pwm: Make the PWM_POLARITY flag in DTB optional

[karo-tx-linux.git] / drivers / pwm / core.c

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 012e27c7f27e4fcd0d95f25f6dff0cd01efbc3fd..e3d6c5437070efcc656c9088c138ccb9971b0ab7 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -137,9 +137,14 @@ 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);
 
@@ -148,11 +153,10 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
                return pwm;
 
        pwm->args.period = args->args[1];
+       pwm->args.polarity = PWM_POLARITY_NORMAL;
 
-       if (args->args[2] & PWM_POLARITY_INVERTED)
+       if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
                pwm->args.polarity = PWM_POLARITY_INVERSED;
-       else
-               pwm->args.polarity = PWM_POLARITY_NORMAL;
 
        return pwm;
 }
@@ -163,9 +167,14 @@ 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);
 
@@ -674,13 +683,6 @@ 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;