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#include "u.h"
#include "mem.h"
#include "../port/lib.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
static ulong gpioreserved;
static Lock gpiolock;
void
gpioreserve(int n)
{
ulong mask;
mask = 1<<n;
ilock(&gpiolock);
if(gpioreserved & mask)
panic("gpioreserve: duplicate use of GPIO %d", n);
gpioreserved |= mask;
iunlock(&gpiolock);
}
/*
* set direction and alternative function bits in the GPIO control register,
* following the configuration bits in cfg.
*/
void
gpioconfig(int n, ulong cfg)
{
GpioReg *g;
ilock(&gpiolock);
g = GPIOREG;
if(cfg & Gpio_out)
g->iopm |= 1<<n;
else
g->iopm &= ~(1<<n);
iunlock(&gpiolock);
}
ulong
gpioget(int n)
{
return GPIOREG->iopd & (1<<n);
}
void
gpioset(int n, int v)
{
GpioReg *g;
ulong mask;
mask = 1<<n;
ilock(&gpiolock);
g = GPIOREG;
if(v)
g->iopd |= mask;
else
g->iopd &= ~mask;
iunlock(&gpiolock);
}
void
gpiorelease(int n)
{
ulong mask;
mask = 1<<n;
ilock(&gpiolock);
if((gpioreserved & mask) != mask)
panic("gpiorelease: unexpected release of GPIO %d", n);
gpioreserved &= ~mask;
iunlock(&gpiolock);
}
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