Change the pwm chip driver registration, so that a chip driver that supports polarity inversion can still be used with DTBs that don't provide the 'PWM_POLARITY' flag.
This is done to provide polarity inversion support for the pwm-imx driver without having to modify all existing DTS files. Signed-off-by: Lothar Waßmann <[email protected]> --- drivers/pwm/core.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 130bbea..0ff1bb0 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -136,9 +136,14 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; + /* check, whether the driver supports a third cell for flags */ if (pc->of_pwm_n_cells < 3) return ERR_PTR(-EINVAL); + /* flags in the third cell are optional */ + if (args->args_count < 2) + return ERR_PTR(-EINVAL); + if (args->args[0] >= pc->npwm) return ERR_PTR(-EINVAL); @@ -148,10 +153,12 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) pwm_set_period(pwm, args->args[1]); - if (args->args[2] & PWM_POLARITY_INVERTED) - pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); - else - pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + if (args->args_count > 2) { + if (args->args[2] & PWM_POLARITY_INVERTED) + pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); + else + pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + } return pwm; } @@ -162,9 +169,14 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; + /* sanity check driver support */ if (pc->of_pwm_n_cells < 2) return ERR_PTR(-EINVAL); + /* all cells are required */ + if (args->args_count != pc->of_pwm_n_cells) + return ERR_PTR(-EINVAL); + if (args->args[0] >= pc->npwm) return ERR_PTR(-EINVAL); @@ -536,13 +548,6 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) goto put; } - if (args.args_count != pc->of_pwm_n_cells) { - pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, - args.np->full_name); - pwm = ERR_PTR(-EINVAL); - goto put; - } - pwm = pc->of_xlate(pc, &args); if (IS_ERR(pwm)) goto put; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
