The TCU channels 0 and 1 were previously reserved for system tasks, and thus unavailable for PWM.
Signed-off-by: Paul Cercueil <p...@crapouillou.net> Tested-by: Mathieu Malaterre <ma...@debian.org> Tested-by: Artur Rojek <cont...@artur-rojek.eu> --- drivers/pwm/pwm-jz4740.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c index f20dc2e19240..85e2110aae4f 100644 --- a/drivers/pwm/pwm-jz4740.c +++ b/drivers/pwm/pwm-jz4740.c @@ -28,6 +28,19 @@ 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); @@ -35,11 +48,7 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) char clk_name[16]; int ret; - /* - * 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(clk_name, sizeof(clk_name), "timer%u", pwm->hwpwm); -- 2.21.0.593.g511ec345e18