pinctrl: pinconf: remove checks on ops->pin_config_get

Commit Message

Alexandre Belloni Dec. 9, 2013, 10:38 a.m. UTC

ops->pin_config_get() is only used in one specific path that will only be taken
for generic pinconf drivers (ops->is_generic == true) when dumping the pinconf
by using debugfs.

By removing the check in pinconf_check_ops(), let's stop pressuring people to
write a pin_config_get() function that will never be used and so will probably
never be tested.

Removing the check in pinconf_pins_show() allows driver to not implement
pin_config_get() but still get a dump of the pinconf in debugfs by implementing
pin_config_dbg_show().

Finally, not implementing pin_config_get() now results in returning -ENOTSUPP
instead of -EINVAL. While this doesn't have any real impact for now, this feels
more right.

Signed-off-by: Alexandre Belloni <[e-mail]>
---
 drivers/pinctrl/pinconf.c | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

Comments

Linus Walleij Dec. 12, 2013, 6:15 p.m. UTC | #1

On Mon, Dec 9, 2013 at 11:38 AM, Alexandre Belloni
<[e-mail]> wrote:

> ops->pin_config_get() is only used in one specific path that will only be taken
> for generic pinconf drivers (ops->is_generic == true) when dumping the pinconf
> by using debugfs.
>
> By removing the check in pinconf_check_ops(), let's stop pressuring people to
> write a pin_config_get() function that will never be used and so will probably
> never be tested.
>
> Removing the check in pinconf_pins_show() allows driver to not implement
> pin_config_get() but still get a dump of the pinconf in debugfs by implementing
> pin_config_dbg_show().
>
> Finally, not implementing pin_config_get() now results in returning -ENOTSUPP
> instead of -EINVAL. While this doesn't have any real impact for now, this feels
> more right.
>
> Signed-off-by: Alexandre Belloni <[e-mail]>

Yeah hm, OK patch applied.

For non-generic pinconf drivers this is more helpful.

Getting pin config or pin multiplexing from the hardware is
somewhat unimplemented in many drivers, that is one of the
holes we need to work on...

Yours,
Linus Walleij

Patch

diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c
index b8fcc38c0d11..4187fe58794d 100644
--- a/drivers/pinctrl/pinconf.c
+++ b/drivers/pinctrl/pinconf.c
@@ -28,12 +28,6 @@  int pinconf_check_ops(struct pinctrl_dev *pctldev)
 {
 	const struct pinconf_ops *ops = pctldev->desc->confops;
 
-	/* We must be able to read out pin status */
-	if (!ops->pin_config_get && !ops->pin_config_group_get) {
-		dev_err(pctldev->dev,
-			"pinconf must be able to read out pin status\n");
-		return -EINVAL;
-	}
 	/* We have to be able to config the pins in SOME way */
 	if (!ops->pin_config_set && !ops->pin_config_group_set) {
 		dev_err(pctldev->dev,
@@ -67,9 +61,9 @@  int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
 	const struct pinconf_ops *ops = pctldev->desc->confops;
 
 	if (!ops || !ops->pin_config_get) {
-		dev_err(pctldev->dev, "cannot get pin configuration, missing "
+		dev_dbg(pctldev->dev, "cannot get pin configuration, missing "
 			"pin_config_get() function in driver\n");
-		return -EINVAL;
+		return -ENOTSUPP;
 	}
 
 	return ops->pin_config_get(pctldev, pin, config);
@@ -93,10 +87,10 @@  int pin_config_group_get(const char *dev_name, const char *pin_group,
 	ops = pctldev->desc->confops;
 
 	if (!ops || !ops->pin_config_group_get) {
-		dev_err(pctldev->dev, "cannot get configuration for pin "
+		dev_dbg(pctldev->dev, "cannot get configuration for pin "
 			"group, missing group config get function in "
 			"driver\n");
-		ret = -EINVAL;
+		ret = -ENOTSUPP;
 		goto unlock;
 	}
 
@@ -305,9 +299,6 @@  static int pinconf_pins_show(struct seq_file *s, void *what)
 	const struct pinconf_ops *ops = pctldev->desc->confops;
 	unsigned i, pin;
 
-	if (!ops || !ops->pin_config_get)
-		return 0;
-
 	seq_puts(s, "Pin config settings per pin\n");
 	seq_puts(s, "Format: pin (name): configs\n");
 
@@ -356,9 +347,6 @@  static int pinconf_groups_show(struct seq_file *s, void *what)
 	unsigned ngroups = pctlops->get_groups_count(pctldev);
 	unsigned selector = 0;
 
-	if (!ops || !ops->pin_config_group_get)
-		return 0;
-
 	seq_puts(s, "Pin config settings per pin group\n");
 	seq_puts(s, "Format: group (name): configs\n");