
This commit is contained in:
cinap_lenrek 2022-06-13 23:24:14 +00:00
parent fe033ae816
commit 04d1e6ffe9
2 changed files with 10 additions and 6 deletions
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2
sys/src/9/imx8/fns.h
View file

@ -156,6 +156,6 @@ extern void iomuxpad(char *pads, char *sel, char *cfg);
extern uint iomuxgpr(int gpr, uint set, uint mask); extern uint iomuxgpr(int gpr, uint set, uint mask);
/* gpio */ /* gpio */
#define GPIO_PIN(n, m) (((n)-1)<<5 | (m)) #define GPIO_PIN(n, m) ((n)<<5 | (m))
extern void gpioout(uint pin, int set); extern void gpioout(uint pin, int set);
extern int gpioin(uint pin); extern int gpioin(uint pin);

14
sys/src/9/imx8/gpio.c
View file

@ -38,17 +38,19 @@ static Ctlr ctlrs[5] = {
static Ctlr* static Ctlr*
enable(uint pin) enable(uint pin)
{ {
Ctlr *ctlr = &ctlrs[pin/32]; Ctlr *ctlr;
assert(ctlr < &ctlrs[nelem(ctlrs)]); pin /= 32;
if(pin < 1 || pin > nelem(ctlrs))
return nil;
ctlr = &ctlrs[pin-1];
if(!ctlr->enabled){ if(!ctlr->enabled){
setclkgate(ctlr->clk, 1); setclkgate(ctlr->clk, 1);
ctlr->reg[GPIO_IMR] = 0; ctlr->reg[GPIO_IMR] = 0;
ctlr->dir = ctlr->reg[GPIO_GDIR]; ctlr->dir = ctlr->reg[GPIO_GDIR];
ctlr->enabled = 1; ctlr->enabled = 1;
} }
return ctlr; return ctlr;
} }
@ -57,7 +59,8 @@ gpioout(uint pin, int set)
{ {
int bit = 1 << (pin % 32); int bit = 1 << (pin % 32);
Ctlr *ctlr = enable(pin); Ctlr *ctlr = enable(pin);
if(ctlr == nil)
return;
if((ctlr->dir & bit) == 0) if((ctlr->dir & bit) == 0)
ctlr->reg[GPIO_GDIR] = ctlr->dir |= bit; ctlr->reg[GPIO_GDIR] = ctlr->dir |= bit;
if(set) if(set)
@ -71,7 +74,8 @@ gpioin(uint pin)
{ {
int bit = 1 << (pin % 32); int bit = 1 << (pin % 32);
Ctlr *ctlr = enable(pin); Ctlr *ctlr = enable(pin);
if(ctlr == nil)
return -1;
if(ctlr->dir & bit) if(ctlr->dir & bit)
ctlr->reg[GPIO_GDIR] = ctlr->dir &= ~bit; ctlr->reg[GPIO_GDIR] = ctlr->dir &= ~bit;
return (ctlr->reg[GPIO_DR] & bit) != 0; return (ctlr->reg[GPIO_DR] & bit) != 0;