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drivers/saul/auto_init: Err on out-of-range input

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This commit is contained in:
chrysn 2020-11-05 19:01:17 +01:00
parent d8ff6cd7b1
commit 1b7cd3d142
1 changed files with 23 additions and 5 deletions
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28
drivers/saul/pwm_saul.c
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@ -27,8 +27,13 @@
/**
* Find factor and shiftback such that for each value entry in the phydat, the
* resulting PWM duty cycle would be (value * factor) >> shiftback.
*
* This also makes the maximum legal input value for that input (which allows
* clipping the input to a value that doesn't wrap during that multiplication,
* or just to err out). If future versions of this take the scale into account,
* they will adjust the maximum accordingly.
*/
static int extract_scaling(const phydat_t *state, int *factor, int *shiftback)
static int extract_scaling(const phydat_t *state, int *factor, int *shiftback, int *max)
{
if (state->scale != 0) {
return -ECANCELED;
@ -43,14 +48,17 @@ static int extract_scaling(const phydat_t *state, int *factor, int *shiftback)
case UNIT_NONE:
*factor = 1;
*shiftback = 0;
*max = saul_pwm_resolution;
break;
case UNIT_BOOL:
*factor = saul_pwm_resolution;
*shiftback = 0;
*max = 1;
break;
case UNIT_PERCENT:
*factor = ((int)saul_pwm_resolution << shift100) / 100;
*shiftback = shift100;
*max = 100;
break;
default:
return -ECANCELED;
@ -70,13 +78,17 @@ static int write_dimmer(const void *dev, phydat_t *state)
{
const saul_pwm_dimmer_params_t *p = dev;
int factor, shiftback;
int factor, shiftback, max;
int err = extract_scaling(state, &factor, &shiftback);
int err = extract_scaling(state, &factor, &shiftback, &max);
if (err < 0) {
return err;
}
if (state->val[0] < 0 || state->val[0] > max) {
return -ECANCELED;
}
setchan(&p->channel, (state->val[0] * factor) >> shiftback);
return 3;
}
@ -91,13 +103,19 @@ static int write_rgb(const void *dev, phydat_t *state)
{
const saul_pwm_rgb_params_t *p = dev;
int factor, shiftback;
int factor, shiftback, max;
int err = extract_scaling(state, &factor, &shiftback);
int err = extract_scaling(state, &factor, &shiftback, &max);
if (err < 0) {
return err;
}
for (int i = 0; i < 3; ++i) {
if (state->val[i] < 0 || state->val[i] > max) {
return -ECANCELED;
}
}
for (int i = 0; i < 3; ++i) {
setchan(&p->channels[i], (state->val[i] * factor) >> shiftback);
}