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pwm: jz4740: Allow selection of PWM channels 0 and 1 

The TCU channels 0 and 1 were previously reserved for system tasks, and
thus unavailable for PWM.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
alistair/sensors
Paul Cercueil 2020-03-23 15:24:21 +01:00 committed by Thierry Reding
parent c2693514a0
commit a2005fc791
1 changed files with 14 additions and 5 deletions
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19
drivers/pwm/pwm-jz4740.c
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@ -33,6 +33,19 @@ static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
return container_of(chip, struct jz4740_pwm_chip, chip);
}
static bool jz4740_pwm_can_use_chn(struct jz4740_pwm_chip *jz,
unsigned int channel)
{
/* Enable all TCU channels for PWM use by default except channels 0/1 */
u32 pwm_channels_mask = GENMASK(NUM_PWM - 1, 2);
device_property_read_u32(jz->chip.dev->parent,
"ingenic,pwm-channels-mask",
&pwm_channels_mask);
return !!(pwm_channels_mask & BIT(channel));
}
static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct jz4740_pwm_chip *jz = to_jz4740(chip);
@ -40,11 +53,7 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
char name[16];
int err;
/*
* Timers 0 and 1 are used for system tasks, so they are unavailable
* for use as PWMs.
*/
if (pwm->hwpwm < 2)
if (!jz4740_pwm_can_use_chn(jz, pwm->hwpwm))
return -EBUSY;
snprintf(name, sizeof(name), "timer%u", pwm->hwpwm);