diff options
Diffstat (limited to 'drivers/pwm/core.c')
| -rw-r--r-- | drivers/pwm/core.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 4527f09a5c50..93772ab8d7e3 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -152,6 +152,32 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) } EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); +struct pwm_device * +of_pwm_single_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + if (pc->of_pwm_n_cells < 1) + return ERR_PTR(-EINVAL); + + /* validate that one cell is specified, optionally with flags */ + if (args->args_count != 1 && args->args_count != 2) + return ERR_PTR(-EINVAL); + + pwm = pwm_request_from_chip(pc, 0, NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm->args.period = args->args[0]; + pwm->args.polarity = PWM_POLARITY_NORMAL; + + if (args->args_count == 2 && args->args[2] & PWM_POLARITY_INVERTED) + pwm->args.polarity = PWM_POLARITY_INVERSED; + + return pwm; +} +EXPORT_SYMBOL_GPL(of_pwm_single_xlate); + static void of_pwmchip_add(struct pwm_chip *chip) { if (!chip->dev || !chip->dev->of_node) @@ -532,6 +558,15 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) struct pwm_chip *chip; int err; + /* + * Some lowlevel driver's implementations of .apply() make use of + * mutexes, also with some drivers only returning when the new + * configuration is active calling pwm_apply_state() from atomic context + * is a bad idea. So make it explicit that calling this function might + * sleep. + */ + might_sleep(); + if (!pwm || !state || !state->period || state->duty_cycle > state->period) return -EINVAL; |