[PATCH v2 2/6] pwm: core: make the PWM_POLARITY flag in DTB optional
Bhuvanchandra DV
bhuvanchandra.dv at toradex.com
Sat Oct 1 03:12:31 PDT 2016
From: Lothar Wassmann <LW at KARO-electronics.de>
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 at KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv at toradex.com>
Suggested-by: Thierry Reding <thierry.reding at gmail.com>
---
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 195373e..aae8db3 100644
--- 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);
@@ -149,10 +154,12 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
pwm->args.period = args->args[1];
- if (args->args[2] & PWM_POLARITY_INVERTED)
- pwm->args.polarity = PWM_POLARITY_INVERSED;
- else
- pwm->args.polarity = 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;
}
@@ -163,9 +170,14 @@ 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);
@@ -672,13 +684,6 @@ 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;
--
2.9.2
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