@@ -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;
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 <LW@KARO-electronics.de> --- drivers/pwm/core.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-)