pinctrl: add some error checking for user interfaces
This patch can avoid kernel oops in case the mux or config
function is not supported by driver.
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c
index eb3a14f..384dcc1 100644
--- a/drivers/pinctrl/pinconf.c
+++ b/drivers/pinctrl/pinconf.c
@@ -448,8 +448,12 @@
static int pinconf_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
+ 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): pinmux setting array\n");