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cpu/samd21: Avoid clearing interrupt bits unintentionally

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The INTENSET, INTENCLR, INTFLAG registers are write-1-to-confirm
registers, so writing zeroes will not affect anything, on the other
hand, a compiler generated read-modify-write cycle may unintentionally
affect more bits than the one being set. Avoid by using direct
assignment instead of or-assignment (|=) or bitfield writes (.bit.xxx=).
This commit is contained in:
Joakim Nohlgård 2018-03-21 13:19:11 +01:00
parent 719515a0c3
commit dfa342b5f8
1 changed files with 26 additions and 26 deletions
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52
cpu/samd21/periph/timer.c
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@ -142,14 +142,14 @@ int timer_set_absolute(tim_t dev, int channel, unsigned int value)
/* set timeout value */
switch (channel) {
case 0:
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_0_DEV.CC[0].reg = value;
TIMER_0_DEV.INTENSET.bit.MC0 = 1;
TIMER_0_DEV.INTENSET.reg = TC_INTENSET_MC0;
break;
case 1:
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_0_DEV.CC[1].reg = value;
TIMER_0_DEV.INTENSET.bit.MC1 = 1;
TIMER_0_DEV.INTENSET.reg = TC_INTENSET_MC1;
break;
default:
return -1;
@ -161,14 +161,14 @@ int timer_set_absolute(tim_t dev, int channel, unsigned int value)
/* set timeout value */
switch (channel) {
case 0:
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_1_DEV.CC[0].reg = value;
TIMER_1_DEV.INTENSET.bit.MC0 = 1;
TIMER_1_DEV.INTENSET.reg = TC_INTENSET_MC0;
break;
case 1:
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_1_DEV.CC[1].reg = value;
TIMER_1_DEV.INTENSET.bit.MC1 = 1;
TIMER_1_DEV.INTENSET.reg = TC_INTENSET_MC1;
break;
default:
return -1;
@ -191,12 +191,12 @@ int timer_clear(tim_t dev, int channel)
case TIMER_0:
switch (channel) {
case 0:
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_0_DEV.INTENCLR.bit.MC0 = 1;
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
break;
case 1:
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_0_DEV.INTENCLR.bit.MC1 = 1;
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
break;
default:
return -1;
@ -207,12 +207,12 @@ int timer_clear(tim_t dev, int channel)
case TIMER_1:
switch (channel) {
case 0:
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_1_DEV.INTENCLR.bit.MC0 = 1;
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
break;
case 1:
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_1_DEV.INTENCLR.bit.MC1 = 1;
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
break;
default:
return -1;
@ -309,16 +309,16 @@ static inline void _irq_enable(tim_t dev)
void TIMER_0_ISR(void)
{
if (TIMER_0_DEV.INTFLAG.bit.MC0 && TIMER_0_DEV.INTENSET.bit.MC0) {
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
if(config[TIMER_0].cb) {
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
config[TIMER_0].cb(config[TIMER_0].arg, 0);
}
}
else if (TIMER_0_DEV.INTFLAG.bit.MC1 && TIMER_0_DEV.INTENSET.bit.MC1) {
if (TIMER_0_DEV.INTFLAG.bit.MC1 && TIMER_0_DEV.INTENSET.bit.MC1) {
TIMER_0_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
if(config[TIMER_0].cb) {
TIMER_0_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_0_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
config[TIMER_0].cb(config[TIMER_0].arg, 1);
}
}
@ -332,16 +332,16 @@ void TIMER_0_ISR(void)
void TIMER_1_ISR(void)
{
if (TIMER_1_DEV.INTFLAG.bit.MC0 && TIMER_1_DEV.INTENSET.bit.MC0) {
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC0;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
if (config[TIMER_1].cb) {
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC0;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC0;
config[TIMER_1].cb(config[TIMER_1].arg, 0);
}
}
else if (TIMER_1_DEV.INTFLAG.bit.MC1 && TIMER_1_DEV.INTENSET.bit.MC1) {
if (TIMER_1_DEV.INTFLAG.bit.MC1 && TIMER_1_DEV.INTENSET.bit.MC1) {
TIMER_1_DEV.INTFLAG.reg = TC_INTFLAG_MC1;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
if(config[TIMER_1].cb) {
TIMER_1_DEV.INTFLAG.reg |= TC_INTFLAG_MC1;
TIMER_1_DEV.INTENCLR.reg = TC_INTENCLR_MC1;
config[TIMER_1].cb(config[TIMER_1].arg, 1);
}
}